diff options
Diffstat (limited to 'documentation/ref-manual/ref-variables.rst')
| -rw-r--r-- | documentation/ref-manual/ref-variables.rst | 8801 |
1 files changed, 8801 insertions, 0 deletions
diff --git a/documentation/ref-manual/ref-variables.rst b/documentation/ref-manual/ref-variables.rst new file mode 100644 index 0000000000..227c81fc39 --- /dev/null +++ b/documentation/ref-manual/ref-variables.rst @@ -0,0 +1,8801 @@ +.. SPDX-License-Identifier: CC-BY-SA-2.0-UK + +****************** +Variables Glossary +****************** + +This chapter lists common variables used in the OpenEmbedded build +system and gives an overview of their function and contents. + +:term:`A <ABIEXTENSION>` :term:`B` :term:`C <CACHE>` +:term:`D` :term:`E <EFI_PROVIDER>` :term:`F <FEATURE_PACKAGES>` +:term:`G <GCCPIE>` :term:`H <HOMEPAGE>` :term:`I <ICECC_DISABLED>` +:term:`K <KARCH>` :term:`L <LABELS>` :term:`M <MACHINE>` +:term:`N <NATIVELSBSTRING>` :term:`O <OBJCOPY>` :term:`P` +:term:`R <RANLIB>` :term:`S` :term:`T` +:term:`U <UBOOT_CONFIG>` :term:`V <VOLATILE_LOG_DIR>` +:term:`W <WARN_QA>` :term:`X <XSERVER>` + +.. glossary:: + + :term:`ABIEXTENSION` + Extension to the Application Binary Interface (ABI) field of the GNU + canonical architecture name (e.g. "eabi"). + + ABI extensions are set in the machine include files. For example, the + ``meta/conf/machine/include/arm/arch-arm.inc`` file sets the + following extension: + :: + + ABIEXTENSION = "eabi" + + :term:`ALLOW_EMPTY` + Specifies whether to produce an output package even if it is empty. + By default, BitBake does not produce empty packages. This default + behavior can cause issues when there is an + :term:`RDEPENDS` or some other hard runtime + requirement on the existence of the package. + + Like all package-controlling variables, you must always use them in + conjunction with a package name override, as in: + :: + + ALLOW_EMPTY_${PN} = "1" + ALLOW_EMPTY_${PN}-dev = "1" + ALLOW_EMPTY_${PN}-staticdev = "1" + + :term:`ALTERNATIVE` + Lists commands in a package that need an alternative binary naming + scheme. Sometimes the same command is provided in multiple packages. + When this occurs, the OpenEmbedded build system needs to use the + alternatives system to create a different binary naming scheme so the + commands can co-exist. + + To use the variable, list out the package's commands that also exist + as part of another package. For example, if the ``busybox`` package + has four commands that also exist as part of another package, you + identify them as follows: + :: + + ALTERNATIVE_busybox = "sh sed test bracket" + + For more information on the alternatives system, see the + ":ref:`update-alternatives.bbclass <ref-classes-update-alternatives>`" + section. + + :term:`ALTERNATIVE_LINK_NAME` + Used by the alternatives system to map duplicated commands to actual + locations. For example, if the ``bracket`` command provided by the + ``busybox`` package is duplicated through another package, you must + use the ``ALTERNATIVE_LINK_NAME`` variable to specify the actual + location: + :: + + ALTERNATIVE_LINK_NAME[bracket] = "/usr/bin/[" + + In this example, the binary for the ``bracket`` command (i.e. ``[``) + from the ``busybox`` package resides in ``/usr/bin/``. + + .. note:: + + If ``ALTERNATIVE_LINK_NAME`` is not defined, it defaults to ``${bindir}/name``. + + For more information on the alternatives system, see the + ":ref:`update-alternatives.bbclass <ref-classes-update-alternatives>`" + section. + + :term:`ALTERNATIVE_PRIORITY` + Used by the alternatives system to create default priorities for + duplicated commands. You can use the variable to create a single + default regardless of the command name or package, a default for + specific duplicated commands regardless of the package, or a default + for specific commands tied to particular packages. Here are the + available syntax forms: + :: + + ALTERNATIVE_PRIORITY = "priority" + ALTERNATIVE_PRIORITY[name] = "priority" + ALTERNATIVE_PRIORITY_pkg[name] = "priority" + + For more information on the alternatives system, see the + ":ref:`update-alternatives.bbclass <ref-classes-update-alternatives>`" + section. + + :term:`ALTERNATIVE_TARGET` + Used by the alternatives system to create default link locations for + duplicated commands. You can use the variable to create a single + default location for all duplicated commands regardless of the + command name or package, a default for specific duplicated commands + regardless of the package, or a default for specific commands tied to + particular packages. Here are the available syntax forms: + :: + + ALTERNATIVE_TARGET = "target" + ALTERNATIVE_TARGET[name] = "target" + ALTERNATIVE_TARGET_pkg[name] = "target" + + .. note:: + + If ``ALTERNATIVE_TARGET`` is not defined, it inherits the value + from the :term:`ALTERNATIVE_LINK_NAME` variable. + + If ``ALTERNATIVE_LINK_NAME`` and ``ALTERNATIVE_TARGET`` are the + same, the target for ``ALTERNATIVE_TARGET`` has "``.{BPN}``" + appended to it. + + Finally, if the file referenced has not been renamed, the + alternatives system will rename it to avoid the need to rename + alternative files in the :ref:`ref-tasks-install` + task while retaining support for the command if necessary. + + For more information on the alternatives system, see the + ":ref:`update-alternatives.bbclass <ref-classes-update-alternatives>`" + section. + + :term:`ANY_OF_DISTRO_FEATURES` + When inheriting the + :ref:`features_check <ref-classes-features_check>` + class, this variable identifies a list of distribution features where + at least one must be enabled in the current configuration in order + for the OpenEmbedded build system to build the recipe. In other words, + if none of the features listed in ``ANY_OF_DISTRO_FEATURES`` + appear in ``DISTRO_FEATURES`` within the current configuration, then + the recipe will be skipped, and if the build system attempts to build + the recipe then an error will be triggered. + + + :term:`APPEND` + An override list of append strings for each target specified with + :term:`LABELS`. + + See the :ref:`grub-efi <ref-classes-grub-efi>` class for more + information on how this variable is used. + + :term:`AR` + The minimal command and arguments used to run ``ar``. + + :term:`ARCHIVER_MODE` + When used with the :ref:`archiver <ref-classes-archiver>` class, + determines the type of information used to create a released archive. + You can use this variable to create archives of patched source, + original source, configured source, and so forth by employing the + following variable flags (varflags): + :: + + ARCHIVER_MODE[src] = "original" # Uses original (unpacked) source files. + ARCHIVER_MODE[src] = "patched" # Uses patched source files. This is the default. + ARCHIVER_MODE[src] = "configured" # Uses configured source files. + ARCHIVER_MODE[diff] = "1" # Uses patches between do_unpack and do_patch. + ARCHIVER_MODE[diff-exclude] ?= "file file ..." # Lists files and directories to exclude from diff. + ARCHIVER_MODE[dumpdata] = "1" # Uses environment data. + ARCHIVER_MODE[recipe] = "1" # Uses recipe and include files. + ARCHIVER_MODE[srpm] = "1" # Uses RPM package files. + + For information on how the variable works, see the + ``meta/classes/archiver.bbclass`` file in the :term:`Source Directory`. + + :term:`AS` + Minimal command and arguments needed to run the assembler. + + :term:`ASSUME_PROVIDED` + Lists recipe names (:term:`PN` values) BitBake does not + attempt to build. Instead, BitBake assumes these recipes have already + been built. + + In OpenEmbedded-Core, ``ASSUME_PROVIDED`` mostly specifies native + tools that should not be built. An example is ``git-native``, which + when specified, allows for the Git binary from the host to be used + rather than building ``git-native``. + + :term:`ASSUME_SHLIBS` + Provides additional ``shlibs`` provider mapping information, which + adds to or overwrites the information provided automatically by the + system. Separate multiple entries using spaces. + + As an example, use the following form to add an ``shlib`` provider of + shlibname in packagename with the optional version: + :: + + shlibname:packagename[_version] + + Here is an example that adds a shared library named ``libEGL.so.1`` + as being provided by the ``libegl-implementation`` package: + :: + + ASSUME_SHLIBS = "libEGL.so.1:libegl-implementation" + + :term:`AUTHOR` + The email address used to contact the original author or authors in + order to send patches and forward bugs. + + :term:`AUTO_LIBNAME_PKGS` + When the :ref:`debian <ref-classes-debian>` class is inherited, + which is the default behavior, ``AUTO_LIBNAME_PKGS`` specifies which + packages should be checked for libraries and renamed according to + Debian library package naming. + + The default value is "${PACKAGES}", which causes the debian class to + act on all packages that are explicitly generated by the recipe. + + :term:`AUTO_SYSLINUXMENU` + Enables creating an automatic menu for the syslinux bootloader. You + must set this variable in your recipe. The + :ref:`syslinux <ref-classes-syslinux>` class checks this variable. + + :term:`AUTOREV` + When ``SRCREV`` is set to the value of this variable, it specifies to + use the latest source revision in the repository. Here is an example: + :: + + SRCREV = "${AUTOREV}" + + If you use the previous statement to retrieve the latest version of + software, you need to be sure :term:`PV` contains + ``${``\ :term:`SRCPV`\ ``}``. For example, suppose you + have a kernel recipe that inherits the + :ref:`kernel <ref-classes-kernel>` class and you use the previous + statement. In this example, ``${SRCPV}`` does not automatically get + into ``PV``. Consequently, you need to change ``PV`` in your recipe + so that it does contain ``${SRCPV}``. + + For more information see the + ":ref:`dev-manual/dev-manual-common-tasks:automatically incrementing a package version number`" + section in the Yocto Project Development Tasks Manual. + + :term:`AVAILABLE_LICENSES` + List of licenses found in the directories specified by + :term:`COMMON_LICENSE_DIR` and + :term:`LICENSE_PATH`. + + .. note:: + + It is assumed that all changes to ``COMMON_LICENSE_DIR`` and + ``LICENSE_PATH`` have been done before ``AVAILABLE_LICENSES`` + is defined (in :ref:`ref-classes-license`). + + :term:`AVAILTUNES` + The list of defined CPU and Application Binary Interface (ABI) + tunings (i.e. "tunes") available for use by the OpenEmbedded build + system. + + The list simply presents the tunes that are available. Not all tunes + may be compatible with a particular machine configuration, or with + each other in a + :ref:`Multilib <dev-manual/dev-manual-common-tasks:combining multiple versions of library files into one image>` + configuration. + + To add a tune to the list, be sure to append it with spaces using the + "+=" BitBake operator. Do not simply replace the list by using the + "=" operator. See the + ":ref:`Basic Syntax <bitbake:bitbake-user-manual/bitbake-user-manual-metadata:basic syntax>`" section in the BitBake + User Manual for more information. + + :term:`B` + The directory within the :term:`Build Directory` in + which the OpenEmbedded build system places generated objects during a + recipe's build process. By default, this directory is the same as the + :term:`S` directory, which is defined as: + :: + + S = "${WORKDIR}/${BP}" + + You can separate the (``S``) directory and the directory pointed to + by the ``B`` variable. Most Autotools-based recipes support + separating these directories. The build system defaults to using + separate directories for ``gcc`` and some kernel recipes. + + :term:`BAD_RECOMMENDATIONS` + Lists "recommended-only" packages to not install. Recommended-only + packages are packages installed only through the + :term:`RRECOMMENDS` variable. You can prevent any + of these "recommended" packages from being installed by listing them + with the ``BAD_RECOMMENDATIONS`` variable: + :: + + BAD_RECOMMENDATIONS = "package_name package_name package_name ..." + + You can set this variable globally in your ``local.conf`` file or you + can attach it to a specific image recipe by using the recipe name + override: + :: + + BAD_RECOMMENDATIONS_pn-target_image = "package_name" + + It is important to realize that if you choose to not install packages + using this variable and some other packages are dependent on them + (i.e. listed in a recipe's :term:`RDEPENDS` + variable), the OpenEmbedded build system ignores your request and + will install the packages to avoid dependency errors. + + Support for this variable exists only when using the IPK and RPM + packaging backend. Support does not exist for DEB. + + See the :term:`NO_RECOMMENDATIONS` and the + :term:`PACKAGE_EXCLUDE` variables for related + information. + + :term:`BASE_LIB` + The library directory name for the CPU or Application Binary + Interface (ABI) tune. The ``BASE_LIB`` applies only in the Multilib + context. See the ":ref:`dev-manual/dev-manual-common-tasks:combining multiple versions of library files into one image`" + section in the Yocto Project Development Tasks Manual for information + on Multilib. + + The ``BASE_LIB`` variable is defined in the machine include files in + the :term:`Source Directory`. If Multilib is not + being used, the value defaults to "lib". + + :term:`BASE_WORKDIR` + Points to the base of the work directory for all recipes. The default + value is "${TMPDIR}/work". + + :term:`BB_ALLOWED_NETWORKS` + Specifies a space-delimited list of hosts that the fetcher is allowed + to use to obtain the required source code. Following are + considerations surrounding this variable: + + - This host list is only used if ``BB_NO_NETWORK`` is either not set + or set to "0". + + - Limited support for wildcard matching against the beginning of + host names exists. For example, the following setting matches + ``git.gnu.org``, ``ftp.gnu.org``, and ``foo.git.gnu.org``. + :: + + BB_ALLOWED_NETWORKS = "*.gnu.org" + + .. note:: + + The use of the "``*``" character only works at the beginning of + a host name and it must be isolated from the remainder of the + host name. You cannot use the wildcard character in any other + location of the name or combined with the front part of the + name. + + For example, ``*.foo.bar`` is supported, while ``*aa.foo.bar`` + is not. + + - Mirrors not in the host list are skipped and logged in debug. + + - Attempts to access networks not in the host list cause a failure. + + Using ``BB_ALLOWED_NETWORKS`` in conjunction with + :term:`PREMIRRORS` is very useful. Adding the host + you want to use to ``PREMIRRORS`` results in the source code being + fetched from an allowed location and avoids raising an error when a + host that is not allowed is in a :term:`SRC_URI` + statement. This is because the fetcher does not attempt to use the + host listed in ``SRC_URI`` after a successful fetch from the + ``PREMIRRORS`` occurs. + + :term:`BB_DANGLINGAPPENDS_WARNONLY` + Defines how BitBake handles situations where an append file + (``.bbappend``) has no corresponding recipe file (``.bb``). This + condition often occurs when layers get out of sync (e.g. ``oe-core`` + bumps a recipe version and the old recipe no longer exists and the + other layer has not been updated to the new version of the recipe + yet). + + The default fatal behavior is safest because it is the sane reaction + given something is out of sync. It is important to realize when your + changes are no longer being applied. + + You can change the default behavior by setting this variable to "1", + "yes", or "true" in your ``local.conf`` file, which is located in the + :term:`Build Directory`: Here is an example: + :: + + BB_DANGLINGAPPENDS_WARNONLY = "1" + + :term:`BB_DISKMON_DIRS` + Monitors disk space and available inodes during the build and allows + you to control the build based on these parameters. + + Disk space monitoring is disabled by default. To enable monitoring, + add the ``BB_DISKMON_DIRS`` variable to your ``conf/local.conf`` file + found in the :term:`Build Directory`. Use the + following form: + + .. code-block:: none + + BB_DISKMON_DIRS = "action,dir,threshold [...]" + + where: + + action is: + ABORT: Immediately abort the build when + a threshold is broken. + STOPTASKS: Stop the build after the currently + executing tasks have finished when + a threshold is broken. + WARN: Issue a warning but continue the + build when a threshold is broken. + Subsequent warnings are issued as + defined by the BB_DISKMON_WARNINTERVAL + variable, which must be defined in + the conf/local.conf file. + + dir is: + Any directory you choose. You can specify one or + more directories to monitor by separating the + groupings with a space. If two directories are + on the same device, only the first directory + is monitored. + + threshold is: + Either the minimum available disk space, + the minimum number of free inodes, or + both. You must specify at least one. To + omit one or the other, simply omit the value. + Specify the threshold using G, M, K for Gbytes, + Mbytes, and Kbytes, respectively. If you do + not specify G, M, or K, Kbytes is assumed by + default. Do not use GB, MB, or KB. + + Here are some examples: + :: + + BB_DISKMON_DIRS = "ABORT,${TMPDIR},1G,100K WARN,${SSTATE_DIR},1G,100K" + BB_DISKMON_DIRS = "STOPTASKS,${TMPDIR},1G" + BB_DISKMON_DIRS = "ABORT,${TMPDIR},,100K" + + The first example works only if you also provide the + :term:`BB_DISKMON_WARNINTERVAL` + variable in the ``conf/local.conf``. This example causes the build + system to immediately abort when either the disk space in + ``${TMPDIR}`` drops below 1 Gbyte or the available free inodes drops + below 100 Kbytes. Because two directories are provided with the + variable, the build system also issue a warning when the disk space + in the ``${SSTATE_DIR}`` directory drops below 1 Gbyte or the number + of free inodes drops below 100 Kbytes. Subsequent warnings are issued + during intervals as defined by the ``BB_DISKMON_WARNINTERVAL`` + variable. + + The second example stops the build after all currently executing + tasks complete when the minimum disk space in the ``${TMPDIR}`` + directory drops below 1 Gbyte. No disk monitoring occurs for the free + inodes in this case. + + The final example immediately aborts the build when the number of + free inodes in the ``${TMPDIR}`` directory drops below 100 Kbytes. No + disk space monitoring for the directory itself occurs in this case. + + :term:`BB_DISKMON_WARNINTERVAL` + Defines the disk space and free inode warning intervals. To set these + intervals, define the variable in your ``conf/local.conf`` file in + the :term:`Build Directory`. + + If you are going to use the ``BB_DISKMON_WARNINTERVAL`` variable, you + must also use the :term:`BB_DISKMON_DIRS` + variable and define its action as "WARN". During the build, + subsequent warnings are issued each time disk space or number of free + inodes further reduces by the respective interval. + + If you do not provide a ``BB_DISKMON_WARNINTERVAL`` variable and you + do use ``BB_DISKMON_DIRS`` with the "WARN" action, the disk + monitoring interval defaults to the following: + :: + + BB_DISKMON_WARNINTERVAL = "50M,5K" + + When specifying the variable in your configuration file, use the + following form: + + .. code-block:: none + + BB_DISKMON_WARNINTERVAL = "disk_space_interval,disk_inode_interval" + + where: + + disk_space_interval is: + An interval of memory expressed in either + G, M, or K for Gbytes, Mbytes, or Kbytes, + respectively. You cannot use GB, MB, or KB. + + disk_inode_interval is: + An interval of free inodes expressed in either + G, M, or K for Gbytes, Mbytes, or Kbytes, + respectively. You cannot use GB, MB, or KB. + + Here is an example: + :: + + BB_DISKMON_DIRS = "WARN,${SSTATE_DIR},1G,100K" + BB_DISKMON_WARNINTERVAL = "50M,5K" + + These variables cause the + OpenEmbedded build system to issue subsequent warnings each time the + available disk space further reduces by 50 Mbytes or the number of + free inodes further reduces by 5 Kbytes in the ``${SSTATE_DIR}`` + directory. Subsequent warnings based on the interval occur each time + a respective interval is reached beyond the initial warning (i.e. 1 + Gbytes and 100 Kbytes). + + :term:`BB_GENERATE_MIRROR_TARBALLS` + Causes tarballs of the source control repositories (e.g. Git + repositories), including metadata, to be placed in the + :term:`DL_DIR` directory. + + For performance reasons, creating and placing tarballs of these + repositories is not the default action by the OpenEmbedded build + system. + :: + + BB_GENERATE_MIRROR_TARBALLS = "1" + + Set this variable in your + ``local.conf`` file in the :term:`Build Directory`. + + Once you have the tarballs containing your source files, you can + clean up your ``DL_DIR`` directory by deleting any Git or other + source control work directories. + + :term:`BB_NUMBER_THREADS` + The maximum number of tasks BitBake should run in parallel at any one + time. The OpenEmbedded build system automatically configures this + variable to be equal to the number of cores on the build system. For + example, a system with a dual core processor that also uses + hyper-threading causes the ``BB_NUMBER_THREADS`` variable to default + to "4". + + For single socket systems (i.e. one CPU), you should not have to + override this variable to gain optimal parallelism during builds. + However, if you have very large systems that employ multiple physical + CPUs, you might want to make sure the ``BB_NUMBER_THREADS`` variable + is not set higher than "20". + + For more information on speeding up builds, see the + ":ref:`dev-manual/dev-manual-common-tasks:speeding up a build`" + section in the Yocto Project Development Tasks Manual. + + :term:`BB_SERVER_TIMEOUT` + Specifies the time (in seconds) after which to unload the BitBake + server due to inactivity. Set ``BB_SERVER_TIMEOUT`` to determine how + long the BitBake server stays resident between invocations. + + For example, the following statement in your ``local.conf`` file + instructs the server to be unloaded after 20 seconds of inactivity: + :: + + BB_SERVER_TIMEOUT = "20" + + If you want the server to never be unloaded, + set ``BB_SERVER_TIMEOUT`` to "-1". + + :term:`BBCLASSEXTEND` + Allows you to extend a recipe so that it builds variants of the + software. Common variants for recipes exist such as "natives" like + ``quilt-native``, which is a copy of Quilt built to run on the build + system; "crosses" such as ``gcc-cross``, which is a compiler built to + run on the build machine but produces binaries that run on the target + :term:`MACHINE`; "nativesdk", which targets the SDK + machine instead of ``MACHINE``; and "mulitlibs" in the form + "``multilib:``\ multilib_name". + + To build a different variant of the recipe with a minimal amount of + code, it usually is as simple as adding the following to your recipe: + :: + + BBCLASSEXTEND =+ "native nativesdk" + BBCLASSEXTEND =+ "multilib:multilib_name" + + .. note:: + + Internally, the ``BBCLASSEXTEND`` mechanism generates recipe + variants by rewriting variable values and applying overrides such + as ``_class-native``. For example, to generate a native version of + a recipe, a :term:`DEPENDS` on "foo" is rewritten + to a ``DEPENDS`` on "foo-native". + + Even when using ``BBCLASSEXTEND``, the recipe is only parsed once. + Parsing once adds some limitations. For example, it is not + possible to include a different file depending on the variant, + since ``include`` statements are processed when the recipe is + parsed. + + :term:`BBFILE_COLLECTIONS` + Lists the names of configured layers. These names are used to find + the other ``BBFILE_*`` variables. Typically, each layer will append + its name to this variable in its ``conf/layer.conf`` file. + + :term:`BBFILE_PATTERN` + Variable that expands to match files from + :term:`BBFILES` in a particular layer. This variable + is used in the ``conf/layer.conf`` file and must be suffixed with the + name of the specific layer (e.g. ``BBFILE_PATTERN_emenlow``). + + :term:`BBFILE_PRIORITY` + Assigns the priority for recipe files in each layer. + + This variable is useful in situations where the same recipe appears + in more than one layer. Setting this variable allows you to + prioritize a layer against other layers that contain the same recipe + - effectively letting you control the precedence for the multiple + layers. The precedence established through this variable stands + regardless of a recipe's version (:term:`PV` variable). For + example, a layer that has a recipe with a higher ``PV`` value but for + which the ``BBFILE_PRIORITY`` is set to have a lower precedence still + has a lower precedence. + + A larger value for the ``BBFILE_PRIORITY`` variable results in a + higher precedence. For example, the value 6 has a higher precedence + than the value 5. If not specified, the ``BBFILE_PRIORITY`` variable + is set based on layer dependencies (see the ``LAYERDEPENDS`` variable + for more information. The default priority, if unspecified for a + layer with no dependencies, is the lowest defined priority + 1 (or 1 + if no priorities are defined). + + .. tip:: + + You can use the command ``bitbake-layers show-layers`` + to list all configured layers along with their priorities. + + :term:`BBFILES` + A space-separated list of recipe files BitBake uses to build + software. + + When specifying recipe files, you can pattern match using Python's + `glob <https://docs.python.org/3/library/glob.html>`_ syntax. + For details on the syntax, see the documentation by following the + previous link. + + :term:`BBFILES_DYNAMIC` + Activates content when identified layers are present. You identify + the layers by the collections that the layers define. + + Use the ``BBFILES_DYNAMIC`` variable to avoid ``.bbappend`` files + whose corresponding ``.bb`` file is in a layer that attempts to + modify other layers through ``.bbappend`` but does not want to + introduce a hard dependency on those other layers. + + Use the following form for ``BBFILES_DYNAMIC``: + collection_name:filename_pattern The following example identifies two + collection names and two filename patterns: + :: + + BBFILES_DYNAMIC += " \ + clang-layer:${LAYERDIR}/bbappends/meta-clang/*/*/*.bbappend \ + core:${LAYERDIR}/bbappends/openembedded-core/meta/*/*/*.bbappend \ + " + + This next example shows an error message that occurs because invalid + entries are found, which cause parsing to abort: + + .. code-block:: none + + ERROR: BBFILES_DYNAMIC entries must be of the form <collection name>:<filename pattern>, not: + /work/my-layer/bbappends/meta-security-isafw/*/*/*.bbappend + /work/my-layer/bbappends/openembedded-core/meta/*/*/*.bbappend + + :term:`BBINCLUDELOGS` + Variable that controls how BitBake displays logs on build failure. + + :term:`BBINCLUDELOGS_LINES` + If :term:`BBINCLUDELOGS` is set, specifies the + maximum number of lines from the task log file to print when + reporting a failed task. If you do not set ``BBINCLUDELOGS_LINES``, + the entire log is printed. + + :term:`BBLAYERS` + Lists the layers to enable during the build. This variable is defined + in the ``bblayers.conf`` configuration file in the :term:`Build Directory`. + Here is an example: + :: + + BBLAYERS = " \ + /home/scottrif/poky/meta \ + /home/scottrif/poky/meta-poky \ + /home/scottrif/poky/meta-yocto-bsp \ + /home/scottrif/poky/meta-mykernel \ + " + + This example enables four layers, one of which is a custom, + user-defined layer named ``meta-mykernel``. + + :term:`BBMASK` + Prevents BitBake from processing recipes and recipe append files. + + You can use the ``BBMASK`` variable to "hide" these ``.bb`` and + ``.bbappend`` files. BitBake ignores any recipe or recipe append + files that match any of the expressions. It is as if BitBake does not + see them at all. Consequently, matching files are not parsed or + otherwise used by BitBake. + + The values you provide are passed to Python's regular expression + compiler. Consequently, the syntax follows Python's Regular + Expression (re) syntax. The expressions are compared against the full + paths to the files. For complete syntax information, see Python's + documentation at https://docs.python.org/3/library/re.html#regular-expression-syntax. + + The following example uses a complete regular expression to tell + BitBake to ignore all recipe and recipe append files in the + ``meta-ti/recipes-misc/`` directory: + :: + + BBMASK = "meta-ti/recipes-misc/" + + If you want to mask out multiple directories or recipes, you can + specify multiple regular expression fragments. This next example + masks out multiple directories and individual recipes: :: + + BBMASK += "/meta-ti/recipes-misc/ meta-ti/recipes-ti/packagegroup/" + BBMASK += "/meta-oe/recipes-support/" + BBMASK += "/meta-foo/.*/openldap" + BBMASK += "opencv.*\.bbappend" + BBMASK += "lzma" + + .. note:: + + When specifying a directory name, use the trailing slash character + to ensure you match just that directory name. + + :term:`BBMULTICONFIG` + Specifies each additional separate configuration when you are + building targets with multiple configurations. Use this variable in + your ``conf/local.conf`` configuration file. Specify a + multiconfigname for each configuration file you are using. For + example, the following line specifies three configuration files: + :: + + BBMULTICONFIG = "configA configB configC" + + Each configuration file you + use must reside in the :term:`Build Directory` + ``conf/multiconfig`` directory (e.g. + build_directory\ ``/conf/multiconfig/configA.conf``). + + For information on how to use ``BBMULTICONFIG`` in an environment + that supports building targets with multiple configurations, see the + ":ref:`dev-building-images-for-multiple-targets-using-multiple-configurations`" + section in the Yocto Project Development Tasks Manual. + + :term:`BBPATH` + Used by BitBake to locate ``.bbclass`` and configuration files. This + variable is analogous to the ``PATH`` variable. + + .. note:: + + If you run BitBake from a directory outside of the + Build Directory + , you must be sure to set + BBPATH + to point to the Build Directory. Set the variable as you would any + environment variable and then run BitBake: + :: + + $ BBPATH = "build_directory" + $ export BBPATH + $ bitbake target + + + :term:`BBSERVER` + If defined in the BitBake environment, ``BBSERVER`` points to the + BitBake remote server. + + Use the following format to export the variable to the BitBake + environment: + :: + + export BBSERVER=localhost:$port + + By default, ``BBSERVER`` also appears in + :term:`bitbake:BB_HASHBASE_WHITELIST`. + Consequently, ``BBSERVER`` is excluded from checksum and dependency + data. + + :term:`BINCONFIG` + When inheriting the + :ref:`binconfig-disabled <ref-classes-binconfig-disabled>` class, + this variable specifies binary configuration scripts to disable in + favor of using ``pkg-config`` to query the information. The + ``binconfig-disabled`` class will modify the specified scripts to + return an error so that calls to them can be easily found and + replaced. + + To add multiple scripts, separate them by spaces. Here is an example + from the ``libpng`` recipe: + :: + + BINCONFIG = "${bindir}/libpng-config ${bindir}/libpng16-config" + + :term:`BINCONFIG_GLOB` + When inheriting the :ref:`binconfig <ref-classes-binconfig>` class, + this variable specifies a wildcard for configuration scripts that + need editing. The scripts are edited to correct any paths that have + been set up during compilation so that they are correct for use when + installed into the sysroot and called by the build processes of other + recipes. + + .. note:: + + The ``BINCONFIG_GLOB`` variable uses + `shell globbing <https://tldp.org/LDP/abs/html/globbingref.html>`__, + which is recognition and expansion of wildcards during pattern + matching. Shell globbing is very similar to + `fnmatch <https://docs.python.org/3/library/fnmatch.html#module-fnmatch>`__ + and `glob <https://docs.python.org/3/library/glob.html>`__. + + For more information on how this variable works, see + ``meta/classes/binconfig.bbclass`` in the :term:`Source Directory`. + You can also find general + information on the class in the + ":ref:`binconfig.bbclass <ref-classes-binconfig>`" section. + + :term:`BP` + The base recipe name and version but without any special recipe name + suffix (i.e. ``-native``, ``lib64-``, and so forth). ``BP`` is + comprised of the following: + :: + + ${BPN}-${PV} + + :term:`BPN` + This variable is a version of the :term:`PN` variable with + common prefixes and suffixes removed, such as ``nativesdk-``, + ``-cross``, ``-native``, and multilib's ``lib64-`` and ``lib32-``. + The exact lists of prefixes and suffixes removed are specified by the + :term:`MLPREFIX` and + :term:`SPECIAL_PKGSUFFIX` variables, + respectively. + + :term:`BUGTRACKER` + Specifies a URL for an upstream bug tracking website for a recipe. + The OpenEmbedded build system does not use this variable. Rather, the + variable is a useful pointer in case a bug in the software being + built needs to be manually reported. + + :term:`BUILD_ARCH` + Specifies the architecture of the build host (e.g. ``i686``). The + OpenEmbedded build system sets the value of ``BUILD_ARCH`` from the + machine name reported by the ``uname`` command. + + :term:`BUILD_AS_ARCH` + Specifies the architecture-specific assembler flags for the build + host. By default, the value of ``BUILD_AS_ARCH`` is empty. + + :term:`BUILD_CC_ARCH` + Specifies the architecture-specific C compiler flags for the build + host. By default, the value of ``BUILD_CC_ARCH`` is empty. + + :term:`BUILD_CCLD` + Specifies the linker command to be used for the build host when the C + compiler is being used as the linker. By default, ``BUILD_CCLD`` + points to GCC and passes as arguments the value of + :term:`BUILD_CC_ARCH`, assuming + ``BUILD_CC_ARCH`` is set. + + :term:`BUILD_CFLAGS` + Specifies the flags to pass to the C compiler when building for the + build host. When building in the ``-native`` context, + :term:`CFLAGS` is set to the value of this variable by + default. + + :term:`BUILD_CPPFLAGS` + Specifies the flags to pass to the C preprocessor (i.e. to both the C + and the C++ compilers) when building for the build host. When + building in the ``-native`` context, :term:`CPPFLAGS` + is set to the value of this variable by default. + + :term:`BUILD_CXXFLAGS` + Specifies the flags to pass to the C++ compiler when building for the + build host. When building in the ``-native`` context, + :term:`CXXFLAGS` is set to the value of this variable + by default. + + :term:`BUILD_FC` + Specifies the Fortran compiler command for the build host. By + default, ``BUILD_FC`` points to Gfortran and passes as arguments the + value of :term:`BUILD_CC_ARCH`, assuming + ``BUILD_CC_ARCH`` is set. + + :term:`BUILD_LD` + Specifies the linker command for the build host. By default, + ``BUILD_LD`` points to the GNU linker (ld) and passes as arguments + the value of :term:`BUILD_LD_ARCH`, assuming + ``BUILD_LD_ARCH`` is set. + + :term:`BUILD_LD_ARCH` + Specifies architecture-specific linker flags for the build host. By + default, the value of ``BUILD_LD_ARCH`` is empty. + + :term:`BUILD_LDFLAGS` + Specifies the flags to pass to the linker when building for the build + host. When building in the ``-native`` context, + :term:`LDFLAGS` is set to the value of this variable + by default. + + :term:`BUILD_OPTIMIZATION` + Specifies the optimization flags passed to the C compiler when + building for the build host or the SDK. The flags are passed through + the :term:`BUILD_CFLAGS` and + :term:`BUILDSDK_CFLAGS` default values. + + The default value of the ``BUILD_OPTIMIZATION`` variable is "-O2 + -pipe". + + :term:`BUILD_OS` + Specifies the operating system in use on the build host (e.g. + "linux"). The OpenEmbedded build system sets the value of + ``BUILD_OS`` from the OS reported by the ``uname`` command - the + first word, converted to lower-case characters. + + :term:`BUILD_PREFIX` + The toolchain binary prefix used for native recipes. The OpenEmbedded + build system uses the ``BUILD_PREFIX`` value to set the + :term:`TARGET_PREFIX` when building for + ``native`` recipes. + + :term:`BUILD_STRIP` + Specifies the command to be used to strip debugging symbols from + binaries produced for the build host. By default, ``BUILD_STRIP`` + points to + ``${``\ :term:`BUILD_PREFIX`\ ``}strip``. + + :term:`BUILD_SYS` + Specifies the system, including the architecture and the operating + system, to use when building for the build host (i.e. when building + ``native`` recipes). + + The OpenEmbedded build system automatically sets this variable based + on :term:`BUILD_ARCH`, + :term:`BUILD_VENDOR`, and + :term:`BUILD_OS`. You do not need to set the + ``BUILD_SYS`` variable yourself. + + :term:`BUILD_VENDOR` + Specifies the vendor name to use when building for the build host. + The default value is an empty string (""). + + :term:`BUILDDIR` + Points to the location of the :term:`Build Directory`. + You can define this directory indirectly through the + :ref:`structure-core-script` script by passing in a Build + Directory path when you run the script. If you run the script and do + not provide a Build Directory path, the ``BUILDDIR`` defaults to + ``build`` in the current directory. + + :term:`BUILDHISTORY_COMMIT` + When inheriting the :ref:`buildhistory <ref-classes-buildhistory>` + class, this variable specifies whether or not to commit the build + history output in a local Git repository. If set to "1", this local + repository will be maintained automatically by the ``buildhistory`` + class and a commit will be created on every build for changes to each + top-level subdirectory of the build history output (images, packages, + and sdk). If you want to track changes to build history over time, + you should set this value to "1". + + By default, the ``buildhistory`` class does not commit the build + history output in a local Git repository: + :: + + BUILDHISTORY_COMMIT ?= "0" + + :term:`BUILDHISTORY_COMMIT_AUTHOR` + When inheriting the :ref:`buildhistory <ref-classes-buildhistory>` + class, this variable specifies the author to use for each Git commit. + In order for the ``BUILDHISTORY_COMMIT_AUTHOR`` variable to work, the + :term:`BUILDHISTORY_COMMIT` variable must + be set to "1". + + Git requires that the value you provide for the + ``BUILDHISTORY_COMMIT_AUTHOR`` variable takes the form of "name + email@host". Providing an email address or host that is not valid + does not produce an error. + + By default, the ``buildhistory`` class sets the variable as follows: + :: + + BUILDHISTORY_COMMIT_AUTHOR ?= "buildhistory <buildhistory@${DISTRO}>" + + :term:`BUILDHISTORY_DIR` + When inheriting the :ref:`buildhistory <ref-classes-buildhistory>` + class, this variable specifies the directory in which build history + information is kept. For more information on how the variable works, + see the ``buildhistory.class``. + + By default, the ``buildhistory`` class sets the directory as follows: + :: + + BUILDHISTORY_DIR ?= "${TOPDIR}/buildhistory" + + :term:`BUILDHISTORY_FEATURES` + When inheriting the :ref:`buildhistory <ref-classes-buildhistory>` + class, this variable specifies the build history features to be + enabled. For more information on how build history works, see the + ":ref:`dev-manual/dev-manual-common-tasks:maintaining build output quality`" + section in the Yocto Project Development Tasks Manual. + + You can specify these features in the form of a space-separated list: + + - *image:* Analysis of the contents of images, which includes the + list of installed packages among other things. + + - *package:* Analysis of the contents of individual packages. + + - *sdk:* Analysis of the contents of the software development kit + (SDK). + + - *task:* Save output file signatures for + :ref:`shared state <overview-manual/overview-manual-concepts:shared state cache>` + (sstate) tasks. + This saves one file per task and lists the SHA-256 checksums for + each file staged (i.e. the output of the task). + + By default, the ``buildhistory`` class enables the following + features: + :: + + BUILDHISTORY_FEATURES ?= "image package sdk" + + :term:`BUILDHISTORY_IMAGE_FILES` + When inheriting the :ref:`buildhistory <ref-classes-buildhistory>` + class, this variable specifies a list of paths to files copied from + the image contents into the build history directory under an + "image-files" directory in the directory for the image, so that you + can track the contents of each file. The default is to copy + ``/etc/passwd`` and ``/etc/group``, which allows you to monitor for + changes in user and group entries. You can modify the list to include + any file. Specifying an invalid path does not produce an error. + Consequently, you can include files that might not always be present. + + By default, the ``buildhistory`` class provides paths to the + following files: + :: + + BUILDHISTORY_IMAGE_FILES ?= "/etc/passwd /etc/group" + + :term:`BUILDHISTORY_PUSH_REPO` + When inheriting the :ref:`buildhistory <ref-classes-buildhistory>` + class, this variable optionally specifies a remote repository to + which build history pushes Git changes. In order for + ``BUILDHISTORY_PUSH_REPO`` to work, + :term:`BUILDHISTORY_COMMIT` must be set to + "1". + + The repository should correspond to a remote address that specifies a + repository as understood by Git, or alternatively to a remote name + that you have set up manually using ``git remote`` within the local + repository. + + By default, the ``buildhistory`` class sets the variable as follows: + :: + + BUILDHISTORY_PUSH_REPO ?