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bsp-guide: Added new section for creating layer using bitbake-layers
Created detailed example using the BeagleBone BSP. (From yocto-docs rev: 7701dc2bd94ae7ee3e4aee37ac97174ad445d286) Signed-off-by: Scott Rifenbark <srifenbark@gmail.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
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Scott Rifenbark
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@@ -1746,25 +1746,20 @@
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<title>Creating a new BSP Layer Using the <filename>bitbake-layers</filename> Script</title>
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<para>
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[INTRODUCE THE PROCEDURE AND LINK BACK TO <link linkend='bsp-layers'>BSP layer</link>.
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IF THERE IS A LAUNDRY LIST OF ITEMS THAT NEED DEFINITION OR GET SET
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UP AS A RESULT OF THIS PROCEDURE, LIST THEM HERE.]
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<itemizedlist>
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<listitem><para>[PARAMETER 1]</para></listitem>
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<listitem><para>[PARAMETER 2]</para></listitem>
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<listitem><para>[PARAMETER 3]</para></listitem>
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<listitem><para>[PARAMETER 4]</para></listitem>
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<listitem><para>[PARAMETER 5]</para></listitem>
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<listitem><para>[PARAMETER 6]</para></listitem>
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<listitem><para>[PARAMETER 7]</para></listitem>
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</itemizedlist>
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The <filename>bitbake-layers create-layer</filename> script
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automates creating a BSP layer.
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What makes a layer a "BSP layer", is the presence of a machine
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configuration file.
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Additionally, a BSP layer usually has a kernel recipe
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or an append file that leverages off an existing kernel recipe.
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The primary requirement, however, is the machine configuration.
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</para>
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<para>
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The following procedure creates a BSP layer:
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Use these steps to create a BSP layer:
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<itemizedlist>
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<listitem><para>
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<emphasis>Create General Layer:</emphasis>
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<emphasis>Create a General Layer:</emphasis>
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Use the <filename>bitbake-layers</filename> script with the
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<filename>create-layer</filename> subcommand to create a
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new general layer.
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@@ -1774,25 +1769,41 @@
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section in the Yocto Project Development Tasks Manual.
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</para></listitem>
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<listitem><para>
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<emphasis>Create a Machine Configuration File:</emphasis>
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Create a <filename>conf/machine/>machine<.conf</filename>
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<emphasis>Create a Layer Configuration File:</emphasis>
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Every layer needs a layer configuration file.
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This configuration file establishes locations for the
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layer's recipes, priorities for the layer, and so forth.
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You can find examples of <filename>layer.conf</filename>
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files in the Yocto Project
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<ulink url='&YOCTO_GIT_URL;'>Source Repositories</ulink>.
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To get examples of what you need in your configuration
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file, locate a layer (e.g. "meta-ti") and examine the
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<ulink url='&YOCTO_GIT_URL;/cgit/cgit.cgi/meta-ti/tree/conf/layer.conf'></ulink>
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file.
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See <filename>meta-yocto-bsp/conf/machine</filename> for sample
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<filename>>machine.conf<</filename> files.
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Other samples exist from other vendors such as
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<filename>meta-intel</filename>, <filename>meta-ti</filename>,
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and <filename>meta-freescale</filename> that have more specific machine
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</para></listitem>
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<listitem><para>
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<emphasis>Create a Machine Configuration File:</emphasis>
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Create a <filename>conf/machine/</filename><replaceable>bsp_root_name</replaceable><filename>.conf</filename>
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file.
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See
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<ulink url='&YOCTO_GIT_URL;/cgit/cgit.cgi/poky/tree/meta-yocto-bsp/conf/machine'><filename>meta-yocto-bsp/conf/machine</filename></ulink>
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for sample
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<replaceable>bsp_root_name</replaceable><filename>.conf</filename>
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files.
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Other samples such as
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<ulink url='&YOCTO_GIT_URL;/cgit/cgit.cgi/meta-ti/tree/conf/machine'><filename>meta-ti</filename></ulink>
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and
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<ulink url='&YOCTO_GIT_URL;/cgit/cgit.cgi/meta-freescale/tree/conf/machine'><filename>meta-freescale</filename></ulink>
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exist from other vendors that have more specific machine
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and tuning examples.
