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diff --git a/documentation/ref-manual/faq.rst b/documentation/ref-manual/faq.rst index 2d2aaad0a9..bab284bbfd 100644 --- a/documentation/ref-manual/faq.rst +++ b/documentation/ref-manual/faq.rst @@ -1,12 +1,18 @@ -.. SPDX-License-Identifier: CC-BY-2.0-UK +.. SPDX-License-Identifier: CC-BY-SA-2.0-UK *** FAQ *** -**Q:** How does Poky differ from `OpenEmbedded <http://www.openembedded.org/>`__? +.. contents:: -**A:** The term ``Poky`` refers to the specific reference build +General questions +================= + +How does Poky differ from OpenEmbedded? +--------------------------------------- + +The term ``Poky`` refers to the specific reference build system that the Yocto Project provides. Poky is based on :term:`OpenEmbedded-Core (OE-Core)` and :term:`BitBake`. Thus, the generic term used here for the build system is the "OpenEmbedded build @@ -15,19 +21,10 @@ OpenEmbedded, with changes always being merged to OE-Core or BitBake first before being pulled back into Poky. This practice benefits both projects immediately. -**Q:** My development system does not meet the required Git, tar, and -Python versions. In particular, I do not have Python 3.5.0 or greater. -Can I still use the Yocto Project? - -**A:** You can get the required tools on your host development system a -couple different ways (i.e. building a tarball or downloading a -tarball). See the "`Required Git, tar, Python and gcc -Versions <#required-git-tar-python-and-gcc-versions>`__" section for -steps on how to update your build tools. - -**Q:** How can you claim Poky / OpenEmbedded-Core is stable? +How can you claim Poky / OpenEmbedded-Core is stable? +----------------------------------------------------- -**A:** There are three areas that help with stability; +There are three areas that help with stability; - The Yocto Project team keeps :term:`OpenEmbedded-Core (OE-Core)` small and focused, containing around 830 recipes as opposed to the thousands @@ -37,95 +34,110 @@ steps on how to update your build tools. - The Yocto Project team runs manual and automated tests using a small, fixed set of reference hardware as well as emulated targets. -- The Yocto Project uses an autobuilder, which provides continuous - build and integration tests. +- The Yocto Project uses an :yocto_ab:`autobuilder <>`, which provides + continuous build and integration tests. -**Q:** How do I get support for my board added to the Yocto Project? +Are there any products built using the OpenEmbedded build system? +----------------------------------------------------------------- -**A:** Support for an additional board is added by creating a Board -Support Package (BSP) layer for it. For more information on how to -create a BSP layer, see the -":ref:`dev-manual/dev-manual-common-tasks:understanding and creating layers`" -section in the Yocto Project Development Tasks Manual and the -:doc:`../bsp-guide/bsp-guide`. +See :yocto_wiki:`Products that use the Yocto Project +</Project_Users#Products_that_use_the_Yocto_Project>` in the Yocto Project +Wiki. Don't hesitate to contribute to this page if you know other such +products. -Usually, if the board is not completely exotic, adding support in the -Yocto Project is fairly straightforward. +Building environment +==================== -**Q:** Are there any products built using the OpenEmbedded build system? +Missing dependencies on the development system? +----------------------------------------------- -**A:** The software running on the `Vernier -LabQuest <http://vernier.com/labquest/>`__ is built using the -OpenEmbedded build system. See the `Vernier -LabQuest <http://www.vernier.com/products/interfaces/labq/>`__ website -for more information. There are a number of pre-production devices using -the OpenEmbedded build system and the Yocto Project team announces them -as soon as they are released. +If your development system does not meet the required Git, tar, and +Python versions, you can get the required tools on your host development +system in different ways (i.e. building a tarball or downloading a +tarball). See the ":ref:`ref-manual/system-requirements:required git, tar, python, make and gcc versions`" +section for steps on how to update your build tools. -**Q:** What does the OpenEmbedded build system produce as output? +How does OpenEmbedded fetch source code? Will it work through a firewall or proxy server? +----------------------------------------------------------------------------------------- -**A:** Because you can use the same set of recipes to create output of -various formats, the output of an OpenEmbedded build depends on how you -start it. Usually, the output is a flashable image ready for the target -device. +The way the build system obtains source code is highly +configurable. You can setup the build system to