= "" + + :term:`BUILDSDK_CFLAGS` + Specifies the flags to pass to the C compiler when building for the + SDK. When building in the ``nativesdk-`` context, + :term:`CFLAGS` is set to the value of this variable by + default. + + :term:`BUILDSDK_CPPFLAGS` + Specifies the flags to pass to the C pre-processor (i.e. to both the + C and the C++ compilers) when building for the SDK. When building in + the ``nativesdk-`` context, :term:`CPPFLAGS` is set + to the value of this variable by default. + + :term:`BUILDSDK_CXXFLAGS` + Specifies the flags to pass to the C++ compiler when building for the + SDK. When building in the ``nativesdk-`` context, + :term:`CXXFLAGS` is set to the value of this variable + by default. + + :term:`BUILDSDK_LDFLAGS` + Specifies the flags to pass to the linker when building for the SDK. + When building in the ``nativesdk-`` context, + :term:`LDFLAGS` is set to the value of this variable + by default. + + :term:`BUILDSTATS_BASE` + Points to the location of the directory that holds build statistics + when you use and enable the + :ref:`buildstats <ref-classes-buildstats>` class. The + ``BUILDSTATS_BASE`` directory defaults to + ``${``\ :term:`TMPDIR`\ ``}/buildstats/``. + + :term:`BUSYBOX_SPLIT_SUID` + For the BusyBox recipe, specifies whether to split the output + executable file into two parts: one for features that require + ``setuid root``, and one for the remaining features (i.e. those that + do not require ``setuid root``). + + The ``BUSYBOX_SPLIT_SUID`` variable defaults to "1", which results in + splitting the output executable file. Set the variable to "0" to get + a single output executable file. + + :term:`CACHE` + Specifies the directory BitBake uses to store a cache of the + :term:`Metadata` so it does not need to be parsed every time + BitBake is started. + + :term:`CC` + The minimal command and arguments used to run the C compiler. + + :term:`CFLAGS` + Specifies the flags to pass to the C compiler. This variable is + exported to an environment variable and thus made visible to the + software being built during the compilation step. + + Default initialization for ``CFLAGS`` varies depending on what is + being built: + + - :term:`TARGET_CFLAGS` when building for the + target + + - :term:`BUILD_CFLAGS` when building for the + build host (i.e. ``-native``) + + - :term:`BUILDSDK_CFLAGS` when building for + an SDK (i.e. ``nativesdk-``) + + :term:`CLASSOVERRIDE` + An internal variable specifying the special class override that + should currently apply (e.g. "class-target", "class-native", and so + forth). The classes that use this variable (e.g. + :ref:`native <ref-classes-native>`, + :ref:`nativesdk <ref-classes-nativesdk>`, and so forth) set the + variable to appropriate values. + + .. note:: + + ``CLASSOVERRIDE`` gets its default "class-target" value from the + ``bitbake.conf`` file. + + As an example, the following override allows you to install extra + files, but only when building for the target: + :: + + do_install_append_class-target() { + install my-extra-file ${D}${sysconfdir} + } + + Here is an example where ``FOO`` is set to + "native" when building for the build host, and to "other" when not + building for the build host: + :: + + FOO_class-native = "native" + FOO = "other" + + The underlying mechanism behind ``CLASSOVERRIDE`` is simply + that it is included in the default value of + :term:`OVERRIDES`. + + :term:`CLEANBROKEN` + If set to "1" within a recipe, ``CLEANBROKEN`` specifies that the + ``make clean`` command does not work for the software being built. + Consequently, the OpenEmbedded build system will not try to run + ``make clean`` during the :ref:`ref-tasks-configure` + task, which is the default behavior. + + :term:`COMBINED_FEATURES` + Provides a list of hardware features that are enabled in both + :term:`MACHINE_FEATURES` and + :term:`DISTRO_FEATURES`. This select list of + features contains features that make sense to be controlled both at + the machine and distribution configuration level. For example, the + "bluetooth" feature requires hardware support but should also be + optional at the distribution level, in case the hardware supports + Bluetooth but you do not ever intend to use it. + + :term:`COMMON_LICENSE_DIR` + Points to ``meta/files/common-licenses`` in the + :term:`Source Directory`, which is where generic license + files reside. + + :term:`COMPATIBLE_HOST` + A regular expression that resolves to one or more hosts (when the + recipe is native) or one or more targets (when the recipe is + non-native) with which a recipe is compatible. The regular expression + is matched against :term:`HOST_SYS`. You can use the + variable to stop recipes from being built for classes of systems with + which the recipes are not compatible. Stopping these builds is + particularly useful with kernels. The variable also helps to increase + parsing speed since the build system skips parsing recipes not + compatible with the current system. + + :term:`COMPATIBLE_MACHINE` + A regular expression that resolves to one or more target machines + with which a recipe is compatible. The regular expression is matched + against :term:`MACHINEOVERRIDES`. You can use + the variable to stop recipes from being built for machines with which + the recipes are not compatible. Stopping these builds is particularly + useful with kernels. The variable also helps to increase parsing + speed since the build system skips parsing recipes not compatible + with the current machine. + + :term:`COMPLEMENTARY_GLOB` + Defines wildcards to match when installing a list of complementary + packages for all the packages explicitly (or implicitly) installed in + an image. + + .. note:: + + The ``COMPLEMENTARY_GLOB`` variable uses Unix filename pattern matching + (`fnmatch <https://docs.python.org/3/library/fnmatch.html#module-fnmatch>`__), + which is similar to the Unix style pathname pattern expansion + (`glob <https://docs.python.org/3/library/glob.html>`__). + + The resulting list of complementary packages is associated with an + item that can be added to + :term:`IMAGE_FEATURES`. An example usage of + this is the "dev-pkgs" item that when added to ``IMAGE_FEATURES`` + will install -dev packages (containing headers and other development + files) for every package in the image. + + To add a new feature item pointing to a wildcard, use a variable flag + to specify the feature item name and use the value to specify the + wildcard. Here is an example: + :: + + COMPLEMENTARY_GLOB[dev-pkgs] = '*-dev' + + :term:`COMPONENTS_DIR` + Stores sysroot components for each recipe. The OpenEmbedded build + system uses ``COMPONENTS_DIR`` when constructing recipe-specific + sysroots for other recipes. + + The default is + "``${``\ :term:`STAGING_DIR`\ ``}-components``." + (i.e. + "``${``\ :term:`TMPDIR`\ ``}/sysroots-components``"). + + :term:`CONF_VERSION` + Tracks the version of the local configuration file (i.e. + ``local.conf``). The value for ``CONF_VERSION`` increments each time + ``build/conf/`` compatibility changes. + + :term:`CONFFILES` + Identifies editable or configurable files that are part of a package. + If the Package Management System (PMS) is being used to update + packages on the target system, it is possible that configuration + files you have changed after the original installation and that you + now want to remain unchanged are overwritten. In other words, + editable files might exist in the package that you do not want reset + as part of the package update process. You can use the ``CONFFILES`` + variable to list the files in the package that you wish to prevent + the PMS from overwriting during this update process. + + To use the ``CONFFILES`` variable, provide a package name override + that identifies the resulting package. Then, provide a + space-separated list of files. Here is an example: + :: + + CONFFILES_${PN} += "${sysconfdir}/file1 \ + ${sysconfdir}/file2 ${sysconfdir}/file3" + + A relationship exists between the ``CONFFILES`` and ``FILES`` + variables. The files listed within ``CONFFILES`` must be a subset of + the files listed within ``FILES``. Because the configuration files + you provide with ``CONFFILES`` are simply being identified so that + the PMS will not overwrite them, it makes sense that the files must + already be included as part of the package through the ``FILES`` + variable. + + .. note:: + + When specifying paths as part of the ``CONFFILES`` variable, it is + good practice to use appropriate path variables. + For example, ``${sysconfdir}`` rather than ``/etc`` or ``${bindir}`` + rather than ``/usr/bin``. You can find a list of these variables at + the top of the ``meta/conf/bitbake.conf`` file in the + :term:`Source Directory`. + + :term:`CONFIG_INITRAMFS_SOURCE` + Identifies the initial RAM filesystem (initramfs) source files. The + OpenEmbedded build system receives and uses this kernel Kconfig + variable as an environment variable. By default, the variable is set + to null (""). + + The ``CONFIG_INITRAMFS_SOURCE`` can be either a single cpio archive + with a ``.cpio`` suffix or a space-separated list of directories and + files for building the initramfs image. A cpio archive should contain + a filesystem archive to be used as an initramfs image. Directories + should contain a filesystem layout to be included in the initramfs + image. Files should contain entries according to the format described + by the ``usr/gen_init_cpio`` program in the kernel tree. + + If you specify multiple directories and files, the initramfs image + will be the aggregate of all of them. + + For information on creating an initramfs, see the + ":ref:`building-an-initramfs-image`" section + in the Yocto Project Development Tasks Manual. + + :term:`CONFIG_SITE` + A list of files that contains ``autoconf`` test results relevant to + the current build. This variable is used by the Autotools utilities + when running ``configure``. + + :term:`CONFIGURE_FLAGS` + The minimal arguments for GNU configure. + + :term:`CONFLICT_DISTRO_FEATURES` + When inheriting the + :ref:`features_check <ref-classes-features_check>` + class, this variable identifies distribution features that would be + in conflict should the recipe be built. In other words, if the + ``CONFLICT_DISTRO_FEATURES`` variable lists a feature that also + appears in ``DISTRO_FEATURES`` within the current configuration, then + the recipe will be skipped, and if the build system attempts to build + the recipe then an error will be triggered. + + :term:`COPYLEFT_LICENSE_EXCLUDE` + A space-separated list of licenses to exclude from the source + archived by the :ref:`archiver <ref-classes-archiver>` class. In + other words, if a license in a recipe's + :term:`LICENSE` value is in the value of + ``COPYLEFT_LICENSE_EXCLUDE``, then its source is not archived by the + class. + + .. note:: + + The ``COPYLEFT_LICENSE_EXCLUDE`` variable takes precedence over the + :term:`COPYLEFT_LICENSE_INCLUDE` variable. + + The default value, which is "CLOSED Proprietary", for + ``COPYLEFT_LICENSE_EXCLUDE`` is set by the + :ref:`copyleft_filter <ref-classes-copyleft_filter>` class, which + is inherited by the ``archiver`` class. + + :term:`COPYLEFT_LICENSE_INCLUDE` + A space-separated list of licenses to include in the source archived + by the :ref:`archiver <ref-classes-archiver>` class. In other + words, if a license in a recipe's :term:`LICENSE` + value is in the value of ``COPYLEFT_LICENSE_INCLUDE``, then its + source is archived by the class. + + The default value is set by the + :ref:`copyleft_filter <ref-classes-copyleft_filter>` class, which + is inherited by the ``archiver`` class. The default value includes + "GPL*", "LGPL*", and "AGPL*". + + :term:`COPYLEFT_PN_EXCLUDE` + A list of recipes to exclude in the source archived by the + :ref:`archiver <ref-classes-archiver>` class. The + ``COPYLEFT_PN_EXCLUDE`` variable overrides the license inclusion and + exclusion caused through the + :term:`COPYLEFT_LICENSE_INCLUDE` and + :term:`COPYLEFT_LICENSE_EXCLUDE` + variables, respectively. + + The default value, which is "" indicating to not explicitly exclude + any recipes by name, for ``COPYLEFT_PN_EXCLUDE`` is set by the + :ref:`copyleft_filter <ref-classes-copyleft_filter>` class, which + is inherited by the ``archiver`` class. + + :term:`COPYLEFT_PN_INCLUDE` + A list of recipes to include in the source archived by the + :ref:`archiver <ref-classes-archiver>` class. The + ``COPYLEFT_PN_INCLUDE`` variable overrides the license inclusion and + exclusion caused through the + :term:`COPYLEFT_LICENSE_INCLUDE` and + :term:`COPYLEFT_LICENSE_EXCLUDE` + variables, respectively. + + The default value, which is "" indicating to not explicitly include + any recipes by name, for ``COPYLEFT_PN_INCLUDE`` is set by the + :ref:`copyleft_filter <ref-classes-copyleft_filter>` class, which + is inherited by the ``archiver`` class. + + :term:`COPYLEFT_RECIPE_TYPES` + A space-separated list of recipe types to include in the source + archived by the :ref:`archiver <ref-classes-archiver>` class. + Recipe types are ``target``, ``native``, ``nativesdk``, ``cross``, + ``crosssdk``, and ``cross-canadian``. + + The default value, which is "target*", for ``COPYLEFT_RECIPE_TYPES`` + is set by the :ref:`copyleft_filter <ref-classes-copyleft_filter>` + class, which is inherited by the ``archiver`` class. + + :term:`COPY_LIC_DIRS` + If set to "1" along with the + :term:`COPY_LIC_MANIFEST` variable, the + OpenEmbedded build system copies into the image the license files, + which are located in ``/usr/share/common-licenses``, for each + package. The license files are placed in directories within the image + itself during build time. + + .. note:: + + The ``COPY_LIC_DIRS`` does not offer a path for adding licenses for + newly installed packages to an image, which might be most suitable for + read-only filesystems that cannot be upgraded. See the + :term:`LICENSE_CREATE_PACKAGE` variable for additional information. + You can also reference the ":ref:`dev-manual/dev-manual-common-tasks:providing license text`" + section in the Yocto Project Development Tasks Manual for + information on providing license text. + + :term:`COPY_LIC_MANIFEST` + If set to "1", the OpenEmbedded build system copies the license + manifest for the image to + ``/usr/share/common-licenses/license.manifest`` within the image + itself during build time. + + .. note:: + + The ``COPY_LIC_MANIFEST`` does not offer a path for adding licenses for + newly installed packages to an image, which might be most suitable for + read-only filesystems that cannot be upgraded. See the + :term:`LICENSE_CREATE_PACKAGE` variable for additional information. + You can also reference the ":ref:`dev-manual/dev-manual-common-tasks:providing license text`" + section in the Yocto Project Development Tasks Manual for + information on providing license text. + + :term:`CORE_IMAGE_EXTRA_INSTALL` + Specifies the list of packages to be added to the image. You should + only set this variable in the ``local.conf`` configuration file found + in the :term:`Build Directory`. + + This variable replaces ``POKY_EXTRA_INSTALL``, which is no longer + supported. + + :term:`COREBASE` + Specifies the parent directory of the OpenEmbedded-Core Metadata + layer (i.e. ``meta``). + + It is an important distinction that ``COREBASE`` points to the parent + of this layer and not the layer itself. Consider an example where you + have cloned the Poky Git repository and retained the ``poky`` name + for your local copy of the repository. In this case, ``COREBASE`` + points to the ``poky`` folder because it is the parent directory of + the ``poky/meta`` layer. + + :term:`COREBASE_FILES` + Lists files from the :term:`COREBASE` directory that + should be copied other than the layers listed in the + ``bblayers.conf`` file. The ``COREBASE_FILES`` variable exists for + the purpose of copying metadata from the OpenEmbedded build system + into the extensible SDK. + + Explicitly listing files in ``COREBASE`` is needed because it + typically contains build directories and other files that should not + normally be copied into the extensible SDK. Consequently, the value + of ``COREBASE_FILES`` is used in order to only copy the files that + are actually needed. + + :term:`CPP` + The minimal command and arguments used to run the C preprocessor. + + :term:`CPPFLAGS` + Specifies the flags to pass to the C pre-processor (i.e. to both the + C and the C++ compilers). This variable is exported to an environment + variable and thus made visible to the software being built during the + compilation step. + + Default initialization for ``CPPFLAGS`` varies depending on what is + being built: + + - :term:`TARGET_CPPFLAGS` when building for + the target + + - :term:`BUILD_CPPFLAGS` when building for the + build host (i.e. ``-native``) + + - :term:`BUILDSDK_CPPFLAGS` when building + for an SDK (i.e. ``nativesdk-``) + + :term:`CROSS_COMPILE` + The toolchain binary prefix for the target tools. The + ``CROSS_COMPILE`` variable is the same as the + :term:`TARGET_PREFIX` variable. + + .. note:: + + The OpenEmbedded build system sets the ``CROSS_COMPILE`` + variable only in certain contexts (e.g. when building for kernel + and kernel module recipes). + + :term:`CVSDIR` + The directory in which files checked out under the CVS system are + stored. + + :term:`CXX` + The minimal command and arguments used to run the C++ compiler. + + :term:`CXXFLAGS` + Specifies the flags to pass to the C++ compiler. This variable is + exported to an environment variable and thus made visible to the + software being built during the compilation step. + + Default initialization for ``CXXFLAGS`` varies depending on what is + being built: + + - :term:`TARGET_CXXFLAGS` when building for + the target + + - :term:`BUILD_CXXFLAGS` when building for the + build host (i.e. ``-native``) + + - :term:`BUILDSDK_CXXFLAGS` when building + for an SDK (i.e. ``nativesdk-``) + + :term:`D` + The destination directory. The location in the :term:`Build Directory` + where components are installed by the + :ref:`ref-tasks-install` task. This location defaults + to: + :: + + ${WORKDIR}/image + + .. note:: + + Tasks that read from or write to this directory should run under + :ref:`fakeroot <overview-manual/overview-manual-concepts:fakeroot and pseudo>`. + + :term:`DATE` + The date the build was started. Dates appear using the year, month, + and day (YMD) format (e.g. "20150209" for February 9th, 2015). + + :term:`DATETIME` + The date and time on which the current build started. The format is + suitable for timestamps. + + :term:`DEBIAN_NOAUTONAME` + When the :ref:`debian <ref-classes-debian>` class is inherited, + which is the default behavior, ``DEBIAN_NOAUTONAME`` specifies a + particular package should not be renamed according to Debian library + package naming. You must use the package name as an override when you + set this variable. Here is an example from the ``fontconfig`` recipe: + :: + + DEBIAN_NOAUTONAME_fontconfig-utils = "1" + + :term:`DEBIANNAME` + When the :ref:`debian <ref-classes-debian>` class is inherited, + which is the default behavior, ``DEBIANNAME`` allows you to override + the library name for an individual package. Overriding the library + name in these cases is rare. You must use the package name as an + override when you set this variable. Here is an example from the + ``dbus`` recipe: + :: + + DEBIANNAME_${PN} = "dbus-1" + + :term:`DEBUG_BUILD` + Specifies to build packages with debugging information. This + influences the value of the ``SELECTED_OPTIMIZATION`` variable. + + :term:`DEBUG_OPTIMIZATION` + The options to pass in ``TARGET_CFLAGS`` and ``CFLAGS`` when + compiling a system for debugging. This variable defaults to "-O + -fno-omit-frame-pointer ${DEBUG_FLAGS} -pipe". + + :term:`DEFAULT_PREFERENCE` + Specifies a weak bias for recipe selection priority. + + The most common usage of this is variable is to set it to "-1" within + a recipe for a development version of a piece of software. Using the + variable in this way causes the stable version of the recipe to build + by default in the absence of ``PREFERRED_VERSION`` being used to + build the development version. + + .. note:: + + The bias provided by ``DEFAULT_PREFERENCE`` is weak and is overridden + by :term:`BBFILE_PRIORITY` if that variable is different between two + layers that contain different versions of the same recipe. + + :term:`DEFAULTTUNE` + The default CPU and Application Binary Interface (ABI) tunings (i.e. + the "tune") used by the OpenEmbedded build system. The + ``DEFAULTTUNE`` helps define + :term:`TUNE_FEATURES`. + + The default tune is either implicitly or explicitly set by the + machine (:term:`MACHINE`). However, you can override + the setting using available tunes as defined with + :term:`AVAILTUNES`. + + :term:`DEPENDS` + Lists a recipe's build-time dependencies. These are dependencies on + other recipes whose contents (e.g. headers and shared libraries) are + needed by the recipe at build time. + + As an example, consider a recipe ``foo`` that contains the following + assignment: + :: + + DEPENDS = "bar" + + The practical effect of the previous + assignment is that all files installed by bar will be available in + the appropriate staging sysroot, given by the + :term:`STAGING_DIR* <STAGING_DIR>` variables, by the time the + :ref:`ref-tasks-configure` task for ``foo`` runs. + This mechanism is implemented by having ``do_configure`` depend on + the :ref:`ref-tasks-populate_sysroot` task of + each recipe listed in ``DEPENDS``, through a + ``[``\ :ref:`deptask <bitbake:bitbake-user-manual/bitbake-user-manual-metadata:variable flags>`\ ``]`` + declaration in the :ref:`base <ref-classes-base>` class. + + .. note:: + + It seldom is necessary to reference, for example, ``STAGING_DIR_HOST`` + explicitly. The standard classes and build-related variables are + configured to automatically use the appropriate staging sysroots. + + As another example, ``DEPENDS`` can also be used to add utilities + that run on the build machine during the build. For example, a recipe + that makes use of a code generator built by the recipe ``codegen`` + might have the following: + :: + + DEPENDS = "codegen-native" + + For more + information, see the :ref:`native <ref-classes-native>` class and + the :term:`EXTRANATIVEPATH` variable. + + .. note:: + + - ``DEPENDS`` is a list of recipe names. Or, to be more precise, + it is a list of :term:`PROVIDES` names, which + usually match recipe names. Putting a package name such as + "foo-dev" in ``DEPENDS`` does not make sense. Use "foo" + instead, as this will put files from all the packages that make + up ``foo``, which includes those from ``foo-dev``, into the + sysroot. + + - One recipe having another recipe in ``DEPENDS`` does not by + itself add any runtime dependencies between the packages + produced by the two recipes. However, as explained in the + ":ref:`overview-manual/overview-manual-concepts:automatically added runtime dependencies`" + section in the Yocto Project Overview and Concepts Manual, + runtime dependencies will often be added automatically, meaning + ``DEPENDS`` alone is sufficient for most recipes. + + - Counterintuitively, ``DEPENDS`` is often necessary even for + recipes that install precompiled components. For example, if + ``libfoo`` is a precompiled library that links against + ``libbar``, then linking against ``libfoo`` requires both + ``libfoo`` and ``libbar`` to be available in the sysroot. + Without a ``DEPENDS`` from the recipe that installs ``libfoo`` + to the recipe that installs ``libbar``, other recipes might + fail to link against ``libfoo``. + + For information on runtime dependencies, see the + :term:`RDEPENDS` variable. You can also see the + ":ref:`Tasks <bitbake:bitbake-user-manual/bitbake-user-manual-metadata:tasks>`" and + ":ref:`Dependencies <bitbake:bitbake-user-manual/bitbake-user-manual-execution:dependencies>`" sections in the + BitBake User Manual for additional information on tasks and + dependencies. + + :term:`DEPLOY_DIR` + Points to the general area that the OpenEmbedded build system uses to + place images, packages, SDKs, and other output files that are ready + to be used outside of the build system. By default, this directory + resides within the :term:`Build Directory` as + ``${TMPDIR}/deploy``. + + For more information on the structure of the Build Directory, see + ":ref:`ref-manual/ref-structure:the build directory - \`\`build/\`\``" section. + For more detail on the contents of the ``deploy`` directory, see the + ":ref:`Images <images-dev-environment>`", ":ref:`Package + Feeds <package-feeds-dev-environment>`", and + ":ref:`sdk-dev-environment`" sections all in the + Yocto Project Overview and Concepts Manual. + + :term:`DEPLOY_DIR_DEB` + Points to the area that the OpenEmbedded build system uses to place + Debian packages that are ready to be used outside of the build + system. This variable applies only when + :term:`PACKAGE_CLASSES` contains + "package_deb". + + The BitBake configuration file initially defines the + ``DEPLOY_DIR_DEB`` variable as a sub-folder of + :term:`DEPLOY_DIR`: + :: + + DEPLOY_DIR_DEB = "${DEPLOY_DIR}/deb" + + The :ref:`package_deb <ref-classes-package_deb>` class uses the + ``DEPLOY_DIR_DEB`` variable to make sure the + :ref:`ref-tasks-package_write_deb` task + writes Debian packages into the appropriate folder. For more + information on how packaging works, see the ":ref:`Package + Feeds <package-feeds-dev-environment>`" section + in the Yocto Project Overview and Concepts Manual. + + :term:`DEPLOY_DIR_IMAGE` + Points to the area that the OpenEmbedded build system uses to place + images and other associated output files that are ready to be + deployed onto the target machine. The directory is machine-specific + as it contains the ``${MACHINE}`` name. By default, this directory + resides within the :term:`Build Directory` as + ``${DEPLOY_DIR}/images/${MACHINE}/``. + + For more information on the structure of the Build Directory, see + ":ref:`ref-manual/ref-structure:the build directory - \`\`build/\`\``" section. + For more detail on the contents of the ``deploy`` directory, see the + ":ref:`Images <images-dev-environment>`" and + ":ref:`sdk-dev-environment`" sections both in + the Yocto Project Overview and Concepts Manual. + + :term:`DEPLOY_DIR_IPK` + Points to the area that the OpenEmbedded build system uses to place + IPK packages that are ready to be used outside of the build system. + This variable applies only when + :term:`PACKAGE_CLASSES` contains + "package_ipk". + + The BitBake configuration file initially defines this variable as a + sub-folder of :term:`DEPLOY_DIR`: + :: + + DEPLOY_DIR_IPK = "${DEPLOY_DIR}/ipk" + + The :ref:`package_ipk <ref-classes-package_ipk>` class uses the + ``DEPLOY_DIR_IPK`` variable to make sure the + :ref:`ref-tasks-package_write_ipk` task + writes IPK packages into the appropriate folder. For more information + on how packaging works, see the ":ref:`Package + Feeds <package-feeds-dev-environment>`" section + in the Yocto Project Overview and Concepts Manual. + + :term:`DEPLOY_DIR_RPM` + Points to the area that the OpenEmbedded build system uses to place + RPM packages that are ready to be used outside of the build system. + This variable applies only when + :term:`PACKAGE_CLASSES` contains + "package_rpm". + + The BitBake configuration file initially defines this variable as a + sub-folder of :term:`DEPLOY_DIR`: + :: + + DEPLOY_DIR_RPM = "${DEPLOY_DIR}/rpm" + + The :ref:`package_rpm <ref-classes-package_rpm>` class uses the + ``DEPLOY_DIR_RPM`` variable to make sure the + :ref:`ref-tasks-package_write_rpm` task + writes RPM packages into the appropriate folder. For more information + on how packaging works, see the ":ref:`Package + Feeds <package-feeds-dev-environment>`" section + in the Yocto Project Overview and Concepts Manual. + + :term:`DEPLOY_DIR_TAR` + Points to the area that the OpenEmbedded build system uses to place + tarballs that are ready to be used outside of the build system. This + variable applies only when + :term:`PACKAGE_CLASSES` contains + "package_tar". + + The BitBake configuration file initially defines this variable as a + sub-folder of :term:`DEPLOY_DIR`: + :: + + DEPLOY_DIR_TAR = "${DEPLOY_DIR}/tar" + + The :ref:`package_tar <ref-classes-package_tar>` class uses the + ``DEPLOY_DIR_TAR`` variable to make sure the + :ref:`ref-tasks-package_write_tar` task + writes TAR packages into the appropriate folder. For more information + on how packaging works, see the ":ref:`Package + Feeds <package-feeds-dev-environment>`" section + in the Yocto Project Overview and Concepts Manual. + + :term:`DEPLOYDIR` + When inheriting the :ref:`deploy <ref-classes-deploy>` class, the + ``DEPLOYDIR`` points to a temporary work area for deployed files that + is set in the ``deploy`` class as follows: + :: + + DEPLOYDIR = "${WORKDIR}/deploy-${PN}" + + Recipes inheriting the ``deploy`` class should copy files to be + deployed into ``DEPLOYDIR``, and the class will take care of copying + them into :term:`DEPLOY_DIR_IMAGE` + afterwards. + + :term:`DESCRIPTION` + The package description used by package managers. If not set, + ``DESCRIPTION`` takes the value of the :term:`SUMMARY` + variable. + + :term:`DISTRO` + The short name of the distribution. For information on the long name + of the distribution, see the :term:`DISTRO_NAME` + variable. + + The ``DISTRO`` variable corresponds to a distribution configuration + file whose root name is the same as the variable's argument and whose + filename extension is ``.conf``. For example, the distribution + configuration file for the Poky distribution is named ``poky.conf`` + and resides in the ``meta-poky/conf/distro`` directory of the + :term:`Source Directory`. + + Within that ``poky.conf`` file, the ``DISTRO`` variable is set as + follows: + :: + + DISTRO = "poky" + + Distribution configuration files are located in a ``conf/distro`` + directory within the :term:`Metadata` that contains the + distribution configuration. The value for ``DISTRO`` must not contain + spaces, and is typically all lower-case. + + .. note:: + + If the ``DISTRO`` variable is blank, a set of default configurations + are used, which are specified within + ``meta/conf/distro/defaultsetup.conf`` also in the Source Directory. + + :term:`DISTRO_CODENAME` + Specifies a codename for the distribution being built. + + :term:`DISTRO_EXTRA_RDEPENDS` + Specifies a list of distro-specific packages to add to all images. + This variable takes affect through ``packagegroup-base`` so the + variable only really applies to the more full-featured images that + include ``packagegroup-base``. You can use this variable to keep + distro policy out of generic images. As with all other distro + variables, you set this variable in the distro ``.conf`` file. + + :term:`DISTRO_EXTRA_RRECOMMENDS` + Specifies a list of distro-specific packages to add to all images if + the packages exist. The packages might not exist or be empty (e.g. + kernel modules). The list of packages are automatically installed but + you can remove them. + + :term:`DISTRO_FEATURES` + The software support you want in your distribution for various + features. You define your distribution features in the distribution + configuration file. + + In most cases, the presence or absence of a feature in + ``DISTRO_FEATURES`` is translated to the appropriate option supplied + to the configure script during the + :ref:`ref-tasks-configure` task for recipes that + optionally support the feature. For example, specifying "x11" in + ``DISTRO_FEATURES``, causes every piece of software built for the + target that can optionally support X11 to have its X11 support + enabled. + + Two more examples are Bluetooth and NFS support. For a more complete + list of features that ships with the Yocto Project and that you can + provide with this variable, see the ":ref:`ref-features-distro`" section. + + :term:`DISTRO_FEATURES_BACKFILL` + Features to be added to ``DISTRO_FEATURES`` if not also present in + ``DISTRO_FEATURES_BACKFILL_CONSIDERED``. + + This variable is set in the ``meta/conf/bitbake.conf`` file. It is + not intended to be user-configurable. It is best to just reference + the variable to see which distro features are being backfilled for + all distro configurations. See the ":ref:`ref-features-backfill`" section + for more information. + + :term:`DISTRO_FEATURES_BACKFILL_CONSIDERED` + Features from ``DISTRO_FEATURES_BACKFILL`` that should not be + backfilled (i.e. added to ``DISTRO_FEATURES``) during the build. See + the ":ref:`ref-features-backfill`" section for more information. + + :term:`DISTRO_FEATURES_DEFAULT` + A convenience variable that gives you the default list of distro + features with the exception of any features specific to the C library + (``libc``). + + When creating a custom distribution, you might find it useful to be + able to reuse the default + :term:`DISTRO_FEATURES` options without the + need to write out the full set. Here is an example that uses + ``DISTRO_FEATURES_DEFAULT`` from a custom distro configuration file: + :: + + DISTRO_FEATURES ?= "${DISTRO_FEATURES_DEFAULT} myfeature" + + :term:`DISTRO_FEATURES_FILTER_NATIVE` + Specifies a list of features that if present in the target + :term:`DISTRO_FEATURES` value should be + included in ``DISTRO_FEATURES`` when building native recipes. This + variable is used in addition to the features filtered using the + :term:`DISTRO_FEATURES_NATIVE` + variable. + + :term:`DISTRO_FEATURES_FILTER_NATIVESDK` + Specifies a list of features that if present in the target + :term:`DISTRO_FEATURES` value should be + included in ``DISTRO_FEATURES`` when building nativesdk recipes. This + variable is used in addition to the features filtered using the + :term:`DISTRO_FEATURES_NATIVESDK` + variable. + + :term:`DISTRO_FEATURES_NATIVE` + Specifies a list of features that should be included in + :term:`DISTRO_FEATURES` when building native + recipes. This variable is used in addition to the features filtered + using the + :term:`DISTRO_FEATURES_FILTER_NATIVE` + variable. + + :term:`DISTRO_FEATURES_NATIVESDK` + Specifies a list of features that should be included in + :term:`DISTRO_FEATURES` when building + nativesdk recipes. This variable is used in addition to the features + filtered using the + :term:`DISTRO_FEATURES_FILTER_NATIVESDK` + variable. + + :term:`DISTRO_NAME` + The long name of the distribution. For information on the short name + of the distribution, see the :term:`DISTRO` variable. + + The ``DISTRO_NAME`` variable corresponds to a distribution + configuration file whose root name is the same as the variable's + argument and whose filename extension is ``.conf``. For example, the + distribution configuration file for the Poky distribution is named + ``poky.conf`` and resides in the ``meta-poky/conf/distro`` directory + of the :term:`Source Directory`. + + Within that ``poky.conf`` file, the ``DISTRO_NAME`` variable is set + as follows: + :: + + DISTRO_NAME = "Poky (Yocto Project Reference Distro)" + + Distribution configuration files are located in a ``conf/distro`` + directory within the :term:`Metadata` that contains the + distribution configuration. + + .. note:: + + If the ``DISTRO_NAME`` variable is blank, a set of default + configurations are used, which are specified within + ``meta/conf/distro/defaultsetup.conf`` also in the Source Directory. + + :term:`DISTRO_VERSION` + The version of the distribution. + + :term:`DISTROOVERRIDES` + A colon-separated list of overrides specific to the current + distribution. By default, this list includes the value of + :term:`DISTRO`. + + You can extend ``DISTROOVERRIDES`` to add extra overrides that should + apply to the distribution. + + The underlying mechanism behind ``DISTROOVERRIDES`` is simply that it + is included in the default value of + :term:`OVERRIDES`. + + :term:`DL_DIR` + The central download directory used by the build process to store + downloads. By default, ``DL_DIR`` gets files suitable for mirroring + for everything except Git repositories. If you want tarballs of Git + repositories, use the + :term:`BB_GENERATE_MIRROR_TARBALLS` + variable. + + You can set this directory by defining the ``DL_DIR`` variable in the + ``conf/local.conf`` file. This directory is self-maintaining and you + should not have to touch it. By default, the directory is + ``downloads`` in the :term:`Build Directory`. + :: + + #DL_DIR ?= "${TOPDIR}/downloads" + + To specify a different download directory, + simply remove the comment from the line and provide your directory. + + During a first build, the system downloads many different source code + tarballs from various upstream projects. Downloading can take a + while, particularly if your network connection is slow. Tarballs are + all stored in the directory defined by ``DL_DIR`` and the build + system looks there first to find source tarballs. + + .. note:: + + When wiping and rebuilding, you can preserve this directory to + speed up this part of subsequent builds. + + You can safely share this directory between multiple builds on the + same development machine. For additional information on how the build + process gets source files when working behind a firewall or proxy + server, see this specific question in the ":doc:`faq`" + chapter. You can also refer to the + ":yocto_wiki:`Working Behind a Network Proxy </wiki/Working_Behind_a_Network_Proxy>`" + Wiki page. + + :term:`DOC_COMPRESS` + When inheriting the :ref:`compress_doc <ref-classes-compress_doc>` + class, this variable sets the compression policy used when the + OpenEmbedded build system compresses man pages and info pages. By + default, the compression method used is gz (gzip). Other policies + available are xz and bz2. + + For information on policies and on how to use this variable, see the + comments in the ``meta/classes/compress_doc.bbclass`` file. + + :term:`EFI_PROVIDER` + When building bootable images (i.e. where ``hddimg``, ``iso``, or + ``wic.vmdk`` is in :term:`IMAGE_FSTYPES`), the + ``EFI_PROVIDER`` variable specifies the EFI bootloader to use. The + default is "grub-efi", but "systemd-boot" can be used instead. + + See the :ref:`systemd-boot <ref-classes-systemd-boot>` and + :ref:`image-live <ref-classes-image-live>` classes for more + information. + + :term:`ENABLE_BINARY_LOCALE_GENERATION` + Variable that controls which locales for ``glibc`` are generated + during the build (useful if the target device has 64Mbytes of RAM or + less). + + :term:`ERR_REPORT_DIR` + When used with the :ref:`report-error <ref-classes-report-error>` + class, specifies the path used for storing the debug files created by + the :ref:`error reporting + tool <dev-manual/dev-manual-common-tasks:using the error reporting tool>`, which + allows you to submit build errors you encounter to a central + database. By default, the value of this variable is + ``${``\ :term:`LOG_DIR`\ ``}/error-report``. + + You can set ``ERR_REPORT_DIR`` to the path you want the error + reporting tool to store the debug files as follows in your + ``local.conf`` file: + :: + + ERR_REPORT_DIR = "path" + + :term:`ERROR_QA` + Specifies the quality assurance checks whose failures are reported as + errors by the OpenEmbedded build system. You set this variable in + your distribution configuration file. For a list of the checks you + can control with this variable, see the + ":ref:`insane.bbclass <ref-classes-insane>`" section. + + :term:`EXCLUDE_FROM_SHLIBS` + Triggers the OpenEmbedded build system's shared libraries resolver to + exclude an entire package when scanning for shared libraries. + + .. note:: + + The shared libraries resolver's functionality results in part from + the internal function ``package_do_shlibs``, which is part of the + :ref:`ref-tasks-package` task. You should be aware that the shared + libraries resolver might implicitly define some dependencies between + packages. + + The ``EXCLUDE_FROM_SHLIBS`` variable is similar to the + :term:`PRIVATE_LIBS` variable, which excludes a + package's particular libraries only and not the whole package. + + Use the ``EXCLUDE_FROM_SHLIBS`` variable by setting it to "1" for a + particular package: + :: + + EXCLUDE_FROM_SHLIBS = "1" + + :term:`EXCLUDE_FROM_WORLD` + Directs BitBake to exclude a recipe from world builds (i.e. + ``bitbake world``). During world builds, BitBake locates, parses and + builds all recipes found in every layer exposed in the + ``bblayers.conf`` configuration file. + + To exclude a recipe from a world build using this variable, set the + variable to "1" in the recipe. + + .. note:: + + Recipes added to ``EXCLUDE_FROM_WORLD`` may still be built during a + world build in order to satisfy dependencies of other recipes. Adding + a recipe to ``EXCLUDE_FROM_WORLD`` only ensures that the recipe is not + explicitly added to the list of build targets in a world build. + + :term:`EXTENDPE` + Used with file and pathnames to create a prefix for a recipe's + version based on the recipe's :term:`PE` value. If ``PE`` + is set and greater than zero for a recipe, ``EXTENDPE`` becomes that + value (e.g if ``PE`` is equal to "1" then ``EXTENDPE`` becomes "1"). + If a recipe's ``PE`` is not set (the default) or is equal to zero, + ``EXTENDPE`` becomes "". + + See the :term:`STAMP` variable for an example. + + :term:`EXTENDPKGV` + The full package version specification as it appears on the final + packages produced by a recipe. The variable's value is normally used + to fix a runtime dependency to the exact same version of another + package in the same recipe: + :: + + RDEPENDS_${PN}-additional-module = "${PN} (= ${EXTENDPKGV})" + + The dependency relationships are intended to force the package + manager to upgrade these types of packages in lock-step. + + :term:`EXTERNAL_KERNEL_TOOLS` + When set, the ``EXTERNAL_KERNEL_TOOLS`` variable indicates that these + tools are not in the source tree. + + When kernel tools are available in the tree, they are preferred over + any externally installed tools. Setting the ``EXTERNAL_KERNEL_TOOLS`` + variable tells the OpenEmbedded build system to prefer the installed + external tools. See the + :ref:`kernel-yocto <ref-classes-kernel-yocto>` class in + ``meta/classes`` to see how the variable is used. + + :term:`EXTERNALSRC` + When inheriting the :ref:`externalsrc <ref-classes-externalsrc>` + class, this variable points to the source tree, which is outside of + the OpenEmbedded build system. When set, this variable sets the + :term:`S` variable, which is what the OpenEmbedded build + system uses to locate unpacked recipe source code. + + For more information on ``externalsrc.bbclass``, see the + ":ref:`externalsrc.bbclass <ref-classes-externalsrc>`" section. You + can also find information on how to use this variable in the + ":ref:`dev-manual/dev-manual-common-tasks:building software from an external source`" + section in the Yocto Project Development Tasks Manual. + + :term:`EXTERNALSRC_BUILD` + When inheriting the :ref:`externalsrc <ref-classes-externalsrc>` + class, this variable points to the directory in which the recipe's + source code is built, which is outside of the OpenEmbedded build + system. When set, this variable sets the :term:`B` variable, + which is what the OpenEmbedded build system uses to locate the Build + Directory. + + For more information on ``externalsrc.bbclass``, see the + ":ref:`externalsrc.bbclass <ref-classes-externalsrc>`" section. You + can also find information on how to use this variable in the + ":ref:`dev-manual/dev-manual-common-tasks:building software from an external source`" + section in the Yocto Project Development Tasks Manual. + + :term:`EXTRA_AUTORECONF` + For recipes inheriting the :ref:`autotools <ref-classes-autotools>` + class, you can use ``EXTRA_AUTORECONF`` to specify extra options to + pass to the ``autoreconf`` command that is executed during the + :ref:`ref-tasks-configure` task. + + The default value is "--exclude=autopoint". + + :term:`EXTRA_IMAGE_FEATURES` + A list of additional features to include in an image. When listing + more than one feature, separate them with a space. + + Typically, you configure this variable in your ``local.conf`` file, + which is found in the :term:`Build Directory`. + Although you can use this variable from within a recipe, best + practices dictate that you do not. + + .. note:: + + To enable primary features from within the image recipe, use the + :term:`IMAGE_FEATURES` variable. + + Here are some examples of features you can add: + + - "dbg-pkgs" - Adds -dbg packages for all installed packages including + symbol information for debugging and profiling. + + - "debug-tweaks" - Makes an image suitable for debugging. For example, allows root logins without passwords and + enables post-installation logging. See the 'allow-empty-password' and + 'post-install-logging' features in the ":ref:`ref-features-image`" + section for more information. + - "dev-pkgs" - Adds -dev packages for all installed packages. This is + useful if you want to develop against the libraries in the image. + - "read-only-rootfs" - Creates an image whose root filesystem is + read-only. See the + ":ref:`dev-manual/dev-manual-common-tasks:creating a read-only root filesystem`" + section in the Yocto Project Development Tasks Manual for more + information + - "tools-debug" - Adds debugging tools such as gdb and strace. + - "tools-sdk" - Adds development tools such as gcc, make, + pkgconfig and so forth. + - "tools-testapps" - Adds useful testing tools + such as ts_print, aplay, arecord and so forth. + + For a complete list of image features that ships with the Yocto + Project, see the ":ref:`ref-features-image`" section. + + For an example that shows how to customize your image by using this + variable, see the ":ref:`usingpoky-extend-customimage-imagefeatures`" + section in the Yocto Project Development Tasks Manual. + + :term:`EXTRA_IMAGECMD` + Specifies additional options for the image creation command that has + been specified in :term:`IMAGE_CMD`. When setting + this variable, use an override for the associated image type. Here is + an example: + :: + + EXTRA_IMAGECMD_ext3 ?