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</para></listitem>
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<listitem><para>
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<emphasis>Create a Kernel Recipe:</emphasis>
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Create a kernel recipe in <filename>recipes-kernel/linux</filename>
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either using a linux-yocto kernel with a <filename>.bbappend</filename>
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file or a new custom kernel recipe file (i.e. <filename>.bb</filename>
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file).
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by either using a kernel append file or a new custom kernel
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recipe file (e.g. <filename>yocto-linux_4.12.bb</filename>).
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The BSP layers mentioned in the previous step also contain different
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kernel examples.
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You can start with the linux-yocto or use a custom kernel.
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See the
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"<ulink url='&YOCTO_DOCS_KERNEL_DEV_URL;#modifying-an-existing-recipe'>Modifying an Existing Recipe</ulink>"
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section in the Yocto Project Linux Kernel Development Manual
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@@ -1802,43 +1813,462 @@
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</para>
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<para>
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[THERE IS MORE INFORMATION THAT NEEDS TO BE FILLED IN HERE. THIS NEEDS TO
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BE PROVIDED BY ENGINEERS.]
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The remainder of this section provides a description of
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the Yocto Project reference BSP for Beaglebone, which
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resides in the
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<ulink url='&YOCTO_DOCS_REF_URL;#term-container-layer'>Container Layer</ulink>
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(i.e.
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<ulink url='&YOCTO_GIT_URL;/cgit/cgit.cgi/poky/tree/meta-yocto-bsp'><filename>meta-yocto-bsp</filename></ulink>).
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</para>
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<para>
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The remainder of this section presents an example that uses
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<filename>myarm</filename> as the machine name and <filename>qemu</filename>
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as the machine architecture.
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Of the available architectures, <filename>qemu</filename> is the only architecture
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that causes the script to prompt you further for an actual architecture.
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In every other way, this architecture is representative of how creating a BSP for
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an actual machine would work.
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The reason the example uses this architecture is because it is an emulated architecture
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and can easily be followed without requiring actual hardware.
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</para>
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<section id='bsp-layer-configuration-example'>
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<title>BSP Layer Configuration Example</title>
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<para>
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Following is a complete example:
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<literallayout class='monospaced'>
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[INSERT EXAMPLE - NEED EXAMPLE]
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</literallayout>
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</para>
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<para>
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The layer's <filename>conf</filename> directory
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contains the <filename>layer.conf</filename>
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configuration file.
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In this example, the
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<filename>conf/layer.conf</filename> is the
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following:
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<literallayout class='monospaced'>
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# We have a conf and classes directory, add to BBPATH
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BBPATH .= ":${LAYERDIR}"
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<para>
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Once the BSP Layer is created, you must add it to your
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<filename>bblayers.conf</filename> file.
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Here is an example:
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<literallayout class='monospaced'>
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BBLAYERS = ? " \
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/usr/local/src/yocto/meta \
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/usr/local/src/yocto/meta-poky \
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/usr/local/src/yocto/meta-yocto-bsp \
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/usr/local/src/yocto/meta-myarm \
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"
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</literallayout>
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Adding the layer to this file allows the build system to build the BSP and
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find the layer along with other Metadata it needs.
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</para>
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# We have recipes-* directories, add to BBFILES
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BBFILES += "${LAYERDIR}/recipes-*/*/*.bb \
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${LAYERDIR}/recipes-*/*/*.bbappend"
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BBFILE_COLLECTIONS += "yoctobsp"
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BBFILE_PATTERN_yoctobsp = "^${LAYERDIR}/"
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BBFILE_PRIORITY_yoctobsp = "5"
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LAYERVERSION_yoctobsp = "4"
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LAYERSERIES_COMPAT_yoctobsp = "&DISTRO_NAME_NO_CAP;"
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</literallayout>
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The variables used in this file configure the
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layer.
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A good way to learn about layer configuration
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files is to examine various files for BSP from
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the
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<ulink url='&YOCTO_GIT_URL;'>Source Repositories</ulink>.
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</para>
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<para>
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For a detailed description of this particular
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layer configuration file, see
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"<ulink url='&YOCTO_DOCS_DEV_URL;#dev-layer-config-file-description'>step 3</ulink>
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in the discussion that describes how to create
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layers in the Yocto Project Development Tasks Manual.