get source code in most +environments if HTTP transport is available. -**Q:** How do I add my package to the Yocto Project? +When the build system searches for source code, it first tries the local +download directory. If that location fails, Poky tries +:term:`PREMIRRORS`, the upstream source, and then +:term:`MIRRORS` in that order. -**A:** To add a package, you need to create a BitBake recipe. For -information on how to create a BitBake recipe, see the -":ref:`dev-manual/dev-manual-common-tasks:writing a new recipe`" -section in the Yocto Project Development Tasks Manual. +Assuming your distribution is "poky", the OpenEmbedded build system uses +the Yocto Project source :term:`PREMIRRORS` by default for SCM-based +sources, upstreams for normal tarballs, and then falls back to a number +of other mirrors including the Yocto Project source mirror if those +fail. -**Q:** Do I have to reflash my entire board with a new Yocto Project -image when recompiling a package? +As an example, 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:: -**A:** The OpenEmbedded build system can build packages in various -formats such as IPK for OPKG, Debian package (``.deb``), or RPM. You can -then upgrade the packages using the package tools on the device, much -like on a desktop distribution such as Ubuntu or Fedora. However, -package management on the target is entirely optional. + PREMIRRORS:prepend = "\ + git://.*/.* &YOCTO_DL_URL;/mirror/sources/ \ + ftp://.*/.* &YOCTO_DL_URL;/mirror/sources/ \ + http://.*/.* &YOCTO_DL_URL;/mirror/sources/ \ + https://.*/.* &YOCTO_DL_URL;/mirror/sources/" + +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. -**Q:** I see the error -'``chmod: XXXXX new permissions are r-xrwxrwx, not r-xr-xr-x``'. What is -wrong? +Another option is to set:: -**A:** You are probably running the build on an NTFS filesystem. Use -``ext2``, ``ext3``, or ``ext4`` instead. + BB_NO_NETWORK = "1" -**Q:** I see lots of 404 responses for files when the OpenEmbedded build -system is trying to download sources. Is something wrong? +This statement tells BitBake to issue an error +instead of trying to access the Internet. This technique is useful if +you want to ensure code builds only from local sources. -**A:** Nothing is wrong. The OpenEmbedded build system checks any -configured source mirrors before downloading from the upstream sources. -The build system does this searching for both source archives and -pre-checked out versions of SCM-managed software. These checks help in -large installations because it can reduce load on the SCM servers -themselves. The address above is one of the default mirrors configured -into the build system. Consequently, if an upstream source disappears, -the team can place sources there so builds continue to work. +Here is another technique:: + + BB_FETCH_PREMIRRORONLY = "1" -**Q:** I have machine-specific data in a package for one machine only -but the package is being marked as machine-specific in all cases, how do -I prevent this? +This statement limits the build system to pulling source from the +:term:`PREMIRRORS` only. Again, this technique is useful for reproducing +builds. -**A:** Set ``SRC_URI_OVERRIDES_PACKAGE_ARCH`` = "0" in the ``.bb`` file -but make sure the package is manually marked as machine-specific for the -case that needs it. The code that handles -``SRC_URI_OVERRIDES_PACKAGE_ARCH`` is in the -``meta/classes/base.bbclass`` file. +Here is yet another technique:: -**Q:** I'm behind a firewall and need to use a proxy server. How do I do -that? + BB_GENERATE_MIRROR_TARBALLS = "1" + +This statement tells the build system to generate mirror tarballs. This +technique is useful if you want to create a mirror server. If not, +however, the technique can simply waste time during the build. -**A:** Most source fetching by the OpenEmbedded build system is done by +Finally, consider an example where you are behind an HTTP-only firewall. +You could make the following changes to the ``local.conf`` configuration +file as long as the :term:`PREMIRRORS` server is current:: + + PREMIRRORS:prepend = "\ + git://.*/.* &YOCTO_DL_URL;/mirror/sources/ \ + ftp://.*/.* &YOCTO_DL_URL;/mirror/sources/ \ + http://.*/.* &YOCTO_DL_URL;/mirror/sources/ \ + https://.*/.