= "-i 4096" + + :term:`EXTRA_IMAGEDEPENDS` + A list of recipes to build that do not provide packages for + installing into the root filesystem. + + Sometimes a recipe is required to build the final image but is not + needed in the root filesystem. You can use the ``EXTRA_IMAGEDEPENDS`` + variable to list these recipes and thus specify the dependencies. A + typical example is a required bootloader in a machine configuration. + + .. note:: + + To add packages to the root filesystem, see the various + \*:term:`RDEPENDS` and \*:term:`RRECOMMENDS` variables. + + :term:`EXTRANATIVEPATH` + A list of subdirectories of + ``${``\ :term:`STAGING_BINDIR_NATIVE`\ ``}`` + added to the beginning of the environment variable ``PATH``. As an + example, the following prepends + "${STAGING_BINDIR_NATIVE}/foo:${STAGING_BINDIR_NATIVE}/bar:" to + ``PATH``: + :: + + EXTRANATIVEPATH = "foo bar" + + :term:`EXTRA_OECMAKE` + Additional `CMake <https://cmake.org/overview/>`__ options. See the + :ref:`cmake <ref-classes-cmake>` class for additional information. + + :term:`EXTRA_OECONF` + Additional ``configure`` script options. See + :term:`PACKAGECONFIG_CONFARGS` for + additional information on passing configure script options. + + :term:`EXTRA_OEMAKE` + Additional GNU ``make`` options. + + Because the ``EXTRA_OEMAKE`` defaults to "", you need to set the + variable to specify any required GNU options. + + :term:`PARALLEL_MAKE` and + :term:`PARALLEL_MAKEINST` also make use of + ``EXTRA_OEMAKE`` to pass the required flags. + + :term:`EXTRA_OESCONS` + When inheriting the :ref:`scons <ref-classes-scons>` class, this + variable specifies additional configuration options you want to pass + to the ``scons`` command line. + + :term:`EXTRA_USERS_PARAMS` + When inheriting the :ref:`extrausers <ref-classes-extrausers>` + class, this variable provides image level user and group operations. + This is a more global method of providing user and group + configuration as compared to using the + :ref:`useradd <ref-classes-useradd>` class, which ties user and + group configurations to a specific recipe. + + The set list of commands you can configure using the + ``EXTRA_USERS_PARAMS`` is shown in the ``extrausers`` class. These + commands map to the normal Unix commands of the same names: + :: + + # EXTRA_USERS_PARAMS = "\ + # useradd -p '' tester; \ + # groupadd developers; \ + # userdel nobody; \ + # groupdel -g video; \ + # groupmod -g 1020 developers; \ + # usermod -s /bin/sh tester; \ + # " + + :term:`FEATURE_PACKAGES` + Defines one or more packages to include in an image when a specific + item is included in :term:`IMAGE_FEATURES`. + When setting the value, ``FEATURE_PACKAGES`` should have the name of + the feature item as an override. Here is an example: + :: + + FEATURE_PACKAGES_widget = "package1 package2" + + In this example, if "widget" were added to ``IMAGE_FEATURES``, + package1 and package2 would be included in the image. + + .. note:: + + Packages installed by features defined through ``FEATURE_PACKAGES`` + are often package groups. While similarly named, you should not + confuse the ``FEATURE_PACKAGES`` variable with package groups, which + are discussed elsewhere in the documentation. + + :term:`FEED_DEPLOYDIR_BASE_URI` + Points to the base URL of the server and location within the + document-root that provides the metadata and packages required by + OPKG to support runtime package management of IPK packages. You set + this variable in your ``local.conf`` file. + + Consider the following example: + :: + + FEED_DEPLOYDIR_BASE_URI = "http://192.168.7.1/BOARD-dir" + + This example assumes you are serving + your packages over HTTP and your databases are located in a directory + named ``BOARD-dir``, which is underneath your HTTP server's + document-root. In this case, the OpenEmbedded build system generates + a set of configuration files for you in your target that work with + the feed. + + :term:`FILES` + The list of files and directories that are placed in a package. The + :term:`PACKAGES` variable lists the packages + generated by a recipe. + + To use the ``FILES`` variable, provide a package name override that + identifies the resulting package. Then, provide a space-separated + list of files or paths that identify the files you want included as + part of the resulting package. Here is an example: + :: + + FILES_${PN} += "${bindir}/mydir1 ${bindir}/mydir2/myfile" + + .. note:: + + - When specifying files or paths, you can pattern match using + Python's + `glob <https://docs.python.org/3/library/glob.html>`_ + syntax. For details on the syntax, see the documentation by + following the previous link. + + - When specifying paths as part of the ``FILES`` variable, it is + good practice to use appropriate path variables. For example, + use ``${sysconfdir}`` rather than ``/etc``, or ``${bindir}`` + rather than ``/usr/bin``. You can find a list of these + variables at the top of the ``meta/conf/bitbake.conf`` file in + the :term:`Source Directory`. You will also + find the default values of the various ``FILES_*`` variables in + this file. + + If some of the files you provide with the ``FILES`` variable are + editable and you know they should not be overwritten during the + package update process by the Package Management System (PMS), you + can identify these files so that the PMS will not overwrite them. See + the :term:`CONFFILES` variable for information on + how to identify these files to the PMS. + + :term:`FILES_SOLIBSDEV` + Defines the file specification to match + :term:`SOLIBSDEV`. In other words, + ``FILES_SOLIBSDEV`` defines the full path name of the development + symbolic link (symlink) for shared libraries on the target platform. + + The following statement from the ``bitbake.conf`` shows how it is + set: + :: + + FILES_SOLIBSDEV ?= "${base_libdir}/lib*${SOLIBSDEV} ${libdir}/lib*${SOLIBSDEV}" + + :term:`FILESEXTRAPATHS` + Extends the search path the OpenEmbedded build system uses when + looking for files and patches as it processes recipes and append + files. The default directories BitBake uses when it processes recipes + are initially defined by the :term:`FILESPATH` + variable. You can extend ``FILESPATH`` variable by using + ``FILESEXTRAPATHS``. + + Best practices dictate that you accomplish this by using + ``FILESEXTRAPATHS`` from within a ``.bbappend`` file and that you + prepend paths as follows: + :: + + FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}:" + + In the above example, the build system first + looks for files in a directory that has the same name as the + corresponding append file. + + .. note:: + + When extending ``FILESEXTRAPATHS``, be sure to use the immediate + expansion (``:=``) operator. Immediate expansion makes sure that + BitBake evaluates :term:`THISDIR` at the time the + directive is encountered rather than at some later time when + expansion might result in a directory that does not contain the + files you need. + + Also, include the trailing separating colon character if you are + prepending. The trailing colon character is necessary because you + are directing BitBake to extend the path by prepending directories + to the search path. + + Here is another common use: + :: + + FILESEXTRAPATHS_prepend := "${THISDIR}/files:" + + In this example, the build system extends the + ``FILESPATH`` variable to include a directory named ``files`` that is + in the same directory as the corresponding append file. + + This next example specifically adds three paths: + :: + + FILESEXTRAPATHS_prepend := "path_1:path_2:path_3:" + + A final example shows how you can extend the search path and include + a :term:`MACHINE`-specific override, which is useful + in a BSP layer: + :: + + FILESEXTRAPATHS_prepend_intel-x86-common := "${THISDIR}/${PN}:" + + The previous statement appears in the + ``linux-yocto-dev.bbappend`` file, which is found in the + :ref:`overview-manual/overview-manual-development-environment:yocto project source repositories` in + ``meta-intel/common/recipes-kernel/linux``. Here, the machine + override is a special :term:`PACKAGE_ARCH` + definition for multiple ``meta-intel`` machines. + + .. note:: + + For a layer that supports a single BSP, the override could just be + the value of ``MACHINE``. + + By prepending paths in ``.bbappend`` files, you allow multiple append + files that reside in different layers but are used for the same + recipe to correctly extend the path. + + :term:`FILESOVERRIDES` + A subset of :term:`OVERRIDES` used by the + OpenEmbedded build system for creating + :term:`FILESPATH`. The ``FILESOVERRIDES`` variable + uses overrides to automatically extend the + :term:`FILESPATH` variable. For an example of how + that works, see the :term:`FILESPATH` variable + description. Additionally, you find more information on how overrides + are handled in the + ":ref:`bitbake:bitbake-user-manual/bitbake-user-manual-metadata:conditional syntax (overrides)`" + section of the BitBake User Manual. + + By default, the ``FILESOVERRIDES`` variable is defined as: + :: + + FILESOVERRIDES = "${TRANSLATED_TARGET_ARCH}:${MACHINEOVERRIDES}:${DISTROOVERRIDES}" + + .. note:: + + Do not hand-edit the ``FILESOVERRIDES`` variable. The values match up + with expected overrides and are used in an expected manner by the + build system. + + :term:`FILESPATH` + The default set of directories the OpenEmbedded build system uses + when searching for patches and files. + + During the build process, BitBake searches each directory in + ``FILESPATH`` in the specified order when looking for files and + patches specified by each ``file://`` URI in a recipe's + :term:`SRC_URI` statements. + + The default value for the ``FILESPATH`` variable is defined in the + ``base.bbclass`` class found in ``meta/classes`` in the + :term:`Source Directory`: + :: + + FILESPATH = "${@base_set_filespath(["${FILE_DIRNAME}/${BP}", \ + "${FILE_DIRNAME}/${BPN}", "${FILE_DIRNAME}/files"], d)}" + + The + ``FILESPATH`` variable is automatically extended using the overrides + from the :term:`FILESOVERRIDES` variable. + + .. note:: + + - Do not hand-edit the ``FILESPATH`` variable. If you want the + build system to look in directories other than the defaults, + extend the ``FILESPATH`` variable by using the + :term:`FILESEXTRAPATHS` variable. + + - Be aware that the default ``FILESPATH`` directories do not map + to directories in custom layers where append files + (``.bbappend``) are used. If you want the build system to find + patches or files that reside with your append files, you need + to extend the ``FILESPATH`` variable by using the + ``FILESEXTRAPATHS`` variable. + + You can take advantage of this searching behavior in useful ways. For + example, consider a case where the following directory structure + exists for general and machine-specific configurations: + :: + + files/defconfig + files/MACHINEA/defconfig + files/MACHINEB/defconfig + + Also in the example, the ``SRC_URI`` statement contains + "file://defconfig". Given this scenario, you can set + :term:`MACHINE` to "MACHINEA" and cause the build + system to use files from ``files/MACHINEA``. Set ``MACHINE`` to + "MACHINEB" and the build system uses files from ``files/MACHINEB``. + Finally, for any machine other than "MACHINEA" and "MACHINEB", the + build system uses files from ``files/defconfig``. + + You can find out more about the patching process in the + ":ref:`patching-dev-environment`" section + in the Yocto Project Overview and Concepts Manual and the + ":ref:`new-recipe-patching-code`" section in + the Yocto Project Development Tasks Manual. See the + :ref:`ref-tasks-patch` task as well. + + :term:`FILESYSTEM_PERMS_TABLES` + Allows you to define your own file permissions settings table as part + of your configuration for the packaging process. For example, suppose + you need a consistent set of custom permissions for a set of groups + and users across an entire work project. It is best to do this in the + packages themselves but this is not always possible. + + By default, the OpenEmbedded build system uses the ``fs-perms.txt``, + which is located in the ``meta/files`` folder in the :term:`Source Directory`. + If you create your own file + permissions setting table, you should place it in your layer or the + distro's layer. + + You define the ``FILESYSTEM_PERMS_TABLES`` variable in the + ``conf/local.conf`` file, which is found in the :term:`Build Directory`, + to point to your custom + ``fs-perms.txt``. You can specify more than a single file permissions + setting table. The paths you specify to these files must be defined + within the :term:`BBPATH` variable. + + For guidance on how to create your own file permissions settings + table file, examine the existing ``fs-perms.txt``. + + :term:`FIT_HASH_ALG` + Specifies the hash algorithm used in creating the FIT Image. For e.g. sha256. + + :term:`FIT_SIGN_ALG` + Specifies the signature algorithm used in creating the FIT Image. + For e.g. rsa2048. + + :term:`FONT_EXTRA_RDEPENDS` + When inheriting the :ref:`fontcache <ref-classes-fontcache>` class, + this variable specifies the runtime dependencies for font packages. + By default, the ``FONT_EXTRA_RDEPENDS`` is set to "fontconfig-utils". + + :term:`FONT_PACKAGES` + When inheriting the :ref:`fontcache <ref-classes-fontcache>` class, + this variable identifies packages containing font files that need to + be cached by Fontconfig. By default, the ``fontcache`` class assumes + that fonts are in the recipe's main package (i.e. + ``${``\ :term:`PN`\ ``}``). Use this variable if fonts you + need are in a package other than that main package. + + :term:`FORCE_RO_REMOVE` + Forces the removal of the packages listed in ``ROOTFS_RO_UNNEEDED`` + during the generation of the root filesystem. + + Set the variable to "1" to force the removal of these packages. + + :term:`FULL_OPTIMIZATION` + The options to pass in ``TARGET_CFLAGS`` and ``CFLAGS`` when + compiling an optimized system. This variable defaults to "-O2 -pipe + ${DEBUG_FLAGS}". + + :term:`GCCPIE` + Enables Position Independent Executables (PIE) within the GNU C + Compiler (GCC). Enabling PIE in the GCC makes Return Oriented + Programming (ROP) attacks much more difficult to execute. + + By default the ``security_flags.inc`` file enables PIE by setting the + variable as follows: + :: + + GCCPIE ?= "--enable-default-pie" + + :term:`GCCVERSION` + Specifies the default version of the GNU C Compiler (GCC) used for + compilation. By default, ``GCCVERSION`` is set to "8.x" in the + ``meta/conf/distro/include/tcmode-default.inc`` include file: + :: + + GCCVERSION ?= "8.%" + + You can override this value by setting it in a + configuration file such as the ``local.conf``. + + :term:`GDB` + The minimal command and arguments to run the GNU Debugger. + + :term:`GITDIR` + The directory in which a local copy of a Git repository is stored + when it is cloned. + + :term:`GLIBC_GENERATE_LOCALES` + Specifies the list of GLIBC locales to generate should you not wish + to generate all LIBC locals, which can be time consuming. + + .. note:: + + If you specifically remove the locale ``en_US.UTF-8``, you must set + :term:`IMAGE_LINGUAS` appropriately. + + You can set ``GLIBC_GENERATE_LOCALES`` in your ``local.conf`` file. + By default, all locales are generated. + :: + + GLIBC_GENERATE_LOCALES = "en_GB.UTF-8 en_US.UTF-8" + + :term:`GROUPADD_PARAM` + When inheriting the :ref:`useradd <ref-classes-useradd>` class, + this variable specifies for a package what parameters should be + passed to the ``groupadd`` command if you wish to add a group to the + system when the package is installed. + + Here is an example from the ``dbus`` recipe: + :: + + GROUPADD_PARAM_${PN} = "-r netdev" + + For information on the standard Linux shell command + ``groupadd``, see http://linux.die.net/man/8/groupadd. + + :term:`GROUPMEMS_PARAM` + When inheriting the :ref:`useradd <ref-classes-useradd>` class, + this variable specifies for a package what parameters should be + passed to the ``groupmems`` command if you wish to modify the members + of a group when the package is installed. + + For information on the standard Linux shell command ``groupmems``, + see http://linux.die.net/man/8/groupmems. + + :term:`GRUB_GFXSERIAL` + Configures the GNU GRand Unified Bootloader (GRUB) to have graphics + and serial in the boot menu. Set this variable to "1" in your + ``local.conf`` or distribution configuration file to enable graphics + and serial in the menu. + + See the :ref:`grub-efi <ref-classes-grub-efi>` class for more + information on how this variable is used. + + :term:`GRUB_OPTS` + Additional options to add to the GNU GRand Unified Bootloader (GRUB) + configuration. Use a semi-colon character (``;``) to separate + multiple options. + + The ``GRUB_OPTS`` variable is optional. See the + :ref:`grub-efi <ref-classes-grub-efi>` class for more information + on how this variable is used. + + :term:`GRUB_TIMEOUT` + Specifies the timeout before executing the default ``LABEL`` in the + GNU GRand Unified Bootloader (GRUB). + + The ``GRUB_TIMEOUT`` variable is optional. See the + :ref:`grub-efi <ref-classes-grub-efi>` class for more information + on how this variable is used. + + :term:`GTKIMMODULES_PACKAGES` + When inheriting the + :ref:`gtk-immodules-cache <ref-classes-gtk-immodules-cache>` class, + this variable specifies the packages that contain the GTK+ input + method modules being installed when the modules are in packages other + than the main package. + + :term:`HOMEPAGE` + Website where more information about the software the recipe is + building can be found. + + :term:`HOST_ARCH` + The name of the target architecture, which is normally the same as + :term:`TARGET_ARCH`. The OpenEmbedded build system + supports many architectures. Here is an example list of architectures + supported. This list is by no means complete as the architecture is + configurable: + + - arm + - i586 + - x86_64 + - powerpc + - powerpc64 + - mips + - mipsel + + :term:`HOST_CC_ARCH` + Specifies architecture-specific compiler flags that are passed to the + C compiler. + + Default initialization for ``HOST_CC_ARCH`` varies depending on what + is being built: + + - :term:`TARGET_CC_ARCH` when building for the + target + + - :term:`BUILD_CC_ARCH` when building for the build host (i.e. + ``-native``) + + - ``BUILDSDK_CC_ARCH`` when building for an SDK (i.e. + ``nativesdk-``) + + :term:`HOST_OS` + Specifies the name of the target operating system, which is normally + the same as the :term:`TARGET_OS`. The variable can + be set to "linux" for ``glibc``-based systems and to "linux-musl" for + ``musl``. For ARM/EABI targets, there are also "linux-gnueabi" and + "linux-musleabi" values possible. + + :term:`HOST_PREFIX` + Specifies the prefix for the cross-compile toolchain. ``HOST_PREFIX`` + is normally the same as :term:`TARGET_PREFIX`. + + :term:`HOST_SYS` + Specifies the system, including the architecture and the operating + system, for which the build is occurring in the context of the + current recipe. + + The OpenEmbedded build system automatically sets this variable based + on :term:`HOST_ARCH`, + :term:`HOST_VENDOR`, and + :term:`HOST_OS` variables. + + .. note:: + + You do not need to set the variable yourself. + + Consider these two examples: + + - Given a native recipe on a 32-bit x86 machine running Linux, the + value is "i686-linux". + + - Given a recipe being built for a little-endian MIPS target running + Linux, the value might be "mipsel-linux". + + :term:`HOSTTOOLS` + A space-separated list (filter) of tools on the build host that + should be allowed to be called from within build tasks. Using this + filter helps reduce the possibility of host contamination. If a tool + specified in the value of ``HOSTTOOLS`` is not found on the build + host, the OpenEmbedded build system produces an error and the build + is not started. + + For additional information, see + :term:`HOSTTOOLS_NONFATAL`. + + :term:`HOSTTOOLS_NONFATAL` + A space-separated list (filter) of tools on the build host that + should be allowed to be called from within build tasks. Using this + filter helps reduce the possibility of host contamination. Unlike + :term:`HOSTTOOLS`, the OpenEmbedded build system + does not produce an error if a tool specified in the value of + ``HOSTTOOLS_NONFATAL`` is not found on the build host. Thus, you can + use ``HOSTTOOLS_NONFATAL`` to filter optional host tools. + + :term:`HOST_VENDOR` + Specifies the name of the vendor. ``HOST_VENDOR`` is normally the + same as :term:`TARGET_VENDOR`. + + :term:`ICECC_DISABLED` + Disables or enables the ``icecc`` (Icecream) function. For more + information on this function and best practices for using this + variable, see the ":ref:`icecc.bbclass <ref-classes-icecc>`" + section. + + Setting this variable to "1" in your ``local.conf`` disables the + function: + :: + + ICECC_DISABLED ??= "1" + + To enable the function, set the variable as follows: + :: + + ICECC_DISABLED = "" + + :term:`ICECC_ENV_EXEC` + Points to the ``icecc-create-env`` script that you provide. This + variable is used by the :ref:`icecc <ref-classes-icecc>` class. You + set this variable in your ``local.conf`` file. + + If you do not point to a script that you provide, the OpenEmbedded + build system uses the default script provided by the + ``icecc-create-env.bb`` recipe, which is a modified version and not + the one that comes with ``icecc``. + + :term:`ICECC_PARALLEL_MAKE` + Extra options passed to the ``make`` command during the + :ref:`ref-tasks-compile` task that specify parallel + compilation. This variable usually takes the form of "-j x", where x + represents the maximum number of parallel threads ``make`` can run. + + .. note:: + + The options passed affect builds on all enabled machines on the + network, which are machines running the ``iceccd`` daemon. + + If your enabled machines support multiple cores, coming up with the + maximum number of parallel threads that gives you the best + performance could take some experimentation since machine speed, + network lag, available memory, and existing machine loads can all + affect build time. Consequently, unlike the + :term:`PARALLEL_MAKE` variable, there is no + rule-of-thumb for setting ``ICECC_PARALLEL_MAKE`` to achieve optimal + performance. + + If you do not set ``ICECC_PARALLEL_MAKE``, the build system does not + use it (i.e. the system does not detect and assign the number of + cores as is done with ``PARALLEL_MAKE``). + + :term:`ICECC_PATH` + The location of the ``icecc`` binary. You can set this variable in + your ``local.conf`` file. If your ``local.conf`` file does not define + this variable, the :ref:`icecc <ref-classes-icecc>` class attempts + to define it by locating ``icecc`` using ``which``. + + :term:`ICECC_USER_CLASS_BL` + Identifies user classes that you do not want the Icecream distributed + compile support to consider. This variable is used by the + :ref:`icecc <ref-classes-icecc>` class. You set this variable in + your ``local.conf`` file. + + When you list classes using this variable, you are "blacklisting" + them from distributed compilation across remote hosts. Any classes + you list will be distributed and compiled locally. + + :term:`ICECC_USER_PACKAGE_BL` + Identifies user recipes that you do not want the Icecream distributed + compile support to consider. This variable is used by the + :ref:`icecc <ref-classes-icecc>` class. You set this variable in + your ``local.conf`` file. + + When you list packages using this variable, you are "blacklisting" + them from distributed compilation across remote hosts. Any packages + you list will be distributed and compiled locally. + + :term:`ICECC_USER_PACKAGE_WL` + Identifies user recipes that use an empty + :term:`PARALLEL_MAKE` variable that you want to + force remote distributed compilation on using the Icecream + distributed compile support. This variable is used by the + :ref:`icecc <ref-classes-icecc>` class. You set this variable in + your ``local.conf`` file. + + :term:`IMAGE_BASENAME` + The base name of image output files. This variable defaults to the + recipe name (``${``\ :term:`PN`\ ``}``). + + :term:`IMAGE_BOOT_FILES` + A space-separated list of files installed into the boot partition + when preparing an image using the Wic tool with the + ``bootimg-partition`` or ``bootimg-efi`` source plugin. By default, + the files are + installed under the same name as the source files. To change the + installed name, separate it from the original name with a semi-colon + (;). Source files need to be located in + :term:`DEPLOY_DIR_IMAGE`. Here are two + examples: + :: + + IMAGE_BOOT_FILES = "u-boot.img uImage;kernel" + IMAGE_BOOT_FILES = "u-boot.${UBOOT_SUFFIX} ${KERNEL_IMAGETYPE}" + + Alternatively, source files can be picked up using a glob pattern. In + this case, the destination file must have the same name as the base + name of the source file path. To install files into a directory + within the target location, pass its name after a semi-colon (;). + Here are two examples: + :: + + IMAGE_BOOT_FILES = "bcm2835-bootfiles/*" + IMAGE_BOOT_FILES = "bcm2835-bootfiles/*;boot/" + + The first example + installs all files from ``${DEPLOY_DIR_IMAGE}/bcm2835-bootfiles`` + into the root of the target partition. The second example installs + the same files into a ``boot`` directory within the target partition. + + You can find information on how to use the Wic tool in the + ":ref:`dev-manual/dev-manual-common-tasks:creating partitioned images using wic`" + section of the Yocto Project Development Tasks Manual. Reference + material for Wic is located in the + ":doc:`../ref-manual/ref-kickstart`" chapter. + + :term:`IMAGE_CLASSES` + A list of classes that all images should inherit. You typically use + this variable to specify the list of classes that register the + different types of images the OpenEmbedded build system creates. + + The default value for ``IMAGE_CLASSES`` is ``image_types``. You can + set this variable in your ``local.conf`` or in a distribution + configuration file. + + For more information, see ``meta/classes/image_types.bbclass`` in the + :term:`Source Directory`. + + :term:`IMAGE_CMD` + Specifies the command to create the image file for a specific image + type, which corresponds to the value set set in + :term:`IMAGE_FSTYPES`, (e.g. ``ext3``, + ``btrfs``, and so forth). When setting this variable, you should use + an override for the associated type. Here is an example: + :: + + IMAGE_CMD_jffs2 = "mkfs.jffs2 --root=${IMAGE_ROOTFS} \ + --faketime --output=${DEPLOY_DIR_IMAGE}/${IMAGE_NAME}.rootfs.jffs2 \ + ${EXTRA_IMAGECMD}" + + You typically do not need to set this variable unless you are adding + support for a new image type. For more examples on how to set this + variable, see the :ref:`image_types <ref-classes-image_types>` + class file, which is ``meta/classes/image_types.bbclass``. + + :term:`IMAGE_DEVICE_TABLES` + Specifies one or more files that contain custom device tables that + are passed to the ``makedevs`` command as part of creating an image. + These files list basic device nodes that should be created under + ``/dev`` within the image. If ``IMAGE_DEVICE_TABLES`` is not set, + ``files/device_table-minimal.txt`` is used, which is located by + :term:`BBPATH`. For details on how you should write + device table files, see ``meta/files/device_table-minimal.txt`` as an + example. + + :term:`IMAGE_FEATURES` + The primary list of features to include in an image. Typically, you + configure this variable in an image recipe. Although you can use this + variable from your ``local.conf`` file, which is found in the + :term:`Build Directory`, best practices dictate that you do + not. + + .. note:: + + To enable extra features from outside the image recipe, use the + :term:`EXTRA_IMAGE_FEATURES` variable. + + For a list of image features that ships with the Yocto Project, see + the ":ref:`ref-features-image`" section. + + For an example that shows how to customize your image by using this + variable, see the ":ref:`usingpoky-extend-customimage-imagefeatures`" + section in the Yocto Project Development Tasks Manual. + + :term:`IMAGE_FSTYPES` + Specifies the formats the OpenEmbedded build system uses during the + build when creating the root filesystem. For example, setting + ``IMAGE_FSTYPES`` as follows causes the build system to create root + filesystems using two formats: ``.ext3`` and ``.tar.bz2``: + :: + + IMAGE_FSTYPES = "ext3 tar.bz2" + + For the complete list of supported image formats from which you can + choose, see :term:`IMAGE_TYPES`. + + .. note:: + + - If an image recipe uses the "inherit image" line and you are + setting ``IMAGE_FSTYPES`` inside the recipe, you must set + ``IMAGE_FSTYPES`` prior to using the "inherit image" line. + + - Due to the way the OpenEmbedded build system processes this + variable, you cannot update its contents by using ``_append`` + or ``_prepend``. You must use the ``+=`` operator to add one or + more options to the ``IMAGE_FSTYPES`` variable. + + :term:`IMAGE_INSTALL` + Used by recipes to specify the packages to install into an image + through the :ref:`image <ref-classes-image>` class. Use the + ``IMAGE_INSTALL`` variable with care to avoid ordering issues. + + Image recipes set ``IMAGE_INSTALL`` to specify the packages to + install into an image through ``image.bbclass``. Additionally, + "helper" classes such as the + :ref:`core-image <ref-classes-core-image>` class exist that can + take lists used with ``IMAGE_FEATURES`` and turn them into + auto-generated entries in ``IMAGE_INSTALL`` in addition to its + default contents. + + When you use this variable, it is best to use it as follows: + :: + + IMAGE_INSTALL_append = " package-name" + + Be sure to include the space + between the quotation character and the start of the package name or + names. + + .. note:: + + - When working with a + :ref:`core-image-minimal-initramfs <ref-manual/ref-images:images>` + image, do not use the ``IMAGE_INSTALL`` variable to specify + packages for installation. Instead, use the + :term:`PACKAGE_INSTALL` variable, which + allows the initial RAM filesystem (initramfs) recipe to use a + fixed set of packages and not be affected by ``IMAGE_INSTALL``. + For information on creating an initramfs, see the + ":ref:`building-an-initramfs-image`" + section in the Yocto Project Development Tasks Manual. + + - Using ``IMAGE_INSTALL`` with the + :ref:`+= <bitbake:appending-and-prepending>` + BitBake operator within the ``/conf/local.conf`` file or from + within an image recipe is not recommended. Use of this operator + in these ways can cause ordering issues. Since + ``core-image.bbclass`` sets ``IMAGE_INSTALL`` to a default + value using the + :ref:`?= <bitbake:bitbake-user-manual/bitbake-user-manual-metadata:setting a default value (?=)>` + operator, using a ``+=`` operation against ``IMAGE_INSTALL`` + results in unexpected behavior when used within + ``conf/local.conf``. Furthermore, the same operation from + within an image recipe may or may not succeed depending on the + specific situation. In both these cases, the behavior is + contrary to how most users expect the ``+=`` operator to work. + + :term:`IMAGE_LINGUAS` + Specifies the list of locales to install into the image during the + root filesystem construction process. The OpenEmbedded build system + automatically splits locale files, which are used for localization, + into separate packages. Setting the ``IMAGE_LINGUAS`` variable + ensures that any locale packages that correspond to packages already + selected for installation into the image are also installed. Here is + an example: + :: + + IMAGE_LINGUAS = "pt-br de-de" + + In this example, the build system ensures any Brazilian Portuguese + and German locale files that correspond to packages in the image are + installed (i.e. ``*-locale-pt-br`` and ``*-locale-de-de`` as well as + ``*-locale-pt`` and ``*-locale-de``, since some software packages + only provide locale files by language and not by country-specific + language). + + See the :term:`GLIBC_GENERATE_LOCALES` + variable for information on generating GLIBC locales. + + + :term:`IMAGE_LINK_NAME` + The name of the output image symlink (which does not include + the version part as :term:`IMAGE_NAME` does). The default value + is derived using the :term:`IMAGE_BASENAME` and :term:`MACHINE` + variables: + :: + + IMAGE_LINK_NAME ?= "${IMAGE_BASENAME}-${MACHINE}" + + + :term:`IMAGE_MANIFEST` + The manifest file for the image. This file lists all the installed + packages that make up the image. The file contains package + information on a line-per-package basis as follows: + :: + + packagename packagearch version + + The :ref:`image <ref-classes-image>` class defines the manifest + file as follows: + :: + + IMAGE_MANIFEST ="${DEPLOY_DIR_IMAGE}/${IMAGE_NAME}.rootfs.manifest" + + The location is + derived using the :term:`DEPLOY_DIR_IMAGE` + and :term:`IMAGE_NAME` variables. You can find + information on how the image is created in the ":ref:`image-generation-dev-environment`" + section in the Yocto Project Overview and Concepts Manual. + + :term:`IMAGE_NAME` + The name of the output image files minus the extension. This variable + is derived using the :term:`IMAGE_BASENAME`, + :term:`MACHINE`, and :term:`IMAGE_VERSION_SUFFIX` + variables: + :: + + IMAGE_NAME ?= "${IMAGE_BASENAME}-${MACHINE}${IMAGE_VERSION_SUFFIX}" + + :term:`IMAGE_NAME_SUFFIX` + Suffix used for the image output file name - defaults to ``".rootfs"`` + to distinguish the image file from other files created during image + building; however if this suffix is redundant or not desired you can + clear the value of this variable (set the value to ""). For example, + this is typically cleared in initramfs image recipes. + + :term:`IMAGE_OVERHEAD_FACTOR` + Defines a multiplier that the build system applies to the initial + image size for cases when the multiplier times the returned disk + usage value for the image is greater than the sum of + ``IMAGE_ROOTFS_SIZE`` and ``IMAGE_ROOTFS_EXTRA_SPACE``. The result of + the multiplier applied to the initial image size creates free disk + space in the image as overhead. By default, the build process uses a + multiplier of 1.3 for this variable. This default value results in + 30% free disk space added to the image when this method is used to + determine the final generated image size. You should be aware that + post install scripts and the package management system uses disk + space inside this overhead area. Consequently, the multiplier does + not produce an image with all the theoretical free disk space. See + ``IMAGE_ROOTFS_SIZE`` for information on how the build system + determines the overall image size. + + The default 30% free disk space typically gives the image enough room + to boot and allows for basic post installs while still leaving a + small amount of free disk space. If 30% free space is inadequate, you + can increase the default value. For example, the following setting + gives you 50% free space added to the image: + :: + + IMAGE_OVERHEAD_FACTOR = "1.5" + + Alternatively, you can ensure a specific amount of free disk space is + added to the image by using the ``IMAGE_ROOTFS_EXTRA_SPACE`` + variable. + + :term:`IMAGE_PKGTYPE` + Defines the package type (i.e. DEB, RPM, IPK, or TAR) used by the + OpenEmbedded build system. The variable is defined appropriately by + the :ref:`package_deb <ref-classes-package_deb>`, + :ref:`package_rpm <ref-classes-package_rpm>`, + :ref:`package_ipk <ref-classes-package_ipk>`, or + :ref:`package_tar <ref-classes-package_tar>` class. + + .. note:: + + The ``package_tar`` class is broken and is not supported. It is + recommended that you do not use it. + + The :ref:`populate_sdk_* <ref-classes-populate-sdk-*>` and + :ref:`image <ref-classes-image>` classes use the ``IMAGE_PKGTYPE`` + for packaging up images and SDKs. + + You should not set the ``IMAGE_PKGTYPE`` manually. Rather, the + variable is set indirectly through the appropriate + :ref:`package_* <ref-classes-package>` class using the + :term:`PACKAGE_CLASSES` variable. The + OpenEmbedded build system uses the first package type (e.g. DEB, RPM, + or IPK) that appears with the variable + + .. note:: + + Files using the ``.tar`` format are never used as a substitute + packaging format for DEB, RPM, and IPK formatted files for your image + or SDK. + + :term:`IMAGE_POSTPROCESS_COMMAND` + Specifies a list of functions to call once the OpenEmbedded build + system creates the final image output files. You can specify + functions separated by semicolons: + :: + + IMAGE_POSTPROCESS_COMMAND += "function; ... " + + If you need to pass the root filesystem path to a command within the + function, you can use ``${IMAGE_ROOTFS}``, which points to the + directory that becomes the root filesystem image. See the + :term:`IMAGE_ROOTFS` variable for more + information. + + :term:`IMAGE_PREPROCESS_COMMAND` + Specifies a list of functions to call before the OpenEmbedded build + system creates the final image output files. You can specify + functions separated by semicolons: + :: + + IMAGE_PREPROCESS_COMMAND += "function; ... " + + If you need to pass the root filesystem path to a command within the + function, you can use ``${IMAGE_ROOTFS}``, which points to the + directory that becomes the root filesystem image. See the + :term:`IMAGE_ROOTFS` variable for more + information. + + :term:`IMAGE_ROOTFS` + The location of the root filesystem while it is under construction + (i.e. during the :ref:`ref-tasks-rootfs` task). This + variable is not configurable. Do not change it. + + :term:`IMAGE_ROOTFS_ALIGNMENT` + Specifies the alignment for the output image file in Kbytes. If the + size of the image is not a multiple of this value, then the size is + rounded up to the nearest multiple of the value. The default value is + "1". See :term:`IMAGE_ROOTFS_SIZE` for + additional information. + + :term:`IMAGE_ROOTFS_EXTRA_SPACE` + Defines additional free disk space created in the image in Kbytes. By + default, this variable is set to "0". This free disk space is added + to the image after the build system determines the image size as + described in ``IMAGE_ROOTFS_SIZE``. + + This variable is particularly useful when you want to ensure that a + specific amount of free disk space is available on a device after an + image is installed and running. For example, to be sure 5 Gbytes of + free disk space is available, set the variable as follows: + :: + + IMAGE_ROOTFS_EXTRA_SPACE = "5242880" + + For example, the Yocto Project Build Appliance specifically requests + 40 Gbytes of extra space with the line: + :: + + IMAGE_ROOTFS_EXTRA_SPACE = "41943040" + + :term:`IMAGE_ROOTFS_SIZE` + Defines the size in Kbytes for the generated image. The OpenEmbedded + build system determines the final size for the generated image using + an algorithm that takes into account the initial disk space used for + the generated image, a requested size for the image, and requested + additional free disk space to be added to the image. Programatically, + the build system determines the final size of the generated image as + follows: + :: + + if (image-du * overhead) < rootfs-size: + internal-rootfs-size = rootfs-size + xspace + else: + internal-rootfs-size = (image-du * overhead) + xspace + where: + image-du = Returned value of the du command on the image. + overhead = IMAGE_OVERHEAD_FACTOR + rootfs-size = IMAGE_ROOTFS_SIZE + internal-rootfs-size = Initial root filesystem size before any modifications. + xspace = IMAGE_ROOTFS_EXTRA_SPACE + + See the :term:`IMAGE_OVERHEAD_FACTOR` + and :term:`IMAGE_ROOTFS_EXTRA_SPACE` + variables for related information. + + :term:`IMAGE_TYPEDEP` + Specifies a dependency from one image type on another. Here is an + example from the :ref:`image-live <ref-classes-image-live>` class: + :: + + IMAGE_TYPEDEP_live = "ext3" + + In the previous example, the variable ensures that when "live" is + listed with the :term:`IMAGE_FSTYPES` variable, + the OpenEmbedded build system produces an ``ext3`` image first since + one of the components of the live image is an ``ext3`` formatted + partition containing the root filesystem. + + :term:`IMAGE_TYPES` + Specifies the complete list of supported image types by default: + + - btrfs + - container + - cpio + - cpio.gz + - cpio.lz4 + - cpio.lzma + - cpio.xz + - cramfs + - ext2 + - ext2.bz2 + - ext2.gz + - ext2.lzma + - ext3 + - ext3.gz + - ext4 + - ext4.gz + - f2fs + - hddimg + - iso + - jffs2 + - jffs2.sum + - multiubi + - squashfs + - squashfs-lz4 + - squashfs-lzo + - squashfs-xz + - tar + - tar.bz2 + - tar.gz + - tar.lz4 + - tar.xz + - tar.zst + - ubi + - ubifs + - wic + - wic.bz2 + - wic.gz + - wic.lzma + + For more information about these types of images, see + ``meta/classes/image_types*.bbclass`` in the :term:`Source Directory`. + + :term:`IMAGE_VERSION_SUFFIX` + Version suffix that is part of the default :term:`IMAGE_NAME` and + :term:`KERNEL_ARTIFACT_NAME` values. + Defaults to ``"-${DATETIME}"``, however you could set this to a + version string that comes from your external build environment if + desired, and this suffix would then be used consistently across + the build artifacts. + + :term:`INC_PR` + Helps define the recipe revision for recipes that share a common + ``include`` file. You can think of this variable as part of the + recipe revision as set from within an include file. + + Suppose, for example, you have a set of recipes that are used across + several projects. And, within each of those recipes the revision (its + :term:`PR` value) is set accordingly. In this case, when + the revision of those recipes changes, the burden is on you to find + all those recipes and be sure that they get changed to reflect the + updated version of the recipe. In this scenario, it can get + complicated when recipes that are used in many places and provide + common functionality are upgraded to a new revision. + + A more efficient way of dealing with this situation is to set the + ``INC_PR`` variable inside the ``include`` files that the recipes + share and then expand the ``INC_PR`` variable within the recipes to + help define the recipe revision. + + The following provides an example that shows how to use the + ``INC_PR`` variable given a common ``include`` file that defines the + variable. Once the variable is defined in the ``include`` file, you + can use the variable to set the ``PR`` values in each recipe. You + will notice that when you set a recipe's ``PR`` you can provide more + granular revisioning by appending values to the ``INC_PR`` variable: + :: + + recipes-graphics/xorg-font/xorg-font-common.inc:INC_PR = "r2" + recipes-graphics/xorg-font/encodings_1.0.4.bb:PR = "${INC_PR}.1" + recipes-graphics/xorg-font/font-util_1.3.0.bb:PR = "${INC_PR}.0" + recipes-graphics/xorg-font/font-alias_1.0.3.bb:PR = "${INC_PR}.3" + + The + first line of the example establishes the baseline revision to be + used for all recipes that use the ``include`` file. The remaining + lines in the example are from individual recipes and show how the + ``PR`` value is set. + + :term:`INCOMPATIBLE_LICENSE` + Specifies a space-separated list of license names (as they would + appear in :term:`LICENSE`) that should be excluded + from the build (if set globally), or from an image (if set locally + in an image recipe). + + When the variable is set globally, recipes that provide no alternatives to listed + incompatible licenses are not built. Packages that are individually + licensed with the specified incompatible licenses will be deleted. + Most of the time this does not allow a feasible build (because it becomes impossible + to satisfy build time dependencies), so the recommended way to + implement license restrictions is to set the variable in specific + image recipes where the restrictions must apply. That way there + are no build time restrictions, but the license check is still + performed when the image's filesystem is assembled from packages. + + .. note:: + + This functionality is only regularly tested using the following + setting: + :: + + INCOMPATIBLE_LICENSE = "GPL-3.0 LGPL-3.0 AGPL-3.0" + + + Although you can use other settings, you might be required to + remove dependencies on or provide alternatives to components that + are required to produce a functional system image. + + .. note:: + + It is possible to define a list of licenses that are allowed to be + used instead of the licenses that are excluded. To do this, define + a variable ``COMPATIBLE_LICENSES`` with the names of the licences + that are allowed. Then define ``INCOMPATIBLE_LICENSE`` as: + :: + + INCOMPATIBLE_LICENSE = "${@' '.join(sorted(set(d.getVar('AVAILABLE_LICENSES').split()) - set(d.getVar('COMPATIBLE_LICENSES').split())))}" + + + This will result in ``INCOMPATIBLE_LICENSE`` containing the names of + all licences from :term:`AVAILABLE_LICENSES` except the ones specified + in ``COMPATIBLE_LICENSES`` , thus only allowing the latter licences to + be used. + + :term:`INHERIT` + Causes the named class or classes to be inherited globally. Anonymous + functions in the class or classes are not executed for the base + configuration and in each individual recipe. The OpenEmbedded build + system ignores changes to ``INHERIT`` in individual recipes. + + For more information on ``INHERIT``, see the + :ref:`bitbake:bitbake-user-manual/bitbake-user-manual-metadata:\`\`inherit\`\` configuration directive`" + section in the Bitbake User Manual. + + :term:`INHERIT_DISTRO` + Lists classes that will be inherited at the distribution level. It is + unlikely that you want to edit this variable. + + The default value of the variable is set as follows in the + ``meta/conf/distro/defaultsetup.conf`` file: + :: + + INHERIT_DISTRO ?