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diff --git a/documentation/bsp-guide/bsp.xml b/documentation/bsp-guide/bsp.xml deleted file mode 100644 index 72a077e806..0000000000 --- a/documentation/bsp-guide/bsp.xml +++ /dev/null @@ -1,2259 +0,0 @@ -<!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" -"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd" -[<!ENTITY % poky SYSTEM "../poky.ent"> %poky; ] > -<!--SPDX-License-Identifier: CC-BY-2.0-UK--> - -<chapter id='bsp'> - -<title>Board Support Packages (BSP) - Developer's Guide</title> - -<para> - A Board Support Package (BSP) is a collection of information that - defines how to support a particular hardware device, set of devices, or - hardware platform. - The BSP includes information about the hardware features - present on the device and kernel configuration information along with any - additional hardware drivers required. - The BSP also lists any additional software - components required in addition to a generic Linux software stack for both - essential and optional platform features. -</para> - -<para> - This guide presents information about BSP layers, defines a structure for components - so that BSPs follow a commonly understood layout, discusses how to customize - a recipe for a BSP, addresses BSP licensing, and provides information that - shows you how to create a - <link linkend='bsp-layers'>BSP Layer</link> using the - <link linkend='creating-a-new-bsp-layer-using-the-bitbake-layers-script'><filename>bitbake-layers</filename></link> - tool. -</para> - -<section id='bsp-layers'> - <title>BSP Layers</title> - - <para> - A BSP consists of a file structure inside a base directory. - Collectively, you can think of the base directory, its file structure, - and the contents as a <firstterm>BSP layer</firstterm>. - Although not a strict requirement, BSP layers in the Yocto Project - use the following well-established naming convention: - <literallayout class='monospaced'> - meta-<replaceable>bsp_root_name</replaceable> - </literallayout> - The string "meta-" is prepended to the machine or platform name, which is - <replaceable>bsp_root_name</replaceable> in the above form. - <note><title>Tip</title> - Because the BSP layer naming convention is well-established, - it is advisable to follow it when creating layers. - Technically speaking, a BSP layer name does not need to - start with <filename>meta-</filename>. - However, various scripts and tools in the Yocto Project - development environment assume this convention. - </note> - </para> - - <para> - To help understand the BSP layer concept, consider the BSPs that the - Yocto Project supports and provides with each release. - You can see the layers in the - <ulink url='&YOCTO_DOCS_OM_URL;#yocto-project-repositories'>Yocto Project Source Repositories</ulink> - through a web interface at - <ulink url='&YOCTO_GIT_URL;'></ulink>. - If you go to that interface, you will find a list of repositories - under "Yocto Metadata Layers". - <note> - Layers that are no longer actively supported as part of the - Yocto Project appear under the heading "Yocto Metadata Layer - Archive." - </note> - Each repository is a BSP layer supported by the Yocto Project - (e.g. <filename>meta-raspberrypi</filename> and - <filename>meta-intel</filename>). - Each of these layers is a repository unto itself and clicking on - the layer name displays two URLs from which you can - clone the layer's repository to your local system. - Here is an example that clones the Raspberry Pi BSP layer: - <literallayout class='monospaced'> - $ git clone git://git.yoctoproject.org/meta-raspberrypi - </literallayout> - </para> - - <para> - In addition to BSP layers, the - <filename>meta-yocto-bsp</filename> layer is part of the - shipped <filename>poky</filename> repository. - The <filename>meta-yocto-bsp</filename> layer maintains several - "reference" BSPs including the ARM-based Beaglebone, MIPS-based - EdgeRouter, and generic versions of - both 32-bit and 64-bit IA machines. - </para> - - <para> - For information on typical BSP development workflow, see the - "<link linkend='developing-a-board-support-package-bsp'>Developing a Board Support Package (BSP)</link>" - section. - For more information on how to set up a local copy of source files - from a Git repository, see the - "<ulink url='&YOCTO_DOCS_DEV_URL;#locating-yocto-project-source-files'>Locating Yocto Project Source Files</ulink>" - section in the Yocto Project Development Tasks Manual. - </para> - - <para> - The BSP layer's base directory - (<filename>meta-<replaceable>bsp_root_name</replaceable></filename>) - is the root directory of that Layer. - This directory is what you add to the - <ulink url='&YOCTO_DOCS_REF_URL;#var-BBLAYERS'><filename>BBLAYERS</filename></ulink> - variable in the <filename>conf/bblayers.conf</filename> file found in your - <ulink url='&YOCTO_DOCS_REF_URL;#build-directory'>Build Directory</ulink>, - which is established after you run the OpenEmbedded build environment - setup script (i.e. - <ulink url='&YOCTO_DOCS_REF_URL;#structure-core-script'><filename>&OE_INIT_FILE;</filename></ulink>). - Adding the root directory allows the - <ulink url='&YOCTO_DOCS_REF_URL;#build-system-term'>OpenEmbedded build system</ulink> - to recognize the BSP layer and from it build an image. - Here is an example: - <literallayout class='monospaced'> - BBLAYERS ?= " \ - /usr/local/src/yocto/meta \ - /usr/local/src/yocto/meta-poky \ - /usr/local/src/yocto/meta-yocto-bsp \ - /usr/local/src/yocto/meta-mylayer \ - " - </literallayout> - <note><title>Tip</title> - Ordering and - <ulink url='&YOCTO_DOCS_REF_URL;#var-BBFILE_PRIORITY'><filename>BBFILE_PRIORITY</filename></ulink> - for the layers listed in <filename>BBLAYERS</filename> - matter. - For example, if multiple layers define a machine - configuration, the OpenEmbedded build system uses - the last layer searched given similar layer - priorities. - The build system works from the top-down through - the layers listed in <filename>BBLAYERS</filename>. - </note> - </para> - - <para> - Some BSPs require or depend on additional layers - beyond the BSP's root layer in order to be functional. - In this case, you need to specify these layers in the - <filename>README</filename> "Dependencies" section of the - BSP's root layer. - Additionally, if any build instructions exist for the - BSP, you must add them to the "Dependencies" section. - </para> - - <para> - Some layers function as a layer to hold other BSP layers. - These layers are knows as - "<ulink url='&YOCTO_DOCS_REF_URL;#term-container-layer'>container layers</ulink>". - An example of this type of layer is OpenEmbedded's - <ulink url='https://github.com/openembedded/meta-openembedded'><filename>meta-openembedded</filename></ulink> - layer. - The <filename>meta-openembedded</filename> layer contains - many <filename>meta-*</filename> layers. - In cases like this, you need to include the names of the actual - layers you want to work with, such as: - <literallayout class='monospaced'> - BBLAYERS ?= " \ - /usr/local/src/yocto/meta \ - /usr/local/src/yocto/meta-poky \ - /usr/local/src/yocto/meta-yocto-bsp \ - /usr/local/src/yocto/meta-mylayer \ - .../meta-openembedded/meta-oe \ - .../meta-openembedded/meta-perl \ - .../meta-openembedded/meta-networking \ - " - </literallayout> - and so on. - </para> - - <para> - For more information on layers, see the - "<ulink url='&YOCTO_DOCS_DEV_URL;#understanding-and-creating-layers'>Understanding and Creating Layers</ulink>" - section of the Yocto Project Development Tasks Manual. - </para> -</section> - -<section id='preparing-your-build-host-to-work-with-bsp-layers'> - <title>Preparing Your Build Host to Work With BSP Layers</title> - - <para> - This section describes how to get your build host ready - to work with BSP layers. - Once you have the host set up, you can create the layer - as described in the - "<link linkend='creating-a-new-bsp-layer-using-the-bitbake-layers-script'>Creating a new BSP Layer Using the <filename>bitbake-layers</filename> Script</link>" - section. - <note> - For structural information on BSPs, see the - <link linkend='bsp-filelayout'>Example Filesystem Layout</link> - section. - </note> - <orderedlist> - <listitem><para> - <emphasis>Set Up the Build Environment:</emphasis> - Be sure you are set up to use BitBake in a shell. - See the - "<ulink url='&YOCTO_DOCS_DEV_URL;#dev-preparing-the-build-host'>Preparing the Build Host</ulink>" - section in the Yocto Project Development Tasks Manual for information - on how to get a build host ready that is either a native - Linux machine or a machine that uses CROPS. - </para></listitem> - <listitem><para> - <emphasis>Clone the <filename>poky</filename> Repository:</emphasis> - You need to have a local copy of the Yocto Project - <ulink url='&YOCTO_DOCS_REF_URL;#source-directory'>Source Directory</ulink> - (i.e. a local <filename>poky</filename> repository). - See the - "<ulink url='&YOCTO_DOCS_DEV_URL;#cloning-the-poky-repository'>Cloning the <filename>poky</filename> Repository</ulink>" - and possibly the - "<ulink url='&YOCTO_DOCS_DEV_URL;#checking-out-by-branch-in-poky'>Checking Out by Branch in Poky</ulink>" - or - "<ulink url='&YOCTO_DOCS_DEV_URL;#checkout-out-by-tag-in-poky'>Checking Out by Tag in Poky</ulink>" - sections all in the Yocto Project Development Tasks Manual for - information on how to clone the <filename>poky</filename> - repository and check out the appropriate branch for your work. - </para></listitem> - <listitem><para> - <emphasis>Determine the BSP Layer You Want:</emphasis> - The Yocto Project supports many BSPs, which are maintained in - their own layers or in layers designed to contain several - BSPs. - To get an idea of machine support through BSP layers, you can - look at the - <ulink url='&YOCTO_RELEASE_DL_URL;/machines'>index of machines</ulink> - for the release. - </para></listitem> - <listitem><para> - <emphasis>Optionally Clone the - <filename>meta-intel</filename> BSP Layer:</emphasis> - If your hardware is based on current Intel CPUs and devices, - you can leverage this BSP layer. - For details on the <filename>meta-intel</filename> BSP layer, - see the layer's - <ulink url='http://git.yoctoproject.org/cgit/cgit.cgi/meta-intel/tree/README'><filename>README</filename></ulink> - file. - <orderedlist> - <listitem><para> - <emphasis>Navigate to Your Source Directory:</emphasis> - Typically, you set up the - <filename>meta-intel</filename> Git repository - inside the - <ulink url='&YOCTO_DOCS_REF_URL;#source-directory'>Source Directory</ulink> - (e.g. <filename>poky</filename>). - <literallayout class='monospaced'> - $ cd /home/<replaceable>you</replaceable>/poky - </literallayout> - </para></listitem> - <listitem><para> - <emphasis>Clone the Layer:</emphasis> - <literallayout class='monospaced'> - $ git clone git://git.yoctoproject.org/meta-intel.git - Cloning into 'meta-intel'... - remote: Counting objects: 15585, done. - remote: Compressing objects: 100% (5056/5056), done. - remote: Total 15585 (delta 9123), reused 15329 (delta 8867) - Receiving objects: 100% (15585/15585), 4.51 MiB | 3.19 MiB/s, done. - Resolving deltas: 100% (9123/9123), done. - Checking connectivity... done. - </literallayout> - </para></listitem> - <listitem><para> - <emphasis>Check Out the Proper Branch:</emphasis> - The branch you check out for - <filename>meta-intel</filename> must match the same - branch you are using for the Yocto Project release - (e.g. &DISTRO_NAME_NO_CAP;): - <literallayout class='monospaced'> - $ cd meta-intel - $ git checkout -b &DISTRO_NAME_NO_CAP; remotes/origin/&DISTRO_NAME_NO_CAP; - Branch &DISTRO_NAME_NO_CAP; set up to track remote branch &DISTRO_NAME_NO_CAP; from origin. - Switched to a new branch '&DISTRO_NAME_NO_CAP;' - </literallayout> - <note> - To see the available branch names in a cloned repository, - use the <filename>git branch -al</filename> command. - See the - "<ulink url='&YOCTO_DOCS_DEV_URL;#checking-out-by-branch-in-poky'>Checking Out By Branch in Poky</ulink>" - section in the Yocto Project Development Tasks - Manual for more information. - </note> - </para></listitem> - </orderedlist> - </para></listitem> - <listitem><para> - <emphasis>Optionally Set Up an Alternative BSP Layer:</emphasis> - If your hardware can be more closely leveraged to an - existing BSP not within the <filename>meta-intel</filename> - BSP layer, you can clone that BSP layer.