* &YOCTO_DL_URL;/mirror/sources/" + BB_FETCH_PREMIRRORONLY = "1" + +These changes would cause the build system to successfully fetch source +over HTTP and any network accesses to anything other than the +:term:`PREMIRRORS` would fail. + +Most source fetching by the OpenEmbedded build system is done by ``wget`` and you therefore need to specify the proxy settings in a ``.wgetrc`` file, which can be in your home directory if you are a single user or can be in ``/usr/local/etc/wgetrc`` as a global user file. -Following is the applicable code for setting various proxy types in the +Here is the applicable code for setting various proxy types in the ``.wgetrc`` file. By default, these settings are disabled with comments. -To use them, remove the comments: :: +To use them, remove the comments:: # You can set the default proxies for Wget to use for http, https, and ftp. # They will override the value in the environment. @@ -136,24 +148,53 @@ To use them, remove the comments: :: # If you do not want to use proxy at all, set this to off. #use_proxy = on +The build system also accepts ``http_proxy``, ``ftp_proxy``, ``https_proxy``, +and ``all_proxy`` set as to standard shell environment variables to redirect +requests through proxy servers. + The Yocto Project also includes a -``meta-poky/conf/site.conf.sample`` file that shows how to configure CVS -and Git proxy servers if needed. For more information on setting up -various proxy types and configuring proxy servers, see the -":yocto_wiki:`Working Behind a Network Proxy </wiki/Working_Behind_a_Network_Proxy>`" -Wiki page. +``meta-poky/conf/templates/default/site.conf.sample`` file that shows +how to configure CVS and Git proxy servers if needed. -**Q:** What's the difference between target and target\ ``-native``? +.. note:: -**A:** The ``*-native`` targets are designed to run on the system being -used for the build. These are usually tools that are needed to assist -the build in some way such as ``quilt-native``, which is used to apply -patches. The non-native version is the one that runs on the target -device. + You can find more information on the + ":yocto_wiki:`Working Behind a Network Proxy </Working_Behind_a_Network_Proxy>`" + Wiki page. + +Using the OpenEmbedded Build system +=================================== + +How do I use an external toolchain? +----------------------------------- + +See the ":ref:`dev-manual/external-toolchain:optionally using an external toolchain`" +section in the Development Task manual. + +Why do I get chmod permission issues? +------------------------------------- + +If you see the error +``chmod: XXXXX new permissions are r-xrwxrwx, not r-xr-xr-x``, +you are probably running the build on an NTFS filesystem. Instead, +run the build system on a partition with a modern Linux filesystem such as +``ext4``, ``btrfs`` or ``xfs``. + +I see many 404 errors trying to download sources. Is anything wrong? +-------------------------------------------------------------------- + +Nothing is wrong. The OpenEmbedded build system checks any +configured source mirrors before downloading from the upstream sources. +The build system does this searching for both source archives and +pre-checked out versions of SCM-managed software. These checks help in +large installations because it can reduce load on the SCM servers +themselves. This can also allow builds to continue to work if an +upstream source disappears. -**Q:** I'm seeing random build failures. Help?! +Why do I get random build failures? +----------------------------------- -**A:** If the same build is failing in totally different and random +If the same build is failing in totally different and random ways, the most likely explanation is: - The hardware you are running the build on has some problem. @@ -166,222 +207,139 @@ causes lots of network, disk and CPU activity and is sensitive to even single-bit failures in any of these areas. True random failures have always been traced back to hardware or virtualization issues. -**Q:** When I try to build a native recipe, the build fails with -``iconv.h`` problems. +Why does the build fail with ``iconv.h`` problems? +-------------------------------------------------- -**A:** If you get an error message that indicates GNU ``libiconv`` is -not in use but ``iconv.h`` has been included from ``libiconv``, you need -to check to see if you have a previously installed version of the header -file in ``/usr/local/include``. -:: +When you try to build a native recipe, you may get an error message that +indicates that GNU ``libiconv`` is not in use but ``iconv.h`` has been +included from ``libiconv``:: #error GNU libiconv not in use but included iconv.h is from libiconv -If you find a previously installed -file, you should either uninstall it or temporarily rename it and try -the build again. +When this happens, you need to check whether you have a previously +installed version of the header file in ``/usr/local/include/``. +If that's the case, you should either uninstall it or temporarily rename +it and try the build again. This issue is just a single manifestation of "system leakage" issues caused when the OpenEmbedded build system finds and uses previously installed files during a native build. This type of issue might not be -limited to ``iconv.h``. Be sure that leakage cannot occur from +limited to ``iconv.h``. Make sure that leakage cannot occur from ``/usr/local/include`` and ``/opt`` locations. -**Q:** What do we need to ship for license compliance? - -**A:** This is a difficult question and you need to consult your lawyer -for the answer for your specific case. It is worth bearing in mind that -for GPL compliance, there needs to be enough information shipped to -allow someone else to rebuild and produce the same end result you are -shipping. This means sharing the source code, any patches applied to it, -and also any configuration information about how that package was -configured and built. - -You can find more information on licensing in the -":ref:`overview-manual/overview-manual-development-environment:licensing`" -section in the Yocto -Project Overview and Concepts Manual and also in the -":ref:`dev-manual/dev-manual-common-tasks:maintaining open source license compliance during your product's lifecycle`" -section in the Yocto Project Development Tasks Manual. - -**Q:** How do I disable the cursor on my touchscreen device? - -**A:** You need to create a form factor file as described in the -":ref:`bsp-filelayout-misc-recipes`" section in -the Yocto Project Board Support Packages (BSP) Developer's Guide. Set -the ``HAVE_TOUCHSCREEN`` variable equal to one as follows: -:: - - HAVE_TOUCHSCREEN=1 - -**Q:** How do I make sure connected network interfaces are brought up by -default? - -**A:** The default interfaces file provided by the netbase recipe does -not automatically bring up network interfaces. Therefore, you will need -to add a BSP-specific netbase that includes an interfaces file. See the -":ref:`bsp-filelayout-misc-recipes`" section in -the Yocto Project Board Support Packages (BSP) Developer's Guide for -information on creating these types of miscellaneous recipe files. - -For example, add the following files to your layer: :: - - meta-MACHINE/recipes-bsp/netbase/netbase/MACHINE/interfaces - meta-MACHINE/recipes-bsp/netbase/netbase_5.0.bbappend - -**Q:** How do I create images with more free space? - -**A:** By default, the OpenEmbedded build system creates images that are -1.3 times the size of the populated root filesystem. To affect the image -size, you need to set various configurations: +Why don't other recipes find the files provided by my ``*-native`` recipe? +-------------------------------------------------------------------------- -- *Image Size:* The OpenEmbedded build system uses the - :term:`IMAGE_ROOTFS_SIZE` variable to define - the size of the image in Kbytes. The build system determines the size - by taking into account the initial root filesystem size before any - modifications such as requested size for the image and any requested - additional free disk space to be added to the image. - -- *Overhead:* Use the - :term:`IMAGE_OVERHEAD_FACTOR` variable - to define the multiplier that the build system applies to the initial - image size, which is 1.3 by default. - -- *Additional Free Space:* Use the - :term:`IMAGE_ROOTFS_EXTRA_SPACE` - variable to add additional free space to the image. The build system - adds this space to the image after it determines its - ``IMAGE_ROOTFS_SIZE``. - -**Q:** Why don't you support directories with spaces in the pathnames? - -**A:** The Yocto Project team has tried to do this before but too many -of the tools the OpenEmbedded build system depends on, such as -``autoconf``, break when they find spaces in pathnames. Until that -situation changes, the team will not support spaces in pathnames. +Files provided by your native recipe could be missing from the native +sysroot, your recipe could also be installing to the wrong place, or you +could be getting permission errors during the :ref:`ref-tasks-install` +task in your recipe. -**Q:** How do I use an external toolchain? - -**A:** The toolchain configuration is very flexible and customizable. It -is primarily controlled with the ``TCMODE`` variable. This variable -controls which ``tcmode-*.inc`` file to include from the -``meta/conf/distro/include`` directory within the :term:`Source Directory`. - -The default value of ``TCMODE`` is "default", which tells the -OpenEmbedded build system to use its internally built toolchain (i.e. -``tcmode-default.inc``). However, other patterns are accepted. In -particular, "external-\*" refers to external toolchains. One example is -the Sourcery G++ Toolchain. The support for this toolchain resides in -the separate ``meta-sourcery`` layer at -http://github.com/MentorEmbedded/meta-sourcery/. - -In addition to the toolchain configuration, you also need a -corresponding toolchain recipe file. This recipe file needs to package -up any pre-built objects in the toolchain such as ``libgcc``, -``libstdcc++``, any locales, and ``libc``. - -**Q:** How does the OpenEmbedded build system obtain source code and -will it work behind my firewall or proxy server? - -**A:** The way the build system