= "debian devshell sstate license" + + :term:`INHIBIT_DEFAULT_DEPS` + Prevents the default dependencies, namely the C compiler and standard + C library (libc), from being added to :term:`DEPENDS`. + This variable is usually used within recipes that do not require any + compilation using the C compiler. + + Set the variable to "1" to prevent the default dependencies from + being added. + + :term:`INHIBIT_PACKAGE_DEBUG_SPLIT` + Prevents the OpenEmbedded build system from splitting out debug + information during packaging. By default, the build system splits out + debugging information during the + :ref:`ref-tasks-package` task. For more information on + how debug information is split out, see the + :term:`PACKAGE_DEBUG_SPLIT_STYLE` + variable. + + To prevent the build system from splitting out debug information + during packaging, set the ``INHIBIT_PACKAGE_DEBUG_SPLIT`` variable as + follows: + :: + + INHIBIT_PACKAGE_DEBUG_SPLIT = "1" + + :term:`INHIBIT_PACKAGE_STRIP` + If set to "1", causes the build to not strip binaries in resulting + packages and prevents the ``-dbg`` package from containing the source + files. + + By default, the OpenEmbedded build system strips binaries and puts + the debugging symbols into ``${``\ :term:`PN`\ ``}-dbg``. + Consequently, you should not set ``INHIBIT_PACKAGE_STRIP`` when you + plan to debug in general. + + :term:`INHIBIT_SYSROOT_STRIP` + If set to "1", causes the build to not strip binaries in the + resulting sysroot. + + By default, the OpenEmbedded build system strips binaries in the + resulting sysroot. When you specifically set the + ``INHIBIT_SYSROOT_STRIP`` variable to "1" in your recipe, you inhibit + this stripping. + + If you want to use this variable, include the + :ref:`staging <ref-classes-staging>` class. This class uses a + ``sys_strip()`` function to test for the variable and acts + accordingly. + + .. note:: + + Use of the ``INHIBIT_SYSROOT_STRIP`` variable occurs in rare and + special circumstances. For example, suppose you are building + bare-metal firmware by using an external GCC toolchain. Furthermore, + even if the toolchain's binaries are strippable, other files exist + that are needed for the build that are not strippable. + + :term:`INITRAMFS_FSTYPES` + Defines the format for the output image of an initial RAM filesystem + (initramfs), which is used during boot. Supported formats are the + same as those supported by the + :term:`IMAGE_FSTYPES` variable. + + The default value of this variable, which is set in the + ``meta/conf/bitbake.conf`` configuration file in the + :term:`Source Directory`, is "cpio.gz". The Linux kernel's + initramfs mechanism, as opposed to the initial RAM filesystem + `initrd <https://en.wikipedia.org/wiki/Initrd>`__ mechanism, expects + an optionally compressed cpio archive. + + :term:`INITRAMFS_IMAGE` + Specifies the :term:`PROVIDES` name of an image + recipe that is used to build an initial RAM filesystem (initramfs) + image. In other words, the ``INITRAMFS_IMAGE`` variable causes an + additional recipe to be built as a dependency to whatever root + filesystem recipe you might be using (e.g. ``core-image-sato``). The + initramfs image recipe you provide should set + :term:`IMAGE_FSTYPES` to + :term:`INITRAMFS_FSTYPES`. + + An initramfs image provides a temporary root filesystem used for + early system initialization (e.g. loading of modules needed to locate + and mount the "real" root filesystem). + + .. note:: + + See the ``meta/recipes-core/images/core-image-minimal-initramfs.bb`` + recipe in the :term:`Source Directory` + for an example initramfs recipe. To select this sample recipe as + the one built to provide the initramfs image, set ``INITRAMFS_IMAGE`` + to "core-image-minimal-initramfs". + + You can also find more information by referencing the + ``meta-poky/conf/local.conf.sample.extended`` configuration file in + the Source Directory, the :ref:`image <ref-classes-image>` class, + and the :ref:`kernel <ref-classes-kernel>` class to see how to use + the ``INITRAMFS_IMAGE`` variable. + + If ``INITRAMFS_IMAGE`` is empty, which is the default, then no + initramfs image is built. + + For more information, you can also see the + :term:`INITRAMFS_IMAGE_BUNDLE` + variable, which allows the generated image to be bundled inside the + kernel image. Additionally, for information on creating an initramfs + image, see the ":ref:`building-an-initramfs-image`" section + in the Yocto Project Development Tasks Manual. + + :term:`INITRAMFS_IMAGE_BUNDLE` + Controls whether or not the image recipe specified by + :term:`INITRAMFS_IMAGE` is run through an + extra pass + (:ref:`ref-tasks-bundle_initramfs`) during + kernel compilation in order to build a single binary that contains + both the kernel image and the initial RAM filesystem (initramfs) + image. This makes use of the + :term:`CONFIG_INITRAMFS_SOURCE` kernel + feature. + + .. note:: + + Using an extra compilation pass to bundle the initramfs avoids a + circular dependency between the kernel recipe and the initramfs + recipe should the initramfs include kernel modules. Should that be + the case, the initramfs recipe depends on the kernel for the + kernel modules, and the kernel depends on the initramfs recipe + since the initramfs is bundled inside the kernel image. + + The combined binary is deposited into the ``tmp/deploy`` directory, + which is part of the :term:`Build Directory`. + + Setting the variable to "1" in a configuration file causes the + OpenEmbedded build system to generate a kernel image with the + initramfs specified in ``INITRAMFS_IMAGE`` bundled within: + :: + + INITRAMFS_IMAGE_BUNDLE = "1" + + By default, the + :ref:`kernel <ref-classes-kernel>` class sets this variable to a + null string as follows: + :: + + INITRAMFS_IMAGE_BUNDLE ?= "" + + .. note:: + + You must set the ``INITRAMFS_IMAGE_BUNDLE`` variable in a + configuration file. You cannot set the variable in a recipe file. + + See the + :yocto_git:`local.conf.sample.extended </cgit/cgit.cgi/poky/tree/meta-poky/conf/local.conf.sample.extended>` + file for additional information. Also, for information on creating an + initramfs, see the ":ref:`building-an-initramfs-image`" section + in the Yocto Project Development Tasks Manual. + + :term:`INITRAMFS_LINK_NAME` + The link name of the initial RAM filesystem image. This variable is + set in the ``meta/classes/kernel-artifact-names.bbclass`` file as + follows: + :: + + INITRAMFS_LINK_NAME ?= "initramfs-${KERNEL_ARTIFACT_LINK_NAME}" + + The value of the + ``KERNEL_ARTIFACT_LINK_NAME`` variable, which is set in the same + file, has the following value: + :: + + KERNEL_ARTIFACT_LINK_NAME ?= "${MACHINE}" + + See the :term:`MACHINE` variable for additional + information. + + :term:`INITRAMFS_NAME` + The base name of the initial RAM filesystem image. This variable is + set in the ``meta/classes/kernel-artifact-names.bbclass`` file as + follows: + :: + + INITRAMFS_NAME ?= "initramfs-${KERNEL_ARTIFACT_NAME}" + + The value of the :term:`KERNEL_ARTIFACT_NAME` + variable, which is set in the same file, has the following value: + :: + + KERNEL_ARTIFACT_NAME ?= "${PKGE}-${PKGV}-${PKGR}-${MACHINE}${IMAGE_VERSION_SUFFIX}" + + :term:`INITRD` + Indicates list of filesystem images to concatenate and use as an + initial RAM disk (``initrd``). + + The ``INITRD`` variable is an optional variable used with the + :ref:`image-live <ref-classes-image-live>` class. + + :term:`INITRD_IMAGE` + When building a "live" bootable image (i.e. when + :term:`IMAGE_FSTYPES` contains "live"), + ``INITRD_IMAGE`` specifies the image recipe that should be built to + provide the initial RAM disk image. The default value is + "core-image-minimal-initramfs". + + See the :ref:`image-live <ref-classes-image-live>` class for more + information. + + :term:`INITSCRIPT_NAME` + The filename of the initialization script as installed to + ``${sysconfdir}/init.d``. + + This variable is used in recipes when using ``update-rc.d.bbclass``. + The variable is mandatory. + + :term:`INITSCRIPT_PACKAGES` + A list of the packages that contain initscripts. If multiple packages + are specified, you need to append the package name to the other + ``INITSCRIPT_*`` as an override. + + This variable is used in recipes when using ``update-rc.d.bbclass``. + The variable is optional and defaults to the :term:`PN` + variable. + + :term:`INITSCRIPT_PARAMS` + Specifies the options to pass to ``update-rc.d``. Here is an example: + :: + + INITSCRIPT_PARAMS = "start 99 5 2 . stop 20 0 1 6 ." + + In this example, the script has a runlevel of 99, starts the script + in initlevels 2 and 5, and stops the script in levels 0, 1 and 6. + + The variable's default value is "defaults", which is set in the + :ref:`update-rc.d <ref-classes-update-rc.d>` class. + + The value in ``INITSCRIPT_PARAMS`` is passed through to the + ``update-rc.d`` command. For more information on valid parameters, + please see the ``update-rc.d`` manual page at + https://manpages.debian.org/buster/init-system-helpers/update-rc.d.8.en.html + + :term:`INSANE_SKIP` + Specifies the QA checks to skip for a specific package within a + recipe. For example, to skip the check for symbolic link ``.so`` + files in the main package of a recipe, add the following to the + recipe. The package name override must be used, which in this example + is ``${PN}``: + :: + + INSANE_SKIP_${PN} += "dev-so" + + See the ":ref:`insane.bbclass <ref-classes-insane>`" section for a + list of the valid QA checks you can specify using this variable. + + :term:`INSTALL_TIMEZONE_FILE` + By default, the ``tzdata`` recipe packages an ``/etc/timezone`` file. + Set the ``INSTALL_TIMEZONE_FILE`` variable to "0" at the + configuration level to disable this behavior. + + :term:`IPK_FEED_URIS` + When the IPK backend is in use and package management is enabled on + the target, you can use this variable to set up ``opkg`` in the + target image to point to package feeds on a nominated server. Once + the feed is established, you can perform installations or upgrades + using the package manager at runtime. + + :term:`KARCH` + Defines the kernel architecture used when assembling the + configuration. Architectures supported for this release are: + + - powerpc + - i386 + - x86_64 + - arm + - qemu + - mips + + You define the ``KARCH`` variable in the :ref:`kernel-dev/kernel-dev-advanced:bsp descriptions`. + + :term:`KBRANCH` + A regular expression used by the build process to explicitly identify + the kernel branch that is validated, patched, and configured during a + build. You must set this variable to ensure the exact kernel branch + you want is being used by the build process. + + Values for this variable are set in the kernel's recipe file and the + kernel's append file. For example, if you are using the + ``linux-yocto_4.12`` kernel, the kernel recipe file is the + ``meta/recipes-kernel/linux/linux-yocto_4.12.bb`` file. ``KBRANCH`` + is set as follows in that kernel recipe file: + :: + + KBRANCH ?= "standard/base" + + This variable is also used from the kernel's append file to identify + the kernel branch specific to a particular machine or target + hardware. Continuing with the previous kernel example, the kernel's + append file (i.e. ``linux-yocto_4.12.bbappend``) is located in the + BSP layer for a given machine. For example, the append file for the + Beaglebone, EdgeRouter, and generic versions of both 32 and 64-bit IA + machines (``meta-yocto-bsp``) is named + ``meta-yocto-bsp/recipes-kernel/linux/linux-yocto_4.12.bbappend``. + Here are the related statements from that append file: + :: + + KBRANCH_genericx86 = "standard/base" + KBRANCH_genericx86-64 = "standard/base" + KBRANCH_edgerouter = "standard/edgerouter" + KBRANCH_beaglebone = "standard/beaglebone" + + The ``KBRANCH`` statements + identify the kernel branch to use when building for each supported + BSP. + + :term:`KBUILD_DEFCONFIG` + When used with the :ref:`kernel-yocto <ref-classes-kernel-yocto>` + class, specifies an "in-tree" kernel configuration file for use + during a kernel build. + + Typically, when using a ``defconfig`` to configure a kernel during a + build, you place the file in your layer in the same manner as you + would place patch files and configuration fragment files (i.e. + "out-of-tree"). However, if you want to use a ``defconfig`` file that + is part of the kernel tree (i.e. "in-tree"), you can use the + ``KBUILD_DEFCONFIG`` variable and append the + :term:`KMACHINE` variable to point to the + ``defconfig`` file. + + To use the variable, set it in the append file for your kernel recipe + using the following form: + :: + + KBUILD_DEFCONFIG_KMACHINE ?= defconfig_file + + Here is an example from a "raspberrypi2" ``KMACHINE`` build that uses + a ``defconfig`` file named "bcm2709_defconfig": + :: + + KBUILD_DEFCONFIG_raspberrypi2 = "bcm2709_defconfig" + + As an alternative, you can use the following within your append file: + :: + + KBUILD_DEFCONFIG_pn-linux-yocto ?= defconfig_file + + For more + information on how to use the ``KBUILD_DEFCONFIG`` variable, see the + ":ref:`kernel-dev/kernel-dev-common:using an "in-tree" \`\`defconfig\`\` file`" + section in the Yocto Project Linux Kernel Development Manual. + + :term:`KERNEL_ALT_IMAGETYPE` + Specifies an alternate kernel image type for creation in addition to + the kernel image type specified using the + :term:`KERNEL_IMAGETYPE` variable. + + :term:`KERNEL_ARTIFACT_NAME` + Specifies the name of all of the build artifacts. You can change the + name of the artifacts by changing the ``KERNEL_ARTIFACT_NAME`` + variable. + + The value of ``KERNEL_ARTIFACT_NAME``, which is set in the + ``meta/classes/kernel-artifact-names.bbclass`` file, has the + following default value: + :: + + KERNEL_ARTIFACT_NAME ?= "${PKGE}-${PKGV}-${PKGR}-${MACHINE}${IMAGE_VERSION_SUFFIX}" + + See the :term:`PKGE`, :term:`PKGV`, :term:`PKGR`, :term:`MACHINE` + and :term:`IMAGE_VERSION_SUFFIX` variables for additional information. + + :term:`KERNEL_CLASSES` + A list of classes defining kernel image types that the + :ref:`kernel <ref-classes-kernel>` class should inherit. You + typically append this variable to enable extended image types. An + example is the "kernel-fitimage", which enables fitImage support and + resides in ``meta/classes/kernel-fitimage.bbclass``. You can register + custom kernel image types with the ``kernel`` class using this + variable. + + :term:`KERNEL_DEVICETREE` + Specifies the name of the generated Linux kernel device tree (i.e. + the ``.dtb``) file. + + .. note:: + + Legacy support exists for specifying the full path to the device + tree. However, providing just the ``.dtb`` file is preferred. + + In order to use this variable, the + :ref:`kernel-devicetree <ref-classes-kernel-devicetree>` class must + be inherited. + + :term:`KERNEL_DTB_LINK_NAME` + The link name of the kernel device tree binary (DTB). This variable + is set in the ``meta/classes/kernel-artifact-names.bbclass`` file as + follows: + :: + + KERNEL_DTB_LINK_NAME ?= "${KERNEL_ARTIFACT_LINK_NAME}" + + The + value of the ``KERNEL_ARTIFACT_LINK_NAME`` variable, which is set in + the same file, has the following value: + :: + + KERNEL_ARTIFACT_LINK_NAME ?= "${MACHINE}" + + See the :term:`MACHINE` variable for additional + information. + + :term:`KERNEL_DTB_NAME` + The base name of the kernel device tree binary (DTB). This variable + is set in the ``meta/classes/kernel-artifact-names.bbclass`` file as + follows: + :: + + KERNEL_DTB_NAME ?= "${KERNEL_ARTIFACT_NAME}" + + The value of the :term:`KERNEL_ARTIFACT_NAME` + variable, which is set in the same file, has the following value: + :: + + KERNEL_ARTIFACT_NAME ?= "${PKGE}-${PKGV}-${PKGR}-${MACHINE}${IMAGE_VERSION_SUFFIX}" + + :term:`KERNEL_DTC_FLAGS` + Specifies the ``dtc`` flags that are passed to the Linux kernel build + system when generating the device trees (via ``DTC_FLAGS`` environment + variable). + + In order to use this variable, the + :ref:`kernel-devicetree <ref-classes-kernel-devicetree>` class must + be inherited. + + :term:`KERNEL_EXTRA_ARGS` + Specifies additional ``make`` command-line arguments the OpenEmbedded + build system passes on when compiling the kernel. + + :term:`KERNEL_FEATURES` + Includes additional kernel metadata. In the OpenEmbedded build + system, the default Board Support Packages (BSPs) + :term:`Metadata` is provided through the + :term:`KMACHINE` and :term:`KBRANCH` + variables. You can use the ``KERNEL_FEATURES`` variable from within + the kernel recipe or kernel append file to further add metadata for + all BSPs or specific BSPs. + + The metadata you add through this variable includes config fragments + and features descriptions, which usually includes patches as well as + config fragments. You typically override the ``KERNEL_FEATURES`` + variable for a specific machine. In this way, you can provide + validated, but optional, sets of kernel configurations and features. + + For example, the following example from the ``linux-yocto-rt_4.12`` + kernel recipe adds "netfilter" and "taskstats" features to all BSPs + as well as "virtio" configurations to all QEMU machines. The last two + statements add specific configurations to targeted machine types: + :: + + KERNEL_EXTRA_FEATURES ?= "features/netfilter/netfilter.scc features/taskstats/taskstats.scc" + KERNEL_FEATURES_append = " ${KERNEL_EXTRA_FEATURES}" + KERNEL_FEATURES_append_qemuall = " cfg/virtio.scc" + KERNEL_FEATURES_append_qemux86 = " cfg/sound.scc cfg/paravirt_kvm.scc" + KERNEL_FEATURES_append_qemux86-64 = " cfg/sound.scc" + + :term:`KERNEL_FIT_LINK_NAME` + The link name of the kernel flattened image tree (FIT) image. This + variable is set in the ``meta/classes/kernel-artifact-names.bbclass`` + file as follows: + :: + + KERNEL_FIT_LINK_NAME ?= "${KERNEL_ARTIFACT_LINK_NAME}" + + The value of the + ``KERNEL_ARTIFACT_LINK_NAME`` variable, which is set in the same + file, has the following value: + :: + + KERNEL_ARTIFACT_LINK_NAME ?= "${MACHINE}" + + See the :term:`MACHINE` variable for additional + information. + + :term:`KERNEL_FIT_NAME` + The base name of the kernel flattened image tree (FIT) image. This + variable is set in the ``meta/classes/kernel-artifact-names.bbclass`` + file as follows: + :: + + KERNEL_FIT_NAME ?= "${KERNEL_ARTIFACT_NAME}" + + The value of the :term:`KERNEL_ARTIFACT_NAME` + variable, which is set in the same file, has the following value: + :: + + KERNEL_ARTIFACT_NAME ?= "${PKGE}-${PKGV}-${PKGR}-${MACHINE}${IMAGE_VERSION_SUFFIX}" + + :term:`KERNEL_IMAGE_LINK_NAME` + The link name for the kernel image. This variable is set in the + ``meta/classes/kernel-artifact-names.bbclass`` file as follows: + :: + + KERNEL_IMAGE_LINK_NAME ?= "${KERNEL_ARTIFACT_LINK_NAME}" + + The value of + the ``KERNEL_ARTIFACT_LINK_NAME`` variable, which is set in the same + file, has the following value: + :: + + KERNEL_ARTIFACT_LINK_NAME ?= "${MACHINE}" + + See the :term:`MACHINE` variable for additional + information. + + :term:`KERNEL_IMAGE_MAXSIZE` + Specifies the maximum size of the kernel image file in kilobytes. If + ``KERNEL_IMAGE_MAXSIZE`` is set, the size of the kernel image file is + checked against the set value during the + :ref:`ref-tasks-sizecheck` task. The task fails if + the kernel image file is larger than the setting. + + ``KERNEL_IMAGE_MAXSIZE`` is useful for target devices that have a + limited amount of space in which the kernel image must be stored. + + By default, this variable is not set, which means the size of the + kernel image is not checked. + + :term:`KERNEL_IMAGE_NAME` + The base name of the kernel image. This variable is set in the + ``meta/classes/kernel-artifact-names.bbclass`` file as follows: + :: + + KERNEL_IMAGE_NAME ?= "${KERNEL_ARTIFACT_NAME}" + + The value of the + :term:`KERNEL_ARTIFACT_NAME` variable, + which is set in the same file, has the following value: + :: + + KERNEL_ARTIFACT_NAME ?= "${PKGE}-${PKGV}-${PKGR}-${MACHINE}${IMAGE_VERSION_SUFFIX}" + + :term:`KERNEL_IMAGETYPE` + The type of kernel to build for a device, usually set by the machine + configuration files and defaults to "zImage". This variable is used + when building the kernel and is passed to ``make`` as the target to + build. + + If you want to build an alternate kernel image type, use the + :term:`KERNEL_ALT_IMAGETYPE` variable. + + :term:`KERNEL_MODULE_AUTOLOAD` + Lists kernel modules that need to be auto-loaded during boot. + + .. note:: + + This variable replaces the deprecated :term:`module_autoload` + variable. + + You can use the ``KERNEL_MODULE_AUTOLOAD`` variable anywhere that it + can be recognized by the kernel recipe or by an out-of-tree kernel + module recipe (e.g. a machine configuration file, a distribution + configuration file, an append file for the recipe, or the recipe + itself). + + Specify it as follows: + :: + + KERNEL_MODULE_AUTOLOAD += "module_name1 module_name2 module_name3" + + Including ``KERNEL_MODULE_AUTOLOAD`` causes the OpenEmbedded build + system to populate the ``/etc/modules-load.d/modname.conf`` file with + the list of modules to be auto-loaded on boot. The modules appear + one-per-line in the file. Here is an example of the most common use + case: + :: + + KERNEL_MODULE_AUTOLOAD += "module_name" + + For information on how to populate the ``modname.conf`` file with + ``modprobe.d`` syntax lines, see the :term:`KERNEL_MODULE_PROBECONF` variable. + + :term:`KERNEL_MODULE_PROBECONF` + Provides a list of modules for which the OpenEmbedded build system + expects to find ``module_conf_``\ modname values that specify + configuration for each of the modules. For information on how to + provide those module configurations, see the + :term:`module_conf_* <module_conf>` variable. + + :term:`KERNEL_PATH` + The location of the kernel sources. This variable is set to the value + of the :term:`STAGING_KERNEL_DIR` within + the :ref:`module <ref-classes-module>` class. For information on + how this variable is used, see the + ":ref:`kernel-dev/kernel-dev-common:incorporating out-of-tree modules`" + section in the Yocto Project Linux Kernel Development Manual. + + To help maximize compatibility with out-of-tree drivers used to build + modules, the OpenEmbedded build system also recognizes and uses the + :term:`KERNEL_SRC` variable, which is identical to + the ``KERNEL_PATH`` variable. Both variables are common variables + used by external Makefiles to point to the kernel source directory. + + :term:`KERNEL_SRC` + The location of the kernel sources. This variable is set to the value + of the :term:`STAGING_KERNEL_DIR` within + the :ref:`module <ref-classes-module>` class. For information on + how this variable is used, see the + ":ref:`kernel-dev/kernel-dev-common:incorporating out-of-tree modules`" + section in the Yocto Project Linux Kernel Development Manual. + + To help maximize compatibility with out-of-tree drivers used to build + modules, the OpenEmbedded build system also recognizes and uses the + :term:`KERNEL_PATH` variable, which is identical + to the ``KERNEL_SRC`` variable. Both variables are common variables + used by external Makefiles to point to the kernel source directory. + + :term:`KERNEL_VERSION` + Specifies the version of the kernel as extracted from ``version.h`` + or ``utsrelease.h`` within the kernel sources. Effects of setting + this variable do not take affect until the kernel has been + configured. Consequently, attempting to refer to this variable in + contexts prior to configuration will not work. + + :term:`KERNELDEPMODDEPEND` + Specifies whether the data referenced through + :term:`PKGDATA_DIR` is needed or not. The + ``KERNELDEPMODDEPEND`` does not control whether or not that data + exists, but simply whether or not it is used. If you do not need to + use the data, set the ``KERNELDEPMODDEPEND`` variable in your + ``initramfs`` recipe. Setting the variable there when the data is not + needed avoids a potential dependency loop. + + :term:`KFEATURE_DESCRIPTION` + Provides a short description of a configuration fragment. You use + this variable in the ``.scc`` file that describes a configuration + fragment file. Here is the variable used in a file named ``smp.scc`` + to describe SMP being enabled: + :: + + define KFEATURE_DESCRIPTION "Enable SMP" + + :term:`KMACHINE` + The machine as known by the kernel. Sometimes the machine name used + by the kernel does not match the machine name used by the + OpenEmbedded build system. For example, the machine name that the + OpenEmbedded build system understands as ``core2-32-intel-common`` + goes by a different name in the Linux Yocto kernel. The kernel + understands that machine as ``intel-core2-32``. For cases like these, + the ``KMACHINE`` variable maps the kernel machine name to the + OpenEmbedded build system machine name. + + These mappings between different names occur in the Yocto Linux + Kernel's ``meta`` branch. As an example take a look in the + ``common/recipes-kernel/linux/linux-yocto_3.19.bbappend`` file: + :: + + LINUX_VERSION_core2-32-intel-common = "3.19.0" + COMPATIBLE_MACHINE_core2-32-intel-common = "${MACHINE}" + SRCREV_meta_core2-32-intel-common = "8897ef68b30e7426bc1d39895e71fb155d694974" + SRCREV_machine_core2-32-intel-common = "43b9eced9ba8a57add36af07736344dcc383f711" + KMACHINE_core2-32-intel-common = "intel-core2-32" + KBRANCH_core2-32-intel-common = "standard/base" + KERNEL_FEATURES_append_core2-32-intel-common = " ${KERNEL_FEATURES_INTEL_COMMON}" + + The ``KMACHINE`` statement says + that the kernel understands the machine name as "intel-core2-32". + However, the OpenEmbedded build system understands the machine as + "core2-32-intel-common". + + :term:`KTYPE` + Defines the kernel type to be used in assembling the configuration. + The linux-yocto recipes define "standard", "tiny", and "preempt-rt" + kernel types. See the ":ref:`kernel-dev/kernel-dev-advanced:kernel types`" + section in the + Yocto Project Linux Kernel Development Manual for more information on + kernel types. + + You define the ``KTYPE`` variable in the + :ref:`kernel-dev/kernel-dev-advanced:bsp descriptions`. The + value you use must match the value used for the + :term:`LINUX_KERNEL_TYPE` value used by the + kernel recipe. + + :term:`LABELS` + Provides a list of targets for automatic configuration. + + See the :ref:`grub-efi <ref-classes-grub-efi>` class for more + information on how this variable is used. + + :term:`LAYERDEPENDS` + Lists the layers, separated by spaces, on which this recipe depends. + Optionally, you can specify a specific layer version for a dependency + by adding it to the end of the layer name. Here is an example: + :: + + LAYERDEPENDS_mylayer = "anotherlayer (=3)" + + In this previous example, + version 3 of "anotherlayer" is compared against + :term:`LAYERVERSION`\ ``_anotherlayer``. + + An error is produced if any dependency is missing or the version + numbers (if specified) do not match exactly. This variable is used in + the ``conf/layer.conf`` file and must be suffixed with the name of + the specific layer (e.g. ``LAYERDEPENDS_mylayer``). + + :term:`LAYERDIR` + When used inside the ``layer.conf`` configuration file, this variable + provides the path of the current layer. This variable is not + available outside of ``layer.conf`` and references are expanded + immediately when parsing of the file completes. + + :term:`LAYERRECOMMENDS` + Lists the layers, separated by spaces, recommended for use with this + layer. + + Optionally, you can specify a specific layer version for a + recommendation by adding the version to the end of the layer name. + Here is an example: + :: + + LAYERRECOMMENDS_mylayer = "anotherlayer (=3)" + + In this previous example, version 3 of "anotherlayer" is compared + against ``LAYERVERSION_anotherlayer``. + + This variable is used in the ``conf/layer.conf`` file and must be + suffixed with the name of the specific layer (e.g. + ``LAYERRECOMMENDS_mylayer``). + + :term:`LAYERSERIES_COMPAT` + Lists the versions of the :term:`OpenEmbedded-Core (OE-Core)` for which + a layer is compatible. Using the ``LAYERSERIES_COMPAT`` variable + allows the layer maintainer to indicate which combinations of the + layer and OE-Core can be expected to work. The variable gives the + system a way to detect when a layer has not been tested with new + releases of OE-Core (e.g. the layer is not maintained). + + To specify the OE-Core versions for which a layer is compatible, use + this variable in your layer's ``conf/layer.conf`` configuration file. + For the list, use the Yocto Project + :yocto_wiki:`Release Name </wiki/Releases>` (e.g. + DISTRO_NAME_NO_CAP). To specify multiple OE-Core versions for the + layer, use a space-separated list: + :: + + LAYERSERIES_COMPAT_layer_root_name = "DISTRO_NAME_NO_CAP DISTRO_NAME_NO_CAP_MINUS_ONE" + + .. note:: + + Setting ``LAYERSERIES_COMPAT`` is required by the Yocto Project + Compatible version 2 standard. + The OpenEmbedded build system produces a warning if the variable + is not set for any given layer. + + See the ":ref:`dev-manual/dev-manual-common-tasks:creating your own layer`" + section in the Yocto Project Development Tasks Manual. + + :term:`LAYERVERSION` + Optionally specifies the version of a layer as a single number. You + can use this within :term:`LAYERDEPENDS` for + another layer in order to depend on a specific version of the layer. + This variable is used in the ``conf/layer.conf`` file and must be + suffixed with the name of the specific layer (e.g. + ``LAYERVERSION_mylayer``). + + :term:`LD` + The minimal command and arguments used to run the linker. + + :term:`LDFLAGS` + Specifies the flags to pass to the linker. This variable is exported + to an environment variable and thus made visible to the software + being built during the compilation step. + + Default initialization for ``LDFLAGS`` varies depending on what is + being built: + + - :term:`TARGET_LDFLAGS` when building for the + target + + - :term:`BUILD_LDFLAGS` when building for the + build host (i.e. ``-native``) + + - :term:`BUILDSDK_LDFLAGS` when building for + an SDK (i.e. ``nativesdk-``) + + :term:`LEAD_SONAME` + Specifies the lead (or primary) compiled library file (i.e. ``.so``) + that the :ref:`debian <ref-classes-debian>` class applies its + naming policy to given a recipe that packages multiple libraries. + + This variable works in conjunction with the ``debian`` class. + + :term:`LIC_FILES_CHKSUM` + Checksums of the license text in the recipe source code. + + This variable tracks changes in license text of the source code + files. If the license text is changed, it will trigger a build + failure, which gives the developer an opportunity to review any + license change. + + This variable must be defined for all recipes (unless + :term:`LICENSE` is set to "CLOSED"). + + For more information, see the ":ref:`usingpoky-configuring-lic_files_chksum`" + section in the Yocto Project Development Tasks Manual. + + :term:`LICENSE` + The list of source licenses for the recipe. Follow these rules: + + - Do not use spaces within individual license names. + + - Separate license names using \| (pipe) when there is a choice + between licenses. + + - Separate license names using & (ampersand) when multiple licenses + exist that cover different parts of the source. + + - You can use spaces between license names. + + - For standard licenses, use the names of the files in + ``meta/files/common-licenses/`` or the + :term:`SPDXLICENSEMAP` flag names defined in + ``meta/conf/licenses.conf``. + + Here are some examples: + :: + + LICENSE = "LGPLv2.1 | GPLv3" + LICENSE = "MPL-1 & LGPLv2.1" + LICENSE = "GPLv2+" + + The first example is from the + recipes for Qt, which the user may choose to distribute under either + the LGPL version 2.1 or GPL version 3. The second example is from + Cairo where two licenses cover different parts of the source code. + The final example is from ``sysstat``, which presents a single + license. + + You can also specify licenses on a per-package basis to handle + situations where components of the output have different licenses. + For example, a piece of software whose code is licensed under GPLv2 + but has accompanying documentation licensed under the GNU Free + Documentation License 1.2 could be specified as follows: + :: + + LICENSE = "GFDL-1.2 & GPLv2" + LICENSE_${PN} = "GPLv2" + LICENSE_${PN}-doc = "GFDL-1.2" + + :term:`LICENSE_CREATE_PACKAGE` + Setting ``LICENSE_CREATE_PACKAGE`` to "1" causes the OpenEmbedded + build system to create an extra package (i.e. + ``${``\ :term:`PN`\ ``}-lic``) for each recipe and to add + those packages to the + :term:`RRECOMMENDS`\ ``_${PN}``. + + The ``${PN}-lic`` package installs a directory in + ``/usr/share/licenses`` named ``${PN}``, which is the recipe's base + name, and installs files in that directory that contain license and + copyright information (i.e. copies of the appropriate license files + from ``meta/common-licenses`` that match the licenses specified in + the :term:`LICENSE` variable of the recipe metadata + and copies of files marked in + :term:`LIC_FILES_CHKSUM` as containing + license text). + + For related information on providing license text, see the + :term:`COPY_LIC_DIRS` variable, the + :term:`COPY_LIC_MANIFEST` variable, and the + ":ref:`dev-manual/dev-manual-common-tasks:providing license text`" + section in the Yocto Project Development Tasks Manual. + + :term:`LICENSE_FLAGS` + Specifies additional flags for a recipe you must whitelist through + :term:`LICENSE_FLAGS_WHITELIST` in + order to allow the recipe to be built. When providing multiple flags, + separate them with spaces. + + This value is independent of :term:`LICENSE` and is + typically used to mark recipes that might require additional licenses + in order to be used in a commercial product. For more information, + see the + ":ref:`dev-manual/dev-manual-common-tasks:enabling commercially licensed recipes`" + section in the Yocto Project Development Tasks Manual. + + :term:`LICENSE_FLAGS_WHITELIST` + Lists license flags that when specified in + :term:`LICENSE_FLAGS` within a recipe should not + prevent that recipe from being built. This practice is otherwise + known as "whitelisting" license flags. For more information, see the + ":ref:`dev-manual/dev-manual-common-tasks:enabling commercially licensed recipes`" + section in the Yocto Project Development Tasks Manual. + + :term:`LICENSE_PATH` + Path to additional licenses used during the build. By default, the + OpenEmbedded build system uses ``COMMON_LICENSE_DIR`` to define the + directory that holds common license text used during the build. The + ``LICENSE_PATH`` variable allows you to extend that location to other + areas that have additional licenses: + :: + + LICENSE_PATH += "path-to-additional-common-licenses" + + :term:`LINUX_KERNEL_TYPE` + Defines the kernel type to be used in assembling the configuration. + The linux-yocto recipes define "standard", "tiny", and "preempt-rt" + kernel types. See the ":ref:`kernel-dev/kernel-dev-advanced:kernel types`" + section in the + Yocto Project Linux Kernel Development Manual for more information on + kernel types. + + If you do not specify a ``LINUX_KERNEL_TYPE``, it defaults to + "standard". Together with :term:`KMACHINE`, the + ``LINUX_KERNEL_TYPE`` variable defines the search arguments used by + the kernel tools to find the appropriate description within the + kernel :term:`Metadata` with which to build out the sources + and configuration. + + :term:`LINUX_VERSION` + The Linux version from ``kernel.org`` on which the Linux kernel image + being built using the OpenEmbedded build system is based. You define + this variable in the kernel recipe. For example, the + ``linux-yocto-3.4.bb`` kernel recipe found in + ``meta/recipes-kernel/linux`` defines the variables as follows: + :: + + LINUX_VERSION ?= "3.4.24" + + The ``LINUX_VERSION`` variable is used to define :term:`PV` + for the recipe: + :: + + PV = "${LINUX_VERSION}+git${SRCPV}" + + :term:`LINUX_VERSION_EXTENSION` + A string extension compiled into the version string of the Linux + kernel built with the OpenEmbedded build system. You define this + variable in the kernel recipe. For example, the linux-yocto kernel + recipes all define the variable as follows: + :: + + LINUX_VERSION_EXTENSION ?= "-yocto-${LINUX_KERNEL_TYPE}" + + Defining this variable essentially sets the Linux kernel + configuration item ``CONFIG_LOCALVERSION``, which is visible through + the ``uname`` command. Here is an example that shows the extension + assuming it was set as previously shown: + :: + + $ uname -r + 3.7.0-rc8-custom + + :term:`LOG_DIR` + Specifies the directory to which the OpenEmbedded build system writes + overall log files. The default directory is ``${TMPDIR}/log``. + + For the directory containing logs specific to each task, see the + :term:`T` variable. + + :term:`MACHINE` + Specifies the target device for which the image is built. You define + ``MACHINE`` in the ``local.conf`` file found in the + :term:`Build Directory`. By default, ``MACHINE`` is set to + "qemux86", which is an x86-based architecture machine to be emulated + using QEMU: + :: + + MACHINE ?= "qemux86" + + The variable corresponds to a machine configuration file of the same + name, through which machine-specific configurations are set. Thus, + when ``MACHINE`` is set to "qemux86" there exists the corresponding + ``qemux86.conf`` machine configuration file, which can be found in + the :term:`Source Directory` in + ``meta/conf/machine``. + + The list of machines supported by the Yocto Project as shipped + include the following: + :: + + MACHINE ?= "qemuarm" + MACHINE ?= "qemuarm64" + MACHINE ?