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</para>
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</section>
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<section id='bsp-machine-configuration-example'>
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<title>BSP Machine Configuration Example</title>
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<para>
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As mentioned earlier in this section, the existence
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of a machine configuration file is what makes a
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layer a BSP layer as compared to a general or
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kernel layer.
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</para>
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<para>
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Machine configuration files exist in the
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<replaceable>bsp_layer</replaceable><filename>/conf/machine/</filename>
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directory of the layer:
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<literallayout class='monospaced'>
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<replaceable>bsp_layer</replaceable><filename>/conf/machine/</filename><replaceable>machine</replaceable><filename>.conf</filename>
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</literallayout>
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For example, the machine configuration file for the
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<ulink url='http://beagleboard.org/bone'>BeagleBone and BeagleBone Black development boards</ulink>
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is located in the container layer
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<filename>poky/meta-yocto-bsp/conf/machine</filename>
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and is named <filename>beaglebone-yocto.conf</filename>:
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<literallayout class='monospaced'>
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#@TYPE: Machine
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#@NAME: Beaglebone-yocto machine
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#@DESCRIPTION: Reference machine configuration for http://beagleboard.org/bone and http://beagleboard.org/black boards
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PREFERRED_PROVIDER_virtual/xserver ?= "xserver-xorg"
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XSERVER ?= "xserver-xorg \
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xf86-video-modesetting \
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"
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MACHINE_EXTRA_RRECOMMENDS = " kernel-modules kernel-devicetree"
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EXTRA_IMAGEDEPENDS += "u-boot"
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DEFAULTTUNE ?= "cortexa8hf-neon"
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include conf/machine/include/tune-cortexa8.inc
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IMAGE_FSTYPES += "tar.bz2 jffs2 wic wic.bmap"
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EXTRA_IMAGECMD_jffs2 = "-lnp "
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WKS_FILE ?= "beaglebone-yocto.wks"
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IMAGE_INSTALL_append = " kernel-devicetree kernel-image-zimage"
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do_image_wic[depends] += "mtools-native:do_populate_sysroot dosfstools-native:do_populate_sysroot"
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SERIAL_CONSOLE = "115200 ttyO0"
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PREFERRED_PROVIDER_virtual/kernel ?= "linux-yocto"
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PREFERRED_VERSION_linux-yocto ?= "4.12%"
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KERNEL_IMAGETYPE = "zImage"
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KERNEL_DEVICETREE = "am335x-bone.dtb am335x-boneblack.dtb am335x-bonegreen.dtb"
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KERNEL_EXTRA_ARGS += "LOADADDR=${UBOOT_ENTRYPOINT}"
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SPL_BINARY = "MLO"
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UBOOT_SUFFIX = "img"
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UBOOT_MACHINE = "am335x_boneblack_config"
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UBOOT_ENTRYPOINT = "0x80008000"
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UBOOT_LOADADDRESS = "0x80008000"
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MACHINE_FEATURES = "usbgadget usbhost vfat alsa"
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IMAGE_BOOT_FILES ?= "u-boot.${UBOOT_SUFFIX} MLO"
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</literallayout>
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The variables used to configure the machine define
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machine-specific properties.
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For example, machine-dependent packages, machine
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tunings, the type of kernel to build, and
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U-Boot configurations.
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</para>
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<para>
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The following list provides some explanation
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for the statements found in the example reference
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machine configuration file for the BeagleBone
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development boards.
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Realize that much more can be defined as part of
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a machines configuration file.
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In general, you can learn about related variables
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that this example does not have by locating the
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variables in the
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"<ulink url='&YOCTO_DOCS_REF_URL;#ref-variables-glos'>Yocto Project Variables Glossary</ulink>"
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in the Yocto Project Reference Manual.
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<itemizedlist>
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<listitem><para>
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<ulink url='&YOCTO_DOCS_REF_URL;#var-PREFERRED_PROVIDER'><filename>PREFERRED_PROVIDER_virtual/xserver</filename></ulink>:
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The recipe that provides "virtual/xserver" when
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more than one provider is found.
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In this case, the recipe that provides
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"virtual/xserver" is "xserver-xorg", which
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exists in
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<filename>poky/meta/recipes-graphics/xserver-xorg</filename>.