obtains source code is highly -configurable. You can setup the build system to get source code in most -environments if HTTP transport is available. - -When the build system searches for source code, it first tries the local -download directory. If that location fails, Poky tries -:term:`PREMIRRORS`, the upstream source, and then -:term:`MIRRORS` in that order. - -Assuming your distribution is "poky", the OpenEmbedded build system uses -the Yocto Project source ``PREMIRRORS`` by default for SCM-based -sources, upstreams for normal tarballs, and then falls back to a number -of other mirrors including the Yocto Project source mirror if those -fail. - -As an example, 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: :: +This situation happens when the build system used by a package does not +recognize the environment variables supplied to it by :term:`BitBake`. The +incident that prompted this FAQ entry involved a Makefile that used an +environment variable named ``BINDIR`` instead of the more standard +variable ``bindir``. The makefile's hardcoded default value of +"/usr/bin" worked most of the time, but not for the recipe's ``-native`` +variant. For another example, permission errors might be caused by a +Makefile that ignores ``DESTDIR`` or uses a different name for that +environment variable. Check the build system of the package to see if +these kinds of issues exist. - 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" +Can I get rid of build output so I can start over? +-------------------------------------------------- -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. +Yes --- you can easily do this. When you use BitBake to build an +image, all the build output goes into the directory created when you run +the build environment setup script (i.e. :ref:`structure-core-script`). +By default, this :term:`Build Directory` is named ``build`` but can be named +anything you want. -Aside from the previous technique, these options also exist: -:: +Within the :term:`Build Directory`, is the ``tmp`` directory. To remove all the +build output yet preserve any source code or downloaded files from +previous builds, simply remove the ``tmp`` directory. - BB_NO_NETWORK = "1" +Customizing generated images +============================ -This statement tells BitBake to issue an error -instead of trying to access the Internet. This technique is useful if -you want to ensure code builds only from local sources. +What does the OpenEmbedded build system produce as output? +---------------------------------------------------------- -Here is another technique: -:: +Because you can use the same set of recipes to create output of +various formats, the output of an OpenEmbedded build depends on how you +start it. Usually, the output is a flashable image ready for the target +device. - BB_FETCH_PREMIRRORONLY = "1" +How do I make the Yocto Project support my board? +------------------------------------------------- -This statement -limits the build system to pulling source from the ``PREMIRRORS`` only. -Again, this technique is useful for reproducing builds. +Support for an additional board is added by creating a Board +Support Package (BSP) layer for it. For more information on how to +create a BSP layer, see the +":ref:`dev-manual/layers:understanding and creating layers`" +section in the Yocto Project Development Tasks Manual and the +:doc:`/bsp-guide/index`. -Here is another technique: -:: +Usually, if the board is not completely exotic, adding support in the +Yocto Project is fairly straightforward. - BB_GENERATE_MIRROR_TARBALLS = "1" +How do I make the Yocto Project support my package? +--------------------------------------------------- -This -statement tells the build system to generate mirror tarballs. This -technique is useful if you want to create a mirror server. If not, -however, the technique can simply waste time during the build. +To add a package, you need to create a BitBake recipe. For +information on how to create a BitBake recipe, see the +":ref:`dev-manual/new-recipe:writing a new recipe`" +section in the Yocto Project Development Tasks Manual. -Finally, consider an example where you are behind an HTTP-only firewall. -You could make the following changes to the ``local.conf`` configuration -file as long as the ``PREMIRRORS`` server is current: :: +What do I need to ship for license compliance? +---------------------------------------------- - PREMIRRORS_prepend = "\ - ftp://.*/.* http://www.yoctoproject.org/sources/ \n \ - http://.*/.* http://www.yoctoproject.org/sources/ \n \ - https://.*/.