</para> - - <para>The process is identical to the process used for the - <filename>meta-intel</filename> layer except for the layer's - name. - For example, if you determine that your hardware most - closely matches the <filename>meta-raspberrypi</filename>, - clone that layer: - <literallayout class='monospaced'> - $ git clone git://git.yoctoproject.org/meta-raspberrypi - Cloning into 'meta-raspberrypi'... - remote: Counting objects: 4743, done. - remote: Compressing objects: 100% (2185/2185), done. - remote: Total 4743 (delta 2447), reused 4496 (delta 2258) - Receiving objects: 100% (4743/4743), 1.18 MiB | 0 bytes/s, done. - Resolving deltas: 100% (2447/2447), done. - Checking connectivity... done. - </literallayout> - </para></listitem> - <listitem><para> - <emphasis>Initialize the Build Environment:</emphasis> - While in the root directory of the Source Directory (i.e. - <filename>poky</filename>), run the - <ulink url='&YOCTO_DOCS_REF_URL;#structure-core-script'><filename>&OE_INIT_FILE;</filename></ulink> - environment setup script to define the OpenEmbedded - build environment on your build host. - <literallayout class='monospaced'> - $ source &OE_INIT_FILE; - </literallayout> - Among other things, the script creates the - <ulink url='&YOCTO_DOCS_REF_URL;#build-directory'>Build Directory</ulink>, - which is <filename>build</filename> in this case - and is located in the - <ulink url='&YOCTO_DOCS_REF_URL;#source-directory'>Source Directory</ulink>. - After the script runs, your current working directory - is set to the <filename>build</filename> directory. - </para></listitem> - </orderedlist> - </para> -</section> - -<section id="bsp-filelayout"> - <title>Example Filesystem Layout</title> - - <para> - Defining a common BSP directory structure allows - end-users to understand and become familiar with - that standard. - A common format also encourages standardization - of software support for hardware. - </para> - - <para> - The proposed form described in this section does - have elements that are specific to the OpenEmbedded - build system. - It is intended that developers can use this structure - with other build systems besides the OpenEmbedded build - system. - It is also intended that it will be be simple to extract - information and convert it to other formats if required. - The OpenEmbedded build system, through its standard - <ulink url='&YOCTO_DOCS_OM_URL;#the-yocto-project-layer-model'>layers mechanism</ulink>, - can directly accept the format described as a layer. - The BSP layer captures all the hardware-specific details - in one place using a standard format, which is useful - for any person wishing to use the hardware platform - regardless of the build system they are using. - </para> - - <para> - The BSP specification does not include a build system - or other tools - the specification is concerned with - the hardware-specific components only. - At the end-distribution point, you can ship the BSP - layer combined with a build system and other tools. - Realize that it is important to maintain the distinction - that the BSP layer, a build system, and tools are - separate components that could be combined in - certain end products. - </para> - - <para> - Before looking at the recommended form for the directory structure - inside a BSP layer, you should be aware that some - requirements do exist in order for a BSP layer to - be considered <firstterm>compliant</firstterm> with the Yocto Project. - For that list of requirements, see the - "<link linkend='released-bsp-requirements'>Released BSP Requirements</link>" - section. - </para> - - <para> - Below is the typical directory structure for a BSP layer. - While this basic form represents the standard, - realize that the actual layout for individual - BSPs could differ. - <literallayout class='monospaced'> - meta-<replaceable>bsp_root_name</replaceable>/ - meta-<replaceable>bsp_root_name</replaceable>/<replaceable>bsp_license_file</replaceable> - meta-<replaceable>bsp_root_name</replaceable>/README - meta-<replaceable>bsp_root_name</replaceable>/README.sources - meta-<replaceable>bsp_root_name</replaceable>/binary/<replaceable>bootable_images</replaceable> - meta-<replaceable>bsp_root_name</replaceable>/conf/layer.conf - meta-<replaceable>bsp_root_name</replaceable>/conf/machine/*.conf - meta-<replaceable>bsp_root_name</replaceable>/recipes-bsp/* - meta-<replaceable>bsp_root_name</replaceable>/recipes-core/* - meta-<replaceable>bsp_root_name</replaceable>/recipes-graphics/* - meta-<replaceable>bsp_root_name</replaceable>/recipes-kernel/linux/linux-yocto_<replaceable>kernel_rev</replaceable>.bbappend - </literallayout> - </para> - - <para> - Below is an example of the Raspberry Pi BSP - layer that is available from the - <ulink url='&YOCTO_GIT_URL;'>Source Respositories</ulink>: - <literallayout class='monospaced'> - meta-raspberrypi/COPYING.MIT - meta-raspberrypi/README.md - meta-raspberrypi/classes - meta-raspberrypi/classes/sdcard_image-rpi.bbclass - meta-raspberrypi/conf/ - meta-raspberrypi/conf/layer.conf - meta-raspberrypi/conf/machine/ - meta-raspberrypi/conf/machine/raspberrypi-cm.conf - meta-raspberrypi/conf/machine/raspberrypi-cm3.conf - meta-raspberrypi/conf/machine/raspberrypi.conf - meta-raspberrypi/conf/machine/raspberrypi0-wifi.conf - meta-raspberrypi/conf/machine/raspberrypi0.conf - meta-raspberrypi/conf/machine/raspberrypi2.conf - meta-raspberrypi/conf/machine/raspberrypi3-64.conf - meta-raspberrypi/conf/machine/raspberrypi3.conf - meta-raspberrypi/conf/machine/include - meta-raspberrypi/conf/machine/include/rpi-base.inc - meta-raspberrypi/conf/machine/include/rpi-default-providers.inc - meta-raspberrypi/conf/machine/include/rpi-default-settings.inc - meta-raspberrypi/conf/machine/include/rpi-default-versions.inc - meta-raspberrypi/conf/machine/include/tune-arm1176jzf-s.inc - meta-raspberrypi/docs - meta-raspberrypi/docs/Makefile - meta-raspberrypi/docs/conf.py - meta-raspberrypi/docs/contributing.md - meta-raspberrypi/docs/extra-apps.md - meta-raspberrypi/docs/extra-build-config.md - meta-raspberrypi/docs/index.rst - meta-raspberrypi/docs/layer-contents.md - meta-raspberrypi/docs/readme.md - meta-raspberrypi/files - meta-raspberrypi/files/custom-licenses - meta-raspberrypi/files/custom-licenses/Broadcom - meta-raspberrypi/recipes-bsp - meta-raspberrypi/recipes-bsp/bootfiles - meta-raspberrypi/recipes-bsp/bootfiles/bcm2835-bootfiles.bb - meta-raspberrypi/recipes-bsp/bootfiles/rpi-config_git.bb - meta-raspberrypi/recipes-bsp/common - meta-raspberrypi/recipes-bsp/common/firmware.inc - meta-raspberrypi/recipes-bsp/formfactor - meta-raspberrypi/recipes-bsp/formfactor/formfactor - meta-raspberrypi/recipes-bsp/formfactor/formfactor/raspberrypi - meta-raspberrypi/recipes-bsp/formfactor/formfactor/raspberrypi/machconfig - meta-raspberrypi/recipes-bsp/formfactor/formfactor_0.0.bbappend - meta-raspberrypi/recipes-bsp/rpi-u-boot-src - meta-raspberrypi/recipes-bsp/rpi-u-boot-src/files - meta-raspberrypi/recipes-bsp/rpi-u-boot-src/files/boot.cmd.in - meta-raspberrypi/recipes-bsp/rpi-u-boot-src/rpi-u-boot-scr.bb - meta-raspberrypi/recipes-bsp/u-boot - meta-raspberrypi/recipes-bsp/u-boot/u-boot - meta-raspberrypi/recipes-bsp/u-boot/u-boot/*.patch - meta-raspberrypi/recipes-bsp/u-boot/u-boot_%.bbappend - meta-raspberrypi/recipes-connectivity - meta-raspberrypi/recipes-connectivity/bluez5 - meta-raspberrypi/recipes-connectivity/bluez5/bluez5 - meta-raspberrypi/recipes-connectivity/bluez5/bluez5/*.patch - meta-raspberrypi/recipes-connectivity/bluez5/bluez5/BCM43430A1.hcd - meta-raspberrypi/recipes-connectivity/bluez5/bluez5brcm43438.service - meta-raspberrypi/recipes-connectivity/bluez5/bluez5_%.bbappend - meta-raspberrypi/recipes-core - meta-raspberrypi/recipes-core/images - meta-raspberrypi/recipes-core/images/rpi-basic-image.bb - meta-raspberrypi/recipes-core/images/rpi-hwup-image.bb - meta-raspberrypi/recipes-core/images/rpi-test-image.bb - meta-raspberrypi/recipes-core/packagegroups - meta-raspberrypi/recipes-core/packagegroups/packagegroup-rpi-test.bb - meta-raspberrypi/recipes-core/psplash - meta-raspberrypi/recipes-core/psplash/files - meta-raspberrypi/recipes-core/psplash/files/psplash-raspberrypi-img.h - meta-raspberrypi/recipes-core/psplash/psplash_git.bbappend - meta-raspberrypi/recipes-core/udev - meta-raspberrypi/recipes-core/udev/udev-rules-rpi - meta-raspberrypi/recipes-core/udev/udev-rules-rpi/99-com.rules - meta-raspberrypi/recipes-core/udev/udev-rules-rpi.bb - meta-raspberrypi/recipes-devtools - meta-raspberrypi/recipes-devtools/bcm2835 - meta-raspberrypi/recipes-devtools/bcm2835/bcm2835_1.52.bb - meta-raspberrypi/recipes-devtools/pi-blaster - meta-raspberrypi/recipes-devtools/pi-blaster/files - meta-raspberrypi/recipes-devtools/pi-blaster/files/*.patch - meta-raspberrypi/recipes-devtools/pi-blaster/pi-blaster_git.bb - meta-raspberrypi/recipes-devtools/python - meta-raspberrypi/recipes-devtools/python/python-rtimu - meta-raspberrypi/recipes-devtools/python/python-rtimu/*.patch - meta-raspberrypi/recipes-devtools/python/python-rtimu_git.bb - meta-raspberrypi/recipes-devtools/python/python-sense-hat_2.2.0.bb - meta-raspberrypi/recipes-devtools/python/rpi-gpio - meta-raspberrypi/recipes-devtools/python/rpi-gpio/*.patch - meta-raspberrypi/recipes-devtools/python/rpi-gpio_0.6.3.bb - meta-raspberrypi/recipes-devtools/python/rpio - meta-raspberrypi/recipes-devtools/python/rpio/*.patch - meta-raspberrypi/recipes-devtools/python/rpio_0.10.0.bb - meta-raspberrypi/recipes-devtools/wiringPi - meta-raspberrypi/recipes-devtools/wiringPi/files - meta-raspberrypi/recipes-devtools/wiringPi/files/*.patch - meta-raspberrypi/recipes-devtools/wiringPi/wiringpi_git.bb - meta-raspberrypi/recipes-graphics - meta-raspberrypi/recipes-graphics/eglinfo - meta-raspberrypi/recipes-graphics/eglinfo/eglinfo-fb_%.bbappend - meta-raspberrypi/recipes-graphics/eglinfo/eglinfo-x11_%.bbappend - meta-raspberrypi/recipes-graphics/mesa - meta-raspberrypi/recipes-graphics/mesa/mesa-gl_%.bbappend - meta-raspberrypi/recipes-graphics/mesa/mesa_%.bbappend - meta-raspberrypi/recipes-graphics/userland - meta-raspberrypi/recipes-graphics/userland/userland - meta-raspberrypi/recipes-graphics/userland/userland/*.patch - meta-raspberrypi/recipes-graphics/userland/userland_git.bb - meta-raspberrypi/recipes-graphics/vc-graphics - meta-raspberrypi/recipes-graphics/vc-graphics/files - meta-raspberrypi/recipes-graphics/vc-graphics/files/egl.pc - meta-raspberrypi/recipes-graphics/vc-graphics/files/vchiq.sh - meta-raspberrypi/recipes-graphics/vc-graphics/vc-graphics-hardfp.bb - meta-raspberrypi/recipes-graphics/vc-graphics/vc-graphics.bb - meta-raspberrypi/recipes-graphics/vc-graphics/vc-graphics.inc - meta-raspberrypi/recipes-graphics/wayland - meta-raspberrypi/recipes-graphics/wayland/weston_%.bbappend - meta-raspberrypi/recipes-graphics/xorg-xserver - meta-raspberrypi/recipes-graphics/xorg-xserver/xserver-xf86-config - meta-raspberrypi/recipes-graphics/xorg-xserver/xserver-xf86-config/rpi - meta-raspberrypi/recipes-graphics/xorg-xserver/xserver-xf86-config/rpi/xorg.conf - meta-raspberrypi/recipes-graphics/xorg-xserver/xserver-xf86-config/rpi/xorg.conf.d - meta-raspberrypi/recipes-graphics/xorg-xserver/xserver-xf86-config/rpi/xorg.conf.d/10-evdev.conf - meta-raspberrypi/recipes-graphics/xorg-xserver/xserver-xf86-config/rpi/xorg.conf.d/98-pitft.conf - meta-raspberrypi/recipes-graphics/xorg-xserver/xserver-xf86-config/rpi/xorg.conf.d/99-calibration.conf - meta-raspberrypi/recipes-graphics/xorg-xserver/xserver-xf86-config_0.1.bbappend - meta-raspberrypi/recipes-graphics/xorg-xserver/xserver-xorg_%.bbappend - meta-raspberrypi/recipes-kernel - meta-raspberrypi/recipes-kernel/linux-firmware - meta-raspberrypi/recipes-kernel/linux-firmware/files - meta-raspberrypi/recipes-kernel/linux-firmware/files/brcmfmac43430-sdio.bin - meta-raspberrypi/recipes-kernel/linux-firmware/files/brcfmac43430-sdio.txt - meta-raspberrypi/recipes-kernel/linux-firmware/linux-firmware_%.bbappend - meta-raspberrypi/recipes-kernel/linux - meta-raspberrypi/recipes-kernel/linux/linux-raspberrypi-dev.bb - meta-raspberrypi/recipes-kernel/linux/linux-raspberrypi.inc - meta-raspberrypi/recipes-kernel/linux/linux-raspberrypi_4.14.bb - meta-raspberrypi/recipes-kernel/linux/linux-raspberrypi_4.9.bb - meta-raspberrypi/recipes-multimedia - meta-raspberrypi/recipes-multimedia/gstreamer - meta-raspberrypi/recipes-multimedia/gstreamer/gstreamer1.0-omx - meta-raspberrypi/recipes-multimedia/gstreamer/gstreamer1.0-omx/*.patch - meta-raspberrypi/recipes-multimedia/gstreamer/gstreamer1.0-omx_%.bbappend - meta-raspberrypi/recipes-multimedia/gstreamer/gstreamer1.0-plugins-bad_%.bbappend - meta-raspberrypi/recipes-multimedia/gstreamer/gstreamer1.0-omx-1.12 - meta-raspberrypi/recipes-multimedia/gstreamer/gstreamer1.0-omx-1.12/*.patch - meta-raspberrypi/recipes-multimedia/omxplayer - meta-raspberrypi/recipes-multimedia/omxplayer/omxplayer - meta-raspberrypi/recipes-multimedia/omxplayer/omxplayer/*.patch - meta-raspberrypi/recipes-multimedia/omxplayer/omxplayer_git.bb - meta-raspberrypi/recipes-multimedia/x264 - meta-raspberrypi/recipes-multimedia/x264/x264_git.bbappend - meta-raspberrypi/wic - meta-raspberrypi/wic/sdimage-raspberrypi.wks - </literallayout> - </para> - - <para> - The following sections describe each part of the proposed - BSP format. - </para> - - <section id="bsp-filelayout-license"> - <title>License Files</title> - - <para> - You can find these files in the BSP Layer at: - <literallayout class='monospaced'> - meta-<replaceable>bsp_root_name</replaceable>/<replaceable>bsp_license_file</replaceable> - </literallayout> - </para> - - <para> - These optional files satisfy licensing requirements - for the BSP. - The type or types of files here can vary depending - on the licensing requirements. - For example, in the Raspberry Pi BSP, all licensing - requirements are handled with the - <filename>COPYING.MIT</filename> file. - </para> - - <para> - Licensing files can be MIT, BSD, GPLv*, and so forth. - These files are recommended for the BSP but are - optional and totally up to the BSP developer. - For information on how to maintain license - compliance, see the - "<ulink url='&YOCTO_DOCS_DEV_URL;#maintaining-open-source-license-compliance-during-your-products-lifecycle'>Maintaining Open Source License Compliance During Your Product's Lifecycle</ulink>" - section in the Yocto Project Development Tasks - Manual. - </para> - </section> - - <section id="bsp-filelayout-readme"> - <title>README File</title> - - <para> - You can find this file in the BSP Layer at: - <literallayout class='monospaced'> - meta-<replaceable>bsp_root_name</replaceable>/README - </literallayout> - </para> - - <para> - This file provides information on how to boot the live - images that are optionally included in the - <filename>binary/</filename> directory. - The <filename>README</filename> file also provides - information needed for building the image. - </para> - - <para> - At a minimum, the <filename>README</filename> file must - contain a list of dependencies, such as the names of - any other layers on which the BSP depends and the name of - the BSP maintainer with his or her contact information. - </para> - </section> - - <section id="bsp-filelayout-readme-sources"> - <title>README.sources File</title> - - <para> - You can find this file in the BSP Layer at: - <literallayout class='monospaced'> - meta-<replaceable>bsp_root_name</replaceable>/README.sources - </literallayout> - </para> - - <para> - This file provides information on where to locate the BSP - source files used to build the images (if any) that - reside in - <filename>meta-<replaceable>bsp_root_name</replaceable>/binary</filename>. - Images in the <filename>binary</filename> would be images - released with the BSP. - The information in the <filename>README.sources</filename> - file also helps you find the - <ulink url='&YOCTO_DOCS_REF_URL;#metadata'>Metadata</ulink> - used to generate the images that ship with the BSP. - <note> - If the BSP's <filename>binary</filename> directory is - missing or the directory has no images, an existing - <filename>README.sources</filename> file is - meaningless and usually does not exist. - </note> - </para> - </section> - - <section id="bsp-filelayout-binary"> - <title>Pre-built User Binaries</title> - - <para> - You can find these files in the BSP Layer at: - <literallayout class='monospaced'> - meta-<replaceable>bsp_root_name</replaceable>/binary/<replaceable>bootable_images</replaceable> - </literallayout> - </para> - - <para> - This optional area contains useful pre-built kernels - and user-space filesystem images released with the - BSP that are appropriate to the target system. - This directory typically contains graphical (e.g. Sato) - and minimal live images when the BSP tarball has been - created and made available in the - <ulink url='&YOCTO_HOME_URL;'>Yocto Project</ulink> - website. - You can use these kernels and images to get a system - running and quickly get started on development tasks. - </para> - - <para> - The exact types of binaries present are highly - hardware-dependent. - The - <link linkend='bsp-filelayout-readme'><filename>README</filename></link> - file should be present in the BSP Layer and it - explains how to use the images with the target hardware. - Additionally, the - <link linkend='bsp-filelayout-readme-sources'><filename>README.sources</filename></link> - file should be present to locate the sources used to - build the images and provide information on the - Metadata. - </para> - </section> - - <section id='bsp-filelayout-layer'> - <title>Layer Configuration File</title> - - <para> - You can find this file in the BSP Layer at: - <literallayout class='monospaced'> - meta-<replaceable>bsp_root_name</replaceable>/conf/layer.conf - </literallayout> - </para> - - <para> - The <filename>conf/layer.conf</filename> file - identifies the file structure as a layer, - identifies the contents of the layer, and - contains information about how the build system should - use it. - Generally, a standard boilerplate file such as the - following works. - In the following example, you would replace - <replaceable>bsp</replaceable> with the actual - name of the BSP (i.e. - <replaceable>bsp_root_name</replaceable> from the example - template). - </para> - - <para> - <literallayout class='monospaced'> - # We have a conf and classes directory, add to BBPATH - BBPATH .= ":${LAYERDIR}" - - # We have a recipes directory, add to BBFILES - BBFILES += "${LAYERDIR}/recipes-*/*/*.bb \ - ${LAYERDIR}/recipes-*/*/*.bbappend" - - BBFILE_COLLECTIONS += "<replaceable>bsp</replaceable>" - BBFILE_PATTERN_<replaceable>bsp</replaceable> = "^${LAYERDIR}/" - BBFILE_PRIORITY_<replaceable>bsp</replaceable> = "6" - - LAYERDEPENDS_<replaceable>bsp</replaceable> = "intel" - </literallayout> - </para> - - <para> - To illustrate the string substitutions, here are - the corresponding statements from the Raspberry - Pi <filename>conf/layer.conf</filename> file: - <literallayout class='monospaced'> - # We have a conf and classes directory, append to BBPATH - BBPATH .