= "qemumips" + MACHINE ?= "qemumips64" + MACHINE ?= "qemuppc" + MACHINE ?= "qemux86" + MACHINE ?= "qemux86-64" + MACHINE ?= "genericx86" + MACHINE ?= "genericx86-64" + MACHINE ?= "beaglebone" + MACHINE ?= "edgerouter" + + The last five are Yocto Project reference hardware + boards, which are provided in the ``meta-yocto-bsp`` layer. + + .. note:: + + Adding additional Board Support Package (BSP) layers to your + configuration adds new possible settings for ``MACHINE``. + + :term:`MACHINE_ARCH` + Specifies the name of the machine-specific architecture. This + variable is set automatically from :term:`MACHINE` or + :term:`TUNE_PKGARCH`. You should not hand-edit + the ``MACHINE_ARCH`` variable. + + :term:`MACHINE_ESSENTIAL_EXTRA_RDEPENDS` + A list of required machine-specific packages to install as part of + the image being built. The build process depends on these packages + being present. Furthermore, because this is a "machine-essential" + variable, the list of packages are essential for the machine to boot. + The impact of this variable affects images based on + ``packagegroup-core-boot``, including the ``core-image-minimal`` + image. + + This variable is similar to the + ``MACHINE_ESSENTIAL_EXTRA_RRECOMMENDS`` variable with the exception + that the image being built has a build dependency on the variable's + list of packages. In other words, the image will not build if a file + in this list is not found. + + As an example, suppose the machine for which you are building + requires ``example-init`` to be run during boot to initialize the + hardware. In this case, you would use the following in the machine's + ``.conf`` configuration file: + :: + + MACHINE_ESSENTIAL_EXTRA_RDEPENDS += "example-init" + + :term:`MACHINE_ESSENTIAL_EXTRA_RRECOMMENDS` + A list of recommended machine-specific packages to install as part of + the image being built. The build process does not depend on these + packages being present. However, because this is a + "machine-essential" variable, the list of packages are essential for + the machine to boot. The impact of this variable affects images based + on ``packagegroup-core-boot``, including the ``core-image-minimal`` + image. + + This variable is similar to the ``MACHINE_ESSENTIAL_EXTRA_RDEPENDS`` + variable with the exception that the image being built does not have + a build dependency on the variable's list of packages. In other + words, the image will still build if a package in this list is not + found. Typically, this variable is used to handle essential kernel + modules, whose functionality may be selected to be built into the + kernel rather than as a module, in which case a package will not be + produced. + + Consider an example where you have a custom kernel where a specific + touchscreen driver is required for the machine to be usable. However, + the driver can be built as a module or into the kernel depending on + the kernel configuration. If the driver is built as a module, you + want it to be installed. But, when the driver is built into the + kernel, you still want the build to succeed. This variable sets up a + "recommends" relationship so that in the latter case, the build will + not fail due to the missing package. To accomplish this, assuming the + package for the module was called ``kernel-module-ab123``, you would + use the following in the machine's ``.conf`` configuration file: + :: + + MACHINE_ESSENTIAL_EXTRA_RRECOMMENDS += "kernel-module-ab123" + + .. note:: + + In this example, the ``kernel-module-ab123`` recipe needs to + explicitly set its :term:`PACKAGES` variable to ensure that BitBake + does not use the kernel recipe's :term:`PACKAGES_DYNAMIC` variable to + satisfy the dependency. + + Some examples of these machine essentials are flash, screen, + keyboard, mouse, or touchscreen drivers (depending on the machine). + + :term:`MACHINE_EXTRA_RDEPENDS` + A list of machine-specific packages to install as part of the image + being built that are not essential for the machine to boot. However, + the build process for more fully-featured images depends on the + packages being present. + + This variable affects all images based on ``packagegroup-base``, + which does not include the ``core-image-minimal`` or + ``core-image-full-cmdline`` images. + + The variable is similar to the ``MACHINE_EXTRA_RRECOMMENDS`` variable + with the exception that the image being built has a build dependency + on the variable's list of packages. In other words, the image will + not build if a file in this list is not found. + + An example is a machine that has WiFi capability but is not essential + for the machine to boot the image. However, if you are building a + more fully-featured image, you want to enable the WiFi. The package + containing the firmware for the WiFi hardware is always expected to + exist, so it is acceptable for the build process to depend upon + finding the package. In this case, assuming the package for the + firmware was called ``wifidriver-firmware``, you would use the + following in the ``.conf`` file for the machine: + :: + + MACHINE_EXTRA_RDEPENDS += "wifidriver-firmware" + + :term:`MACHINE_EXTRA_RRECOMMENDS` + A list of machine-specific packages to install as part of the image + being built that are not essential for booting the machine. The image + being built has no build dependency on this list of packages. + + This variable affects only images based on ``packagegroup-base``, + which does not include the ``core-image-minimal`` or + ``core-image-full-cmdline`` images. + + This variable is similar to the ``MACHINE_EXTRA_RDEPENDS`` variable + with the exception that the image being built does not have a build + dependency on the variable's list of packages. In other words, the + image will build if a file in this list is not found. + + An example is a machine that has WiFi capability but is not essential + For the machine to boot the image. However, if you are building a + more fully-featured image, you want to enable WiFi. In this case, the + package containing the WiFi kernel module will not be produced if the + WiFi driver is built into the kernel, in which case you still want + the build to succeed instead of failing as a result of the package + not being found. To accomplish this, assuming the package for the + module was called ``kernel-module-examplewifi``, you would use the + following in the ``.conf`` file for the machine: + :: + + MACHINE_EXTRA_RRECOMMENDS += "kernel-module-examplewifi" + + :term:`MACHINE_FEATURES` + Specifies the list of hardware features the + :term:`MACHINE` is capable of supporting. For related + information on enabling features, see the + :term:`DISTRO_FEATURES`, + :term:`COMBINED_FEATURES`, and + :term:`IMAGE_FEATURES` variables. + + For a list of hardware features supported by the Yocto Project as + shipped, see the ":ref:`ref-features-machine`" section. + + :term:`MACHINE_FEATURES_BACKFILL` + Features to be added to ``MACHINE_FEATURES`` if not also present in + ``MACHINE_FEATURES_BACKFILL_CONSIDERED``. + + This variable is set in the ``meta/conf/bitbake.conf`` file. It is + not intended to be user-configurable. It is best to just reference + the variable to see which machine features are being backfilled for + all machine configurations. See the ":ref:`ref-features-backfill`" + section for more information. + + :term:`MACHINE_FEATURES_BACKFILL_CONSIDERED` + Features from ``MACHINE_FEATURES_BACKFILL`` that should not be + backfilled (i.e. added to ``MACHINE_FEATURES``) during the build. See + the ":ref:`ref-features-backfill`" section for more information. + + :term:`MACHINEOVERRIDES` + A colon-separated list of overrides that apply to the current + machine. By default, this list includes the value of + :term:`MACHINE`. + + You can extend ``MACHINEOVERRIDES`` to add extra overrides that + should apply to a machine. For example, all machines emulated in QEMU + (e.g. ``qemuarm``, ``qemux86``, and so forth) include a file named + ``meta/conf/machine/include/qemu.inc`` that prepends the following + override to ``MACHINEOVERRIDES``: + :: + + MACHINEOVERRIDES =. "qemuall:" + + This + override allows variables to be overridden for all machines emulated + in QEMU, like in the following example from the ``connman-conf`` + recipe: + :: + + SRC_URI_append_qemuall = " file://wired.config \ + file://wired-setup \ + " + + The underlying mechanism behind + ``MACHINEOVERRIDES`` is simply that it is included in the default + value of :term:`OVERRIDES`. + + :term:`MAINTAINER` + The email address of the distribution maintainer. + + :term:`MIRRORS` + Specifies additional paths from which the OpenEmbedded build system + gets source code. When the build system searches for source code, it + first tries the local download directory. If that location fails, the + build system tries locations defined by + :term:`PREMIRRORS`, the upstream source, and then + locations specified by ``MIRRORS`` in that order. + + Assuming your distribution (:term:`DISTRO`) is "poky", + the default value for ``MIRRORS`` is defined in the + ``conf/distro/poky.conf`` file in the ``meta-poky`` Git repository. + + :term:`MLPREFIX` + Specifies a prefix has been added to :term:`PN` to create a + special version of a recipe or package (i.e. a Multilib version). The + variable is used in places where the prefix needs to be added to or + removed from a the name (e.g. the :term:`BPN` variable). + ``MLPREFIX`` gets set when a prefix has been added to ``PN``. + + .. note:: + + The "ML" in ``MLPREFIX`` stands for "MultiLib". This representation is + historical and comes from a time when ``nativesdk`` was a suffix + rather than a prefix on the recipe name. When ``nativesdk`` was turned + into a prefix, it made sense to set ``MLPREFIX`` for it as well. + + To help understand when ``MLPREFIX`` might be needed, consider when + :term:`BBCLASSEXTEND` is used to provide a + ``nativesdk`` version of a recipe in addition to the target version. + If that recipe declares build-time dependencies on tasks in other + recipes by using :term:`DEPENDS`, then a dependency on + "foo" will automatically get rewritten to a dependency on + "nativesdk-foo". However, dependencies like the following will not + get rewritten automatically: + :: + + do_foo[depends] += "recipe:do_foo" + + If you want such a dependency to also get transformed, you can do the + following: + :: + + do_foo[depends] += "${MLPREFIX}recipe:do_foo" + + module_autoload + This variable has been replaced by the ``KERNEL_MODULE_AUTOLOAD`` + variable. You should replace all occurrences of ``module_autoload`` + with additions to ``KERNEL_MODULE_AUTOLOAD``, for example: + :: + + module_autoload_rfcomm = "rfcomm" + + should now be replaced with: + :: + + KERNEL_MODULE_AUTOLOAD += "rfcomm" + + See the :term:`KERNEL_MODULE_AUTOLOAD` variable for more information. + + module_conf + Specifies `modprobe.d <http://linux.die.net/man/5/modprobe.d>`_ + syntax lines for inclusion in the ``/etc/modprobe.d/modname.conf`` + file. + + You can use this variable anywhere that it can be recognized by the + kernel recipe or out-of-tree kernel module recipe (e.g. a machine + configuration file, a distribution configuration file, an append file + for the recipe, or the recipe itself). If you use this variable, you + must also be sure to list the module name in the + :term:`KERNEL_MODULE_AUTOLOAD` + variable. + + Here is the general syntax: + :: + + module_conf_module_name = "modprobe.d-syntax" + + You must use the kernel module name override. + + Run ``man modprobe.d`` in the shell to find out more information on + the exact syntax you want to provide with ``module_conf``. + + Including ``module_conf`` causes the OpenEmbedded build system to + populate the ``/etc/modprobe.d/modname.conf`` file with + ``modprobe.d`` syntax lines. Here is an example that adds the options + ``arg1`` and ``arg2`` to a module named ``mymodule``: + :: + + module_conf_mymodule = "options mymodule arg1=val1 arg2=val2" + + For information on how to specify kernel modules to auto-load on + boot, see the :term:`KERNEL_MODULE_AUTOLOAD` variable. + + :term:`MODULE_TARBALL_DEPLOY` + Controls creation of the ``modules-*.tgz`` file. Set this variable to + "0" to disable creation of this file, which contains all of the + kernel modules resulting from a kernel build. + + :term:`MODULE_TARBALL_LINK_NAME` + The link name of the kernel module tarball. This variable is set in + the ``meta/classes/kernel-artifact-names.bbclass`` file as follows: + :: + + MODULE_TARBALL_LINK_NAME ?= "${KERNEL_ARTIFACT_LINK_NAME}" + + The value + of the ``KERNEL_ARTIFACT_LINK_NAME`` variable, which is set in the + same file, has the following value: + :: + + KERNEL_ARTIFACT_LINK_NAME ?= "${MACHINE}" + + See the :term:`MACHINE` variable for additional information. + + :term:`MODULE_TARBALL_NAME` + The base name of the kernel module tarball. This variable is set in + the ``meta/classes/kernel-artifact-names.bbclass`` file as follows: + :: + + MODULE_TARBALL_NAME ?= "${KERNEL_ARTIFACT_NAME}" + + The value of the :term:`KERNEL_ARTIFACT_NAME` variable, + which is set in the same file, has the following value: + :: + + KERNEL_ARTIFACT_NAME ?= "${PKGE}-${PKGV}-${PKGR}-${MACHINE}${IMAGE_VERSION_SUFFIX}" + + :term:`MULTIMACH_TARGET_SYS` + Uniquely identifies the type of the target system for which packages + are being built. This variable allows output for different types of + target systems to be put into different subdirectories of the same + output directory. + + The default value of this variable is: + :: + + ${PACKAGE_ARCH}${TARGET_VENDOR}-${TARGET_OS} + + Some classes (e.g. + :ref:`cross-canadian <ref-classes-cross-canadian>`) modify the + ``MULTIMACH_TARGET_SYS`` value. + + See the :term:`STAMP` variable for an example. See the + :term:`STAGING_DIR_TARGET` variable for more information. + + :term:`NATIVELSBSTRING` + A string identifying the host distribution. Strings consist of the + host distributor ID followed by the release, as reported by the + ``lsb_release`` tool or as read from ``/etc/lsb-release``. For + example, when running a build on Ubuntu 12.10, the value is + "Ubuntu-12.10". If this information is unable to be determined, the + value resolves to "Unknown". + + This variable is used by default to isolate native shared state + packages for different distributions (e.g. to avoid problems with + ``glibc`` version incompatibilities). Additionally, the variable is + checked against + :term:`SANITY_TESTED_DISTROS` if that + variable is set. + + :term:`NM` + The minimal command and arguments to run ``nm``. + + :term:`NO_GENERIC_LICENSE` + Avoids QA errors when you use a non-common, non-CLOSED license in a + recipe. Packages exist, such as the linux-firmware package, with many + licenses that are not in any way common. Also, new licenses are added + occasionally to avoid introducing a lot of common license files, + which are only applicable to a specific package. + ``NO_GENERIC_LICENSE`` is used to allow copying a license that does + not exist in common licenses. + + The following example shows how to add ``NO_GENERIC_LICENSE`` to a + recipe: + :: + + NO_GENERIC_LICENSE[license_name] = "license_file_in_fetched_source" + + The following is an example that + uses the ``LICENSE.Abilis.txt`` file as the license from the fetched + source: + :: + + NO_GENERIC_LICENSE[Firmware-Abilis] = "LICENSE.Abilis.txt" + + :term:`NO_RECOMMENDATIONS` + Prevents installation of all "recommended-only" packages. + Recommended-only packages are packages installed only through the + :term:`RRECOMMENDS` variable). Setting the + ``NO_RECOMMENDATIONS`` variable to "1" turns this feature on: :: + + NO_RECOMMENDATIONS = "1" + + You can set this variable globally in your ``local.conf`` file or you + can attach it to a specific image recipe by using the recipe name + override: :: + + NO_RECOMMENDATIONS_pn-target_image = "1" + + It is important to realize that if you choose to not install packages + using this variable and some other packages are dependent on them + (i.e. listed in a recipe's :term:`RDEPENDS` + variable), the OpenEmbedded build system ignores your request and + will install the packages to avoid dependency errors. + + .. note:: + + Some recommended packages might be required for certain system + functionality, such as kernel modules. It is up to you to add + packages with the :term:`IMAGE_INSTALL` variable. + + Support for this variable exists only when using the IPK and RPM + packaging backend. Support does not exist for DEB. + + See the :term:`BAD_RECOMMENDATIONS` and + the :term:`PACKAGE_EXCLUDE` variables for + related information. + + :term:`NOAUTOPACKAGEDEBUG` + Disables auto package from splitting ``.debug`` files. If a recipe + requires ``FILES_${PN}-dbg`` to be set manually, the + ``NOAUTOPACKAGEDEBUG`` can be defined allowing you to define the + content of the debug package. For example: + :: + + NOAUTOPACKAGEDEBUG = "1" + FILES_${PN}-dev = "${includedir}/${QT_DIR_NAME}/Qt/*" + FILES_${PN}-dbg = "/usr/src/debug/" + FILES_${QT_BASE_NAME}-demos-doc = "${docdir}/${QT_DIR_NAME}/qch/qt.qch" + + :term:`OBJCOPY` + The minimal command and arguments to run ``objcopy``. + + :term:`OBJDUMP` + The minimal command and arguments to run ``objdump``. + + :term:`OE_BINCONFIG_EXTRA_MANGLE` + When inheriting the :ref:`binconfig <ref-classes-binconfig>` class, + this variable specifies additional arguments passed to the "sed" + command. The sed command alters any paths in configuration scripts + that have been set up during compilation. Inheriting this class + results in all paths in these scripts being changed to point into the + ``sysroots/`` directory so that all builds that use the script will + use the correct directories for the cross compiling layout. + + See the ``meta/classes/binconfig.bbclass`` in the + :term:`Source Directory` for details on how this class + applies these additional sed command arguments. For general + information on the ``binconfig`` class, see the + ":ref:`binconfig.bbclass <ref-classes-binconfig>`" section. + + :term:`OE_IMPORTS` + An internal variable used to tell the OpenEmbedded build system what + Python modules to import for every Python function run by the system. + + .. note:: + + Do not set this variable. It is for internal use only. + + :term:`OE_INIT_ENV_SCRIPT` + The name of the build environment setup script for the purposes of + setting up the environment within the extensible SDK. The default + value is "oe-init-build-env". + + If you use a custom script to set up your build environment, set the + ``OE_INIT_ENV_SCRIPT`` variable to its name. + + :term:`OE_TERMINAL` + Controls how the OpenEmbedded build system spawns interactive + terminals on the host development system (e.g. using the BitBake + command with the ``-c devshell`` command-line option). For more + information, see the ":ref:`platdev-appdev-devshell`" section in + the Yocto Project Development Tasks Manual. + + You can use the following values for the ``OE_TERMINAL`` variable: + + - auto + - gnome + - xfce + - rxvt + - screen + - konsole + - none + + :term:`OEROOT` + The directory from which the top-level build environment setup script + is sourced. The Yocto Project provides a top-level build environment + setup script: :ref:`structure-core-script`. When you run this + script, the ``OEROOT`` variable resolves to the directory that + contains the script. + + For additional information on how this variable is used, see the + initialization script. + + :term:`OLDEST_KERNEL` + Declares the oldest version of the Linux kernel that the produced + binaries must support. This variable is passed into the build of the + Embedded GNU C Library (``glibc``). + + The default for this variable comes from the + ``meta/conf/bitbake.conf`` configuration file. You can override this + default by setting the variable in a custom distribution + configuration file. + + :term:`OVERRIDES` + A colon-separated list of overrides that currently apply. Overrides + are a BitBake mechanism that allows variables to be selectively + overridden at the end of parsing. The set of overrides in + ``OVERRIDES`` represents the "state" during building, which includes + the current recipe being built, the machine for which it is being + built, and so forth. + + As an example, if the string "an-override" appears as an element in + the colon-separated list in ``OVERRIDES``, then the following + assignment will override ``FOO`` with the value "overridden" at the + end of parsing: + :: + + FOO_an-override = "overridden" + + See the + ":ref:`bitbake:bitbake-user-manual/bitbake-user-manual-metadata:conditional syntax (overrides)`" + section in the BitBake User Manual for more information on the + overrides mechanism. + + The default value of ``OVERRIDES`` includes the values of the + :term:`CLASSOVERRIDE`, + :term:`MACHINEOVERRIDES`, and + :term:`DISTROOVERRIDES` variables. Another + important override included by default is ``pn-${PN}``. This override + allows variables to be set for a single recipe within configuration + (``.conf``) files. Here is an example: + :: + + FOO_pn-myrecipe = "myrecipe-specific value" + + .. note:: + + An easy way to see what overrides apply is to search for ``OVERRIDES`` + in the output of the ``bitbake -e`` command. See the + ":ref:`dev-debugging-viewing-variable-values`" section in the Yocto + Project Development Tasks Manual for more information. + + :term:`P` + The recipe name and version. ``P`` is comprised of the following: + :: + + ${PN}-${PV} + + :term:`PACKAGE_ADD_METADATA` + This variable defines additional metdata to add to packages. + + You may find you need to inject additional metadata into packages. + This variable allows you to do that by setting the injected data as + the value. Multiple fields can be added by splitting the content with + the literal separator "\n". + + The suffixes '_IPK', '_DEB', or '_RPM' can be applied to the variable + to do package type specific settings. It can also be made package + specific by using the package name as a suffix. + + You can find out more about applying this variable in the + ":ref:`dev-manual/dev-manual-common-tasks:adding custom metadata to packages`" + section in the Yocto Project Development Tasks Manual. + + :term:`PACKAGE_ARCH` + The architecture of the resulting package or packages. + + By default, the value of this variable is set to + :term:`TUNE_PKGARCH` when building for the + target, :term:`BUILD_ARCH` when building for the + build host, and "${SDK_ARCH}-${SDKPKGSUFFIX}" when building for the + SDK. + + .. note:: + + See :term:`SDK_ARCH` for more information. + + However, if your recipe's output packages are built specific to the + target machine rather than generally for the architecture of the + machine, you should set ``PACKAGE_ARCH`` to the value of + :term:`MACHINE_ARCH` in the recipe as follows: + :: + + PACKAGE_ARCH = "${MACHINE_ARCH}" + + :term:`PACKAGE_ARCHS` + Specifies a list of architectures compatible with the target machine. + This variable is set automatically and should not normally be + hand-edited. Entries are separated using spaces and listed in order + of priority. The default value for ``PACKAGE_ARCHS`` is "all any + noarch ${PACKAGE_EXTRA_ARCHS} ${MACHINE_ARCH}". + + :term:`PACKAGE_BEFORE_PN` + Enables easily adding packages to ``PACKAGES`` before ``${PN}`` so + that those added packages can pick up files that would normally be + included in the default package. + + :term:`PACKAGE_CLASSES` + This variable, which is set in the ``local.conf`` configuration file + found in the ``conf`` folder of the + :term:`Build Directory`, specifies the package manager the + OpenEmbedded build system uses when packaging data. + + You can provide one or more of the following arguments for the + variable: PACKAGE_CLASSES ?= "package_rpm package_deb package_ipk + package_tar" + + .. note:: + + While it is a legal option, the ``package_tar`` + class has limited functionality due to no support for package + dependencies by that backend. Therefore, it is recommended that + you do not use it. + + The build system uses only the first argument in the list as the + package manager when creating your image or SDK. However, packages + will be created using any additional packaging classes you specify. + For example, if you use the following in your ``local.conf`` file: + :: + + PACKAGE_CLASSES ?= "package_ipk" + + The OpenEmbedded build system uses + the IPK package manager to create your image or SDK. + + For information on packaging and build performance effects as a + result of the package manager in use, see the + ":ref:`package.bbclass <ref-classes-package>`" section. + + :term:`PACKAGE_DEBUG_SPLIT_STYLE` + Determines how to split up the binary and debug information when + creating ``*-dbg`` packages to be used with the GNU Project Debugger + (GDB). + + With the ``PACKAGE_DEBUG_SPLIT_STYLE`` variable, you can control + where debug information, which can include or exclude source files, + is stored: + + - ".debug": Debug symbol files are placed next to the binary in a + ``.debug`` directory on the target. For example, if a binary is + installed into ``/bin``, the corresponding debug symbol files are + installed in ``/bin/.debug``. Source files are placed in + ``/usr/src/debug``. + + - "debug-file-directory": Debug symbol files are placed under + ``/usr/lib/debug`` on the target, and separated by the path from + where the binary is installed. For example, if a binary is + installed in ``/bin``, the corresponding debug symbols are + installed in ``/usr/lib/debug/bin``. Source files are placed in + ``/usr/src/debug``. + + - "debug-without-src": The same behavior as ".debug" previously + described with the exception that no source files are installed. + + - "debug-with-srcpkg": The same behavior as ".debug" previously + described with the exception that all source files are placed in a + separate ``*-src`` pkg. This is the default behavior. + + You can find out more about debugging using GDB by reading the + ":ref:`platdev-gdb-remotedebug`" section + in the Yocto Project Development Tasks Manual. + + :term:`PACKAGE_EXCLUDE_COMPLEMENTARY` + Prevents specific packages from being installed when you are + installing complementary packages. + + You might find that you want to prevent installing certain packages + when you are installing complementary packages. For example, if you + are using :term:`IMAGE_FEATURES` to install + ``dev-pkgs``, you might not want to install all packages from a + particular multilib. If you find yourself in this situation, you can + use the ``PACKAGE_EXCLUDE_COMPLEMENTARY`` variable to specify regular + expressions to match the packages you want to exclude. + + :term:`PACKAGE_EXCLUDE` + Lists packages that should not be installed into an image. For + example: + :: + + PACKAGE_EXCLUDE = "package_name package_name package_name ..." + + You can set this variable globally in your ``local.conf`` file or you + can attach it to a specific image recipe by using the recipe name + override: + :: + + PACKAGE_EXCLUDE_pn-target_image = "package_name" + + If you choose to not install a package using this variable and some + other package is dependent on it (i.e. listed in a recipe's + :term:`RDEPENDS` variable), the OpenEmbedded build + system generates a fatal installation error. Because the build system + halts the process with a fatal error, you can use the variable with + an iterative development process to remove specific components from a + system. + + Support for this variable exists only when using the IPK and RPM + packaging backend. Support does not exist for DEB. + + See the :term:`NO_RECOMMENDATIONS` and the + :term:`BAD_RECOMMENDATIONS` variables for + related information. + + :term:`PACKAGE_EXTRA_ARCHS` + Specifies the list of architectures compatible with the device CPU. + This variable is useful when you build for several different devices + that use miscellaneous processors such as XScale and ARM926-EJS. + + :term:`PACKAGE_FEED_ARCHS` + Optionally specifies the package architectures used as part of the + package feed URIs during the build. When used, the + ``PACKAGE_FEED_ARCHS`` variable is appended to the final package feed + URI, which is constructed using the + :term:`PACKAGE_FEED_URIS` and + :term:`PACKAGE_FEED_BASE_PATHS` + variables. + + .. note:: + + You can use the ``PACKAGE_FEED_ARCHS`` + variable to whitelist specific package architectures. If you do + not need to whitelist specific architectures, which is a common + case, you can omit this variable. Omitting the variable results in + all available architectures for the current machine being included + into remote package feeds. + + Consider the following example where the ``PACKAGE_FEED_URIS``, + ``PACKAGE_FEED_BASE_PATHS``, and ``PACKAGE_FEED_ARCHS`` variables are + defined in your ``local.conf`` file: + :: + + PACKAGE_FEED_URIS = "https://example.com/packagerepos/release \ + https://example.com/packagerepos/updates" + PACKAGE_FEED_BASE_PATHS = "rpm rpm-dev" + PACKAGE_FEED_ARCHS = "all core2-64" + + Given these settings, the resulting package feeds are as follows: + + .. code-block:: none + + https://example.com/packagerepos/release/rpm/all + https://example.com/packagerepos/release/rpm/core2-64 + https://example.com/packagerepos/release/rpm-dev/all + https://example.com/packagerepos/release/rpm-dev/core2-64 + https://example.com/packagerepos/updates/rpm/all + https://example.com/packagerepos/updates/rpm/core2-64 + https://example.com/packagerepos/updates/rpm-dev/all + https://example.com/packagerepos/updates/rpm-dev/core2-64 + + :term:`PACKAGE_FEED_BASE_PATHS` + Specifies the base path used when constructing package feed URIs. The + ``PACKAGE_FEED_BASE_PATHS`` variable makes up the middle portion of a + package feed URI used by the OpenEmbedded build system. The base path + lies between the :term:`PACKAGE_FEED_URIS` + and :term:`PACKAGE_FEED_ARCHS` variables. + + Consider the following example where the ``PACKAGE_FEED_URIS``, + ``PACKAGE_FEED_BASE_PATHS``, and ``PACKAGE_FEED_ARCHS`` variables are + defined in your ``local.conf`` file: + :: + + PACKAGE_FEED_URIS = "https://example.com/packagerepos/release \ + https://example.com/packagerepos/updates" + PACKAGE_FEED_BASE_PATHS = "rpm rpm-dev" + PACKAGE_FEED_ARCHS = "all core2-64" + + Given these settings, the resulting package feeds are as follows: + + .. code-block:: none + + https://example.com/packagerepos/release/rpm/all + https://example.com/packagerepos/release/rpm/core2-64 + https://example.com/packagerepos/release/rpm-dev/all + https://example.com/packagerepos/release/rpm-dev/core2-64 + https://example.com/packagerepos/updates/rpm/all + https://example.com/packagerepos/updates/rpm/core2-64 + https://example.com/packagerepos/updates/rpm-dev/all + https://example.com/packagerepos/updates/rpm-dev/core2-64 + + :term:`PACKAGE_FEED_URIS` + Specifies the front portion of the package feed URI used by the + OpenEmbedded build system. Each final package feed URI is comprised + of ``PACKAGE_FEED_URIS``, + :term:`PACKAGE_FEED_BASE_PATHS`, and + :term:`PACKAGE_FEED_ARCHS` variables. + + Consider the following example where the ``PACKAGE_FEED_URIS``, + ``PACKAGE_FEED_BASE_PATHS``, and ``PACKAGE_FEED_ARCHS`` variables are + defined in your ``local.conf`` file: + :: + + PACKAGE_FEED_URIS = "https://example.com/packagerepos/release \ + https://example.com/packagerepos/updates" + PACKAGE_FEED_BASE_PATHS = "rpm rpm-dev" + PACKAGE_FEED_ARCHS = "all core2-64" + + Given these settings, the resulting package feeds are as follows: + + .. code-block:: none + + https://example.com/packagerepos/release/rpm/all + https://example.com/packagerepos/release/rpm/core2-64 + https://example.com/packagerepos/release/rpm-dev/all + https://example.com/packagerepos/release/rpm-dev/core2-64 + https://example.com/packagerepos/updates/rpm/all + https://example.com/packagerepos/updates/rpm/core2-64 + https://example.com/packagerepos/updates/rpm-dev/all + https://example.com/packagerepos/updates/rpm-dev/core2-64 + + :term:`PACKAGE_INSTALL` + The final list of packages passed to the package manager for + installation into the image. + + Because the package manager controls actual installation of all + packages, the list of packages passed using ``PACKAGE_INSTALL`` is + not the final list of packages that are actually installed. This + variable is internal to the image construction code. Consequently, in + general, you should use the + :term:`IMAGE_INSTALL` variable to specify + packages for installation. The exception to this is when working with + the :ref:`core-image-minimal-initramfs <ref-manual/ref-images:images>` + image. When working with an initial RAM filesystem (initramfs) image, + use the ``PACKAGE_INSTALL`` variable. For information on creating an + initramfs, see the ":ref:`building-an-initramfs-image`" section + in the Yocto Project Development Tasks Manual. + + :term:`PACKAGE_INSTALL_ATTEMPTONLY` + Specifies a list of packages the OpenEmbedded build system attempts + to install when creating an image. If a listed package fails to + install, the build system does not generate an error. This variable + is generally not user-defined. + + :term:`PACKAGE_PREPROCESS_FUNCS` + Specifies a list of functions run to pre-process the + :term:`PKGD` directory prior to splitting the files out + to individual packages. + + :term:`PACKAGE_WRITE_DEPS` + Specifies a list of dependencies for post-installation and + pre-installation scripts on native/cross tools. If your + post-installation or pre-installation script can execute at rootfs + creation time rather than on the target but depends on a native tool + in order to execute, you need to list the tools in + ``PACKAGE_WRITE_DEPS``. + + For information on running post-installation scripts, see the + ":ref:`dev-manual/dev-manual-common-tasks:post-installation scripts`" + section in the Yocto Project Development Tasks Manual. + + :term:`PACKAGECONFIG` + This variable provides a means of enabling or disabling features of a + recipe on a per-recipe basis. ``PACKAGECONFIG`` blocks are defined in + recipes when you specify features and then arguments that define + feature behaviors. Here is the basic block structure (broken over + multiple lines for readability): + :: + + PACKAGECONFIG ??= "f1 f2 f3 ..." + PACKAGECONFIG[f1] = "\ + --with-f1, \ + --without-f1, \ + build-deps-for-f1, \ + runtime-deps-for-f1, \ + runtime-recommends-for-f1, \ + packageconfig-conflicts-for-f1" + PACKAGECONFIG[f2] = "\ + ... and so on and so on ... + + The ``PACKAGECONFIG`` variable itself specifies a space-separated + list of the features to enable. Following the features, you can + determine the behavior of each feature by providing up to six + order-dependent arguments, which are separated by commas. You can + omit any argument you like but must retain the separating commas. The + order is important and specifies the following: + + 1. Extra arguments that should be added to the configure script + argument list (:term:`EXTRA_OECONF` or + :term:`PACKAGECONFIG_CONFARGS`) if + the feature is enabled. + + 2. Extra arguments that should be added to ``EXTRA_OECONF`` or + ``PACKAGECONFIG_CONFARGS`` if the feature is disabled. + + 3. Additional build dependencies (:term:`DEPENDS`) + that should be added if the feature is enabled. + + 4. Additional runtime dependencies (:term:`RDEPENDS`) + that should be added if the feature is enabled. + + 5. Additional runtime recommendations + (:term:`RRECOMMENDS`) that should be added if + the feature is enabled. + + 6. Any conflicting (that is, mutually exclusive) ``PACKAGECONFIG`` + settings for this feature. + + Consider the following ``PACKAGECONFIG`` block taken from the + ``librsvg`` recipe. In this example the feature is ``gtk``, which has + three arguments that determine the feature's behavior. + :: + + PACKAGECONFIG[gtk] = "--with-gtk3,--without-gtk3,gtk+3" + + The + ``--with-gtk3`` and ``gtk+3`` arguments apply only if the feature is + enabled. In this case, ``--with-gtk3`` is added to the configure + script argument list and ``gtk+3`` is added to ``DEPENDS``. On the + other hand, if the feature is disabled say through a ``.bbappend`` + file in another layer, then the second argument ``--without-gtk3`` is + added to the configure script instead. + + The basic ``PACKAGECONFIG`` structure previously described holds true + regardless of whether you are creating a block or changing a block. + When creating a block, use the structure inside your recipe. + + If you want to change an existing ``PACKAGECONFIG`` block, you can do + so one of two ways: + + - *Append file:* Create an append file named + recipename\ ``.bbappend`` in your layer and override the value of + ``PACKAGECONFIG``. You can either completely override the + variable: + :: + + PACKAGECONFIG = "f4 f5" + + Or, you can just append the variable: + :: + + PACKAGECONFIG_append = " f4" + + - *Configuration file:* This method is identical to changing the + block through an append file except you edit your ``local.conf`` + or ``mydistro.conf`` file. As with append files previously + described, you can either completely override the variable: + :: + + PACKAGECONFIG_pn-recipename = "f4 f5" + + Or, you can just amend the variable: + :: + + PACKAGECONFIG_append_pn-recipename = " f4" + + :term:`PACKAGECONFIG_CONFARGS` + A space-separated list of configuration options generated from the + :term:`PACKAGECONFIG` setting. + + Classes such as :ref:`autotools <ref-classes-autotools>` and + :ref:`cmake <ref-classes-cmake>` use ``PACKAGECONFIG_CONFARGS`` to + pass ``PACKAGECONFIG`` options to ``configure`` and ``cmake``, + respectively. If you are using ``PACKAGECONFIG`` but not a class that + handles the ``do_configure`` task, then you need to use + ``PACKAGECONFIG_CONFARGS`` appropriately. + + :term:`PACKAGEGROUP_DISABLE_COMPLEMENTARY` + For recipes inheriting the + :ref:`packagegroup <ref-classes-packagegroup>` class, setting + ``PACKAGEGROUP_DISABLE_COMPLEMENTARY`` to "1" specifies that the + normal complementary packages (i.e. ``-dev``, ``-dbg``, and so forth) + should not be automatically created by the ``packagegroup`` recipe, + which is the default behavior. + + :term:`PACKAGES` + The list of packages the recipe creates. The default value is the + following: + :: + + ${PN}-dbg ${PN}-staticdev ${PN}-dev ${PN}-doc ${PN}-locale ${PACKAGE_BEFORE_PN} ${PN} + + During packaging, the :ref:`ref-tasks-package` task + goes through ``PACKAGES`` and uses the :term:`FILES` + variable corresponding to each package to assign files to the + package. If a file matches the ``FILES`` variable for more than one + package in ``PACKAGES``, it will be assigned to the earliest + (leftmost) package. + + Packages in the variable's list that are empty (i.e. where none of + the patterns in ``FILES_``\ pkg match any files installed by the + :ref:`ref-tasks-install` task) are not generated, + unless generation is forced through the + :term:`ALLOW_EMPTY` variable. + + :term:`PACKAGES_DYNAMIC` + A promise that your recipe satisfies runtime dependencies for + optional modules that are found in other recipes. + ``PACKAGES_DYNAMIC`` does not actually satisfy the dependencies, it + only states that they should be satisfied. For example, if a hard, + runtime dependency (:term:`RDEPENDS`) of another + package is satisfied at build time through the ``PACKAGES_DYNAMIC`` + variable, but a package with the module name is never actually + produced, then the other package will be broken. Thus, if you attempt + to include that package in an image, you will get a dependency + failure from the packaging system during the + :ref:`ref-tasks-rootfs` task. + + Typically, if there is a chance that such a situation can occur and + the package that is not created is valid without the dependency being + satisfied, then you should use :term:`RRECOMMENDS` + (a soft runtime dependency) instead of ``RDEPENDS``. + + For an example of how to use the ``PACKAGES_DYNAMIC`` variable when + you are splitting packages, see the + ":ref:`dev-manual/dev-manual-common-tasks:handling optional module packaging`" + section in the Yocto Project Development Tasks Manual. + + :term:`PACKAGESPLITFUNCS` + Specifies a list of functions run to perform additional splitting of + files into individual packages. Recipes can either prepend to this + variable or prepend to the ``populate_packages`` function in order to + perform additional package splitting. In either case, the function + should set :term:`PACKAGES`, + :term:`FILES`, :term:`RDEPENDS` and + other packaging variables appropriately in order to perform the + desired splitting. + + :term:`PARALLEL_MAKE` + Extra options passed to the ``make`` command during the + :ref:`ref-tasks-compile` task in order to specify + parallel compilation on the local build host. This variable is + usually in the form "-j x", where x represents the maximum number of + parallel threads ``make`` can run. + + .. note:: + + In order for ``PARALLEL_MAKE`` to be effective, ``make`` must be + called with ``${``\ :term:`EXTRA_OEMAKE`\ ``}``. An easy way to ensure + this is to use the ``oe_runmake`` function. + + By default, the OpenEmbedded build system automatically sets this + variable to be equal to the number of cores the build system uses. + + .. note:: + + If the software being built experiences dependency issues during + the ``do_compile`` task that result in race conditions, you can clear + the ``PARALLEL_MAKE`` variable within the recipe as a workaround. For + information on addressing race conditions, see the + ":ref:`dev-manual/dev-manual-common-tasks:debugging parallel make races`" + section in the Yocto Project Development Tasks Manual. + + For single socket systems (i.e. one CPU), you should not have to + override this variable to gain optimal parallelism during builds. + However, if you have very large systems that employ multiple physical + CPUs, you might want to make sure the ``PARALLEL_MAKE`` variable is + not set higher than "-j 20". + + For more information on speeding up builds, see the + ":ref:`dev-manual/dev-manual-common-tasks:speeding up a build`" + section in the Yocto Project Development Tasks Manual. + + :term:`PARALLEL_MAKEINST` + Extra options passed to the ``make install`` command during the + :ref:`ref-tasks-install` task in order to specify + parallel installation. This variable defaults to the value of + :term:`PARALLEL_MAKE`. + + .. note:: + + In order for ``PARALLEL_MAKEINST`` to be effective, ``make`` must + be called with + ``${``\ :term:`EXTRA_OEMAKE`\ ``}``. An easy + way to ensure this is to use the ``oe_runmake`` function. + + If the software being built experiences dependency issues during + the ``do_install`` task that result in race conditions, you can + clear the ``PARALLEL_MAKEINST`` variable within the recipe as a + workaround. For information on addressing race