* http://www.yoctoproject.org/sources/ \n" - BB_FETCH_PREMIRRORONLY = "1" +This is a difficult question and you need to consult your lawyer +for the answer for your specific case. It is worth bearing in mind that +for GPL compliance, there needs to be enough information shipped to +allow someone else to rebuild and produce the same end result you are +shipping. This means sharing the source code, any patches applied to it, +and also any configuration information about how that package was +configured and built. -These changes would cause the build system to successfully fetch source -over HTTP and any network accesses to anything other than the -``PREMIRRORS`` would fail. +You can find more information on licensing in the +":ref:`overview-manual/development-environment:licensing`" +section in the Yocto Project Overview and Concepts Manual and also in the +":ref:`dev-manual/licenses:maintaining open source license compliance during your product's lifecycle`" +section in the Yocto Project Development Tasks Manual. -The build system also honors the standard shell environment variables -``http_proxy``, ``ftp_proxy``, ``https_proxy``, and ``all_proxy`` to -redirect requests through proxy servers. +Do I have to make a full reflash after recompiling one package? +--------------------------------------------------------------- -.. note:: +The OpenEmbedded build system can build packages in various +formats such as IPK for OPKG, Debian package (``.deb``), or RPM. You can +then upgrade only the modified packages using the package tools on the device, +much like on a desktop distribution such as Ubuntu or Fedora. However, +package management on the target is entirely optional. - You can find more information on the - ":yocto_wiki:`Working Behind a Network Proxy </wiki/Working_Behind_a_Network_Proxy>`" - Wiki page. +How to prevent my package from being marked as machine specific? +---------------------------------------------------------------- -**Q:** Can I get rid of build output so I can start over? +If you have machine-specific data in a package for one machine only +but the package is being marked as machine-specific in all cases, +you can set :term:`SRC_URI_OVERRIDES_PACKAGE_ARCH` = "0" in the ``.bb`` file. +However, but make sure the package is manually marked as machine-specific for the +case that needs it. The code that handles :term:`SRC_URI_OVERRIDES_PACKAGE_ARCH` +is in the ``meta/classes-global/base.bbclass`` file. -**A:** Yes - you can easily do this. When you use BitBake to build an -image, all the build output goes into the directory created when you run -the build environment setup script (i.e. -````` <#structure-core-script>`__). By default, this :term:`Build Directory` -is named ``build`` but can be named -anything you want. +What's the difference between ``target`` and ``target-native``? +--------------------------------------------------------------- -Within the Build Directory, is the ``tmp`` directory. To remove all the -build output yet preserve any source code or downloaded files from -previous builds, simply remove the ``tmp`` directory. +The ``*-native`` targets are designed to run on the system being +used for the build. These are usually tools that are needed to assist +the build in some way such as ``quilt-native``, which is used to apply +patches. The non-native version is the one that runs on the target +device. -**Q:** Why do ``${bindir}`` and ``${libdir}`` have strange values for -``-native`` recipes? +Why do ``${bindir}`` and ``${libdir}`` have strange values for ``-native`` recipes? +----------------------------------------------------------------------------------- -**A:** Executables and libraries might need to be used from a directory +Executables and libraries might need to be used from a directory other than the directory into which they were initially installed. Complicating this situation is the fact that sometimes these executables and libraries are compiled with the expectation of being run from that @@ -408,13 +366,13 @@ system of that image. Thus, the build system provides a value of forth. Meanwhile, ``DESTDIR`` is a path within the :term:`Build Directory`. -However, when the recipe builds a -native program (i.e. one that is intended to run on the build machine), -that program is never installed directly to the build machine's root -file system. Consequently, the build system uses paths within the Build -Directory for ``DESTDIR``, ``bindir`` and related variables. To better -understand this, consider the following two paths where the first is -relatively normal and the second is not: :: +However, when the recipe builds a native program (i.e. one that is +intended to run on the build machine), that program is never installed +directly to the build machine's root file system. Consequently, the build +system uses paths within the Build Directory for ``DESTDIR``, ``bindir`` +and related variables. To better understand this, consider the following +two paths (artificially broken across lines for readability) where the +first is relatively normal and the second is