= ":${LAYERDIR}" - - # We have a recipes directory containing .bb and .bbappend files, add to BBFILES - BBFILES += "${LAYERDIR}/recipes*/*/*.bb \ - ${LAYERDIR}/recipes*/*/*.bbappend" - - BBFILE_COLLECTIONS += "raspberrypi" - BBFILE_PATTERN_raspberrypi := "^${LAYERDIR}/" - BBFILE_PRIORITY_raspberrypi = "9" - - # Additional license directories. - LICENSE_PATH += "${LAYERDIR}/files/custom-licenses" - . - . - . - </literallayout> - </para> - - <para> - This file simply makes - <ulink url='&YOCTO_DOCS_REF_URL;#bitbake-term'>BitBake</ulink> - aware of the recipes and configuration directories. - The file must exist so that the OpenEmbedded build system - can recognize the BSP. - </para> - </section> - - <section id="bsp-filelayout-machine"> - <title>Hardware Configuration Options</title> - - <para> - You can find these files in the BSP Layer at: - <literallayout class='monospaced'> - meta-<replaceable>bsp_root_name</replaceable>/conf/machine/*.conf - </literallayout> - </para> - - <para> - The machine files bind together all the information - contained elsewhere in the BSP into a format that - the build system can understand. - Each BSP Layer requires at least one machine file. - If the BSP supports multiple machines, multiple - machine configuration files can exist. - These filenames correspond to the values to which - users have set the - <ulink url='&YOCTO_DOCS_REF_URL;#var-MACHINE'><filename>MACHINE</filename></ulink> variable. - </para> - - <para> - These files define things such as the kernel package - to use - (<ulink url='&YOCTO_DOCS_REF_URL;#var-PREFERRED_PROVIDER'><filename>PREFERRED_PROVIDER</filename></ulink> - of - <ulink url='&YOCTO_DOCS_DEV_URL;#metadata-virtual-providers'>virtual/kernel</ulink>), - the hardware drivers to include in different types - of images, any special software components that are - needed, any bootloader information, and also any - special image format requirements. - </para> - - <para> - This configuration file could also include a hardware - "tuning" file that is commonly used to define the - package architecture and specify optimization flags, - which are carefully chosen to give best performance - on a given processor. - </para> - - <para> - Tuning files are found in the - <filename>meta/conf/machine/include</filename> - directory within the - <ulink url='&YOCTO_DOCS_REF_URL;#source-directory'>Source Directory</ulink>. - For example, many <filename>tune-*</filename> files - (e.g. <filename>tune-arm1136jf-s.inc</filename>, - <filename>tune-1586-nlp.inc</filename>, and so forth) - reside in the - <filename>poky/meta/conf/machine/include</filename> - directory. - </para> - - <para> - To use an include file, you simply include them in the - machine configuration file. - For example, the Raspberry Pi BSP - <filename>raspberrypi3.conf</filename> contains the - following statement: - <literallayout class='monospaced'> - include conf/machine/include/rpi-base.inc - </literallayout> - </para> - </section> - - <section id='bsp-filelayout-misc-recipes'> - <title>Miscellaneous BSP-Specific Recipe Files</title> - - <para> - You can find these files in the BSP Layer at: - <literallayout class='monospaced'> - meta-<replaceable>bsp_root_name</replaceable>/recipes-bsp/* - </literallayout> - </para> - - <para> - This optional directory contains miscellaneous recipe - files for the BSP. - Most notably would be the formfactor files. - For example, in the Raspberry Pi BSP, there is the - <filename>formfactor_0.0.bbappend</filename> file, - which is an append file used to augment the recipe - that starts the build. - Furthermore, there are machine-specific settings used - during the build that are defined by the - <filename>machconfig</filename> file further down in - the directory. - Here is the <filename>machconfig</filename> file for - the Raspberry Pi BSP: - <literallayout class='monospaced'> - HAVE_TOUCHSCREEN=0 - HAVE_KEYBOARD=1 - - DISPLAY_CAN_ROTATE=0 - DISPLAY_ORIENTATION=0 - DISPLAY_DPI=133 - </literallayout> - </para> - - <note><para> - If a BSP does not have a formfactor entry, defaults - are established according to the formfactor - configuration file that is installed by the main - formfactor recipe - <filename>meta/recipes-bsp/formfactor/formfactor_0.0.bb</filename>, - which is found in the - <ulink url='&YOCTO_DOCS_REF_URL;#source-directory'>Source Directory</ulink>. - </para></note> - </section> - - <section id='bsp-filelayout-recipes-graphics'> - <title>Display Support Files</title> - - <para> - You can find these files in the BSP Layer at: - <literallayout class='monospaced'> - meta-<replaceable>bsp_root_name</replaceable>/recipes-graphics/* - </literallayout> - </para> - - <para> - This optional directory contains recipes for the - BSP if it has special requirements for graphics - support. - All files that are needed for the BSP to support - a display are kept here. - </para> - </section> - - <section id='bsp-filelayout-kernel'> - <title>Linux Kernel Configuration</title> - - <para> - You can find these files in the BSP Layer at: - <literallayout class='monospaced'> - meta-<replaceable>bsp_root_name</replaceable>/recipes-kernel/linux/linux*.bbappend - meta-<replaceable>bsp_root_name</replaceable>/recipes-kernel/linux/*.bb - </literallayout> - </para> - - <para> - Append files (<filename>*.bbappend</filename>) modify - the main kernel recipe being used to build the image. - The <filename>*.bb</filename> files would be a - developer-supplied kernel recipe. - This area of the BSP hierarchy can contain both these - types of files although, in practice, it is likely that - you would have one or the other. - </para> - - <para> - For your BSP, you typically want to use an existing Yocto - Project kernel recipe found in the - <ulink url='&YOCTO_DOCS_REF_URL;#source-directory'>Source Directory</ulink> - at <filename>meta/recipes-kernel/linux</filename>. - You can append machine-specific changes to the - kernel recipe by using a similarly named append - file, which is located in the BSP Layer for your - target device (e.g. the - <filename>meta-<replaceable>bsp_root_name</replaceable>/recipes-kernel/linux</filename> directory). - </para> - - <para> - Suppose you are using the - <filename>linux-yocto_4.4.bb</filename> recipe to - build the kernel. - In other words, you have selected the kernel in your - <replaceable>bsp_root_name</replaceable><filename>.conf</filename> - file by adding - <ulink url='&YOCTO_DOCS_REF_URL;#var-PREFERRED_PROVIDER'><filename>PREFERRED_PROVIDER</filename></ulink> - and - <ulink url='&YOCTO_DOCS_REF_URL;#var-PREFERRED_VERSION'><filename>PREFERRED_VERSION</filename></ulink> - statements as follows: - <literallayout class='monospaced'> - PREFERRED_PROVIDER_virtual/kernel ?= "linux-yocto" - PREFERRED_VERSION_linux-yocto ?= "4.4%" - </literallayout> - <note> - When the preferred provider is assumed by - default, the - <filename>PREFERRED_PROVIDER</filename> - statement does not appear in the - <replaceable>bsp_root_name</replaceable><filename>.conf</filename> file. - </note> - You would use the - <filename>linux-yocto_4.4.bbappend</filename> - file to append specific BSP settings to the kernel, - thus configuring the kernel for your particular BSP. - </para> - - <para> - You can find more information on what your append file - should contain in the - "<ulink url='&YOCTO_DOCS_KERNEL_DEV_URL;#creating-the-append-file'>Creating the Append File</ulink>" - section in the Yocto Project Linux Kernel Development - Manual. - </para> - - <para> - An alternate scenario is when you create your own - kernel recipe for the BSP. - A good example of this is the Raspberry Pi BSP. - If you examine the - <filename>recipes-kernel/linux</filename> directory - you see the following: - <literallayout class='monospaced'> - linux-raspberrypi-dev.bb - linux-raspberrypi.inc - linux-raspberrypi_4.14.bb - linux-raspberrypi_4.9.bb - </literallayout> - The directory contains three kernel recipes and a - common include file. - </para> - </section> -</section> - -<section id='developing-a-board-support-package-bsp'> - <title>Developing a Board Support Package (BSP)</title> - - <para> - This section describes the high-level procedure you can - follow to create a BSP. - Although not required for BSP creation, the - <filename>meta-intel</filename> repository, which - contains many BSPs supported by the Yocto Project, - is part of the example. - </para> - - <para> - For an example that shows how to create a new - layer using the tools, see the - "<link linkend='creating-a-new-bsp-layer-using-the-bitbake-layers-script'>Creating a New BSP Layer Using the <filename>bitbake-layers</filename> Script</link>" - section. - </para> - - <para> - The following illustration and list summarize the BSP - creation general workflow. - </para> - - <para> - <imagedata fileref="figures/bsp-dev-flow.png" width="7in" depth="5in" align="center" scalefit="1" /> - </para> - - <para> - <orderedlist> - <listitem><para> - <emphasis>Set up Your Host Development System - to Support Development Using the Yocto - Project</emphasis>: - See the - "<ulink url='&YOCTO_DOCS_DEV_URL;#dev-preparing-the-build-host'>Preparing the Build Host</ulink>" - section in the Yocto Project Development Tasks - Manual for options on how to get a system ready - to use the Yocto Project. - </para></listitem> - <listitem><para> - <emphasis>Establish the - <filename>meta-intel</filename> - Repository on Your System:</emphasis> - Having local copies of these supported BSP layers - on your system gives you access to layers you - might be able to leverage when creating your BSP. - For information on how to get these files, see the - "<link linkend='preparing-your-build-host-to-work-with-bsp-layers'>Preparing Your Build Host to Work with BSP Layers</link>" - section. - </para></listitem> - <listitem><para> - <emphasis>Create Your Own BSP Layer Using the - <filename>bitbake-layers</filename> - Script:</emphasis> - Layers are ideal for isolating and storing work - for a given piece of hardware. - A layer is really just a location or area in which you - place the recipes and configurations for your BSP. - In fact, a BSP is, in itself, a special type of layer. - The simplest way to create a new BSP layer that is - compliant with the Yocto Project is to use the - <filename>bitbake-layers</filename> script. - For information about that script, see the - "<link linkend='creating-a-new-bsp-layer-using-the-bitbake-layers-script'>Creating a New BSP Layer Using the <filename>bitbake-layers</filename> Script</link>" - section.</para> - - <para>Another example that illustrates a layer - is an application. - Suppose you are creating an application that has - library or other dependencies in order for it to - compile and run. - The layer, in this case, would be where all the - recipes that define those dependencies are kept. - The key point for a layer is that it is an - isolated area that contains all the relevant - information for the project that the - OpenEmbedded build system knows about. - For more information on layers, see the - "<ulink url='&YOCTO_DOCS_OM_URL;#the-yocto-project-layer-model'>The Yocto Project Layer Model</ulink>" - section in the Yocto Project Overview and Concepts - Manual. - You can also reference the - "<ulink url='&YOCTO_DOCS_DEV_URL;#understanding-and-creating-layers'>Understanding and Creating Layers</ulink>" - section in the Yocto Project Development Tasks - Manual. - For more information on BSP layers, see the - "<link linkend='bsp-layers'>BSP Layers</link>" - section. - <note><title>Notes</title> - <itemizedlist> - <listitem><para> - Five hardware reference BSPs exist - that are part of the Yocto Project release - and are located in the - <filename>poky/meta-yocto-bsp</filename> BSP - layer: - <itemizedlist> - <listitem><para> - Texas Instruments Beaglebone - (<filename>beaglebone-yocto</filename>) - </para></listitem> - <listitem><para> - Ubiquiti Networks EdgeRouter Lite - (<filename>edgerouter</filename>) - </para></listitem> - <listitem><para> - Two general IA platforms - (<filename>genericx86</filename> and - <filename>genericx86-64</filename>) - </para></listitem> - </itemizedlist> - </para></listitem> - <listitem><para> - Three core Intel BSPs exist as part of - the Yocto Project release in the - <filename>meta-intel</filename> layer: - <itemizedlist> - <listitem><para> - <filename>intel-core2-32</filename>, - which is a BSP optimized for the Core2 - family of CPUs as well as all CPUs - prior to the Silvermont core. - </para></listitem> - <listitem><para> - <filename>intel-corei7-64</filename>, - which is a BSP optimized for Nehalem - and later Core and Xeon CPUs as well - as Silvermont and later Atom CPUs, - such as the Baytrail SoCs. - </para></listitem> - <listitem><para> - <filename>intel-quark</filename>, - which is a BSP optimized for the - Intel Galileo gen1 & gen2 - development boards. - </para></listitem> - </itemizedlist> - </para></listitem> - </itemizedlist> - </note></para> - - <para>When you set up a layer for a new BSP, - you should follow a standard layout. - This layout is described in the - "<link linkend='bsp-filelayout'>Example Filesystem Layout</link>" - section. - In the standard layout, notice the suggested - structure for recipes and configuration - information. - You can see the standard layout for a BSP - by examining any supported BSP found in the - <filename>meta-intel</filename> layer inside - the Source Directory. - </para></listitem> - <listitem><para> - <emphasis>Make Configuration Changes to Your New - BSP Layer:</emphasis> - The standard BSP layer structure organizes the - files you need to edit in - <filename>conf</filename> and several - <filename>recipes-*</filename> directories - within the BSP layer. - Configuration changes identify where your new - layer is on the local system and identifies the - kernel you are going to use. - When you run the - <filename>bitbake-layers</filename> script, - you are able to interactively configure many - things for the BSP (e.g. keyboard, touchscreen, - and so forth). - </para></listitem> - <listitem><para> - <emphasis>Make Recipe Changes to Your New BSP - Layer:</emphasis> - Recipe changes include altering recipes - (<filename>*.bb</filename> files), removing - recipes you do not use, and adding new recipes - or append files (<filename>.bbappend</filename>) - that support your hardware. - </para></listitem> - <listitem><para> - <emphasis>Prepare for the Build:</emphasis> - Once you have made all the changes to your BSP - layer, there remains a few things you need to - do for the OpenEmbedded build system in order - for it to create your image. - You need to get the build environment ready by - sourcing an environment setup script - (i.e. <filename>oe-init-build-env</filename>) - and you need to be sure two key configuration - files are configured appropriately: the - <filename>conf/local.conf</filename> and the - <filename>conf/bblayers.conf</filename> file. - You must make the OpenEmbedded build system aware - of your new layer. - See the - "<ulink url='&YOCTO_DOCS_DEV_URL;#enabling-your-layer'>Enabling Your Layer</ulink>" - section in the Yocto Project Development Tasks Manual - for information on how to let the build system - know about your new layer. - </para></listitem> - <listitem><para> - <emphasis>Build the Image:</emphasis> - The OpenEmbedded build system uses the BitBake tool - to build images based on the type of image you want to - create. - You can find more information about BitBake in the - <ulink url='&YOCTO_DOCS_BB_URL;'>BitBake User Manual</ulink>. - </para> - - <para>The build process supports several types of - images to satisfy different needs. - See the - "<ulink url='&YOCTO_DOCS_REF_URL;#ref-images'>Images</ulink>" - chapter in the Yocto Project Reference Manual for - information on supported images. - </para></listitem> - </orderedlist> - </para> -</section> - -<section id='requirements-and-recommendations-for-released-bsps'> - <title>Requirements and Recommendations for Released BSPs</title> - - <para> - Certain requirements exist for a released BSP to be - considered compliant with the Yocto Project. - Additionally, recommendations also exist. - This section describes the requirements and - recommendations for released BSPs. - </para> - - <section id='released-bsp-requirements'> - <title>Released BSP Requirements</title> - - <para> - Before looking at BSP requirements, you should consider - the following: - <itemizedlist> - <listitem><para> - The requirements here assume the BSP layer - is a well-formed, "legal" layer that can be - added to the Yocto Project. - For guidelines on creating a layer that meets - these base requirements, see the - "<link linkend='bsp-layers'>BSP Layers</link>" - section in this manual and the - "<ulink url='&YOCTO_DOCS_DEV_URL;#understanding-and-creating-layers'>Understanding and Creating Layers"</ulink>" - section in the Yocto Project Development Tasks - Manual. - </para></listitem> - <listitem><para> - The requirements in this section apply - regardless of how you package a BSP. - You should consult the packaging and distribution - guidelines for your specific release process. - For an example of packaging and distribution - requirements, see the - "<ulink url='https://wiki.yoctoproject.org/wiki/Third_Party_BSP_Release_Process'>Third Party BSP Release Process</ulink>" - wiki page. - </para></listitem> - <listitem><para> - The requirements for the BSP as it is made - available to a developer are completely - independent of the released form of the BSP. - For example, the BSP Metadata can be contained - within a Git repository and could have a directory - structure completely different from what appears - in the officially released BSP layer. - </para></listitem> - <listitem><para> - It is not required that specific packages or - package modifications exist in the BSP layer, - beyond the requirements for general - compliance with the Yocto Project. - For example, no requirement exists dictating - that a specific kernel or kernel version be - used in a given BSP. - </para></listitem> - </itemizedlist> - </para> - - <para> - Following are the requirements for a released BSP - that conform to the Yocto Project: - <itemizedlist> - <listitem><para> - <emphasis>Layer Name:</emphasis> - The BSP must have a layer name that follows - the Yocto Project standards. - For information on BSP layer names, see the - "<link linkend='bsp-layers'>BSP Layers</link>" section. - </para></listitem> - <listitem><para> - <emphasis>File System Layout:</emphasis> - When possible, use the same directory names - in your BSP layer as listed in the - <filename>recipes.txt</filename> file, which - is found in <filename>poky/meta</filename> - directory of the - <ulink url='&YOCTO_DOCS_REF_URL;#source-directory'>Source Directory</ulink> - or in the OpenEmbedded-Core Layer - (<filename>openembedded-core</filename>) at - <ulink url='http://git.openembedded.org/openembedded-core/tree/meta'></ulink>. - </para> - - <para>You should place recipes - (<filename>*.bb</filename> files) and recipe - modifications (<filename>*.bbappend</filename> - files) into <filename>recipes-*</filename> - subdirectories by functional area as outlined - in <filename>recipes.txt</filename>. - If you cannot find a category in - <filename>recipes.txt</filename> to fit a - particular recipe, you can make up your own - <filename>recipes-*</filename> subdirectory. - </para> - - <para>Within any particular - <filename>recipes-*</filename> category, the - layout should match what is found in the - OpenEmbedded-Core Git repository - (<filename>openembedded-core</filename>) - or the Source Directory (<filename>poky</filename>). - In other words, make sure you place related - files in appropriately-related - <filename>recipes-*</filename> subdirectories - specific to the recipe's function, or within - a subdirectory containing a set of closely-related - recipes. - The recipes themselves should follow the general - guidelines for recipes used in the Yocto Project - found in the - "<ulink url='http://openembedded.org/wiki/Styleguide'>OpenEmbedded Style Guide</ulink>". - </para></listitem> - <listitem><para> - <emphasis>License File:</emphasis> - You must include a license file in the - <filename>meta-</filename><replaceable>bsp_root_name</replaceable> - directory. - This license covers the BSP Metadata as a whole. - You must specify which license to use since no - default license exists when one is not specified. - See the - <ulink url='&YOCTO_GIT_URL;/cgit.cgi/meta-raspberrypi/tree/COPYING.MIT'><filename>COPYING.MIT</filename></ulink> - file for the Raspberry Pi BSP in the - <filename>meta-raspberrypi</filename> BSP layer - as an example. - </para></listitem> - <listitem><para> - <emphasis>README File:</emphasis> - You must include a <filename>README</filename> - file in the - <filename>meta-</filename><replaceable>bsp_root_name</replaceable> - directory. - See the - <ulink url='&YOCTO_GIT_URL;/cgit.cgi/meta-raspberrypi/tree/README.md'><filename>README.md</filename></ulink> - file for the Raspberry Pi BSP in the - <filename>meta-raspberrypi</filename> BSP layer - as an example.</para> - - <para>At a minimum, the <filename>README</filename> - file should contain the following: - <itemizedlist> - <listitem><para> - A brief description of the target hardware. - </para></listitem> - <listitem><para> - A list of all the dependencies of the BSP. - These dependencies are typically a list - of required layers needed to build the - BSP. - However, the dependencies should also - contain information regarding any other - dependencies the BSP might have. - </para></listitem> - <listitem><para> - Any required special licensing information. - For example, this information includes - information on special variables needed - to satisfy a EULA, or instructions on - information needed to build or distribute - binaries built from the BSP Metadata. - </para></listitem> - <listitem><para> - The name and contact information for the - BSP layer maintainer. - This is the person to whom patches and - questions should be sent. - For information on how to find the right - person, see the - "<ulink url='&YOCTO_DOCS_DEV_URL;#how-to-submit-a-change'>Submitting a Change to the Yocto Project</ulink>" - section in the Yocto Project Development - Tasks Manual. - </para></listitem> - <listitem><para> - Instructions on how to build the BSP using - the BSP layer. - </para></listitem> - <listitem><para> - Instructions on how to boot the BSP build - from the BSP layer. - </para></listitem> - <listitem><para> - Instructions on how to boot the binary - images contained in the - <filename>binary</filename> directory, - if present. - </para></listitem> - <listitem><para> - Information on any known bugs or issues - that users should know about when either - building or booting the BSP binaries. - </para></listitem> - </itemizedlist> - </para></listitem> - <listitem><para> - <emphasis>README.sources File:</emphasis> - If you BSP contains binary images in the - <filename>binary</filename> directory, you must - include a <filename>README.sources</filename> - file in the - <filename>meta-</filename><replaceable>bsp_root_name</replaceable> - directory. - This file specifies exactly where you can find - the sources used to generate