conditions, see the + ":ref:`dev-manual/dev-manual-common-tasks:debugging parallel make races`" + section in the Yocto Project Development Tasks Manual. + + :term:`PATCHRESOLVE` + Determines the action to take when a patch fails. You can set this + variable to one of two values: "noop" and "user". + + The default value of "noop" causes the build to simply fail when the + OpenEmbedded build system cannot successfully apply a patch. Setting + the value to "user" causes the build system to launch a shell and + places you in the right location so that you can manually resolve the + conflicts. + + Set this variable in your ``local.conf`` file. + + :term:`PATCHTOOL` + Specifies the utility used to apply patches for a recipe during the + :ref:`ref-tasks-patch` task. You can specify one of + three utilities: "patch", "quilt", or "git". The default utility used + is "quilt" except for the quilt-native recipe itself. Because the + quilt tool is not available at the time quilt-native is being + patched, it uses "patch". + + If you wish to use an alternative patching tool, set the variable in + the recipe using one of the following: + :: + + PATCHTOOL = "patch" + PATCHTOOL = "quilt" + PATCHTOOL = "git" + + :term:`PE` + The epoch of the recipe. By default, this variable is unset. The + variable is used to make upgrades possible when the versioning scheme + changes in some backwards incompatible way. + + ``PE`` is the default value of the :term:`PKGE` variable. + + :term:`PF` + Specifies the recipe or package name and includes all version and + revision numbers (i.e. ``glibc-2.13-r20+svnr15508/`` and + ``bash-4.2-r1/``). This variable is comprised of the following: + ${:term:`PN`}-${:term:`EXTENDPE`}${:term:`PV`}-${:term:`PR`} + + :term:`PIXBUF_PACKAGES` + When inheriting the :ref:`pixbufcache <ref-classes-pixbufcache>` + class, this variable identifies packages that contain the pixbuf + loaders used with ``gdk-pixbuf``. By default, the ``pixbufcache`` + class assumes that the loaders are in the recipe's main package (i.e. + ``${``\ :term:`PN`\ ``}``). Use this variable if the + loaders you need are in a package other than that main package. + + :term:`PKG` + The name of the resulting package created by the OpenEmbedded build + system. + + .. note:: + + When using the ``PKG`` variable, you must use a package name override. + + For example, when the :ref:`debian <ref-classes-debian>` class + renames the output package, it does so by setting + ``PKG_packagename``. + + :term:`PKG_CONFIG_PATH` + The path to ``pkg-config`` files for the current build context. + ``pkg-config`` reads this variable from the environment. + + :term:`PKGD` + Points to the destination directory for files to be packaged before + they are split into individual packages. This directory defaults to + the following: + :: + + ${WORKDIR}/package + + Do not change this default. + + :term:`PKGDATA_DIR` + Points to a shared, global-state directory that holds data generated + during the packaging process. During the packaging process, the + :ref:`ref-tasks-packagedata` task packages data + for each recipe and installs it into this temporary, shared area. + This directory defaults to the following, which you should not + change: + :: + + ${STAGING_DIR_HOST}/pkgdata + + For examples of how this data is used, see the + ":ref:`overview-manual/overview-manual-concepts:automatically added runtime dependencies`" + section in the Yocto Project Overview and Concepts Manual and the + ":ref:`dev-manual/dev-manual-common-tasks:viewing package information with \`\`oe-pkgdata-util\`\``" + section in the Yocto Project Development Tasks Manual. For more + information on the shared, global-state directory, see + :term:`STAGING_DIR_HOST`. + + :term:`PKGDEST` + Points to the parent directory for files to be packaged after they + have been split into individual packages. This directory defaults to + the following: + :: + + ${WORKDIR}/packages-split + + Under this directory, the build system creates directories for each + package specified in :term:`PACKAGES`. Do not change + this default. + + :term:`PKGDESTWORK` + Points to a temporary work area where the + :ref:`ref-tasks-package` task saves package metadata. + The ``PKGDESTWORK`` location defaults to the following: + :: + + ${WORKDIR}/pkgdata + + Do not change this default. + + The :ref:`ref-tasks-packagedata` task copies the + package metadata from ``PKGDESTWORK`` to + :term:`PKGDATA_DIR` to make it available globally. + + :term:`PKGE` + The epoch of the package(s) built by the recipe. By default, ``PKGE`` + is set to :term:`PE`. + + :term:`PKGR` + The revision of the package(s) built by the recipe. By default, + ``PKGR`` is set to :term:`PR`. + + :term:`PKGV` + The version of the package(s) built by the recipe. By default, + ``PKGV`` is set to :term:`PV`. + + :term:`PN` + This variable can have two separate functions depending on the + context: a recipe name or a resulting package name. + + ``PN`` refers to a recipe name in the context of a file used by the + OpenEmbedded build system as input to create a package. The name is + normally extracted from the recipe file name. For example, if the + recipe is named ``expat_2.0.1.bb``, then the default value of ``PN`` + will be "expat". + + The variable refers to a package name in the context of a file + created or produced by the OpenEmbedded build system. + + If applicable, the ``PN`` variable also contains any special suffix + or prefix. For example, using ``bash`` to build packages for the + native machine, ``PN`` is ``bash-native``. Using ``bash`` to build + packages for the target and for Multilib, ``PN`` would be ``bash`` + and ``lib64-bash``, respectively. + + :term:`PNBLACKLIST` + Lists recipes you do not want the OpenEmbedded build system to build. + This variable works in conjunction with the + :ref:`blacklist <ref-classes-blacklist>` class, which is inherited + globally. + + To prevent a recipe from being built, use the ``PNBLACKLIST`` + variable in your ``local.conf`` file. Here is an example that + prevents ``myrecipe`` from being built: + :: + + PNBLACKLIST[myrecipe] = "Not supported by our organization." + + :term:`POPULATE_SDK_POST_HOST_COMMAND` + Specifies a list of functions to call once the OpenEmbedded build + system has created the host part of the SDK. You can specify + functions separated by semicolons: + :: + + POPULATE_SDK_POST_HOST_COMMAND += "function; ... " + + If you need to pass the SDK path to a command within a function, you + can use ``${SDK_DIR}``, which points to the parent directory used by + the OpenEmbedded build system when creating SDK output. See the + :term:`SDK_DIR` variable for more information. + + :term:`POPULATE_SDK_POST_TARGET_COMMAND` + Specifies a list of functions to call once the OpenEmbedded build + system has created the target part of the SDK. You can specify + functions separated by semicolons: + :: + + POPULATE_SDK_POST_TARGET_COMMAND += "function; ... " + + If you need to pass the SDK path to a command within a function, you + can use ``${SDK_DIR}``, which points to the parent directory used by + the OpenEmbedded build system when creating SDK output. See the + :term:`SDK_DIR` variable for more information. + + :term:`PR` + The revision of the recipe. The default value for this variable is + "r0". Subsequent revisions of the recipe conventionally have the + values "r1", "r2", and so forth. When :term:`PV` increases, + ``PR`` is conventionally reset to "r0". + + .. note:: + + The OpenEmbedded build system does not need the aid of ``PR`` + to know when to rebuild a recipe. The build system uses the task + :ref:`input checksums <overview-checksums>` along with the + :ref:`stamp <structure-build-tmp-stamps>` and + :ref:`overview-manual/overview-manual-concepts:shared state cache` + mechanisms. + + The ``PR`` variable primarily becomes significant when a package + manager dynamically installs packages on an already built image. In + this case, ``PR``, which is the default value of + :term:`PKGR`, helps the package manager distinguish which + package is the most recent one in cases where many packages have the + same ``PV`` (i.e. ``PKGV``). A component having many packages with + the same ``PV`` usually means that the packages all install the same + upstream version, but with later (``PR``) version packages including + packaging fixes. + + .. note:: + + ``PR`` does not need to be increased for changes that do not change the + package contents or metadata. + + Because manually managing ``PR`` can be cumbersome and error-prone, + an automated solution exists. See the + ":ref:`dev-manual/dev-manual-common-tasks:working with a pr service`" section + in the Yocto Project Development Tasks Manual for more information. + + :term:`PREFERRED_PROVIDER` + If multiple recipes provide the same item, this variable determines + which recipe is preferred and thus provides the item (i.e. the + preferred provider). You should always suffix this variable with the + name of the provided item. And, you should define the variable using + the preferred recipe's name (:term:`PN`). Here is a common + example: + :: + + PREFERRED_PROVIDER_virtual/kernel ?= "linux-yocto" + + In the previous example, multiple recipes are providing "virtual/kernel". + The ``PREFERRED_PROVIDER`` variable is set with the name (``PN``) of + the recipe you prefer to provide "virtual/kernel". + + Following are more examples: + :: + + PREFERRED_PROVIDER_virtual/xserver = "xserver-xf86" + PREFERRED_PROVIDER_virtual/libgl ?= "mesa" + + For more + information, see the ":ref:`metadata-virtual-providers`" + section in the Yocto Project Development Tasks Manual. + + .. note:: + + If you use a ``virtual/\*`` item with ``PREFERRED_PROVIDER``, then any + recipe that :term:`PROVIDES` that item but is not selected (defined) + by ``PREFERRED_PROVIDER`` is prevented from building, which is usually + desirable since this mechanism is designed to select between mutually + exclusive alternative providers. + + :term:`PREFERRED_VERSION` + If multiple versions of recipes exist, this variable determines which + version is given preference. You must always suffix the variable with + the :term:`PN` you want to select, and you should set the + :term:`PV` accordingly for precedence. + + The ``PREFERRED_VERSION`` variable supports limited wildcard use + through the "``%``" character. You can use the character to match any + number of characters, which can be useful when specifying versions + that contain long revision numbers that potentially change. Here are + two examples: + :: + + PREFERRED_VERSION_python = "3.4.0" + PREFERRED_VERSION_linux-yocto = "5.0%" + + .. note:: + + The use of the "%" character is limited in that it only works at the end of the + string. You cannot use the wildcard character in any other + location of the string. + + The specified version is matched against :term:`PV`, which + does not necessarily match the version part of the recipe's filename. + For example, consider two recipes ``foo_1.2.bb`` and ``foo_git.bb`` + where ``foo_git.bb`` contains the following assignment: + :: + + PV = "1.1+git${SRCPV}" + + In this case, the correct way to select + ``foo_git.bb`` is by using an assignment such as the following: + :: + + PREFERRED_VERSION_foo = "1.1+git%" + + Compare that previous example + against the following incorrect example, which does not work: + :: + + PREFERRED_VERSION_foo = "git" + + Sometimes the ``PREFERRED_VERSION`` variable can be set by + configuration files in a way that is hard to change. You can use + :term:`OVERRIDES` to set a machine-specific + override. Here is an example: + :: + + PREFERRED_VERSION_linux-yocto_qemux86 = "5.0%" + + Although not recommended, worst case, you can also use the + "forcevariable" override, which is the strongest override possible. + Here is an example: + :: + + PREFERRED_VERSION_linux-yocto_forcevariable = "5.0%" + + .. note:: + + The ``\_forcevariable`` override is not handled specially. This override + only works because the default value of ``OVERRIDES`` includes "forcevariable". + + :term:`PREMIRRORS` + Specifies additional paths from which the OpenEmbedded build system + gets source code. When the build system searches for source code, it + first tries the local download directory. If that location fails, the + build system tries locations defined by ``PREMIRRORS``, the upstream + source, and then locations specified by + :term:`MIRRORS` in that order. + + Assuming your distribution (:term:`DISTRO`) is "poky", + the default value for ``PREMIRRORS`` is defined in the + ``conf/distro/poky.conf`` file in the ``meta-poky`` Git repository. + + Typically, you could add a specific server for the build system to + attempt before any others by adding something like the following to + the ``local.conf`` configuration file in the + :term:`Build Directory`: + :: + + PREMIRRORS_prepend = "\ + git://.*/.* http://www.yoctoproject.org/sources/ \n \ + ftp://.*/.* http://www.yoctoproject.org/sources/ \n \ + http://.*/.* http://www.yoctoproject.org/sources/ \n \ + https://.*/.* http://www.yoctoproject.org/sources/ \n" + + These changes cause the + build system to intercept Git, FTP, HTTP, and HTTPS requests and + direct them to the ``http://`` sources mirror. You can use + ``file://`` URLs to point to local directories or network shares as + well. + + :term:`PRIORITY` + Indicates the importance of a package. + + ``PRIORITY`` is considered to be part of the distribution policy + because the importance of any given recipe depends on the purpose for + which the distribution is being produced. Thus, ``PRIORITY`` is not + normally set within recipes. + + You can set ``PRIORITY`` to "required", "standard", "extra", and + "optional", which is the default. + + :term:`PRIVATE_LIBS` + Specifies libraries installed within a recipe that should be ignored + by the OpenEmbedded build system's shared library resolver. This + variable is typically used when software being built by a recipe has + its own private versions of a library normally provided by another + recipe. In this case, you would not want the package containing the + private libraries to be set as a dependency on other unrelated + packages that should instead depend on the package providing the + standard version of the library. + + Libraries specified in this variable should be specified by their + file name. For example, from the Firefox recipe in meta-browser: + :: + + PRIVATE_LIBS = "libmozjs.so \ + libxpcom.so \ + libnspr4.so \ + libxul.so \ + libmozalloc.so \ + libplc4.so \ + libplds4.so" + + For more information, see the + ":ref:`overview-manual/overview-manual-concepts:automatically added runtime dependencies`" + section in the Yocto Project Overview and Concepts Manual. + + :term:`PROVIDES` + A list of aliases by which a particular recipe can be known. By + default, a recipe's own ``PN`` is implicitly already in its + ``PROVIDES`` list and therefore does not need to mention that it + provides itself. If a recipe uses ``PROVIDES``, the additional + aliases are synonyms for the recipe and can be useful for satisfying + dependencies of other recipes during the build as specified by + ``DEPENDS``. + + Consider the following example ``PROVIDES`` statement from the recipe + file ``eudev_3.2.9.bb``: + :: + + PROVIDES = "udev" + + The ``PROVIDES`` statement + results in the "eudev" recipe also being available as simply "udev". + + .. note:: + + Given that a recipe's own recipe name is already implicitly in its + own PROVIDES list, it is unnecessary to add aliases with the "+=" operator; + using a simple assignment will be sufficient. In other words, + while you could write: + :: + + PROVIDES += "udev" + + + in the above, the "+=" is overkill and unnecessary. + + In addition to providing recipes under alternate names, the + ``PROVIDES`` mechanism is also used to implement virtual targets. A + virtual target is a name that corresponds to some particular + functionality (e.g. a Linux kernel). Recipes that provide the + functionality in question list the virtual target in ``PROVIDES``. + Recipes that depend on the functionality in question can include the + virtual target in ``DEPENDS`` to leave the choice of provider open. + + Conventionally, virtual targets have names on the form + "virtual/function" (e.g. "virtual/kernel"). The slash is simply part + of the name and has no syntactical significance. + + The :term:`PREFERRED_PROVIDER` variable is + used to select which particular recipe provides a virtual target. + + .. note:: + + A corresponding mechanism for virtual runtime dependencies + (packages) exists. However, the mechanism does not depend on any + special functionality beyond ordinary variable assignments. For + example, ``VIRTUAL-RUNTIME_dev_manager`` refers to the package of + the component that manages the ``/dev`` directory. + + Setting the "preferred provider" for runtime dependencies is as + simple as using the following assignment in a configuration file: + :: + + VIRTUAL-RUNTIME_dev_manager = "udev" + + + :term:`PRSERV_HOST` + The network based :term:`PR` service host and port. + + The ``conf/local.conf.sample.extended`` configuration file in the + :term:`Source Directory` shows how the + ``PRSERV_HOST`` variable is set: + :: + + PRSERV_HOST = "localhost:0" + + You must + set the variable if you want to automatically start a local :ref:`PR + service <dev-manual/dev-manual-common-tasks:working with a pr service>`. You can + set ``PRSERV_HOST`` to other values to use a remote PR service. + + :term:`PTEST_ENABLED` + Specifies whether or not :ref:`Package + Test <dev-manual/dev-manual-common-tasks:testing packages with ptest>` (ptest) + functionality is enabled when building a recipe. You should not set + this variable directly. Enabling and disabling building Package Tests + at build time should be done by adding "ptest" to (or removing it + from) :term:`DISTRO_FEATURES`. + + :term:`PV` + The version of the recipe. The version is normally extracted from the + recipe filename. For example, if the recipe is named + ``expat_2.0.1.bb``, then the default value of ``PV`` will be "2.0.1". + ``PV`` is generally not overridden within a recipe unless it is + building an unstable (i.e. development) version from a source code + repository (e.g. Git or Subversion). + + ``PV`` is the default value of the :term:`PKGV` variable. + + :term:`PYTHON_ABI` + When used by recipes that inherit the + :ref:`distutils3 <ref-classes-distutils3>`, + :ref:`setuptools3 <ref-classes-setuptools3>`, + :ref:`distutils <ref-classes-distutils>`, or + :ref:`setuptools <ref-classes-setuptools>` classes, denotes the + Application Binary Interface (ABI) currently in use for Python. By + default, the ABI is "m". You do not have to set this variable as the + OpenEmbedded build system sets it for you. + + The OpenEmbedded build system uses the ABI to construct directory + names used when installing the Python headers and libraries in + sysroot (e.g. ``.../python3.3m/...``). + + Recipes that inherit the ``distutils`` class during cross-builds also + use this variable to locate the headers and libraries of the + appropriate Python that the extension is targeting. + + :term:`PYTHON_PN` + When used by recipes that inherit the + `distutils3 <ref-classes-distutils3>`, + :ref:`setuptools3 <ref-classes-setuptools3>`, + :ref:`distutils <ref-classes-distutils>`, or + :ref:`setuptools <ref-classes-setuptools>` classes, specifies the + major Python version being built. For Python 3.x, ``PYTHON_PN`` would + be "python3". You do not have to set this variable as the + OpenEmbedded build system automatically sets it for you. + + The variable allows recipes to use common infrastructure such as the + following: + :: + + DEPENDS += "${PYTHON_PN}-native" + + In the previous example, + the version of the dependency is ``PYTHON_PN``. + + :term:`RANLIB` + The minimal command and arguments to run ``ranlib``. + + :term:`RCONFLICTS` + The list of packages that conflict with packages. Note that packages + will not be installed if conflicting packages are not first removed. + + Like all package-controlling variables, you must always use them in + conjunction with a package name override. Here is an example: + :: + + RCONFLICTS_${PN} = "another_conflicting_package_name" + + BitBake, which the OpenEmbedded build system uses, supports + specifying versioned dependencies. Although the syntax varies + depending on the packaging format, BitBake hides these differences + from you. Here is the general syntax to specify versions with the + ``RCONFLICTS`` variable: + :: + + RCONFLICTS_${PN} = "package (operator version)" + + For ``operator``, you can specify the following: + + - = + - < + - > + - <= + - >= + + For example, the following sets up a dependency on version 1.2 or + greater of the package ``foo``: + :: + + RCONFLICTS_${PN} = "foo (>= 1.2)" + + :term:`RDEPENDS` + Lists runtime dependencies of a package. These dependencies are other + packages that must be installed in order for the package to function + correctly. As an example, the following assignment declares that the + package ``foo`` needs the packages ``bar`` and ``baz`` to be + installed: + :: + + RDEPENDS_foo = "bar baz" + + The most common types of package + runtime dependencies are automatically detected and added. Therefore, + most recipes do not need to set ``RDEPENDS``. For more information, + see the + ":ref:`overview-manual/overview-manual-concepts:automatically added runtime dependencies`" + section in the Yocto Project Overview and Concepts Manual. + + The practical effect of the above ``RDEPENDS`` assignment is that + ``bar`` and ``baz`` will be declared as dependencies inside the + package ``foo`` when it is written out by one of the + :ref:`do_package_write_\* <ref-tasks-package_write_deb>` tasks. + Exactly how this is done depends on which package format is used, + which is determined by + :term:`PACKAGE_CLASSES`. When the + corresponding package manager installs the package, it will know to + also install the packages on which it depends. + + To ensure that the packages ``bar`` and ``baz`` get built, the + previous ``RDEPENDS`` assignment also causes a task dependency to be + added. This dependency is from the recipe's + :ref:`ref-tasks-build` (not to be confused with + :ref:`ref-tasks-compile`) task to the + ``do_package_write_*`` task of the recipes that build ``bar`` and + ``baz``. + + The names of the packages you list within ``RDEPENDS`` must be the + names of other packages - they cannot be recipe names. Although + package names and recipe names usually match, the important point + here is that you are providing package names within the ``RDEPENDS`` + variable. For an example of the default list of packages created from + a recipe, see the :term:`PACKAGES` variable. + + Because the ``RDEPENDS`` variable applies to packages being built, + you should always use the variable in a form with an attached package + name (remember that a single recipe can build multiple packages). For + example, suppose you are building a development package that depends + on the ``perl`` package. In this case, you would use the following + ``RDEPENDS`` statement: + :: + + RDEPENDS_${PN}-dev += "perl" + + In the example, + the development package depends on the ``perl`` package. Thus, the + ``RDEPENDS`` variable has the ``${PN}-dev`` package name as part of + the variable. + + .. note:: + + ``RDEPENDS_${PN}-dev`` includes ``${``\ :term:`PN`\ ``}`` + by default. This default is set in the BitBake configuration file + (``meta/conf/bitbake.conf``). Be careful not to accidentally remove + ``${PN}`` when modifying ``RDEPENDS_${PN}-dev``. Use the "+=" operator + rather than the "=" operator. + + The package names you use with ``RDEPENDS`` must appear as they would + in the ``PACKAGES`` variable. The :term:`PKG` variable + allows a different name to be used for the final package (e.g. the + :ref:`debian <ref-classes-debian>` class uses this to rename + packages), but this final package name cannot be used with + ``RDEPENDS``, which makes sense as ``RDEPENDS`` is meant to be + independent of the package format used. + + BitBake, which the OpenEmbedded build system uses, supports + specifying versioned dependencies. Although the syntax varies + depending on the packaging format, BitBake hides these differences + from you. Here is the general syntax to specify versions with the + ``RDEPENDS`` variable: + :: + + RDEPENDS_${PN} = "package (operator version)" + + For ``operator``, you can specify the following: + + - = + - < + - > + - <= + - >= + + For version, provide the version number. + + .. note:: + + You can use ``EXTENDPKGV`` to provide a full package version + specification. + + For example, the following sets up a dependency on version 1.2 or + greater of the package ``foo``: + :: + + RDEPENDS_${PN} = "foo (>= 1.2)" + + For information on build-time dependencies, see the + :term:`DEPENDS` variable. You can also see the + ":ref:`Tasks <bitbake:bitbake-user-manual/bitbake-user-manual-metadata:tasks>`" and + ":ref:`Dependencies <bitbake:bitbake-user-manual/bitbake-user-manual-execution:dependencies>`" sections in the + BitBake User Manual for additional information on tasks and + dependencies. + + :term:`REQUIRED_DISTRO_FEATURES` + When inheriting the + :ref:`features_check <ref-classes-features_check>` + class, this variable identifies distribution features that must exist + in the current configuration in order for the OpenEmbedded build + system to build the recipe. In other words, if the + ``REQUIRED_DISTRO_FEATURES`` variable lists a feature that does not + appear in ``DISTRO_FEATURES`` within the current configuration, then + the recipe will be skipped, and if the build system attempts to build + the recipe then an error will be triggered. + + :term:`RM_WORK_EXCLUDE` + With ``rm_work`` enabled, this variable specifies a list of recipes + whose work directories should not be removed. See the + ":ref:`rm_work.bbclass <ref-classes-rm-work>`" section for more + details. + + :term:`ROOT_HOME` + Defines the root home directory. By default, this directory is set as + follows in the BitBake configuration file: + :: + + ROOT_HOME ??= "/home/root" + + .. note:: + + This default value is likely used because some embedded solutions + prefer to have a read-only root filesystem and prefer to keep + writeable data in one place. + + You can override the default by setting the variable in any layer or + in the ``local.conf`` file. Because the default is set using a "weak" + assignment (i.e. "??="), you can use either of the following forms to + define your override: + :: + + ROOT_HOME = "/root" + ROOT_HOME ?= "/root" + + These + override examples use ``/root``, which is probably the most commonly + used override. + + :term:`ROOTFS` + Indicates a filesystem image to include as the root filesystem. + + The ``ROOTFS`` variable is an optional variable used with the + :ref:`image-live <ref-classes-image-live>` class. + + :term:`ROOTFS_POSTINSTALL_COMMAND` + Specifies a list of functions to call after the OpenEmbedded build + system has installed packages. You can specify functions separated by + semicolons: + :: + + ROOTFS_POSTINSTALL_COMMAND += "function; ... " + + If you need to pass the root filesystem path to a command within a + function, you can use ``${IMAGE_ROOTFS}``, which points to the + directory that becomes the root filesystem image. See the + :term:`IMAGE_ROOTFS` variable for more + information. + + :term:`ROOTFS_POSTPROCESS_COMMAND` + Specifies a list of functions to call once the OpenEmbedded build + system has created the root filesystem. You can specify functions + separated by semicolons: + :: + + ROOTFS_POSTPROCESS_COMMAND += "function; ... " + + If you need to pass the root filesystem path to a command within a + function, you can use ``${IMAGE_ROOTFS}``, which points to the + directory that becomes the root filesystem image. See the + :term:`IMAGE_ROOTFS` variable for more + information. + + :term:`ROOTFS_POSTUNINSTALL_COMMAND` + Specifies a list of functions to call after the OpenEmbedded build + system has removed unnecessary packages. When runtime package + management is disabled in the image, several packages are removed + including ``base-passwd``, ``shadow``, and ``update-alternatives``. + You can specify functions separated by semicolons: + :: + + ROOTFS_POSTUNINSTALL_COMMAND += "function; ... " + + If you need to pass the root filesystem path to a command within a + function, you can use ``${IMAGE_ROOTFS}``, which points to the + directory that becomes the root filesystem image. See the + :term:`IMAGE_ROOTFS` variable for more + information. + + :term:`ROOTFS_PREPROCESS_COMMAND` + Specifies a list of functions to call before the OpenEmbedded build + system has created the root filesystem. You can specify functions + separated by semicolons: + :: + + ROOTFS_PREPROCESS_COMMAND += "function; ... " + + If you need to pass the root filesystem path to a command within a + function, you can use ``${IMAGE_ROOTFS}``, which points to the + directory that becomes the root filesystem image. See the + :term:`IMAGE_ROOTFS` variable for more + information. + + :term:`RPROVIDES` + A list of package name aliases that a package also provides. These + aliases are useful for satisfying runtime dependencies of other + packages both during the build and on the target (as specified by + ``RDEPENDS``). + + .. note:: + + A package's own name is implicitly already in its ``RPROVIDES`` list. + + As with all package-controlling variables, you must always use the + variable in conjunction with a package name override. Here is an + example: + :: + + RPROVIDES_${PN} = "widget-abi-2" + + :term:`RRECOMMENDS` + A list of packages that extends the usability of a package being + built. The package being built does not depend on this list of + packages in order to successfully build, but rather uses them for + extended usability. To specify runtime dependencies for packages, see + the ``RDEPENDS`` variable. + + The package manager will automatically install the ``RRECOMMENDS`` + list of packages when installing the built package. However, you can + prevent listed packages from being installed by using the + :term:`BAD_RECOMMENDATIONS`, + :term:`NO_RECOMMENDATIONS`, and + :term:`PACKAGE_EXCLUDE` variables. + + Packages specified in ``RRECOMMENDS`` need not actually be produced. + However, a recipe must exist that provides each package, either + through the :term:`PACKAGES` or + :term:`PACKAGES_DYNAMIC` variables or the + :term:`RPROVIDES` variable, or an error will occur + during the build. If such a recipe does exist and the package is not + produced, the build continues without error. + + Because the ``RRECOMMENDS`` variable applies to packages being built, + you should always attach an override to the variable to specify the + particular package whose usability is being extended. For example, + suppose you are building a development package that is extended to + support wireless functionality. In this case, you would use the + following: + :: + + RRECOMMENDS_${PN}-dev += "wireless_package_name" + + In the + example, the package name (``${PN}-dev``) must appear as it would in + the ``PACKAGES`` namespace before any renaming of the output package + by classes such as ``debian.bbclass``. + + BitBake, which the OpenEmbedded build system uses, supports + specifying versioned recommends. Although the syntax varies depending + on the packaging format, BitBake hides these differences from you. + Here is the general syntax to specify versions with the + ``RRECOMMENDS`` variable: + :: + + RRECOMMENDS_${PN} = "package (operator version)" + + For ``operator``, you can specify the following: + + - = + - < + - > + - <= + - >= + + For example, the following sets up a recommend on version 1.2 or + greater of the package ``foo``: + :: + + RRECOMMENDS_${PN} = "foo (>= 1.2)" + + :term:`RREPLACES` + A list of packages replaced by a package. The package manager uses + this variable to determine which package should be installed to + replace other package(s) during an upgrade. In order to also have the + other package(s) removed at the same time, you must add the name of + the other package to the ``RCONFLICTS`` variable. + + As with all package-controlling variables, you must use this variable + in conjunction with a package name override. Here is an example: + :: + + RREPLACES_${PN} = "other_package_being_replaced" + + BitBake, which the OpenEmbedded build system uses, supports + specifying versioned replacements. Although the syntax varies + depending on the packaging format, BitBake hides these differences + from you. Here is the general syntax to specify versions with the + ``RREPLACES`` variable: + :: + + RREPLACES_${PN} = "package (operator version)" + + For ``operator``, you can specify the following: + + - = + - < + - > + - <= + - >= + + For example, the following sets up a replacement using version 1.2 + or greater of the package ``foo``: + :: + + RREPLACES_${PN} = "foo (>= 1.2)" + + :term:`RSUGGESTS` + A list of additional packages that you can suggest for installation + by the package manager at the time a package is installed. Not all + package managers support this functionality. + + As with all package-controlling variables, you must always use this + variable in conjunction with a package name override. Here is an + example: + :: + + RSUGGESTS_${PN} = "useful_package another_package" + + :term:`S` + The location in the :term:`Build Directory` where + unpacked recipe source code resides. By default, this directory is + ``${``\ :term:`WORKDIR`\ ``}/${``\ :term:`BPN`\ ``}-${``\ :term:`PV`\ ``}``, + where ``${BPN}`` is the base recipe name and ``${PV}`` is the recipe + version. If the source tarball extracts the code to a directory named + anything other than ``${BPN}-${PV}``, or if the source code is + fetched from an SCM such as Git or Subversion, then you must set + ``S`` in the recipe so that the OpenEmbedded build system knows where + to find the unpacked source. + + As an example, assume a :term:`Source Directory` + top-level folder named ``poky`` and a default Build Directory at + ``poky/build``. In this case, the work directory the build system + uses to keep the unpacked recipe for ``db`` is the following: + :: + + poky/build/tmp/work/qemux86-poky-linux/db/5.1.19-r3/db-5.1.19 + + The unpacked source code resides in the ``db-5.1.19`` folder. + + This next example assumes a Git repository. By default, Git + repositories are cloned to ``${WORKDIR}/git`` during + :ref:`ref-tasks-fetch`. Since this path is different + from the default value of ``S``, you must set it specifically so the + source can be located: + :: + + SRC_URI = "git://path/to/repo.git" + S = "${WORKDIR}/git" + + :term:`SANITY_REQUIRED_UTILITIES` + Specifies a list of command-line utilities that should be checked for + during the initial sanity checking process when running BitBake. If + any of the utilities are not installed on the build host, then + BitBake immediately exits with an error. + + :term:`SANITY_TESTED_DISTROS` + A list of the host distribution identifiers that the build system has + been tested against. Identifiers consist of the host distributor ID + followed by the release, as reported by the ``lsb_release`` tool or + as read from ``/etc/lsb-release``. Separate the list items with + explicit newline characters (``\n``). If ``SANITY_TESTED_DISTROS`` is + not empty and the current value of + :term:`NATIVELSBSTRING` does not appear in the + list, then the build system reports a warning that indicates the + current host distribution has not been tested as a build host. + + :term:`SDK_ARCH` + The target architecture for the SDK. Typically, you do not directly + set this variable. Instead, use :term:`SDKMACHINE`. + + :term:`SDK_DEPLOY` + The directory set up and used by the + :ref:`populate_sdk_base <ref-classes-populate-sdk>` class to which + the SDK is deployed. The ``populate_sdk_base`` class defines + ``SDK_DEPLOY`` as follows: + :: + + SDK_DEPLOY = "${TMPDIR}/deploy/sdk" + + :term:`SDK_DIR` + The parent directory used by the OpenEmbedded build system when + creating SDK output. The + :ref:`populate_sdk_base <ref-classes-populate-sdk-*>` class defines + the variable as follows: + :: + + SDK_DIR = "${WORKDIR}/sdk" + + .. note:: + + The ``SDK_DIR`` directory is a temporary directory as it is part of + ``WORKDIR``. The final output directory is :term:`SDK_DEPLOY`. + + :term:`SDK_EXT_TYPE` + Controls whether or not shared state artifacts are copied into the + extensible SDK. The default value of "full" copies all of the + required shared state artifacts into the extensible SDK. The value + "minimal" leaves these artifacts out of the SDK. + + .. note:: + + If you set the variable to "minimal", you need to ensure + :term:`SSTATE_MIRRORS` is set in the SDK's configuration to enable the + artifacts to be fetched as needed. + + :term:`SDK_HOST_MANIFEST` + The manifest file for the host part of the SDK. This file lists all + the installed packages that make up the host part of the SDK. The + file contains package information on a line-per-package basis as + follows: + :: + + packagename packagearch version + + The :ref:`populate_sdk_base <ref-classes-populate-sdk-*>` class + defines the manifest file as follows: + :: + + SDK_HOST_MANIFEST = "${SDK_DEPLOY}/${TOOLCHAIN_OUTPUTNAME}.host.manifest" + + The location is derived using the :term:`SDK_DEPLOY` and + :term:`TOOLCHAIN_OUTPUTNAME` variables. + + :term:`SDK_INCLUDE_PKGDATA` + When set to "1", specifies to include the packagedata for all recipes + in the "world" target in the extensible SDK. Including this data + allows the ``devtool search`` command to find these recipes in search + results, as well as allows the ``devtool add`` command to map + dependencies more effectively. + + .. note:: + + Enabling the ``SDK_INCLUDE_PKGDATA`` + variable significantly increases build time because all of world + needs to be built. Enabling the variable also slightly increases + the size of the extensible SDK. + + :term:`SDK_INCLUDE_TOOLCHAIN` + When set to "1", specifies to include the toolchain in the extensible + SDK. Including the toolchain is useful particularly when + :term:`SDK_EXT_TYPE` is set to "minimal" to keep + the SDK reasonably small but you still want to provide a usable + toolchain. For example, suppose you want to use the toolchain from an + IDE or from other tools and you do not want to perform additional + steps to install the toolchain. + + The ``SDK_INCLUDE_TOOLCHAIN`` variable defaults to "0" if + ``SDK_EXT_TYPE`` is set to "minimal", and defaults to "1" if + ``SDK_EXT_TYPE`` is set to "full". + + :term:`SDK_INHERIT_BLACKLIST` + A list of classes to remove from the :term:`INHERIT` + value globally within the extensible SDK configuration. The + :ref:`populate-sdk-ext <ref-classes-populate-sdk-*>` class sets the + default value: + :: + + SDK_INHERIT_BLACKLIST ?= "buildhistory icecc" + + Some classes are not generally applicable within the extensible SDK + context. You can use this variable to disable those classes. + + For additional information on how to customize the extensible SDK's + configuration, see the + ":ref:`sdk-manual/sdk-appendix-customizing:configuring the extensible sdk`" + section in the Yocto Project Application Development and the + Extensible Software Development Kit (eSDK) manual. + + :term:`SDK_LOCAL_CONF_BLACKLIST` + A list of variables not allowed through from the OpenEmbedded build + system configuration into the extensible SDK configuration. Usually, + these are variables that are specific to the machine on which the + build system is running and thus would be potentially problematic + within the extensible SDK. + + By default, ``SDK_LOCAL_CONF_BLACKLIST`` is set in the + :ref:`populate-sdk-ext <ref-classes-populate-sdk-*>` class and + excludes the following variables: + + - :term:`CONF_VERSION` + - :term:`BB_NUMBER_THREADS` + - :term:`bitbake:BB_NUMBER_PARSE_THREADS` + - :term:`PARALLEL_MAKE` + - :term:`PRSERV_HOST` + - :term:`SSTATE_MIRRORS` :term:`DL_DIR` + - :term:`SSTATE_DIR` :term:`TMPDIR` + - :term:`BB_SERVER_TIMEOUT` + + For additional information on how to customize the extensible SDK's + configuration, see the + ":ref:`sdk-manual/sdk-appendix-customizing:configuring the extensible sdk`" + section in the Yocto Project Application Development and the + Extensible Software Development Kit (eSDK) manual. + + :term:`SDK_LOCAL_CONF_WHITELIST` + A list of variables allowed through from the OpenEmbedded build + system configuration into the extensible SDK configuration. By + default, the list of variables is empty and is set in the + :ref:`populate-sdk-ext <ref-classes-populate-sdk-*>` class. + + This list overrides the variables specified using the + :term:`SDK_LOCAL_CONF_BLACKLIST` + variable as well as any variables identified by automatic + blacklisting due to the "/" character being found at the start of the + value, which is usually indicative of being a path and thus might not + be valid on the system where the SDK is installed. + + For additional information on how to customize the extensible SDK's + configuration, see the + ":ref:`sdk-manual/sdk-appendix-customizing:configuring the extensible sdk`" + section in the Yocto Project Application Development and the + Extensible Software Development Kit (eSDK) manual. + + :term:`SDK_NAME` + The base name for SDK output files. The name is derived from the + :term:`DISTRO`, :term:`TCLIBC`, + :term:`SDK_ARCH`, + :term:`IMAGE_BASENAME`, and + :term:`TUNE_PKGARCH` variables: + :: + + SDK_NAME = "${DISTRO}-${TCLIBC}-${SDK_ARCH}-${IMAGE_BASENAME}-${TUNE_PKGARCH}" + + :term:`SDK_OS` + Specifies the operating system for which the SDK will be built. The + default value is the value of :term:`BUILD_OS`. + + :term:`SDK_OUTPUT` + The location used by the OpenEmbedded build system when creating SDK + output. The :ref:`populate_sdk_base <ref-classes-populate-sdk-*>` + class defines the variable as follows: + :: + + SDK_DIR = "${WORKDIR}/sdk" + SDK_OUTPUT = "${SDK_DIR}/image" + SDK_DEPLOY = "${DEPLOY_DIR}/sdk" + + .. note:: + + The ``SDK_OUTPUT`` directory is a temporary directory as it is part of + :term:`WORKDIR` by way of :term:`SDK_DIR`. The final output directory is + :term:`SDK_DEPLOY`. + + :term:`SDK_PACKAGE_ARCHS` + Specifies a list of architectures compatible with the SDK machine. + This variable is set automatically and should not normally be + hand-edited. Entries are separated using spaces and listed in order + of priority. The default value for ``SDK_PACKAGE_ARCHS`` is "all any + noarch ${SDK_ARCH}-${SDKPKGSUFFIX}". + + :term:`SDK_POSTPROCESS_COMMAND` + Specifies a list of functions to call once the OpenEmbedded build + system creates the SDK. You can specify functions separated by + semicolons: SDK_POSTPROCESS_COMMAND += "function; ... " + + If you need to pass an SDK path to a command within a function, you + can use ``${SDK_DIR}``, which points to the parent directory used by + the OpenEmbedded build system when creating SDK output. See the + :term:`SDK_DIR` variable for more information. + + :term:`SDK_PREFIX` + The toolchain binary prefix used for ``nativesdk`` recipes. The + OpenEmbedded build system uses the ``SDK_PREFIX`` value to set the + :term:`TARGET_PREFIX` when building + ``nativesdk`` recipes. The default value is "${SDK_SYS}-". + + :term:`SDK_RECRDEP_TASKS` + A list of shared state tasks added to the extensible SDK. By default, + the following tasks are added: + + - do_populate_lic + - do_package_qa + - do_populate_sysroot + - do_deploy + + Despite the default value of "" for the + ``SDK_RECRDEP_TASKS`` variable, the above four tasks are always added + to the SDK. To specify tasks beyond these four, you need to use the + ``SDK_RECRDEP_TASKS`` variable (e.g. you are defining additional + tasks that are needed in order to build + :term:`SDK_TARGETS`). + + :term:`SDK_SYS` + Specifies the system, including the architecture and the operating + system, for which the SDK will be built. + + The OpenEmbedded build system automatically sets this variable based + on :term:`SDK_ARCH`, + :term:`SDK_VENDOR`, and + :term:`SDK_OS`. You do not need to set the ``SDK_SYS`` + variable yourself. + + :term:`SDK_TARGET_MANIFEST` + The manifest file for the target part of the SDK. This file lists all + the installed packages that make up the target part of the SDK. The + file contains package information on a line-per-package basis as + follows: + :: + + packagename packagearch version + + The :ref:`populate_sdk_base <ref-classes-populate-sdk-*>` class + defines the manifest file as follows: + :: + + SDK_TARGET_MANIFEST = "${SDK_DEPLOY}/${TOOLCHAIN_OUTPUTNAME}.target.manifest" + + The location is derived using the :term:`SDK_DEPLOY` and + :term:`TOOLCHAIN_OUTPUTNAME` variables. + + :term:`SDK_TARGETS` + A list of targets to install from shared state as part of the + standard or extensible SDK installation. The default value is "${PN}" + (i.e. the image from which the SDK is built). + + The ``SDK_TARGETS`` variable is an internal variable and typically + would not be changed. + + :term:`SDK_TITLE` + The title to be printed when running the SDK installer. By default, + this title is based on the :term:`DISTRO_NAME` or + :term:`DISTRO` variable and is set in the + :ref:`populate_sdk_base <ref-classes-populate-sdk-*>` class as + follows: + :: + + SDK_TITLE ??