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</para></listitem>
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<listitem><para>
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<ulink url='&YOCTO_DOCS_REF_URL;#var-XSERVER'><filename>XSERVER</filename></ulink>:
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The packages that should be installed to provide
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an X server and drivers for the machine.
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In this example, the "xserver-xorg" and
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"xf86-video-modesetting" are installed.
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</para></listitem>
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<listitem><para>
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<ulink url='&YOCTO_DOCS_REF_URL;#var-MACHINE_EXTRA_RRECOMMENDS'><filename>MACHINE_EXTRA_RRECOMMENDS</filename></ulink>:
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A list of machine-dependent packages
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not essential for booting the image.
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Thus, the build does not fail if the packages
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do not exist.
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However, the packages are required for a
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fully-featured image.
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<note><title>Tip</title>
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Many <filename>MACHINE*</filename> variables
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exist that help you configure a particular
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piece of hardware.
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</note>
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</para></listitem>
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<listitem><para>
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<ulink url='&YOCTO_DOCS_REF_URL;#var-EXTRA_IMAGEDEPENDS'><filename>EXTRA_IMAGEDEPENDS</filename></ulink>:
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Recipes to build that do not provide packages
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for installing into the root filesystem
|
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but building the image depends on the
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recipes.
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Sometimes a recipe is required to build
|
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the final image but is not needed in the
|
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root filesystem.
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In this case, the U-Boot recipe must be
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built for the image.
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</para></listitem>
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<listitem><para>
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<ulink url='&YOCTO_DOCS_REF_URL;#var-DEFAULTTUNE'><filename>DEFAULTTUNE</filename></ulink>:
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Machines use tunings to optimize machine,
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CPU, and application performance.
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These features, which are collectively known
|
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as "tuning features", exist in the
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<ulink url='&YOCTO_DOCS_REF_URL;#oe-core'>OpenEmbedded Core (OE-Core)</ulink>
|
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layer (e.g.
|
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<filename>poky/meta/conf/machine/include</filename>).
|
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In this example, the default tunning file is
|
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"cortexa8hf-neon".
|
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<note>
|
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The <filename>include</filename> statement
|
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that pulls in the
|
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<filename>conf/machine/include/tune-cortexa8.inc</filename>
|
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file provides many tuning possibilities.
|
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</note>
|
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</para></listitem>
|
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<listitem><para>
|
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<ulink url='&YOCTO_DOCS_REF_URL;#var-IMAGE_FSTYPES'><filename>IMAGE_FSTYPES</filename></ulink>:
|
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The formats the OpenEmbedded build system
|
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uses during the build when creating the
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root filesystem.
|
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In this example, four types of images are
|
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supported.
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</para></listitem>
|
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<listitem><para>
|
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<ulink url='&YOCTO_DOCS_REF_URL;#var-EXTRA_IMAGECMD'><filename>EXTRA_IMAGECMD</filename></ulink>:
|
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Specifies additional options for image
|
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creation commands.
|
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In this example, the "-lnp " option is used
|
||||
when creating the
|
||||
<ulink url='https://en.wikipedia.org/wiki/JFFS2'>JFFS2</ulink>
|
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image.
|
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</para></listitem>
|
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<listitem><para>
|
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<ulink url='&YOCTO_DOCS_REF_URL;#var-WKS_FILE'><filename>WKS_FILE</filename></ulink>:
|
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The location of the
|
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<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).
|
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</para></listitem>
|
||||
<listitem><para>
|
||||
<ulink url='&YOCTO_DOCS_REF_URL;#var-IMAGE_INSTALL'><filename>IMAGE_INSTALL</filename></ulink>:
|
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Specifies packages to install into an image
|
||||
through the
|
||||
<ulink url='&YOCTO_DOCS_REF_URL;#ref-classes-image'><filename>image</filename></ulink>
|
||||
class.
|
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Recipes use the <filename>IMAGE_INSTALL</filename>
|
||||
variable.
|
||||
</para></listitem>
|
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<listitem><para>
|
||||
<filename>do_image_wic[depends]</filename>:
|
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A task that is constructed during the build.
|
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In this example, the task depends on specific tools
|
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in order to create the sysroot when buiding a Wic
|
||||
image.