not:: /home/maxtothemax/poky-bootchart2/build/tmp/work/i586-poky-linux/zlib/ 1.2.8-r0/sysroot-destdir/usr/bin @@ -423,29 +381,76 @@ relatively normal and the second is not: :: zlib-native/1.2.8-r0/sysroot-destdir/home/maxtothemax/poky-bootchart2/ build/tmp/sysroots/x86_64-linux/usr/bin -.. note:: +Even if the paths look unusual, they both are correct --- the first for +a target and the second for a native recipe. These paths are a consequence +of the ``DESTDIR`` mechanism and while they appear strange, they are correct +and in practice very effective. - Due to these lengthy examples, the paths are artificially broken - across lines for readability. +How do I create images with more free space? +-------------------------------------------- -Even if the paths look unusual, -they both are correct - the first for a target and the second for a -native recipe. These paths are a consequence of the ``DESTDIR`` -mechanism and while they appear strange, they are correct and in -practice very effective. +By default, the OpenEmbedded build system creates images that are +1.3 times the size of the populated root filesystem. To affect the image +size, you need to set various configurations: -**Q:** The files provided by my ``*-native`` recipe do not appear to be -available to other recipes. Files are missing from the native sysroot, -my recipe is installing to the wrong place, or I am getting permissions -errors during the do_install task in my recipe! What is wrong? +- *Image Size:* The OpenEmbedded build system uses the + :term:`IMAGE_ROOTFS_SIZE` variable to define + the size of the image in Kbytes. The build system determines the size + by taking into account the initial root filesystem size before any + modifications such as requested size for the image and any requested + additional free disk space to be added to the image. -**A:** This situation results when a build system does not recognize the -environment variables supplied to it by :term:`BitBake`. The -incident that prompted this FAQ entry involved a Makefile that used an -environment variable named ``BINDIR`` instead of the more standard -variable ``bindir``. The makefile's hardcoded default value of -"/usr/bin" worked most of the time, but not for the recipe's ``-native`` -variant. For another example, permissions errors might be caused by a -Makefile that ignores ``DESTDIR`` or uses a different name for that -environment variable. Check the the build system to see if these kinds -of issues exist. +- *Overhead:* Use the + :term:`IMAGE_OVERHEAD_FACTOR` variable + to define the multiplier that the build system applies to the initial + image size, which is 1.3 by default. + +- *Additional Free Space:* Use the + :term:`IMAGE_ROOTFS_EXTRA_SPACE` + variable to add additional free space to the image. The build system + adds this space to the image after it determines its + :term:`IMAGE_ROOTFS_SIZE`. + +Why aren't spaces in path names supported? +------------------------------------------ + +The Yocto Project team has tried to do this before but too many +of the tools the OpenEmbedded build system depends on, such as +``autoconf``, break when they find spaces in pathnames. Until that +situation changes, the team will not support spaces in pathnames. + +I'm adding a binary in a recipe. Why is it different in the image? +------------------------------------------------------------------ + +The first most obvious change is the system stripping debug symbols from +it. Setting :term:`INHIBIT_PACKAGE_STRIP` to stop debug symbols being +stripped and/or :term:`INHIBIT_PACKAGE_DEBUG_SPLIT` to stop debug symbols +being split into a separate file will ensure the binary is unchanged. + +Issues on the running system +============================ + +How do I disable the cursor on my touchscreen device? +----------------------------------------------------- + +You need to create a form factor file as described in the +":ref:`bsp-guide/bsp:miscellaneous bsp-specific recipe files`" section in +the Yocto Project Board Support Packages (BSP) Developer's Guide. Set +the ``HAVE_TOUCHSCREEN`` variable equal to one as follows:: + + HAVE_TOUCHSCREEN=1 + +How to always bring up connected network interfaces? +---------------------------------------------------- + +The default interfaces file provided by the netbase recipe does +not automatically bring up network interfaces. Therefore, you will need +to add a BSP-specific netbase that includes an interfaces file. See the +":ref:`bsp-guide/bsp:miscellaneous bsp-specific recipe files`" section in +the Yocto Project Board Support Packages (BSP) Developer's Guide for +information on creating these types of miscellaneous recipe files. + +For example, add the following files to your layer:: + + meta-MACHINE/recipes-bsp/netbase/netbase/MACHINE/interfaces + meta-MACHINE/recipes-bsp/netbase/netbase_5.0.bbappend |