= "${@d.getVar('DISTRO_NAME') or d.getVar('DISTRO')} SDK" + + For the default distribution "poky", + ``SDK_TITLE`` is set to "Poky (Yocto Project Reference Distro)". + + For information on how to change this default title, see the + ":ref:`sdk-manual/sdk-appendix-customizing:changing the extensible sdk installer title`" + section in the Yocto Project Application Development and the + Extensible Software Development Kit (eSDK) manual. + + :term:`SDK_UPDATE_URL` + An optional URL for an update server for the extensible SDK. If set, + the value is used as the default update server when running + ``devtool sdk-update`` within the extensible SDK. + + :term:`SDK_VENDOR` + Specifies the name of the SDK vendor. + + :term:`SDK_VERSION` + Specifies the version of the SDK. The distribution configuration file + (e.g. ``/meta-poky/conf/distro/poky.conf``) defines the + ``SDK_VERSION`` as follows: + :: + + SDK_VERSION = "${@d.getVar('DISTRO_VERSION').replace('snapshot-${DATE}','snapshot')}" + + For additional information, see the + :term:`DISTRO_VERSION` and + :term:`DATE` variables. + + :term:`SDKEXTPATH` + The default installation directory for the Extensible SDK. By + default, this directory is based on the :term:`DISTRO` + variable and is set in the + :ref:`populate_sdk_base <ref-classes-populate-sdk-*>` class as + follows: + :: + + SDKEXTPATH ??= "~/${@d.getVar('DISTRO')}_sdk" + + For the + default distribution "poky", the ``SDKEXTPATH`` is set to "poky_sdk". + + For information on how to change this default directory, see the + ":ref:`sdk-manual/sdk-appendix-customizing:changing the default sdk installation directory`" + section in the Yocto Project Application Development and the + Extensible Software Development Kit (eSDK) manual. + + :term:`SDKIMAGE_FEATURES` + Equivalent to ``IMAGE_FEATURES``. However, this variable applies to + the SDK generated from an image using the following command: + :: + + $ bitbake -c populate_sdk imagename + + :term:`SDKMACHINE` + The machine for which the SDK is built. In other words, the SDK is + built such that it runs on the target you specify with the + ``SDKMACHINE`` value. The value points to a corresponding ``.conf`` + file under ``conf/machine-sdk/``. + + You can use "i686" and "x86_64" as possible values for this variable. + The variable defaults to "i686" and is set in the local.conf file in + the Build Directory. + :: + + SDKMACHINE ?= "i686" + + .. note:: + + You cannot set the ``SDKMACHINE`` + variable in your distribution configuration file. If you do, the + configuration will not take affect. + + :term:`SDKPATH` + Defines the path offered to the user for installation of the SDK that + is generated by the OpenEmbedded build system. The path appears as + the default location for installing the SDK when you run the SDK's + installation script. You can override the offered path when you run + the script. + + :term:`SDKTARGETSYSROOT` + The full path to the sysroot used for cross-compilation within an SDK + as it will be when installed into the default + :term:`SDKPATH`. + + :term:`SECTION` + The section in which packages should be categorized. Package + management utilities can make use of this variable. + + :term:`SELECTED_OPTIMIZATION` + Specifies the optimization flags passed to the C compiler when + building for the target. The flags are passed through the default + value of the :term:`TARGET_CFLAGS` variable. + + The ``SELECTED_OPTIMIZATION`` variable takes the value of + ``FULL_OPTIMIZATION`` unless ``DEBUG_BUILD`` = "1". If that is the + case, the value of ``DEBUG_OPTIMIZATION`` is used. + + :term:`SERIAL_CONSOLE` + Defines a serial console (TTY) to enable using + `getty <https://en.wikipedia.org/wiki/Getty_(Unix)>`__. Provide a + value that specifies the baud rate followed by the TTY device name + separated by a space. You cannot specify more than one TTY device: + :: + + SERIAL_CONSOLE = "115200 ttyS0" + + .. note:: + + The ``SERIAL_CONSOLE`` variable is deprecated. Please use the + :term:`SERIAL_CONSOLES` variable. + + :term:`SERIAL_CONSOLES` + Defines a serial console (TTY) to enable using + `getty <https://en.wikipedia.org/wiki/Getty_(Unix)>`__. Provide a + value that specifies the baud rate followed by the TTY device name + separated by a semicolon. Use spaces to separate multiple devices: + :: + + SERIAL_CONSOLES = "115200;ttyS0 115200;ttyS1" + + :term:`SERIAL_CONSOLES_CHECK` + Specifies serial consoles, which must be listed in + :term:`SERIAL_CONSOLES`, to check against + ``/proc/console`` before enabling them using getty. This variable + allows aliasing in the format: <device>:<alias>. If a device was + listed as "sclp_line0" in ``/dev/`` and "ttyS0" was listed in + ``/proc/console``, you would do the following: :: + + SERIAL_CONSOLES_CHECK = "slcp_line0:ttyS0" + + This variable is currently only supported with SysVinit (i.e. not + with systemd). + + :term:`SIGGEN_EXCLUDE_SAFE_RECIPE_DEPS` + A list of recipe dependencies that should not be used to determine + signatures of tasks from one recipe when they depend on tasks from + another recipe. For example: :: + + SIGGEN_EXCLUDE_SAFE_RECIPE_DEPS += "intone->mplayer2" + + In the previous example, ``intone`` depends on ``mplayer2``. + + You can use the special token ``"*"`` on the left-hand side of the + dependency to match all recipes except the one on the right-hand + side. Here is an example: :: + + SIGGEN_EXCLUDE_SAFE_RECIPE_DEPS += "*->quilt-native" + + In the previous example, all recipes except ``quilt-native`` ignore + task signatures from the ``quilt-native`` recipe when determining + their task signatures. + + Use of this variable is one mechanism to remove dependencies that + affect task signatures and thus force rebuilds when a recipe changes. + + .. note:: + + If you add an inappropriate dependency for a recipe relationship, + the software might break during runtime if the interface of the + second recipe was changed after the first recipe had been built. + + :term:`SIGGEN_EXCLUDERECIPES_ABISAFE` + A list of recipes that are completely stable and will never change. + The ABI for the recipes in the list are presented by output from the + tasks run to build the recipe. Use of this variable is one way to + remove dependencies from one recipe on another that affect task + signatures and thus force rebuilds when the recipe changes. + + .. note:: + + If you add an inappropriate variable to this list, the software + might break at runtime if the interface of the recipe was changed + after the other had been built. + + :term:`SITEINFO_BITS` + Specifies the number of bits for the target system CPU. The value + should be either "32" or "64". + + :term:`SITEINFO_ENDIANNESS` + Specifies the endian byte order of the target system. The value + should be either "le" for little-endian or "be" for big-endian. + + :term:`SKIP_FILEDEPS` + Enables removal of all files from the "Provides" section of an RPM + package. Removal of these files is required for packages containing + prebuilt binaries and libraries such as ``libstdc++`` and ``glibc``. + + To enable file removal, set the variable to "1" in your + ``conf/local.conf`` configuration file in your: + :term:`Build Directory`. + :: + + SKIP_FILEDEPS = "1" + + :term:`SOC_FAMILY` + Groups together machines based upon the same family of SOC (System On + Chip). You typically set this variable in a common ``.inc`` file that + you include in the configuration files of all the machines. + + .. note:: + + You must include ``conf/machine/include/soc-family.inc`` for this + variable to appear in :term:`MACHINEOVERRIDES`. + + :term:`SOLIBS` + Defines the suffix for shared libraries used on the target platform. + By default, this suffix is ".so.*" for all Linux-based systems and is + defined in the ``meta/conf/bitbake.conf`` configuration file. + + You will see this variable referenced in the default values of + ``FILES_${PN}``. + + :term:`SOLIBSDEV` + Defines the suffix for the development symbolic link (symlink) for + shared libraries on the target platform. By default, this suffix is + ".so" for Linux-based systems and is defined in the + ``meta/conf/bitbake.conf`` configuration file. + + You will see this variable referenced in the default values of + ``FILES_${PN}-dev``. + + :term:`SOURCE_MIRROR_FETCH` + When you are fetching files to create a mirror of sources (i.e. + creating a source mirror), setting ``SOURCE_MIRROR_FETCH`` to "1" in + your ``local.conf`` configuration file ensures the source for all + recipes are fetched regardless of whether or not a recipe is + compatible with the configuration. A recipe is considered + incompatible with the currently configured machine when either or + both the :term:`COMPATIBLE_MACHINE` + variable and :term:`COMPATIBLE_HOST` variables + specify compatibility with a machine other than that of the current + machine or host. + + .. note:: + + Do not set the ``SOURCE_MIRROR_FETCH`` + variable unless you are creating a source mirror. In other words, + do not set the variable during a normal build. + + :term:`SOURCE_MIRROR_URL` + Defines your own :term:`PREMIRRORS` from which to + first fetch source before attempting to fetch from the upstream + specified in :term:`SRC_URI`. + + To use this variable, you must globally inherit the + :ref:`own-mirrors <ref-classes-own-mirrors>` class and then provide + the URL to your mirrors. Here is the general syntax: + :: + + INHERIT += "own-mirrors" + SOURCE_MIRROR_URL = "http://example.com/my_source_mirror" + + .. note:: + + You can specify only a single URL in ``SOURCE_MIRROR_URL``. + + :term:`SPDXLICENSEMAP` + Maps commonly used license names to their SPDX counterparts found in + ``meta/files/common-licenses/``. For the default ``SPDXLICENSEMAP`` + mappings, see the ``meta/conf/licenses.conf`` file. + + For additional information, see the :term:`LICENSE` + variable. + + :term:`SPECIAL_PKGSUFFIX` + A list of prefixes for :term:`PN` used by the OpenEmbedded + build system to create variants of recipes or packages. The list + specifies the prefixes to strip off during certain circumstances such + as the generation of the :term:`BPN` variable. + + :term:`SPL_BINARY` + The file type for the Secondary Program Loader (SPL). Some devices + use an SPL from which to boot (e.g. the BeagleBone development + board). For such cases, you can declare the file type of the SPL + binary in the ``u-boot.inc`` include file, which is used in the + U-Boot recipe. + + The SPL file type is set to "null" by default in the ``u-boot.inc`` + file as follows: + :: + + # Some versions of u-boot build an SPL (Second Program Loader) image that + # should be packaged along with the u-boot binary as well as placed in the + # deploy directory. For those versions they can set the following variables + # to allow packaging the SPL. + SPL_BINARY ?= "" + SPL_BINARYNAME ?= "${@os.path.basename(d.getVar("SPL_BINARY"))}" + SPL_IMAGE ?= "${SPL_BINARYNAME}-${MACHINE}-${PV}-${PR}" + SPL_SYMLINK ?= "${SPL_BINARYNAME}-${MACHINE}" + + The ``SPL_BINARY`` variable helps form + various ``SPL_*`` variables used by the OpenEmbedded build system. + + See the BeagleBone machine configuration example in the + ":ref:`dev-manual/dev-manual-common-tasks:adding a layer using the \`\`bitbake-layers\`\` script`" + section in the Yocto Project Board Support Package Developer's Guide + for additional information. + + :term:`SRC_URI` + The list of source files - local or remote. This variable tells the + OpenEmbedded build system which bits to pull in for the build and how + to pull them in. For example, if the recipe or append file only needs + to fetch a tarball from the Internet, the recipe or append file uses + a single ``SRC_URI`` entry. On the other hand, if the recipe or + append file needs to fetch a tarball, apply two patches, and include + a custom file, the recipe or append file would include four instances + of the variable. + + The following list explains the available URI protocols. URI + protocols are highly dependent on particular BitBake Fetcher + submodules. Depending on the fetcher BitBake uses, various URL + parameters are employed. For specifics on the supported Fetchers, see + the ":ref:`Fetchers <bitbake:bb-fetchers>`" section in the + BitBake User Manual. + + - ``file://`` - Fetches files, which are usually files shipped + with the :term:`Metadata`, from the local machine (e.g. + :ref:`patch <patching-dev-environment>` files). + The path is relative to the :term:`FILESPATH` + variable. Thus, the build system searches, in order, from the + following directories, which are assumed to be a subdirectories of + the directory in which the recipe file (``.bb``) or append file + (``.bbappend``) resides: + + - ``${BPN}`` - The base recipe name without any special suffix + or version numbers. + + - ``${BP}`` - ``${BPN}-${PV}``. The base recipe name and + version but without any special package name suffix. + + - *files -* Files within a directory, which is named ``files`` + and is also alongside the recipe or append file. + + .. note:: + + If you want the build system to pick up files specified through + a + SRC_URI + statement from your append file, you need to be sure to extend + the + FILESPATH + variable by also using the + FILESEXTRAPATHS + variable from within your append file. + + - ``bzr://`` - Fetches files from a Bazaar revision control + repository. + + - ``git://`` - Fetches files from a Git revision control + repository. + + - ``osc://`` - Fetches files from an OSC (OpenSUSE Build service) + revision control repository. + + - ``repo://`` - Fetches files from a repo (Git) repository. + + - ``ccrc://`` - Fetches files from a ClearCase repository. + + - ``http://`` - Fetches files from the Internet using ``http``. + + - ``https://`` - Fetches files from the Internet using ``https``. + + - ``ftp://`` - Fetches files from the Internet using ``ftp``. + + - ``cvs://`` - Fetches files from a CVS revision control + repository. + + - ``hg://`` - Fetches files from a Mercurial (``hg``) revision + control repository. + + - ``p4://`` - Fetches files from a Perforce (``p4``) revision + control repository. + + - ``ssh://`` - Fetches files from a secure shell. + + - ``svn://`` - Fetches files from a Subversion (``svn``) revision + control repository. + + - ``npm://`` - Fetches JavaScript modules from a registry. + + Standard and recipe-specific options for ``SRC_URI`` exist. Here are + standard options: + + - ``apply`` - Whether to apply the patch or not. The default + action is to apply the patch. + + - ``striplevel`` - Which striplevel to use when applying the + patch. The default level is 1. + + - ``patchdir`` - Specifies the directory in which the patch should + be applied. The default is ``${``\ :term:`S`\ ``}``. + + Here are options specific to recipes building code from a revision + control system: + + - ``mindate`` - Apply the patch only if + :term:`SRCDATE` is equal to or greater than + ``mindate``. + + - ``maxdate`` - Apply the patch only if ``SRCDATE`` is not later + than ``maxdate``. + + - ``minrev`` - Apply the patch only if ``SRCREV`` is equal to or + greater than ``minrev``. + + - ``maxrev`` - Apply the patch only if ``SRCREV`` is not later + than ``maxrev``. + + - ``rev`` - Apply the patch only if ``SRCREV`` is equal to + ``rev``. + + - ``notrev`` - Apply the patch only if ``SRCREV`` is not equal to + ``rev``. + + Here are some additional options worth mentioning: + + - ``unpack`` - Controls whether or not to unpack the file if it is + an archive. The default action is to unpack the file. + + - ``destsuffix`` - Places the file (or extracts its contents) into + the specified subdirectory of :term:`WORKDIR` when + the Git fetcher is used. + + - ``subdir`` - Places the file (or extracts its contents) into the + specified subdirectory of ``WORKDIR`` when the local (``file://``) + fetcher is used. + + - ``localdir`` - Places the file (or extracts its contents) into + the specified subdirectory of ``WORKDIR`` when the CVS fetcher is + used. + + - ``subpath`` - Limits the checkout to a specific subpath of the + tree when using the Git fetcher is used. + + - ``name`` - Specifies a name to be used for association with + ``SRC_URI`` checksums or :term:`SRCREV` when you have more than one + file or git repository specified in ``SRC_URI``. For example: + :: + + SRC_URI = "git://example.com/foo.git;name=first \ + git://example.com/bar.git;name=second \ + http://example.com/file.tar.gz;name=third" + + SRCREV_first = "f1d2d2f924e986ac86fdf7b36c94bcdf32beec15" + SRCREV_second = "e242ed3bffccdf271b7fbaf34ed72d089537b42f" + SRC_URI[third.sha256sum] = "13550350a8681c84c861aac2e5b440161c2b33a3e4f302ac680ca5b686de48de" + + + - ``downloadfilename`` - Specifies the filename used when storing + the downloaded file. + + :term:`SRC_URI_OVERRIDES_PACKAGE_ARCH` + By default, the OpenEmbedded build system automatically detects + whether ``SRC_URI`` contains files that are machine-specific. If so, + the build system automatically changes ``PACKAGE_ARCH``. Setting this + variable to "0" disables this behavior. + + :term:`SRCDATE` + The date of the source code used to build the package. This variable + applies only if the source was fetched from a Source Code Manager + (SCM). + + :term:`SRCPV` + Returns the version string of the current package. This string is + used to help define the value of :term:`PV`. + + The ``SRCPV`` variable is defined in the ``meta/conf/bitbake.conf`` + configuration file in the :term:`Source Directory` as + follows: + :: + + SRCPV = "${@bb.fetch2.get_srcrev(d)}" + + Recipes that need to define ``PV`` do so with the help of the + ``SRCPV``. For example, the ``ofono`` recipe (``ofono_git.bb``) + located in ``meta/recipes-connectivity`` in the Source Directory + defines ``PV`` as follows: + :: + + PV = "0.12-git${SRCPV}" + + :term:`SRCREV` + The revision of the source code used to build the package. This + variable applies to Subversion, Git, Mercurial, and Bazaar only. Note + that if you want to build a fixed revision and you want to avoid + performing a query on the remote repository every time BitBake parses + your recipe, you should specify a ``SRCREV`` that is a full revision + identifier and not just a tag. + + .. note:: + + For information on limitations when inheriting the latest revision + of software using ``SRCREV``, see the :term:`AUTOREV` variable + description and the + ":ref:`automatically-incrementing-a-binary-package-revision-number`" + section, which is in the Yocto Project Development Tasks Manual. + + :term:`SSTATE_DIR` + The directory for the shared state cache. + + :term:`SSTATE_EXCLUDEDEPS_SYSROOT` + This variable allows to specify indirect dependencies to exclude + from sysroots, for example to avoid the situations when a dependency on + any ``-native`` recipe will pull in all dependencies of that recipe + in the recipe sysroot. This behaviour might not always be wanted, + for example when that ``-native`` recipe depends on build tools + that are not relevant for the current recipe. + + This way, irrelevant dependencies are ignored, which could have + prevented the reuse of prebuilt artifacts stored in the Shared + State Cache. + + :term:`SSTATE_EXCLUDEDEPS_SYSROOT` is evaluated as two regular + expressions of recipe and dependency to ignore. An example + is the rule in :oe_git:`meta/conf/layer.conf </openembedded-core/tree/meta/conf/layer.conf>`:: + + # Nothing needs to depend on libc-initial + # base-passwd/shadow-sysroot don't need their dependencies + SSTATE_EXCLUDEDEPS_SYSROOT += "\ + .*->.*-initial.* \ + .*(base-passwd|shadow-sysroot)->.* \ + " + + The ``->`` substring represents the dependency between + the two regular expressions. + + :term:`SSTATE_MIRROR_ALLOW_NETWORK` + If set to "1", allows fetches from mirrors that are specified in + :term:`SSTATE_MIRRORS` to work even when + fetching from the network is disabled by setting ``BB_NO_NETWORK`` to + "1". Using the ``SSTATE_MIRROR_ALLOW_NETWORK`` variable is useful if + you have set ``SSTATE_MIRRORS`` to point to an internal server for + your shared state cache, but you want to disable any other fetching + from the network. + + :term:`SSTATE_MIRRORS` + Configures the OpenEmbedded build system to search other mirror + locations for prebuilt cache data objects before building out the + data. This variable works like fetcher :term:`MIRRORS` + and :term:`PREMIRRORS` and points to the cache + locations to check for the shared state (sstate) objects. + + You can specify a filesystem directory or a remote URL such as HTTP + or FTP. The locations you specify need to contain the shared state + cache (sstate-cache) results from previous builds. The sstate-cache + you point to can also be from builds on other machines. + + When pointing to sstate build artifacts on another machine that uses + a different GCC version for native builds, you must configure + ``SSTATE_MIRRORS`` with a regular expression that maps local search + paths to server paths. The paths need to take into account + :term:`NATIVELSBSTRING` set by the + :ref:`uninative <ref-classes-uninative>` class. For example, the + following maps the local search path ``universal-4.9`` to the + server-provided path server_url_sstate_path: + :: + + SSTATE_MIRRORS ?= "file://universal-4.9/(.*) http://server_url_sstate_path/universal-4.8/\1 \n" + + If a mirror uses the same structure as + :term:`SSTATE_DIR`, you need to add "PATH" at the + end as shown in the examples below. The build system substitutes the + correct path within the directory structure. + :: + + SSTATE_MIRRORS ?= "\ + file://.* http://someserver.tld/share/sstate/PATH;downloadfilename=PATH \n \ + file://.* file:///some-local-dir/sstate/PATH" + + :term:`SSTATE_SCAN_FILES` + Controls the list of files the OpenEmbedded build system scans for + hardcoded installation paths. The variable uses a space-separated + list of filenames (not paths) with standard wildcard characters + allowed. + + During a build, the OpenEmbedded build system creates a shared state + (sstate) object during the first stage of preparing the sysroots. + That object is scanned for hardcoded paths for original installation + locations. The list of files that are scanned for paths is controlled + by the ``SSTATE_SCAN_FILES`` variable. Typically, recipes add files + they want to be scanned to the value of ``SSTATE_SCAN_FILES`` rather + than the variable being comprehensively set. The + :ref:`sstate <ref-classes-sstate>` class specifies the default list + of files. + + For details on the process, see the + :ref:`staging <ref-classes-staging>` class. + + :term:`STAGING_BASE_LIBDIR_NATIVE` + Specifies the path to the ``/lib`` subdirectory of the sysroot + directory for the build host. + + :term:`STAGING_BASELIBDIR` + Specifies the path to the ``/lib`` subdirectory of the sysroot + directory for the target for which the current recipe is being built + (:term:`STAGING_DIR_HOST`). + + :term:`STAGING_BINDIR` + Specifies the path to the ``/usr/bin`` subdirectory of the sysroot + directory for the target for which the current recipe is being built + (:term:`STAGING_DIR_HOST`). + + :term:`STAGING_BINDIR_CROSS` + Specifies the path to the directory containing binary configuration + scripts. These scripts provide configuration information for other + software that wants to make use of libraries or include files + provided by the software associated with the script. + + .. note:: + + This style of build configuration has been largely replaced by + ``pkg-config``. Consequently, if ``pkg-config`` is supported by the + library to which you are linking, it is recommended you use + ``pkg-config`` instead of a provided configuration script. + + :term:`STAGING_BINDIR_NATIVE` + Specifies the path to the ``/usr/bin`` subdirectory of the sysroot + directory for the build host. + + :term:`STAGING_DATADIR` + Specifies the path to the ``/usr/share`` subdirectory of the sysroot + directory for the target for which the current recipe is being built + (:term:`STAGING_DIR_HOST`). + + :term:`STAGING_DATADIR_NATIVE` + Specifies the path to the ``/usr/share`` subdirectory of the sysroot + directory for the build host. + + :term:`STAGING_DIR` + Helps construct the ``recipe-sysroots`` directory, which is used + during packaging. + + For information on how staging for recipe-specific sysroots occurs, + see the :ref:`ref-tasks-populate_sysroot` + task, the ":ref:`sdk-manual/sdk-extensible:sharing files between recipes`" + section in the Yocto Project Development Tasks Manual, the + ":ref:`configuration-compilation-and-staging-dev-environment`" + section in the Yocto Project Overview and Concepts Manual, and the + :term:`SYSROOT_DIRS` variable. + + .. note:: + + Recipes should never write files directly under the ``STAGING_DIR`` + directory because the OpenEmbedded build system manages the + directory automatically. Instead, files should be installed to + ``${``\ :term:`D`\ ``}`` within your recipe's :ref:`ref-tasks-install` + task and then the OpenEmbedded build system will stage a subset of + those files into the sysroot. + + :term:`STAGING_DIR_HOST` + Specifies the path to the sysroot directory for the system on which + the component is built to run (the system that hosts the component). + For most recipes, this sysroot is the one in which that recipe's + :ref:`ref-tasks-populate_sysroot` task copies + files. Exceptions include ``-native`` recipes, where the + ``do_populate_sysroot`` task instead uses + :term:`STAGING_DIR_NATIVE`. Depending on + the type of recipe and the build target, ``STAGING_DIR_HOST`` can + have the following values: + + - For recipes building for the target machine, the value is + "${:term:`STAGING_DIR`}/${:term:`MACHINE`}". + + - For native recipes building for the build host, the value is empty + given the assumption that when building for the build host, the + build host's own directories should be used. + + .. note:: + + ``-native`` recipes are not installed into host paths like such + as ``/usr``. Rather, these recipes are installed into + ``STAGING_DIR_NATIVE``. When compiling ``-native`` recipes, + standard build environment variables such as + :term:`CPPFLAGS` and + :term:`CFLAGS` are set up so that both host paths + and ``STAGING_DIR_NATIVE`` are searched for libraries and + headers using, for example, GCC's ``-isystem`` option. + + Thus, the emphasis is that the ``STAGING_DIR*`` variables + should be viewed as input variables by tasks such as + :ref:`ref-tasks-configure`, + :ref:`ref-tasks-compile`, and + :ref:`ref-tasks-install`. Having the real system + root correspond to ``STAGING_DIR_HOST`` makes conceptual sense + for ``-native`` recipes, as they make use of host headers and + libraries. + + :term:`STAGING_DIR_NATIVE` + Specifies the path to the sysroot directory used when building + components that run on the build host itself. + + :term:`STAGING_DIR_TARGET` + Specifies the path to the sysroot used for the system for which the + component generates code. For components that do not generate code, + which is the majority, ``STAGING_DIR_TARGET`` is set to match + :term:`STAGING_DIR_HOST`. + + Some recipes build binaries that can run on the target system but + those binaries in turn generate code for another different system + (e.g. cross-canadian recipes). Using terminology from GNU, the + primary system is referred to as the "HOST" and the secondary, or + different, system is referred to as the "TARGET". Thus, the binaries + run on the "HOST" system and generate binaries for the "TARGET" + system. The ``STAGING_DIR_HOST`` variable points to the sysroot used + for the "HOST" system, while ``STAGING_DIR_TARGET`` points to the + sysroot used for the "TARGET" system. + + :term:`STAGING_ETCDIR_NATIVE` + Specifies the path to the ``/etc`` subdirectory of the sysroot + directory for the build host. + + :term:`STAGING_EXECPREFIXDIR` + Specifies the path to the ``/usr`` subdirectory of the sysroot + directory for the target for which the current recipe is being built + (:term:`STAGING_DIR_HOST`). + + :term:`STAGING_INCDIR` + Specifies the path to the ``/usr/include`` subdirectory of the + sysroot directory for the target for which the current recipe being + built (:term:`STAGING_DIR_HOST`). + + :term:`STAGING_INCDIR_NATIVE` + Specifies the path to the ``/usr/include`` subdirectory of the + sysroot directory for the build host. + + :term:`STAGING_KERNEL_BUILDDIR` + Points to the directory containing the kernel build artifacts. + Recipes building software that needs to access kernel build artifacts + (e.g. ``systemtap-uprobes``) can look in the directory specified with + the ``STAGING_KERNEL_BUILDDIR`` variable to find these artifacts + after the kernel has been built. + + :term:`STAGING_KERNEL_DIR` + The directory with kernel headers that are required to build + out-of-tree modules. + + :term:`STAGING_LIBDIR` + Specifies the path to the ``/usr/lib`` subdirectory of the sysroot + directory for the target for which the current recipe is being built + (:term:`STAGING_DIR_HOST`). + + :term:`STAGING_LIBDIR_NATIVE` + Specifies the path to the ``/usr/lib`` subdirectory of the sysroot + directory for the build host. + + :term:`STAMP` + Specifies the base path used to create recipe stamp files. The path + to an actual stamp file is constructed by evaluating this string and + then appending additional information. Currently, the default + assignment for ``STAMP`` as set in the ``meta/conf/bitbake.conf`` + file is: + :: + + STAMP = "${STAMPS_DIR}/${MULTIMACH_TARGET_SYS}/${PN}/${EXTENDPE}${PV}-${PR}" + + For information on how BitBake uses stamp files to determine if a + task should be rerun, see the + ":ref:`overview-manual/overview-manual-concepts:stamp files and the rerunning of tasks`" + section in the Yocto Project Overview and Concepts Manual. + + See :term:`STAMPS_DIR`, + :term:`MULTIMACH_TARGET_SYS`, + :term:`PN`, :term:`EXTENDPE`, + :term:`PV`, and :term:`PR` for related variable + information. + + :term:`STAMPS_DIR` + Specifies the base directory in which the OpenEmbedded build system + places stamps. The default directory is ``${TMPDIR}/stamps``. + + :term:`STRIP` + The minimal command and arguments to run ``strip``, which is used to + strip symbols. + + :term:`SUMMARY` + The short (72 characters or less) summary of the binary package for + packaging systems such as ``opkg``, ``rpm``, or ``dpkg``. By default, + ``SUMMARY`` is used to define the + :term:`DESCRIPTION` variable if ``DESCRIPTION`` is + not set in the recipe. + + :term:`SVNDIR` + The directory in which files checked out of a Subversion system are + stored. + + :term:`SYSLINUX_DEFAULT_CONSOLE` + Specifies the kernel boot default console. If you want to use a + console other than the default, set this variable in your recipe as + follows where "X" is the console number you want to use: + :: + + SYSLINUX_DEFAULT_CONSOLE = "console=ttyX" + + The :ref:`syslinux <ref-classes-syslinux>` class initially sets + this variable to null but then checks for a value later. + + :term:`SYSLINUX_OPTS` + Lists additional options to add to the syslinux file. You need to set + this variable in your recipe. If you want to list multiple options, + separate the options with a semicolon character (``;``). + + The :ref:`syslinux <ref-classes-syslinux>` class uses this variable + to create a set of options. + + :term:`SYSLINUX_SERIAL` + Specifies the alternate serial port or turns it off. To turn off + serial, set this variable to an empty string in your recipe. The + variable's default value is set in the + :ref:`syslinux <ref-classes-syslinux>` class as follows: + :: + + SYSLINUX_SERIAL ?= "0 115200" + + The class checks for and uses the variable as needed. + + :term:`SYSLINUX_SERIAL_TTY` + Specifies the alternate console=tty... kernel boot argument. The + variable's default value is set in the + :ref:`syslinux <ref-classes-syslinux>` class as follows: + :: + + SYSLINUX_SERIAL_TTY ?= "console=ttyS0,115200" + + The class checks for and uses the variable as needed. + + :term:`SYSLINUX_SPLASH` + An ``.LSS`` file used as the background for the VGA boot menu when + you use the boot menu. You need to set this variable in your recipe. + + The :ref:`syslinux <ref-classes-syslinux>` class checks for this + variable and if found, the OpenEmbedded build system installs the + splash screen. + + :term:`SYSROOT_DESTDIR` + Points to the temporary directory under the work directory (default + "``${``\ :term:`WORKDIR`\ ``}/sysroot-destdir``") + where the files populated into the sysroot are assembled during the + :ref:`ref-tasks-populate_sysroot` task. + + :term:`SYSROOT_DIRS` + Directories that are staged into the sysroot by the + :ref:`ref-tasks-populate_sysroot` task. By + default, the following directories are staged: + :: + + SYSROOT_DIRS = " \ + ${includedir} \ + ${libdir} \ + ${base_libdir} \ + ${nonarch_base_libdir} \ + ${datadir} \ + " + + :term:`SYSROOT_DIRS_BLACKLIST` + Directories that are not staged into the sysroot by the + :ref:`ref-tasks-populate_sysroot` task. You + can use this variable to exclude certain subdirectories of + directories listed in :term:`SYSROOT_DIRS` from + staging. By default, the following directories are not staged: + :: + + SYSROOT_DIRS_BLACKLIST = " \ + ${mandir} \ + ${docdir} \ + ${infodir} \ + ${datadir}/locale \ + ${datadir}/applications \ + ${datadir}/fonts \ + ${datadir}/pixmaps \ + " + + :term:`SYSROOT_DIRS_NATIVE` + Extra directories staged into the sysroot by the + :ref:`ref-tasks-populate_sysroot` task for + ``-native`` recipes, in addition to those specified in + :term:`SYSROOT_DIRS`. By default, the following + extra directories are staged: + :: + + SYSROOT_DIRS_NATIVE = " \ + ${bindir} \ + ${sbindir} \ + ${base_bindir} \ + ${base_sbindir} \ + ${libexecdir} \ + ${sysconfdir} \ + ${localstatedir} \ + " + + .. note:: + + Programs built by ``-native`` recipes run directly from the sysroot + (:term:`STAGING_DIR_NATIVE`), which is why additional directories + containing program executables and supporting files need to be staged. + + :term:`SYSROOT_PREPROCESS_FUNCS` + A list of functions to execute after files are staged into the + sysroot. These functions are usually used to apply additional + processing on the staged files, or to stage additional files. + + :term:`SYSTEMD_AUTO_ENABLE` + When inheriting the :ref:`systemd <ref-classes-systemd>` class, + this variable specifies whether the specified service in + :term:`SYSTEMD_SERVICE` should start + automatically or not. By default, the service is enabled to + automatically start at boot time. The default setting is in the + :ref:`systemd <ref-classes-systemd>` class as follows: + :: + + SYSTEMD_AUTO_ENABLE ??= "enable" + + You can disable the service by setting the variable to "disable". + + :term:`SYSTEMD_BOOT_CFG` + When :term:`EFI_PROVIDER` is set to + "systemd-boot", the ``SYSTEMD_BOOT_CFG`` variable specifies the + configuration file that should be used. By default, the + :ref:`systemd-boot <ref-classes-systemd-boot>` class sets the + ``SYSTEMD_BOOT_CFG`` as follows: + :: + + SYSTEMD_BOOT_CFG ?= "${S}/loader.conf" + + For information on Systemd-boot, see the `Systemd-boot + documentation <http://www.freedesktop.org/wiki/Software/systemd/systemd-boot/>`__. + + :term:`SYSTEMD_BOOT_ENTRIES` + When :term:`EFI_PROVIDER` is set to + "systemd-boot", the ``SYSTEMD_BOOT_ENTRIES`` variable specifies a + list of entry files (``*.conf``) to install that contain one boot + entry per file. By default, the + :ref:`systemd-boot <ref-classes-systemd-boot>` class sets the + ``SYSTEMD_BOOT_ENTRIES`` as follows: + :: + + SYSTEMD_BOOT_ENTRIES ?= "" + + For information on Systemd-boot, see the `Systemd-boot + documentation <http://www.freedesktop.org/wiki/Software/systemd/systemd-boot/>`__. + + :term:`SYSTEMD_BOOT_TIMEOUT` + When :term:`EFI_PROVIDER` is set to + "systemd-boot", the ``SYSTEMD_BOOT_TIMEOUT`` variable specifies the + boot menu timeout in seconds. By default, the + :ref:`systemd-boot <ref-classes-systemd-boot>` class sets the + ``SYSTEMD_BOOT_TIMEOUT`` as follows: + :: + + SYSTEMD_BOOT_TIMEOUT ?= "10" + + For information on Systemd-boot, see the `Systemd-boot + documentation <http://www.freedesktop.org/wiki/Software/systemd/systemd-boot/>`__. + + :term:`SYSTEMD_PACKAGES` + When inheriting the :ref:`systemd <ref-classes-systemd>` class, + this variable locates the systemd unit files when they are not found + in the main recipe's package. By default, the ``SYSTEMD_PACKAGES`` + variable is set such that the systemd unit files are assumed to + reside in the recipes main package: + :: + + SYSTEMD_PACKAGES ?