|
||||
</para></listitem>
|
||||
<listitem><para>
|
||||
<ulink url='&YOCTO_DOCS_REF_URL;#var-SERIAL_CONSOLE'><filename>SERIAL_CONSOLE</filename></ulink>:
|
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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 "4.12" 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 name of the generated Linux kernel device
|
||||
tree (i.e. the <filename>.dtb</filename>) file.
|
||||
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 a
|
||||
MLO file in order to boot.
|
||||
Consequently, the machine configuration needs to
|
||||
define the SPL as an MLO type file and use it
|
||||
as the Xloader.
|
||||
<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>
|
||||
<!--
|
||||
There is an SPL Framework documented here - http://git.denx.de/?p=u-boot.git;a=blob;f=doc/README.SPL;hb=HEAD.
|
||||
SPL is the "secondary program loader." Here is some stuff from the
|
||||
poky/meta/recipes-bsp/u-boot/u-boot.inc file:
|
||||
-->
|
||||
<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.
|
||||
In this case, the "u-boot.${UBOOT_SUFFIX}" and
|
||||
"MLO" files are installed.
|
||||
</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 ?= "4.12%"
|
||||
</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 is used to
|
||||
override an established kernel recipe, which is
|
||||
located in
|
||||
<ulink url='&YOCTO_GIT_URL;/cgit/cgit.cgi/poky/tree/meta/recipes-kernel/linux'></ulink>
|
||||
and named
|
||||
<filename>linux-yocto_4.12.bb</filename>.
|
||||
</para>
|
||||
|
||||
<para>
|
||||
Following is the contents of the append file:
|
||||
<literallayout class='monospaced'>
|
||||
KBRANCH_genericx86 = "standard/base"
|
||||
KBRANCH_genericx86-64 = "standard/base"
|
||||
|
||||
KMACHINE_genericx86 ?= "common-pc"
|
||||
KMACHINE_genericx86-64 ?= "common-pc-64"
|
||||
KBRANCH_edgerouter = "standard/edgerouter"
|
||||
KBRANCH_beaglebone-yocto = "standard/beaglebone"
|
||||
KMACHINE_beaglebone-yocto = "beaglebone"
|
||||
KBRANCH_mpc8315e-rdb = "standard/fsl-mpc8315e-rdb"
|
||||
|
||||
SRCREV_machine_genericx86 ?= "1c4ad569af3e23a77994235435040e322908687f"
|
||||
SRCREV_machine_genericx86-64 ?= "1c4ad569af3e23a77994235435040e322908687f"
|
||||
SRCREV_machine_edgerouter ?= "257f843ea367744620f1d92910afd2f454e31483"
|
||||
SRCREV_machine_beaglebone-yocto ?= "257f843ea367744620f1d92910afd2f454e31483"
|
||||
SRCREV_machine_mpc8315e-rdb ?= "014560874f9eb2a86138c9cc35046ff1720485e1"
|
||||
|
||||
|
||||
COMPATIBLE_MACHINE_genericx86 = "genericx86"
|
||||
COMPATIBLE_MACHINE_genericx86-64 = "genericx86-64"
|
||||
COMPATIBLE_MACHINE_edgerouter = "edgerouter"
|
||||
COMPATIBLE_MACHINE_beaglebone-yocto = "beaglebone-yocto"
|
||||
COMPATIBLE_MACHINE_mpc8315e-rdb = "mpc8315e-rdb"
|
||||
|
||||
LINUX_VERSION_genericx86 = "4.12.20"
|
||||
LINUX_VERSION_genericx86-64 = "4.12.20"
|
||||
LINUX_VERSION_edgerouter = "4.12.19"
|
||||
LINUX_VERSION_beaglebone-yocto = "4.12.19"
|
||||
LINUX_VERSION_mpc8315e-rdb = "4.12.19"
|
||||
</literallayout>
|
||||
This particular append file works for all the
|
||||
machines that are part of the
|
||||
<filename>meta-yocto-bsp</filename> container
|
||||
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.
|
||||
<!--
|
||||
You find out about that point in the kernel source tree by
|
||||
doing the following command:
|
||||
|
||||
git log ‐‐decorate 257f843ea367744620f1d92910afd2f454e31483
|
||||
|
||||
Returns information about the commit, which is usually
|
||||
that it is a merge point for a stable kernel release.
|
||||
-->
|
||||
</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>
|
||||
|
||||
Reference in New Issue
Block a user