the binary images. - </para></listitem> - <listitem><para> - <emphasis>Layer Configuration File:</emphasis> - You must include a - <filename>conf/layer.conf</filename> file in - the - <filename>meta-</filename><replaceable>bsp_root_name</replaceable> - directory. - This file identifies the - <filename>meta-</filename><replaceable>bsp_root_name</replaceable> - BSP layer as a layer to the build system. - </para></listitem> - <listitem><para> - <emphasis>Machine Configuration File:</emphasis> - You must include one or more - <filename>conf/machine/</filename><replaceable>bsp_root_name</replaceable><filename>.conf</filename> - files in the - <filename>meta-</filename><replaceable>bsp_root_name</replaceable> - directory. - These configuration files define machine targets - that can be built using the BSP layer. - Multiple machine configuration files define - variations of machine configurations that the - BSP supports. - If a BSP supports multiple machine variations, - you need to adequately describe each variation - in the BSP <filename>README</filename> file. - Do not use multiple machine configuration files - to describe disparate hardware. - If you do have very different targets, you should - create separate BSP layers for each target. - <note> - It is completely possible for a developer to - structure the working repository as a - conglomeration of unrelated BSP files, and to - possibly generate BSPs targeted for release - from that directory using scripts or some - other mechanism - (e.g. <filename>meta-yocto-bsp</filename> layer). - Such considerations are outside the scope of - this document. - </note> - </para></listitem> - </itemizedlist> - </para> - </section> - - <section id='released-bsp-recommendations'> - <title>Released BSP Recommendations</title> - - <para> - Following are recommendations for released BSPs that - conform to the Yocto Project: - <itemizedlist> - <listitem><para> - <emphasis>Bootable Images:</emphasis> - Released BSPs can contain one or more bootable - images. - Including bootable images allows users to easily - try out the BSP using their own hardware.</para> - - <para>In some cases, it might not be convenient - to include a bootable image. - If so, you might want to make two versions of the - BSP available: one that contains binary images, and - one that does not. - The version that does not contain bootable images - avoids unnecessary download times for users not - interested in the images.</para> - - <para>If you need to distribute a BSP and include - bootable images or build kernel and filesystems - meant to allow users to boot the BSP for evaluation - purposes, you should put the images and artifacts - within a - <filename>binary/</filename> subdirectory located - in the - <filename>meta-</filename><replaceable>bsp_root_name</replaceable> - directory. - <note> - If you do include a bootable image as part - of the BSP and the image was built by software - covered by the GPL or other open source licenses, - it is your responsibility to understand - and meet all licensing requirements, which could - include distribution of source files. - </note> - </para></listitem> - <listitem><para> - <emphasis>Use a Yocto Linux Kernel:</emphasis> - Kernel recipes in the BSP should be based on a - Yocto Linux kernel. - Basing your recipes on these kernels reduces - the costs for maintaining the BSP and increases - its scalability. - See the <filename>Yocto Linux Kernel</filename> - category in the - <ulink url='&YOCTO_GIT_URL;'>Source Repositories</ulink> - for these kernels. - </para></listitem> - </itemizedlist> - </para> - </section> -</section> - -<section id='customizing-a-recipe-for-a-bsp'> - <title>Customizing a Recipe for a BSP</title> - - <para> - If you plan on customizing a recipe for a particular BSP, - you need to do the following: - <itemizedlist> - <listitem><para> - Create a <filename>*.bbappend</filename> file for - the modified recipe. - For information on using append files, see the - "<ulink url='&YOCTO_DOCS_DEV_URL;#using-bbappend-files'>Using .bbappend Files in Your Layer</ulink>" - section in the Yocto Project Development Tasks - Manual. - </para></listitem> - <listitem><para> - Ensure your directory structure in the BSP layer - that supports your machine is such that the - OpenEmbedded build system can find it. - See the example later in this section for more - information. - </para></listitem> - <listitem><para> - Put the append file in a directory whose name matches - the machine's name and is located in an appropriate - sub-directory inside the BSP layer (i.e. - <filename>recipes-bsp</filename>, - <filename>recipes-graphics</filename>, - <filename>recipes-core</filename>, and so forth). - </para></listitem> - <listitem><para> - Place the BSP-specific files in the proper - directory inside the BSP layer. - How expansive the layer is affects where you must - place these files. - For example, if your layer supports several - different machine types, you need to be sure your - layer's directory structure includes hierarchy - that separates the files according to machine. - If your layer does not support multiple machines, - the layer would not have that additional hierarchy - and the files would obviously not be able to reside - in a machine-specific directory. - </para></listitem> - </itemizedlist> - </para> - - <para> - Following is a specific example to help you better understand - the process. - This example customizes customizes a recipe by adding a - BSP-specific configuration file named - <filename>interfaces</filename> to the - <filename>init-ifupdown_1.0.bb</filename> recipe for machine - "xyz" where the BSP layer also supports several other - machines: - <orderedlist> - <listitem><para> - Edit the - <filename>init-ifupdown_1.0.bbappend</filename> file - so that it contains the following: - <literallayout class='monospaced'> - FILESEXTRAPATHS_prepend := "${THISDIR}/files:" - </literallayout> - The append file needs to be in the - <filename>meta-xyz/recipes-core/init-ifupdown</filename> - directory. - </para></listitem> - <listitem><para> - Create and place the new - <filename>interfaces</filename> configuration file in - the BSP's layer here: - <literallayout class='monospaced'> - meta-xyz/recipes-core/init-ifupdown/files/xyz-machine-one/interfaces - </literallayout> - <note> - If the <filename>meta-xyz</filename> layer did - not support multiple machines, you would place - the <filename>interfaces</filename> configuration - file in the layer here: - <literallayout class='monospaced'> - meta-xyz/recipes-core/init-ifupdown/files/interfaces - </literallayout> - </note> - The - <ulink url='&YOCTO_DOCS_REF_URL;#var-FILESEXTRAPATHS'><filename>FILESEXTRAPATHS</filename></ulink> - variable in the append files extends the search path - the build system uses to find files during the build. - Consequently, for this example you need to have the - <filename>files</filename> directory in the same - location as your append file. - </para></listitem> - </orderedlist> - </para> -</section> - -<section id='bsp-licensing-considerations'> - <title>BSP Licensing Considerations</title> - - <para> - In some cases, a BSP contains separately-licensed - Intellectual Property (IP) for a component or components. - For these cases, you are required to accept the terms - of a commercial or other type of license that requires - some kind of explicit End User License Agreement (EULA). - Once you accept the license, the OpenEmbedded build system - can then build and include the corresponding component - in the final BSP image. - If the BSP is available as a pre-built image, you can - download the image after agreeing to the license or EULA. - </para> - - <para> - You could find that some separately-licensed components - that are essential for normal operation of the system might - not have an unencumbered (or free) substitute. - Without these essential components, the system would be - non-functional. - Then again, you might find that other licensed components - that are simply 'good-to-have' or purely elective do have - an unencumbered, free replacement component that you can - use rather than agreeing to the separately-licensed - component. - Even for components essential to the system, you might - find an unencumbered component that is not identical but - will work as a less-capable version of the licensed version - in the BSP recipe. - </para> - - <para> - For cases where you can substitute a free component and - still maintain the system's functionality, the "DOWNLOADS" - selection from the "SOFTWARE" tab on the - <ulink url='&YOCTO_HOME_URL;'>Yocto Project website</ulink> - makes available de-featured BSPs that are completely free - of any IP encumbrances. - For these cases, you can use the substitution directly and - without any further licensing requirements. - If present, these fully de-featured BSPs are named - appropriately different as compared to the names of their - respective encumbered BSPs. - If available, these substitutions are your simplest and - most preferred options. - Obviously, use of these substitutions assumes the resulting - functionality meets system requirements. - <note> - If however, a non-encumbered version is unavailable or - it provides unsuitable functionality or quality, you can - use an encumbered version. - </note> - </para> - - <para> - A couple different methods exist within the OpenEmbedded - build system to satisfy the licensing requirements for an - encumbered BSP. - The following list describes them in order of preference: - <orderedlist> - <listitem><para> - <emphasis>Use the - <ulink url='&YOCTO_DOCS_REF_URL;#var-LICENSE_FLAGS'><filename>LICENSE_FLAGS</filename></ulink> - Variable to Define the Recipes that Have Commercial - or Other Types of Specially-Licensed Packages:</emphasis> - For each of those recipes, you can specify a - matching license string in a - <filename>local.conf</filename> variable named - <ulink url='&YOCTO_DOCS_REF_URL;#var-LICENSE_FLAGS_WHITELIST'><filename>LICENSE_FLAGS_WHITELIST</filename></ulink>. - Specifying the matching license string signifies - that you agree to the license. - Thus, the build system can build the corresponding - recipe and include the component in the image. - See the - "<ulink url='&YOCTO_DOCS_DEV_URL;#enabling-commercially-licensed-recipes'>Enabling Commercially Licensed Recipes</ulink>" - section in the Yocto Project Development Tasks - Manual for details on how to use these variables. - </para> - - <para>If you build as you normally would, without - specifying any recipes in the - <filename>LICENSE_FLAGS_WHITELIST</filename>, the - build stops and provides you with the list of recipes - that you have tried to include in the image that - need entries in the - <filename>LICENSE_FLAGS_WHITELIST</filename>. - Once you enter the appropriate license flags into - the whitelist, restart the build to continue where - it left off. - During the build, the prompt will not appear again - since you have satisfied the requirement.