= "${PN}" + + If these unit files are not in this recipe's main package, you need + to use ``SYSTEMD_PACKAGES`` to list the package or packages in which + the build system can find the systemd unit files. + + :term:`SYSTEMD_SERVICE` + When inheriting the :ref:`systemd <ref-classes-systemd>` class, + this variable specifies the systemd service name for a package. + + When you specify this file in your recipe, use a package name + override to indicate the package to which the value applies. Here is + an example from the connman recipe: + :: + + SYSTEMD_SERVICE_${PN} = "connman.service" + + :term:`SYSVINIT_ENABLED_GETTYS` + When using + :ref:`SysVinit <dev-manual/dev-manual-common-tasks:enabling system services>`, + specifies a space-separated list of the virtual terminals that should + run a `getty <http://en.wikipedia.org/wiki/Getty_%28Unix%29>`__ + (allowing login), assuming :term:`USE_VT` is not set to + "0". + + The default value for ``SYSVINIT_ENABLED_GETTYS`` is "1" (i.e. only + run a getty on the first virtual terminal). + + :term:`T` + This variable points to a directory were BitBake places temporary + files, which consist mostly of task logs and scripts, when building a + particular recipe. The variable is typically set as follows: + :: + + T = "${WORKDIR}/temp" + + The :term:`WORKDIR` is the directory into which + BitBake unpacks and builds the recipe. The default ``bitbake.conf`` + file sets this variable. + + The ``T`` variable is not to be confused with the + :term:`TMPDIR` variable, which points to the root of + the directory tree where BitBake places the output of an entire + build. + + :term:`TARGET_ARCH` + The target machine's architecture. The OpenEmbedded build system + supports many architectures. Here is an example list of architectures + supported. This list is by no means complete as the architecture is + configurable: + + - arm + - i586 + - x86_64 + - powerpc + - powerpc64 + - mips + - mipsel + + For additional information on machine architectures, see the + :term:`TUNE_ARCH` variable. + + :term:`TARGET_AS_ARCH` + Specifies architecture-specific assembler flags for the target + system. ``TARGET_AS_ARCH`` is initialized from + :term:`TUNE_ASARGS` by default in the BitBake + configuration file (``meta/conf/bitbake.conf``): + :: + + TARGET_AS_ARCH = "${TUNE_ASARGS}" + + :term:`TARGET_CC_ARCH` + Specifies architecture-specific C compiler flags for the target + system. ``TARGET_CC_ARCH`` is initialized from + :term:`TUNE_CCARGS` by default. + + .. note:: + + It is a common workaround to append :term:`LDFLAGS` to + ``TARGET_CC_ARCH`` in recipes that build software for the target that + would not otherwise respect the exported ``LDFLAGS`` variable. + + :term:`TARGET_CC_KERNEL_ARCH` + This is a specific kernel compiler flag for a CPU or Application + Binary Interface (ABI) tune. The flag is used rarely and only for + cases where a userspace :term:`TUNE_CCARGS` is not + compatible with the kernel compilation. The ``TARGET_CC_KERNEL_ARCH`` + variable allows the kernel (and associated modules) to use a + different configuration. See the + ``meta/conf/machine/include/arm/feature-arm-thumb.inc`` file in the + :term:`Source Directory` for an example. + + :term:`TARGET_CFLAGS` + Specifies the flags to pass to the C compiler when building for the + target. When building in the target context, + :term:`CFLAGS` is set to the value of this variable by + default. + + Additionally, the SDK's environment setup script sets the ``CFLAGS`` + variable in the environment to the ``TARGET_CFLAGS`` value so that + executables built using the SDK also have the flags applied. + + :term:`TARGET_CPPFLAGS` + Specifies the flags to pass to the C pre-processor (i.e. to both the + C and the C++ compilers) when building for the target. When building + in the target context, :term:`CPPFLAGS` is set to the + value of this variable by default. + + Additionally, the SDK's environment setup script sets the + ``CPPFLAGS`` variable in the environment to the ``TARGET_CPPFLAGS`` + value so that executables built using the SDK also have the flags + applied. + + :term:`TARGET_CXXFLAGS` + Specifies the flags to pass to the C++ compiler when building for the + target. When building in the target context, + :term:`CXXFLAGS` is set to the value of this variable + by default. + + Additionally, the SDK's environment setup script sets the + ``CXXFLAGS`` variable in the environment to the ``TARGET_CXXFLAGS`` + value so that executables built using the SDK also have the flags + applied. + + :term:`TARGET_FPU` + Specifies the method for handling FPU code. For FPU-less targets, + which include most ARM CPUs, the variable must be set to "soft". If + not, the kernel emulation gets used, which results in a performance + penalty. + + :term:`TARGET_LD_ARCH` + Specifies architecture-specific linker flags for the target system. + ``TARGET_LD_ARCH`` is initialized from + :term:`TUNE_LDARGS` by default in the BitBake + configuration file (``meta/conf/bitbake.conf``): + :: + + TARGET_LD_ARCH = "${TUNE_LDARGS}" + + :term:`TARGET_LDFLAGS` + Specifies the flags to pass to the linker when building for the + target. When building in the target context, + :term:`LDFLAGS` is set to the value of this variable + by default. + + Additionally, the SDK's environment setup script sets the + :term:`LDFLAGS` variable in the environment to the + ``TARGET_LDFLAGS`` value so that executables built using the SDK also + have the flags applied. + + :term:`TARGET_OS` + Specifies the target's operating system. The variable can be set to + "linux" for glibc-based systems (GNU C Library) and to "linux-musl" + for musl libc. For ARM/EABI targets, "linux-gnueabi" and + "linux-musleabi" possible values exist. + + :term:`TARGET_PREFIX` + Specifies the prefix used for the toolchain binary target tools. + + Depending on the type of recipe and the build target, + ``TARGET_PREFIX`` is set as follows: + + - For recipes building for the target machine, the value is + "${:term:`TARGET_SYS`}-". + + - For native recipes, the build system sets the variable to the + value of ``BUILD_PREFIX``. + + - For native SDK recipes (``nativesdk``), the build system sets the + variable to the value of ``SDK_PREFIX``. + + :term:`TARGET_SYS` + Specifies the system, including the architecture and the operating + system, for which the build is occurring in the context of the + current recipe. + + The OpenEmbedded build system automatically sets this variable based + on :term:`TARGET_ARCH`, + :term:`TARGET_VENDOR`, and + :term:`TARGET_OS` variables. + + .. note:: + + You do not need to set the ``TARGET_SYS`` variable yourself. + + Consider these two examples: + + - Given a native recipe on a 32-bit, x86 machine running Linux, the + value is "i686-linux". + + - Given a recipe being built for a little-endian, MIPS target + running Linux, the value might be "mipsel-linux". + + :term:`TARGET_VENDOR` + Specifies the name of the target vendor. + + :term:`TCLIBC` + Specifies the GNU standard C library (``libc``) variant to use during + the build process. This variable replaces ``POKYLIBC``, which is no + longer supported. + + You can select "glibc", "musl", "newlib", or "baremetal" + + :term:`TCLIBCAPPEND` + Specifies a suffix to be appended onto the + :term:`TMPDIR` value. The suffix identifies the + ``libc`` variant for building. When you are building for multiple + variants with the same :term:`Build Directory`, this + mechanism ensures that output for different ``libc`` variants is kept + separate to avoid potential conflicts. + + In the ``defaultsetup.conf`` file, the default value of + ``TCLIBCAPPEND`` is "-${TCLIBC}". However, distros such as poky, + which normally only support one ``libc`` variant, set + ``TCLIBCAPPEND`` to "" in their distro configuration file resulting + in no suffix being applied. + + :term:`TCMODE` + Specifies the toolchain selector. ``TCMODE`` controls the + characteristics of the generated packages and images by telling the + OpenEmbedded build system which toolchain profile to use. By default, + the OpenEmbedded build system builds its own internal toolchain. The + variable's default value is "default", which uses that internal + toolchain. + + .. note:: + + If ``TCMODE`` is set to a value other than "default", then it is your + responsibility to ensure that the toolchain is compatible with the + default toolchain. Using older or newer versions of these + components might cause build problems. See the Release Notes for + the Yocto Project release for the specific components with which + the toolchain must be compatible. To access the Release Notes, go + to the :yocto_home:`Downloads </software-overview/downloads>` + page on the Yocto Project website and click on the "RELEASE + INFORMATION" link for the appropriate release. + + The ``TCMODE`` variable is similar to :term:`TCLIBC`, + which controls the variant of the GNU standard C library (``libc``) + used during the build process: ``glibc`` or ``musl``. + + With additional layers, it is possible to use a pre-compiled external + toolchain. One example is the Sourcery G++ Toolchain. The support for + this toolchain resides in the separate Mentor Graphics + ``meta-sourcery`` layer at + http://github.com/MentorEmbedded/meta-sourcery/. + + The layer's ``README`` file contains information on how to use the + Sourcery G++ Toolchain as an external toolchain. In summary, you must + be sure to add the layer to your ``bblayers.conf`` file in front of + the ``meta`` layer and then set the ``EXTERNAL_TOOLCHAIN`` variable + in your ``local.conf`` file to the location in which you installed + the toolchain. + + The fundamentals used for this example apply to any external + toolchain. You can use ``meta-sourcery`` as a template for adding + support for other external toolchains. + + :term:`TEST_EXPORT_DIR` + The location the OpenEmbedded build system uses to export tests when + the :term:`TEST_EXPORT_ONLY` variable is set + to "1". + + The ``TEST_EXPORT_DIR`` variable defaults to + ``"${TMPDIR}/testimage/${PN}"``. + + :term:`TEST_EXPORT_ONLY` + Specifies to export the tests only. Set this variable to "1" if you + do not want to run the tests but you want them to be exported in a + manner that you to run them outside of the build system. + + :term:`TEST_LOG_DIR` + Holds the SSH log and the boot log for QEMU machines. The + ``TEST_LOG_DIR`` variable defaults to ``"${WORKDIR}/testimage"``. + + .. note:: + + Actual test results reside in the task log (``log.do_testimage``), + which is in the ``${WORKDIR}/temp/`` directory. + + :term:`TEST_POWERCONTROL_CMD` + For automated hardware testing, specifies the command to use to + control the power of the target machine under test. Typically, this + command would point to a script that performs the appropriate action + (e.g. interacting with a web-enabled power strip). The specified + command should expect to receive as the last argument "off", "on" or + "cycle" specifying to power off, on, or cycle (power off and then + power on) the device, respectively. + + :term:`TEST_POWERCONTROL_EXTRA_ARGS` + For automated hardware testing, specifies additional arguments to + pass through to the command specified in + :term:`TEST_POWERCONTROL_CMD`. Setting + ``TEST_POWERCONTROL_EXTRA_ARGS`` is optional. You can use it if you + wish, for example, to separate the machine-specific and + non-machine-specific parts of the arguments. + + :term:`TEST_QEMUBOOT_TIMEOUT` + The time in seconds allowed for an image to boot before automated + runtime tests begin to run against an image. The default timeout + period to allow the boot process to reach the login prompt is 500 + seconds. You can specify a different value in the ``local.conf`` + file. + + For more information on testing images, see the + ":ref:`dev-manual/dev-manual-common-tasks:performing automated runtime testing`" + section in the Yocto Project Development Tasks Manual. + + :term:`TEST_SERIALCONTROL_CMD` + For automated hardware testing, specifies the command to use to + connect to the serial console of the target machine under test. This + command simply needs to connect to the serial console and forward + that connection to standard input and output as any normal terminal + program does. + + For example, to use the Picocom terminal program on serial device + ``/dev/ttyUSB0`` at 115200bps, you would set the variable as follows: + :: + + TEST_SERIALCONTROL_CMD = "picocom /dev/ttyUSB0 -b 115200" + + :term:`TEST_SERIALCONTROL_EXTRA_ARGS` + For automated hardware testing, specifies additional arguments to + pass through to the command specified in + :term:`TEST_SERIALCONTROL_CMD`. Setting + ``TEST_SERIALCONTROL_EXTRA_ARGS`` is optional. You can use it if you + wish, for example, to separate the machine-specific and + non-machine-specific parts of the command. + + :term:`TEST_SERVER_IP` + The IP address of the build machine (host machine). This IP address + is usually automatically detected. However, if detection fails, this + variable needs to be set to the IP address of the build machine (i.e. + where the build is taking place). + + .. note:: + + The ``TEST_SERVER_IP`` variable is only used for a small number of + tests such as the "dnf" test suite, which needs to download packages + from ``WORKDIR/oe-rootfs-repo``. + + :term:`TEST_SUITES` + An ordered list of tests (modules) to run against an image when + performing automated runtime testing. + + The OpenEmbedded build system provides a core set of tests that can + be used against images. + + .. note:: + + Currently, there is only support for running these tests under + QEMU. + + Tests include ``ping``, ``ssh``, ``df`` among others. You can add + your own tests to the list of tests by appending ``TEST_SUITES`` as + follows: + :: + + TEST_SUITES_append = " mytest" + + Alternatively, you can + provide the "auto" option to have all applicable tests run against + the image. + :: + + TEST_SUITES_append = " auto" + + Using this option causes the + build system to automatically run tests that are applicable to the + image. Tests that are not applicable are skipped. + + The order in which tests are run is important. Tests that depend on + another test must appear later in the list than the test on which + they depend. For example, if you append the list of tests with two + tests (``test_A`` and ``test_B``) where ``test_B`` is dependent on + ``test_A``, then you must order the tests as follows: + :: + + TEST_SUITES = "test_A test_B" + + For more information on testing images, see the + ":ref:`dev-manual/dev-manual-common-tasks:performing automated runtime testing`" + section in the Yocto Project Development Tasks Manual. + + :term:`TEST_TARGET` + Specifies the target controller to use when running tests against a + test image. The default controller to use is "qemu": + :: + + TEST_TARGET = "qemu" + + A target controller is a class that defines how an image gets + deployed on a target and how a target is started. A layer can extend + the controllers by adding a module in the layer's + ``/lib/oeqa/controllers`` directory and by inheriting the + ``BaseTarget`` class, which is an abstract class that cannot be used + as a value of ``TEST_TARGET``. + + You can provide the following arguments with ``TEST_TARGET``: + + - *"qemu":* Boots a QEMU image and runs the tests. See the + ":ref:`qemu-image-enabling-tests`" section + in the Yocto Project Development Tasks Manual for more + information. + + - *"simpleremote":* Runs the tests on target hardware that is + already up and running. The hardware can be on the network or it + can be a device running an image on QEMU. You must also set + :term:`TEST_TARGET_IP` when you use + "simpleremote". + + .. note:: + + This argument is defined in + ``meta/lib/oeqa/controllers/simpleremote.py``. + + For information on running tests on hardware, see the + ":ref:`hardware-image-enabling-tests`" + section in the Yocto Project Development Tasks Manual. + + :term:`TEST_TARGET_IP` + The IP address of your hardware under test. The ``TEST_TARGET_IP`` + variable has no effect when :term:`TEST_TARGET` is + set to "qemu". + + When you specify the IP address, you can also include a port. Here is + an example: + :: + + TEST_TARGET_IP = "192.168.1.4:2201" + + Specifying a port is + useful when SSH is started on a non-standard port or in cases when + your hardware under test is behind a firewall or network that is not + directly accessible from your host and you need to do port address + translation. + + :term:`TESTIMAGE_AUTO` + Automatically runs the series of automated tests for images when an + image is successfully built. Setting ``TESTIMAGE_AUTO`` to "1" causes + any image that successfully builds to automatically boot under QEMU. + Using the variable also adds in dependencies so that any SDK for + which testing is requested is automatically built first. + + These tests are written in Python making use of the ``unittest`` + module, and the majority of them run commands on the target system + over ``ssh``. You can set this variable to "1" in your ``local.conf`` + file in the :term:`Build Directory` to have the + OpenEmbedded build system automatically run these tests after an + image successfully builds: + + TESTIMAGE_AUTO = "1" + + For more information + on enabling, running, and writing these tests, see the + ":ref:`dev-manual/dev-manual-common-tasks:performing automated runtime testing`" + section in the Yocto Project Development Tasks Manual and the + ":ref:`testimage*.bbclass <ref-classes-testimage*>`" section. + + :term:`THISDIR` + The directory in which the file BitBake is currently parsing is + located. Do not manually set this variable. + + :term:`TIME` + The time the build was started. Times appear using the hour, minute, + and second (HMS) format (e.g. "140159" for one minute and fifty-nine + seconds past 1400 hours). + + :term:`TMPDIR` + This variable is the base directory the OpenEmbedded build system + uses for all build output and intermediate files (other than the + shared state cache). By default, the ``TMPDIR`` variable points to + ``tmp`` within the :term:`Build Directory`. + + If you want to establish this directory in a location other than the + default, you can uncomment and edit the following statement in the + ``conf/local.conf`` file in the :term:`Source Directory`: + :: + + #TMPDIR = "${TOPDIR}/tmp" + + An example use for this scenario is to set ``TMPDIR`` to a local disk, + which does not use NFS, while having the Build Directory use NFS. + + The filesystem used by ``TMPDIR`` must have standard filesystem + semantics (i.e. mixed-case files are unique, POSIX file locking, and + persistent inodes). Due to various issues with NFS and bugs in some + implementations, NFS does not meet this minimum requirement. + Consequently, ``TMPDIR`` cannot be on NFS. + + :term:`TOOLCHAIN_HOST_TASK` + This variable lists packages the OpenEmbedded build system uses when + building an SDK, which contains a cross-development environment. The + packages specified by this variable are part of the toolchain set + that runs on the :term:`SDKMACHINE`, and each + package should usually have the prefix ``nativesdk-``. For example, + consider the following command when building an SDK: + :: + + $ bitbake -c populate_sdk imagename + + In this case, a default list of packages is + set in this variable, but you can add additional packages to the + list. See the + ":ref:`sdk-manual/sdk-appendix-customizing-standard:adding individual packages to the standard sdk`" section + in the Yocto Project Application Development and the Extensible + Software Development Kit (eSDK) manual for more information. + + For background information on cross-development toolchains in the + Yocto Project development environment, see the + ":ref:`sdk-manual/sdk-intro:the cross-development toolchain`" + section in the Yocto Project Overview and Concepts Manual. For + information on setting up a cross-development environment, see the + :doc:`../sdk-manual/sdk-manual` manual. + + :term:`TOOLCHAIN_OUTPUTNAME` + This variable defines the name used for the toolchain output. The + :ref:`populate_sdk_base <ref-classes-populate-sdk-*>` class sets + the ``TOOLCHAIN_OUTPUTNAME`` variable as follows: + :: + + TOOLCHAIN_OUTPUTNAME ?= "${SDK_NAME}-toolchain-${SDK_VERSION}" + + See + the :term:`SDK_NAME` and + :term:`SDK_VERSION` variables for additional + information. + + :term:`TOOLCHAIN_TARGET_TASK` + This variable lists packages the OpenEmbedded build system uses when + it creates the target part of an SDK (i.e. the part built for the + target hardware), which includes libraries and headers. Use this + variable to add individual packages to the part of the SDK that runs + on the target. See the + ":ref:`sdk-manual/sdk-appendix-customizing-standard:adding individual packages to the standard sdk`" section + in the Yocto Project Application Development and the Extensible + Software Development Kit (eSDK) manual for more information. + + For background information on cross-development toolchains in the + Yocto Project development environment, see the + ":ref:`sdk-manual/sdk-intro:the cross-development toolchain`" + section in the Yocto Project Overview and Concepts Manual. For + information on setting up a cross-development environment, see the + :doc:`../sdk-manual/sdk-manual` manual. + + :term:`TOPDIR` + The top-level :term:`Build Directory`. BitBake + automatically sets this variable when you initialize your build + environment using :ref:`structure-core-script`. + + :term:`TRANSLATED_TARGET_ARCH` + A sanitized version of :term:`TARGET_ARCH`. This + variable is used where the architecture is needed in a value where + underscores are not allowed, for example within package filenames. In + this case, dash characters replace any underscore characters used in + ``TARGET_ARCH``. + + Do not edit this variable. + + :term:`TUNE_ARCH` + The GNU canonical architecture for a specific architecture (i.e. + ``arm``, ``armeb``, ``mips``, ``mips64``, and so forth). BitBake uses + this value to setup configuration. + + ``TUNE_ARCH`` definitions are specific to a given architecture. The + definitions can be a single static definition, or can be dynamically + adjusted. You can see details for a given CPU family by looking at + the architecture's ``README`` file. For example, the + ``meta/conf/machine/include/mips/README`` file in the + :term:`Source Directory` provides information for + ``TUNE_ARCH`` specific to the ``mips`` architecture. + + ``TUNE_ARCH`` is tied closely to + :term:`TARGET_ARCH`, which defines the target + machine's architecture. The BitBake configuration file + (``meta/conf/bitbake.conf``) sets ``TARGET_ARCH`` as follows: + :: + + TARGET_ARCH = "${TUNE_ARCH}" + + The following list, which is by no means complete since architectures + are configurable, shows supported machine architectures: + + - arm + - i586 + - x86_64 + - powerpc + - powerpc64 + - mips + - mipsel + + :term:`TUNE_ASARGS` + Specifies architecture-specific assembler flags for the target + system. The set of flags is based on the selected tune features. + ``TUNE_ASARGS`` is set using the tune include files, which are + typically under ``meta/conf/machine/include/`` and are influenced + through :term:`TUNE_FEATURES`. For example, the + ``meta/conf/machine/include/x86/arch-x86.inc`` file defines the flags + for the x86 architecture as follows: + :: + + TUNE_ASARGS += "${@bb.utils.contains("TUNE_FEATURES", "mx32", "-x32", "", d)}" + + .. note:: + + Board Support Packages (BSPs) select the tune. The selected tune, + in turn, affects the tune variables themselves (i.e. the tune can + supply its own set of flags). + + :term:`TUNE_CCARGS` + Specifies architecture-specific C compiler flags for the target + system. The set of flags is based on the selected tune features. + ``TUNE_CCARGS`` is set using the tune include files, which are + typically under ``meta/conf/machine/include/`` and are influenced + through :term:`TUNE_FEATURES`. + + .. note:: + + Board Support Packages (BSPs) select the tune. The selected tune, + in turn, affects the tune variables themselves (i.e. the tune can + supply its own set of flags). + + :term:`TUNE_FEATURES` + Features used to "tune" a compiler for optimal use given a specific + processor. The features are defined within the tune files and allow + arguments (i.e. ``TUNE_*ARGS``) to be dynamically generated based on + the features. + + The OpenEmbedded build system verifies the features to be sure they + are not conflicting and that they are supported. + + The BitBake configuration file (``meta/conf/bitbake.conf``) defines + ``TUNE_FEATURES`` as follows: + :: + + TUNE_FEATURES ??= "${TUNE_FEATURES_tune-${DEFAULTTUNE}}" + + See the :term:`DEFAULTTUNE` variable for more information. + + :term:`TUNE_LDARGS` + Specifies architecture-specific linker flags for the target system. + The set of flags is based on the selected tune features. + ``TUNE_LDARGS`` is set using the tune include files, which are + typically under ``meta/conf/machine/include/`` and are influenced + through :term:`TUNE_FEATURES`. For example, the + ``meta/conf/machine/include/x86/arch-x86.inc`` file defines the flags + for the x86 architecture as follows: + :: + + TUNE_LDARGS += "${@bb.utils.contains("TUNE_FEATURES", "mx32", "-m elf32_x86_64", "", d)}" + + .. note:: + + Board Support Packages (BSPs) select the tune. The selected tune, + in turn, affects the tune variables themselves (i.e. the tune can + supply its own set of flags). + + :term:`TUNE_PKGARCH` + The package architecture understood by the packaging system to define + the architecture, ABI, and tuning of output packages. The specific + tune is defined using the "_tune" override as follows: + :: + + TUNE_PKGARCH_tune-tune = "tune" + + These tune-specific package architectures are defined in the machine + include files. Here is an example of the "core2-32" tuning as used in + the ``meta/conf/machine/include/tune-core2.inc`` file: + :: + + TUNE_PKGARCH_tune-core2-32 = "core2-32" + + :term:`TUNEABI` + An underlying Application Binary Interface (ABI) used by a particular + tuning in a given toolchain layer. Providers that use prebuilt + libraries can use the ``TUNEABI``, + :term:`TUNEABI_OVERRIDE`, and + :term:`TUNEABI_WHITELIST` variables to check + compatibility of tunings against their selection of libraries. + + If ``TUNEABI`` is undefined, then every tuning is allowed. See the + :ref:`sanity <ref-classes-sanity>` class to see how the variable is + used. + + :term:`TUNEABI_OVERRIDE` + If set, the OpenEmbedded system ignores the + :term:`TUNEABI_WHITELIST` variable. + Providers that use prebuilt libraries can use the + ``TUNEABI_OVERRIDE``, ``TUNEABI_WHITELIST``, and + :term:`TUNEABI` variables to check compatibility of a + tuning against their selection of libraries. + + See the :ref:`sanity <ref-classes-sanity>` class to see how the + variable is used. + + :term:`TUNEABI_WHITELIST` + A whitelist of permissible :term:`TUNEABI` values. If + ``TUNEABI_WHITELIST`` is not set, all tunes are allowed. Providers + that use prebuilt libraries can use the ``TUNEABI_WHITELIST``, + :term:`TUNEABI_OVERRIDE`, and ``TUNEABI`` + variables to check compatibility of a tuning against their selection + of libraries. + + See the :ref:`sanity <ref-classes-sanity>` class to see how the + variable is used. + + :term:`TUNECONFLICTS[feature]` + Specifies CPU or Application Binary Interface (ABI) tuning features + that conflict with feature. + + Known tuning conflicts are specified in the machine include files in + the :term:`Source Directory`. Here is an example from + the ``meta/conf/machine/include/mips/arch-mips.inc`` include file + that lists the "o32" and "n64" features as conflicting with the "n32" + feature: + :: + + TUNECONFLICTS[n32] = "o32 n64" + + :term:`TUNEVALID[feature]` + Specifies a valid CPU or Application Binary Interface (ABI) tuning + feature. The specified feature is stored as a flag. Valid features + are specified in the machine include files (e.g. + ``meta/conf/machine/include/arm/arch-arm.inc``). Here is an example + from that file: + :: + + TUNEVALID[bigendian] = "Enable big-endian mode." + + See the machine include files in the :term:`Source Directory` + for these features. + + :term:`UBOOT_CONFIG` + Configures the :term:`UBOOT_MACHINE` and can + also define :term:`IMAGE_FSTYPES` for individual + cases. + + Following is an example from the ``meta-fsl-arm`` layer. :: + + UBOOT_CONFIG ??= "sd" + UBOOT_CONFIG[sd] = "mx6qsabreauto_config,sdcard" + UBOOT_CONFIG[eimnor] = "mx6qsabreauto_eimnor_config" + UBOOT_CONFIG[nand] = "mx6qsabreauto_nand_config,ubifs" + UBOOT_CONFIG[spinor] = "mx6qsabreauto_spinor_config" + + In this example, "sd" is selected as the configuration of the possible four for the + ``UBOOT_MACHINE``. The "sd" configuration defines + "mx6qsabreauto_config" as the value for ``UBOOT_MACHINE``, while the + "sdcard" specifies the ``IMAGE_FSTYPES`` to use for the U-boot image. + + For more information on how the ``UBOOT_CONFIG`` is handled, see the + :ref:`uboot-config <ref-classes-uboot-config>` + class. + + :term:`UBOOT_DTB_LOADADDRESS` + Specifies the load address for the dtb image used by U-boot. During FIT + image creation, the ``UBOOT_DTB_LOADADDRESS`` variable is used in + :ref:`kernel-fitimage <ref-classes-kernel-fitimage>` class to specify + the load address to be used in + creating the dtb sections of Image Tree Source for the FIT image. + + :term:`UBOOT_DTBO_LOADADDRESS` + Specifies the load address for the dtbo image used by U-boot. During FIT + image creation, the ``UBOOT_DTBO_LOADADDRESS`` variable is used in + :ref:`kernel-fitimage <ref-classes-kernel-fitimage>` class to specify the load address to be used in + creating the dtbo sections of Image Tree Source for the FIT image. + + :term:`UBOOT_ENTRYPOINT` + Specifies the entry point for the U-Boot image. During U-Boot image + creation, the ``UBOOT_ENTRYPOINT`` variable is passed as a + command-line parameter to the ``uboot-mkimage`` utility. + + :term:`UBOOT_LOADADDRESS` + Specifies the load address for the U-Boot image. During U-Boot image + creation, the ``UBOOT_LOADADDRESS`` variable is passed as a + command-line parameter to the ``uboot-mkimage`` utility. + + :term:`UBOOT_LOCALVERSION` + Appends a string to the name of the local version of the U-Boot + image. For example, assuming the version of the U-Boot image built + was "2013.10", the full version string reported by U-Boot would be + "2013.10-yocto" given the following statement: + :: + + UBOOT_LOCALVERSION = "-yocto" + + :term:`UBOOT_MACHINE` + Specifies the value passed on the ``make`` command line when building + a U-Boot image. The value indicates the target platform + configuration. You typically set this variable from the machine + configuration file (i.e. ``conf/machine/machine_name.conf``). + + Please see the "Selection of Processor Architecture and Board Type" + section in the U-Boot README for valid values for this variable. + + :term:`UBOOT_MAKE_TARGET` + Specifies the target called in the ``Makefile``. The default target + is "all". + + :term:`UBOOT_MKIMAGE_DTCOPTS` + Options for the device tree compiler passed to mkimage '-D' + feature while creating FIT image in :ref:`kernel-fitimage <ref-classes-kernel-fitimage>` class. + + :term:`UBOOT_RD_ENTRYPOINT` + Specifies the entrypoint for the RAM disk image. + During FIT image creation, the + ``UBOOT_RD_ENTRYPOINT`` variable is used + in :ref:`kernel-fitimage <ref-classes-kernel-fitimage>` class to specify the + entrypoint to be used in creating the Image Tree Source for + the FIT image. + + :term:`UBOOT_RD_LOADADDRESS` + Specifies the load address for the RAM disk image. + During FIT image creation, the + ``UBOOT_RD_LOADADDRESS`` variable is used + in :ref:`kernel-fitimage <ref-classes-kernel-fitimage>` class to specify the + load address to be used in creating the Image Tree Source for + the FIT image. + + :term:`UBOOT_SIGN_ENABLE` + Enable signing of FIT image. The default value is "0". + + :term:`UBOOT_SIGN_KEYDIR` + Location of the directory containing the RSA key and + certificate used for signing FIT image. + + :term:`UBOOT_SIGN_KEYNAME` + The name of keys used for signing U-boot FIT image stored in + :term:`UBOOT_SIGN_KEYDIR` directory. For e.g. dev.key key and dev.crt + certificate stored in :term:`UBOOT_SIGN_KEYDIR` directory will have + :term:`UBOOT_SIGN_KEYNAME` set to "dev". + + :term:`UBOOT_SUFFIX` + Points to the generated U-Boot extension. For example, ``u-boot.sb`` + has a ``.sb`` extension. + + The default U-Boot extension is ``.bin`` + + :term:`UBOOT_TARGET` + Specifies the target used for building U-Boot. The target is passed + directly as part of the "make" command (e.g. SPL and AIS). If you do + not specifically set this variable, the OpenEmbedded build process + passes and uses "all" for the target during the U-Boot building + process. + + :term:`UNKNOWN_CONFIGURE_WHITELIST` + Specifies a list of options that, if reported by the configure script + as being invalid, should not generate a warning during the + :ref:`ref-tasks-configure` task. Normally, invalid + configure options are simply not passed to the configure script (e.g. + should be removed from :term:`EXTRA_OECONF` or + :term:`PACKAGECONFIG_CONFARGS`). + However, common options, for example, exist that are passed to all + configure scripts at a class level that might not be valid for some + configure scripts. It follows that no benefit exists in seeing a + warning about these options. For these cases, the options are added + to ``UNKNOWN_CONFIGURE_WHITELIST``. + + The configure arguments check that uses + ``UNKNOWN_CONFIGURE_WHITELIST`` is part of the + :ref:`insane <ref-classes-insane>` class and is only enabled if the + recipe inherits the :ref:`autotools <ref-classes-autotools>` class. + + :term:`UPDATERCPN` + For recipes inheriting the + :ref:`update-rc.d <ref-classes-update-rc.d>` class, ``UPDATERCPN`` + specifies the package that contains the initscript that is enabled. + + The default value is "${PN}". Given that almost all recipes that + install initscripts package them in the main package for the recipe, + you rarely need to set this variable in individual recipes. + + :term:`UPSTREAM_CHECK_GITTAGREGEX` + You can perform a per-recipe check for what the latest upstream + source code version is by calling ``bitbake -c checkpkg`` recipe. If + the recipe source code is provided from Git repositories, the + OpenEmbedded build system determines the latest upstream version by + picking the latest tag from the list of all repository tags. + + You can use the ``UPSTREAM_CHECK_GITTAGREGEX`` variable to provide a + regular expression to filter only the relevant tags should the + default filter not work correctly. + :: + + UPSTREAM_CHECK_GITTAGREGEX = "git_tag_regex" + + :term:`UPSTREAM_CHECK_REGEX` + Use the ``UPSTREAM_CHECK_REGEX`` variable to specify a different + regular expression instead of the default one when the package + checking system is parsing the page found using + :term:`UPSTREAM_CHECK_URI`. + :: + + UPSTREAM_CHECK_REGEX = "package_regex" + + :term:`UPSTREAM_CHECK_URI` + You can perform a per-recipe check for what the latest upstream + source code version is by calling ``bitbake -c checkpkg`` recipe. If + the source code is provided from tarballs, the latest version is + determined by fetching the directory listing where the tarball is and + attempting to find a later tarball. When this approach does not work, + you can use ``UPSTREAM_CHECK_URI`` to provide a different URI that + contains the link to the latest tarball. + :: + + UPSTREAM_CHECK_URI = "recipe_url" + + :term:`USE_DEVFS` + Determines if ``devtmpfs`` is used for ``/dev`` population. The + default value used for ``USE_DEVFS`` is "1" when no value is + specifically set. Typically, you would set ``USE_DEVFS`` to "0" for a + statically populated ``/dev`` directory. + + See the ":ref:`selecting-dev-manager`" section in + the Yocto Project Development Tasks Manual for information on how to + use this variable. + + :term:`USE_VT` + When using + :ref:`SysVinit <new-recipe-enabling-system-services>`, + determines whether or not to run a + `getty <http://en.wikipedia.org/wiki/Getty_%28Unix%29>`__ on any + virtual terminals in order to enable logging in through those + terminals. + + The default value used for ``USE_VT`` is "1" when no default value is + specifically set. Typically, you would set ``USE_VT`` to "0" in the + machine configuration file for machines that do not have a graphical + display attached and therefore do not need virtual terminal + functionality. + + :term:`USER_CLASSES` + A list of classes to globally inherit. These classes are used by the + OpenEmbedded build system to enable extra features (e.g. + ``buildstats``, ``image-mklibs``, and so forth). + + The default list is set in your ``local.conf`` file: + :: + + USER_CLASSES ?= "buildstats image-mklibs image-prelink" + + For more information, see + ``meta-poky/conf/local.conf.sample`` in the :term:`Source Directory`. + + :term:`USERADD_ERROR_DYNAMIC` + If set to ``error``, forces the OpenEmbedded build system to produce + an error if the user identification (``uid``) and group + identification (``gid``) values are not defined in any of the files + listed in :term:`USERADD_UID_TABLES` and + :term:`USERADD_GID_TABLES`. If set to + ``warn``, a warning will be issued instead. + + The default behavior for the build system is to dynamically apply + ``uid`` and ``gid`` values. Consequently, the + ``USERADD_ERROR_DYNAMIC`` variable is by default not set. If you plan + on using statically assigned ``gid`` and ``uid`` values, you should + set the ``USERADD_ERROR_DYNAMIC`` variable in your ``local.conf`` + file as follows: + :: + + USERADD_ERROR_DYNAMIC = "error" + + Overriding the + default behavior implies you are going to also take steps to set + static ``uid`` and ``gid`` values through use of the + :term:`USERADDEXTENSION`, + :term:`USERADD_UID_TABLES`, and + :term:`USERADD_GID_TABLES` variables. + + .. note:: + + There is a difference in behavior between setting + ``USERADD_ERROR_DYNAMIC`` to ``error`` and setting it to ``warn``. + When it is set to ``warn``, the build system will report a warning for + every undefined ``uid`` and ``gid`` in any recipe. But when it is set + to ``error``, it will only report errors for recipes that are actually + built. + This saves you from having to add static IDs for recipes that you + know will never be built. + + :term:`USERADD_GID_TABLES` + Specifies a password file to use for obtaining static group + identification (``gid``) values when the OpenEmbedded build system + adds a group to the system during package installation. + + When applying static group identification (``gid``) values, the + OpenEmbedded build system looks in :term:`BBPATH` for a + ``files/group`` file and then applies those ``uid`` values. Set the + variable as follows in your ``local.conf`` file: + :: + + + USERADD_GID_TABLES = "files/group" + + .. note:: + + Setting the :term:`USERADDEXTENSION` variable to "useradd-staticids" + causes the build system to use static ``gid`` values. + + :term:`USERADD_PACKAGES` + When inheriting the :ref:`useradd <ref-classes-useradd>` class, + this variable specifies the individual packages within the recipe + that require users and/or groups to be added. + + You must set this variable if the recipe inherits the class. For + example, the following enables adding a user for the main package in + a recipe: + :: + + USERADD_PACKAGES = "${PN}" + + .. note:: + + It follows that if you are going to use the ``USERADD_PACKAGES`` + variable, you need to set one or more of the :term:`USERADD_PARAM`, + :term:`GROUPADD_PARAM`, or :term:`GROUPMEMS_PARAM` variables. + + :term:`USERADD_PARAM` + When inheriting the :ref:`useradd <ref-classes-useradd>` class, + this variable specifies for a package what parameters should pass to + the ``useradd`` command if you add a user to the system when the + package is installed. + + Here is an example from the ``dbus`` recipe: + :: + + USERADD_PARAM_${PN} = "--system --home ${localstatedir}/lib/dbus \ + --no-create-home --shell /bin/false \ + --user-group messagebus" + + For information on the + standard Linux shell command ``useradd``, see + http://linux.die.net/man/8/useradd. + + :term:`USERADD_UID_TABLES` + Specifies a password file to use for obtaining static user + identification (``uid``) values when the OpenEmbedded build system + adds a user to the system during package installation. + + When applying static user identification (``uid``) values, the + OpenEmbedded build system looks in :term:`BBPATH` for a + ``files/passwd`` file and then applies those ``uid`` values. Set the + variable as follows in your ``local.conf`` file: + :: + + USERADD_UID_TABLES = "files/passwd" + + .. note:: + + Setting the :term:`USERADDEXTENSION` variable to "useradd-staticids" + causes the build system to use static ``uid`` values. + + :term:`USERADDEXTENSION` + When set to "useradd-staticids", causes the OpenEmbedded build system + to base all user and group additions on a static ``passwd`` and + ``group`` files found in :term:`BBPATH`. + + To use static user identification (``uid``) and group identification + (``gid``) values, set the variable as follows in your ``local.conf`` + file: USERADDEXTENSION = "useradd-staticids" + + .. note:: + + Setting this variable to use static ``uid`` and ``gid`` + values causes the OpenEmbedded build system to employ the + :ref:`ref-classes-useradd` class. + + If you use static ``uid`` and ``gid`` information, you must also + specify the ``files/passwd`` and ``files/group`` files by setting the + :term:`USERADD_UID_TABLES` and + :term:`USERADD_GID_TABLES` variables. + Additionally, you should also set the + :term:`USERADD_ERROR_DYNAMIC` variable. + + :term:`VOLATILE_LOG_DIR` + Specifies the persistence of the target's ``/var/log`` directory, + which is used to house postinstall target log files. + + By default, ``VOLATILE_LOG_DIR`` is set to "yes", which means the + file is not persistent. You can override this setting by setting the + variable to "no" to make the log directory persistent. + + :term:`WARN_QA` + Specifies the quality assurance checks whose failures are reported as + warnings by the OpenEmbedded build system. You set this variable in + your distribution configuration file. For a list of the checks you + can control with this variable, see the + ":ref:`insane.bbclass <ref-classes-insane>`" section. + + :term:`WKS_FILE` + Specifies the location of the Wic kickstart file that is used by the + OpenEmbedded build system to create a partitioned image + (image\ ``.wic``). For information on how to create a partitioned + image, see the + ":ref:`dev-manual/dev-manual-common-tasks:creating partitioned images using wic`" + section in the Yocto Project Development Tasks Manual. For details on + the kickstart file format, see the ":doc:`../ref-manual/ref-kickstart`" Chapter. + + :term:`WKS_FILE_DEPENDS` + When placed in the recipe that builds your image, this variable lists + build-time dependencies. The ``WKS_FILE_DEPENDS`` variable is only + applicable when Wic images are active (i.e. when + :term:`IMAGE_FSTYPES` contains entries related + to Wic). If your recipe does not create Wic images, the variable has + no effect. + + The ``WKS_FILE_DEPENDS`` variable is similar to the + :term:`DEPENDS` variable. When you use the variable in + your recipe that builds the Wic image, dependencies you list in the + ``WIC_FILE_DEPENDS`` variable are added to the ``DEPENDS`` variable. + + With the ``WKS_FILE_DEPENDS`` variable, you have the possibility to + specify a list of additional dependencies (e.g. native tools, + bootloaders, and so forth), that are required to build Wic images. + Following is an example: + :: + + WKS_FILE_DEPENDS = "some-native-tool" + + In the + previous example, some-native-tool would be replaced with an actual + native tool on which the build would depend. + + :term:`WORKDIR` + The pathname of the work directory in which the OpenEmbedded build + system builds a recipe. This directory is located within the + :term:`TMPDIR` directory structure and is specific to + the recipe being built and the system for which it is being built. + + The ``WORKDIR`` directory is defined as follows: + :: + + ${TMPDIR}/work/${MULTIMACH_TARGET_SYS}/${PN}/${EXTENDPE}${PV}-${PR} + + The actual directory depends on several things: + + - :term:`TMPDIR`: The top-level build output directory + - :term:`MULTIMACH_TARGET_SYS`: The target system identifier + - :term:`PN`: The recipe name + - :term:`EXTENDPE`: The epoch - (if :term:`PE` is not specified, which + is usually the case for most recipes, then `EXTENDPE` is blank) + - :term:`PV`: The recipe version + - :term:`PR`: The recipe revision + + As an example, assume a Source Directory top-level folder name + ``poky``, a default Build Directory at ``poky/build``, and a + ``qemux86-poky-linux`` machine target system. Furthermore, suppose + your recipe is named ``foo_1.3.0-r0.bb``. In this case, the work + directory the build system uses to build the package would be as + follows: + :: + + poky/build/tmp/work/qemux86-poky-linux/foo/1.3.0-r0 + + :term:`XSERVER` + Specifies the packages that should be installed to provide an X + server and drivers for the current machine, assuming your image + directly includes ``packagegroup-core-x11-xserver`` or, perhaps + indirectly, includes "x11-base" in + :term:`IMAGE_FEATURES`. + + The default value of ``XSERVER``, if not specified in the machine + configuration, is "xserver-xorg xf86-video-fbdev xf86-input-evdev". + + :term:`XZ_THREADS` + Specifies the number of parallel threads that should be used when + using xz compression. + + By default this scales with core count, but is never set less than 2 + to ensure that multi-threaded mode is always used so that the output + file contents are deterministic. Builds will work with a value of 1 + but the output will differ compared to the output from the compression + generated when more than one thread is used. + + On systems where many tasks run in parallel, setting a limit to this + can be helpful in controlling system resource usage. + + :term:`XZ_MEMLIMIT` + Specifies the maximum memory the xz compression should use as a percentage + of system memory. If unconstrained the xz compressor can use large amounts of + memory and become problematic with parallelism elsewhere in the build. + "50%" has been found to be a good value. |