</para> - - <para>Once the appropriate license flags are on the - white list in the - <filename>LICENSE_FLAGS_WHITELIST</filename> variable, - you can build the encumbered image with no change - at all to the normal build process. - </para></listitem> - <listitem><para> - <emphasis>Get a Pre-Built Version of the BSP:</emphasis> - You can get this type of BSP by selecting the - "DOWNLOADS" item from the "SOFTWARE" tab on the - <ulink url='&YOCTO_HOME_URL;'>Yocto Project website</ulink>. - You can download BSP tarballs that contain - proprietary components after agreeing to the - licensing requirements of each of the individually - encumbered packages as part of the download process. - Obtaining the BSP this way allows you to access an - encumbered image immediately after agreeing to the - click-through license agreements presented by the - website. - If you want to build the image yourself using - the recipes contained within the BSP tarball, - you will still need to create an appropriate - <filename>LICENSE_FLAGS_WHITELIST</filename> - to match the encumbered recipes in the BSP. - </para></listitem> - </orderedlist> - <note> - Pre-compiled images are bundled with a time-limited - kernel that runs for a predetermined amount of time - (10 days) before it forces the system to reboot. - This limitation is meant to discourage direct - redistribution of the image. - You must eventually rebuild the image if you want - to remove this restriction. - </note> - </para> -</section> - -<section id='creating-a-new-bsp-layer-using-the-bitbake-layers-script'> - <title>Creating a new BSP Layer Using the <filename>bitbake-layers</filename> Script</title> - - <para> - The <filename>bitbake-layers create-layer</filename> script - automates creating a BSP layer. - What makes a layer a "BSP layer" is the presence of at least one machine - configuration file. - Additionally, a BSP layer usually has a kernel recipe - or an append file that leverages off an existing kernel recipe. - The primary requirement, however, is the machine configuration. - </para> - - <para> - Use these steps to create a BSP layer: - <itemizedlist> - <listitem><para> - <emphasis>Create a General Layer:</emphasis> - Use the <filename>bitbake-layers</filename> script with the - <filename>create-layer</filename> subcommand to create a - new general layer. - For instructions on how to create a general layer using the - <filename>bitbake-layers</filename> script, see the - "<ulink url='&YOCTO_DOCS_DEV_URL;#creating-a-general-layer-using-the-bitbake-layers-script'>Creating a General Layer Using the <filename>bitbake-layers</filename> Script</ulink>" - section in the Yocto Project Development Tasks Manual. - </para></listitem> - <listitem><para> - <emphasis>Create a Layer Configuration File:</emphasis> - Every layer needs a layer configuration file. - This configuration file establishes locations for the - layer's recipes, priorities for the layer, and so forth. - You can find examples of <filename>layer.conf</filename> - files in the Yocto Project - <ulink url='&YOCTO_GIT_URL;'>Source Repositories</ulink>. - To get examples of what you need in your configuration - file, locate a layer (e.g. "meta-ti") and examine the - <ulink url='&YOCTO_GIT_URL;/cgit/cgit.cgi/meta-ti/tree/conf/layer.conf'></ulink> - file. - </para></listitem> - <listitem><para> - <emphasis>Create a Machine Configuration File:</emphasis> - Create a <filename>conf/machine/</filename><replaceable>bsp_root_name</replaceable><filename>.conf</filename> - file. - See - <ulink url='&YOCTO_GIT_URL;/cgit/cgit.cgi/poky/tree/meta-yocto-bsp/conf/machine'><filename>meta-yocto-bsp/conf/machine</filename></ulink> - for sample - <replaceable>bsp_root_name</replaceable><filename>.conf</filename> - files. - Other samples such as - <ulink url='&YOCTO_GIT_URL;/cgit/cgit.cgi/meta-ti/tree/conf/machine'><filename>meta-ti</filename></ulink> - and - <ulink url='&YOCTO_GIT_URL;/cgit/cgit.cgi/meta-freescale/tree/conf/machine'><filename>meta-freescale</filename></ulink> - exist from other vendors that have more specific machine - and tuning examples. - </para></listitem> - <listitem><para> - <emphasis>Create a Kernel Recipe:</emphasis> - Create a kernel recipe in <filename>recipes-kernel/linux</filename> - by either using a kernel append file or a new custom kernel - recipe file (e.g. <filename>yocto-linux_4.12.bb</filename>). - The BSP layers mentioned in the previous step also contain different - kernel examples. - See the - "<ulink url='&YOCTO_DOCS_KERNEL_DEV_URL;#modifying-an-existing-recipe'>Modifying an Existing Recipe</ulink>" - section in the Yocto Project Linux Kernel Development Manual - for information on how to create a custom kernel. - </para></listitem> - </itemizedlist> - </para> - - <para> - The remainder of this section provides a description of - the Yocto Project reference BSP for Beaglebone, which - resides in the - <ulink url='&YOCTO_GIT_URL;/cgit/cgit.cgi/poky/tree/meta-yocto-bsp'><filename>meta-yocto-bsp</filename></ulink> - layer. - </para> - - <section id='bsp-layer-configuration-example'> - <title>BSP Layer Configuration Example</title> - - <para> - The layer's <filename>conf</filename> directory - contains the <filename>layer.conf</filename> - configuration file. - In this example, the - <filename>conf/layer.conf</filename> is the - following: - <literallayout class='monospaced'> - # We have a conf and classes directory, add to BBPATH - BBPATH .= ":${LAYERDIR}" - - # We have recipes-* directories, add to BBFILES - BBFILES += "${LAYERDIR}/recipes-*/*/*.bb \ - ${LAYERDIR}/recipes-*/*/*.bbappend" - - BBFILE_COLLECTIONS += "yoctobsp" - BBFILE_PATTERN_yoctobsp = "^${LAYERDIR}/" - BBFILE_PRIORITY_yoctobsp = "5" - LAYERVERSION_yoctobsp = "4" - LAYERSERIES_COMPAT_yoctobsp = "&DISTRO_NAME_NO_CAP;" - </literallayout> - The variables used in this file configure the - layer. - A good way to learn about layer configuration - files is to examine various files for BSP from - the - <ulink url='&YOCTO_GIT_URL;'>Source Repositories</ulink>. - </para> - - <para> - For a detailed description of this particular - layer configuration file, see - "<ulink url='&YOCTO_DOCS_DEV_URL;#dev-layer-config-file-description'>step 3</ulink> - in the discussion that describes how to create - layers in the Yocto Project Development Tasks Manual. - </para> - </section> - - <section id='bsp-machine-configuration-example'> - <title>BSP Machine Configuration Example</title> - - <para> - As mentioned earlier in this section, the existence - of a machine configuration file is what makes a - layer a BSP layer as compared to a general or - kernel layer. - </para> - - <para> - One or more machine configuration files exist in the - <replaceable>bsp_layer</replaceable><filename>/conf/machine/</filename> - directory of the layer: - <literallayout class='monospaced'> - <replaceable>bsp_layer</replaceable><filename>/conf/machine/</filename><replaceable>machine1</replaceable><filename>.conf</filename> - <replaceable>bsp_layer</replaceable><filename>/conf/machine/</filename><replaceable>machine2</replaceable><filename>.conf</filename> - <replaceable>bsp_layer</replaceable><filename>/conf/machine/</filename><replaceable>machine3</replaceable><filename>.conf</filename> - ... more ... - </literallayout> - For example, the machine configuration file for the - <ulink url='http://beagleboard.org/bone'>BeagleBone and BeagleBone Black development boards</ulink> - is located in the layer - <filename>poky/meta-yocto-bsp/conf/machine</filename> - and is named <filename>beaglebone-yocto.conf</filename>: - <literallayout class='monospaced'> - #@TYPE: Machine - #@NAME: Beaglebone-yocto machine - #@DESCRIPTION: Reference machine configuration for http://beagleboard.org/bone and http://beagleboard.org/black boards - - PREFERRED_PROVIDER_virtual/xserver ?= "xserver-xorg" - XSERVER ?= "xserver-xorg \ - xf86-video-modesetting \ - " - - MACHINE_EXTRA_RRECOMMENDS = "kernel-modules kernel-devicetree" - - EXTRA_IMAGEDEPENDS += "u-boot" - - DEFAULTTUNE ?= "cortexa8hf-neon" - include conf/machine/include/tune-cortexa8.inc - - IMAGE_FSTYPES += "tar.bz2 jffs2 wic wic.bmap" - EXTRA_IMAGECMD_jffs2 = "-lnp " - WKS_FILE ?= "beaglebone-yocto.wks" - IMAGE_INSTALL_append = " kernel-devicetree kernel-image-zimage" - do_image_wic[depends] += "mtools-native:do_populate_sysroot dosfstools-native:do_populate_sysroot" - - SERIAL_CONSOLES ?= "115200;ttyS0 115200;ttyO0" - SERIAL_CONSOLES_CHECK = "${SERIAL_CONSOLES}" - - PREFERRED_PROVIDER_virtual/kernel ?= "linux-yocto" - PREFERRED_VERSION_linux-yocto ?= "5.0%" - - KERNEL_IMAGETYPE = "zImage" - KERNEL_DEVICETREE = "am335x-bone.dtb am335x-boneblack.dtb am335x-bonegreen.dtb" - KERNEL_EXTRA_ARGS += "LOADADDR=${UBOOT_ENTRYPOINT}" - - SPL_BINARY = "MLO" - UBOOT_SUFFIX = "img" - UBOOT_MACHINE = "am335x_evm_defconfig" - UBOOT_ENTRYPOINT = "0x80008000" - UBOOT_LOADADDRESS = "0x80008000" - - MACHINE_FEATURES = "usbgadget usbhost vfat alsa" - - IMAGE_BOOT_FILES ?= "u-boot.${UBOOT_SUFFIX} MLO zImage am335x-bone.dtb am335x-boneblack.dtb am335x-bonegreen.dtb" - </literallayout> - The variables used to configure the machine define - machine-specific properties; - for example, machine-dependent packages, machine - tunings, the type of kernel to build, and - U-Boot configurations. - </para> - - <para> - The following list provides some explanation - for the statements found in the example reference - machine configuration file for the BeagleBone - development boards. - Realize that much more can be defined as part of - a machine's configuration file. - In general, you can learn about related variables - that this example does not have by locating the - variables in the - "<ulink url='&YOCTO_DOCS_REF_URL;#ref-variables-glos'>Yocto Project Variables Glossary</ulink>" - in the Yocto Project Reference Manual. - <itemizedlist> - <listitem><para> - <ulink url='&YOCTO_DOCS_REF_URL;#var-PREFERRED_PROVIDER'><filename>PREFERRED_PROVIDER_virtual/xserver</filename></ulink>: - The recipe that provides "virtual/xserver" when - more than one provider is found. - In this case, the recipe that provides - "virtual/xserver" is "xserver-xorg", which - exists in - <filename>poky/meta/recipes-graphics/xorg-xserver</filename>. - </para></listitem> - <listitem><para> - <ulink url='&YOCTO_DOCS_REF_URL;#var-XSERVER'><filename>XSERVER</filename></ulink>: - The packages that should be installed to provide - an X server and drivers for the machine. - In this example, the "xserver-xorg" and - "xf86-video-modesetting" are installed. - </para></listitem> - <listitem><para> - <ulink url='&YOCTO_DOCS_REF_URL;#var-MACHINE_EXTRA_RRECOMMENDS'><filename>MACHINE_EXTRA_RRECOMMENDS</filename></ulink>: - A list of machine-dependent packages - not essential for booting the image. - Thus, the build does not fail if the packages - do not exist. - However, the packages are required for a - fully-featured image. - <note><title>Tip</title> - Many <filename>MACHINE*</filename> variables - exist that help you configure a particular - piece of hardware. - </note> - </para></listitem> - <listitem><para> - <ulink url='&YOCTO_DOCS_REF_URL;#var-EXTRA_IMAGEDEPENDS'><filename>EXTRA_IMAGEDEPENDS</filename></ulink>: - Recipes to build that do not provide packages - for installing into the root filesystem - but building the image depends on the - recipes. - Sometimes a recipe is required to build - the final image but is not needed in the - root filesystem. - In this case, the U-Boot recipe must be - built for the image. - </para></listitem> - <listitem><para> - <ulink url='&YOCTO_DOCS_REF_URL;#var-DEFAULTTUNE'><filename>DEFAULTTUNE</filename></ulink>: - Machines use tunings to optimize machine, - CPU, and application performance. - These features, which are collectively known - as "tuning features", exist in the - <ulink url='&YOCTO_DOCS_REF_URL;#oe-core'>OpenEmbedded-Core (OE-Core)</ulink> - layer (e.g. - <filename>poky/meta/conf/machine/include</filename>). - In this example, the default tunning file is - "cortexa8hf-neon". - <note> - The <filename>include</filename> statement - that pulls in the - <filename>conf/machine/include/tune-cortexa8.inc</filename> - file provides many tuning possibilities. - </note> - </para></listitem> - <listitem><para> - <ulink url='&YOCTO_DOCS_REF_URL;#var-IMAGE_FSTYPES'><filename>IMAGE_FSTYPES</filename></ulink>: - The formats the OpenEmbedded build system - uses during the build when creating the - root filesystem. - In this example, four types of images are - supported. - </para></listitem> - <listitem><para> - <ulink url='&YOCTO_DOCS_REF_URL;#var-EXTRA_IMAGECMD'><filename>EXTRA_IMAGECMD</filename></ulink>: - Specifies additional options for image - creation commands. - In this example, the "-lnp " option is used - when creating the - <ulink url='https://en.wikipedia.org/wiki/JFFS2'>JFFS2</ulink> - image. - </para></listitem> - <listitem><para> - <ulink url='&YOCTO_DOCS_REF_URL;#var-WKS_FILE'><filename>WKS_FILE</filename></ulink>: - The location of the - <ulink url='&YOCTO_DOCS_REF_URL;#ref-kickstart'>Wic kickstart</ulink> - file used by the OpenEmbedded build system to - create a partitioned image (image.wic). - </para></listitem> - <listitem><para> - <ulink url='&YOCTO_DOCS_REF_URL;#var-IMAGE_INSTALL'><filename>IMAGE_INSTALL</filename></ulink>: - Specifies packages to install into an image - through the - <ulink url='&YOCTO_DOCS_REF_URL;#ref-classes-image'><filename>image</filename></ulink> - class. - Recipes use the <filename>IMAGE_INSTALL</filename> - variable. - </para></listitem> - <listitem><para> - <filename>do_image_wic[depends]</filename>: - A task that is constructed during the build. - In this example, the task depends on specific tools - in order to create the sysroot when buiding a Wic - image. - </para></listitem> - <listitem><para> - <ulink url='&YOCTO_DOCS_REF_URL;#var-SERIAL_CONSOLES'><filename>SERIAL_CONSOLES</filename></ulink>: - Defines a serial console (TTY) to enable using - getty. - In this case, the baud rate is "115200" and the - device name is "ttyO0". - </para></listitem> - <listitem><para> - <ulink url='&YOCTO_DOCS_REF_URL;#var-PREFERRED_PROVIDER'><filename>PREFERRED_PROVIDER_virtual/kernel</filename></ulink>: - Specifies the recipe that provides - "virtual/kernel" when more than one provider - is found. - In this case, the recipe that provides - "virtual/kernel" is "linux-yocto", which - exists in the layer's - <filename>recipes-kernel/linux</filename> directory. - </para></listitem> - <listitem><para> - <ulink url='&YOCTO_DOCS_REF_URL;#var-PREFERRED_VERSION'><filename>PREFERRED_VERSION_linux-yocto</filename></ulink>: - Defines the version of the recipe used - to build the kernel, which is "5.0" in this - case. - </para></listitem> - <listitem><para> - <ulink url='&YOCTO_DOCS_REF_URL;#var-KERNEL_IMAGETYPE'><filename>KERNEL_IMAGETYPE</filename></ulink>: - The type of kernel to build for the device. - In this case, the OpenEmbedded build system - creates a "zImage" image type. - </para></listitem> - <listitem><para> - <ulink url='&YOCTO_DOCS_REF_URL;#var-KERNEL_DEVICETREE'><filename>KERNEL_DEVICETREE</filename></ulink>: - The names of the generated Linux kernel device - trees (i.e. the <filename>*.dtb</filename>) files. - All the device trees for the various BeagleBone - devices are included. -<!-- - You have to include some *.inc files according to the definition of KERNEL_DEVICETREE. - I don't see where these are being provided. ---> - </para></listitem> - <listitem><para> - <ulink url='&YOCTO_DOCS_REF_URL;#var-KERNEL_EXTRA_ARGS'><filename>KERNEL_EXTRA_ARGS</filename></ulink>: - Additional <filename>make</filename> - command-line arguments the OpenEmbedded build - system passes on when compiling the kernel. - In this example, "LOADADDR=${UBOOT_ENTRYPOINT}" - is passed as a command-line argument. - </para></listitem> - <listitem><para> - <ulink url='&YOCTO_DOCS_REF_URL;#var-SPL_BINARY'><filename>SPL_BINARY</filename></ulink>: - Defines the Secondary Program Loader (SPL) binary - type. - In this case, the SPL binary is set to - "MLO", which stands for Multimedia card LOader. - </para> - - <para>The BeagleBone development board requires an - SPL to boot and that SPL file type must be MLO. - Consequently, the machine configuration needs to - define <filename>SPL_BINARY</filename> as "MLO". - <note> - For more information on how the SPL variables - are used, see the - <ulink url='&YOCTO_GIT_URL;/cgit/cgit.cgi/poky/tree/meta/recipes-bsp/u-boot/u-boot.inc'><filename>u-boot.inc</filename></ulink> - include file. - </note> - </para></listitem> - <listitem><para> - <ulink url='&YOCTO_DOCS_REF_URL;#var-UBOOT_ENTRYPOINT'><filename>UBOOT_*</filename></ulink>: - Defines various U-Boot configurations needed - to build a U-Boot image. - In this example, a U-Boot image is required - to boot the BeagleBone device. - See the following variables for more information: - <itemizedlist> - <listitem><para> - <ulink url='&YOCTO_DOCS_REF_URL;#var-UBOOT_SUFFIX'><filename>UBOOT_SUFFIX</filename></ulink>: - Points to the generated U-Boot extension. - </para></listitem> - <listitem><para> - <ulink url='&YOCTO_DOCS_REF_URL;#var-UBOOT_MACHINE'><filename>UBOOT_MACHINE</filename></ulink>: - Specifies the value passed on the make command line when building a U-Boot image. - </para></listitem> - <listitem><para> - <ulink url='&YOCTO_DOCS_REF_URL;#var-UBOOT_ENTRYPOINT'><filename>UBOOT_ENTRYPOINT</filename></ulink>: - Specifies the entry point for the U-Boot image. - </para></listitem> - <listitem><para> - <ulink url='&YOCTO_DOCS_REF_URL;#var-UBOOT_LOADADDRESS'><filename>UBOOT_LOADADDRESS</filename></ulink>: - Specifies the load address for the U-Boot image. - </para></listitem> - </itemizedlist> - </para></listitem> - <listitem><para> - <ulink url='&YOCTO_DOCS_REF_URL;#var-MACHINE_FEATURES'><filename>MACHINE_FEATURES</filename></ulink>: - Specifies the list of hardware features the - BeagleBone device is capable of supporting. - In this case, the device supports - "usbgadget usbhost vfat alsa". - </para></listitem> - <listitem><para> - <ulink url='&YOCTO_DOCS_REF_URL;#var-IMAGE_BOOT_FILES'><filename>IMAGE_BOOT_FILES</filename></ulink>: - Files installed into the device's boot partition - when preparing the image using the Wic tool - with the <filename>bootimg-partition</filename> - source plugin. - </para></listitem> - </itemizedlist> - </para> - </section> - - <section id='bsp-kernel-recipe-example'> - <title>BSP Kernel Recipe Example</title> - - <para> - The kernel recipe used to build the kernel image - for the BeagleBone device was established in the - machine configuration: - <literallayout class='monospaced'> - PREFERRED_PROVIDER_virtual/kernel ?= "linux-yocto" - PREFERRED_VERSION_linux-yocto ?= "5.0%" - </literallayout> - The <filename>meta-yocto-bsp/recipes-kernel/linux</filename> - directory in the layer contains metadata used - to build the kernel. - In this case, a kernel append file (i.e. - <filename>linux-yocto_5.0.bbappend</filename>) is used to - override an established kernel recipe (i.e. - <filename>linux-yocto_5.0.bb</filename>), which is - located in - <ulink url='&YOCTO_GIT_URL;/cgit/cgit.cgi/poky/tree/meta/recipes-kernel/linux'></ulink>. - </para> - - <para> - Following is the contents of the append file: - <literallayout class='monospaced'> - KBRANCH_genericx86 = "v5.0/standard/base" - KBRANCH_genericx86-64 = "v5.0/standard/base" - KBRANCH_edgerouter = "v5.0/standard/edgerouter" - KBRANCH_beaglebone-yocto = "v5.0/standard/beaglebone" - - KMACHINE_genericx86 ?= "common-pc" - KMACHINE_genericx86-64 ?= "common-pc-64" - KMACHINE_beaglebone-yocto ?= "beaglebone" - - SRCREV_machine_genericx86 ?= "3df4aae6074e94e794e27fe7f17451d9353cdf3d" - SRCREV_machine_genericx86-64 ?= "3df4aae6074e94e794e27fe7f17451d9353cdf3d" - SRCREV_machine_edgerouter ?= "3df4aae6074e94e794e27fe7f17451d9353cdf3d" - SRCREV_machine_beaglebone-yocto ?= "3df4aae6074e94e794e27fe7f17451d9353cdf3d" - - COMPATIBLE_MACHINE_genericx86 = "genericx86" - COMPATIBLE_MACHINE_genericx86-64 = "genericx86-64" - COMPATIBLE_MACHINE_edgerouter = "edgerouter" - COMPATIBLE_MACHINE_beaglebone-yocto = "beaglebone-yocto" - - LINUX_VERSION_genericx86 = "5.0.3" - LINUX_VERSION_genericx86-64 = "5.0.3" - LINUX_VERSION_edgerouter = "5.0.3" - LINUX_VERSION_beaglebone-yocto = "5.0.3" - </literallayout> - This particular append file works for all the - machines that are part of the - <filename>meta-yocto-bsp</filename> layer. - The relevant statements are appended with - the "beaglebone-yocto" string. - The OpenEmbedded build system uses these - statements to override similar statements - in the kernel recipe: - <itemizedlist> - <listitem><para> - <ulink url='&YOCTO_DOCS_REF_URL;#var-KBRANCH'><filename>KBRANCH</filename></ulink>: - Identifies the kernel branch that is validated, - patched, and configured during the build. - </para></listitem> - <listitem><para> - <ulink url='&YOCTO_DOCS_REF_URL;#var-KMACHINE'><filename>KMACHINE</filename></ulink>: - Identifies the machine name as known by the - kernel, which is sometimes a different name - than what is known by the OpenEmbedded build - system. - </para></listitem> - <listitem><para> - <ulink url='&YOCTO_DOCS_REF_URL;#var-SRCREV'><filename>SRCREV</filename></ulink>: - Identifies the revision of the source code used - to build the image. - </para></listitem> - <listitem><para> - <ulink url='&YOCTO_DOCS_REF_URL;#var-COMPATIBLE_MACHINE'><filename>COMPATIBLE_MACHINE</filename></ulink>: - A regular expression that resolves to one or - more target machines with which the recipe - is compatible. - </para></listitem> - <listitem><para> - <ulink url='&YOCTO_DOCS_REF_URL;#var-LINUX_VERSION'><filename>LINUX_VERSION</filename></ulink>: - The Linux version from kernel.org used by - the OpenEmbedded build system to build the - kernel image. - </para></listitem> - </itemizedlist> - </para> - </section> -</section> -</chapter> |