mirror of
https://git.yoctoproject.org/poky
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kernel-dev: Edits to the devtool kernel development method.
Changes based on a run through of the procedure. (From yocto-docs rev: 0a526bb15f597843d1e5da1eeca0a952c6c5016f) Signed-off-by: Scott Rifenbark <srifenbark@gmail.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
This commit is contained in:
Scott Rifenbark
committed by
Richard Purdie
Richard Purdie
parent
b673c3b990
commit
8f7df8648a
@@ -70,7 +70,7 @@
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<listitem><para>
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<emphasis>Initialize the BitBake Environment:</emphasis>
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Before building an extensible SDK, you need to
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initialize the BitBake build environment by sourcing a
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initialize the BitBake build environment by sourcing the
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build environment script
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(i.e. <ulink url='&YOCTO_DOCS_REF_URL;#structure-core-script'><filename>oe-init-build-env</filename></ulink>):
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<literallayout class='monospaced'>
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@@ -155,8 +155,8 @@
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</para></listitem>
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<listitem><para>
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<emphasis>Build the Extensible SDK:</emphasis>
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Use BitBake to build the extensible SDK specifically for
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the Minnowboard:
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Use BitBake to build the extensible SDK specifically
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for use with images to be run using QEMU:
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<literallayout class='monospaced'>
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$ cd ~/poky/build
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$ bitbake core-image-minimal -c populate_sdk_ext
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@@ -280,7 +280,7 @@
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<listitem><para>
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<emphasis>Initialize the BitBake Environment:</emphasis>
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Before you can do anything using BitBake, you need to
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initialize the BitBake build environment by sourcing a
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initialize the BitBake build environment by sourcing the
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build environment script
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(i.e. <ulink url='&YOCTO_DOCS_REF_URL;#structure-core-script'><filename>oe-init-build-env</filename></ulink>).
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Also, for this example, be sure that the local branch
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@@ -1009,66 +1009,58 @@
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"<link linkend='getting-ready-to-develop-using-devtool'>Getting Ready to Develop using <filename>devtool</filename></link>"
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Section.
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</note>
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</para>
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<para>
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Also, for more information on patching the kernel, see the
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"<link linkend='applying-patches'>Applying Patches</link>"
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section.
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</para>
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<orderedlist>
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<listitem><para>
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<emphasis>Check Out the Kernel Source Files:</emphasis>
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First you must use <filename>devtool</filename> to checkout
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the kernel source code in its workspace.
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Be sure you are in the terminal set up to do work
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with the extensible SDK.
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<note>
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See this
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<link linkend='setting-up-the-esdk-terminal'>step</link>
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in the
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"<link linkend='getting-ready-to-develop-using-devtool'>Getting Ready to Develop Using <filename>devtool</filename></link>"
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section for more information.
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</note>
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Use the following <filename>devtool</filename> command
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to check out the code:
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<literallayout class='monospaced'>
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$ devtool modify linux-yocto
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</literallayout>
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<note>
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During the checkout operation, a bug exists that could
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cause errors such as the following to appear:
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<orderedlist>
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<listitem><para>
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<emphasis>Check Out the Kernel Source Files:</emphasis>
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First you must use <filename>devtool</filename> to checkout
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the kernel source code in its workspace.
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Be sure you are in the terminal set up to do work
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with the extensible SDK.
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<note>
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See this
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<link linkend='setting-up-the-esdk-terminal'>step</link>
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in the
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"<link linkend='getting-ready-to-develop-using-devtool'>Getting Ready to Develop Using <filename>devtool</filename></link>"
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section for more information.
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</note>
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Use the following <filename>devtool</filename> command
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to check out the code:
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<literallayout class='monospaced'>
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$ devtool modify linux-yocto
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</literallayout>
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<note>
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During the checkout operation, a bug exists that could
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cause errors such as the following to appear:
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<literallayout class='monospaced'>
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ERROR: Taskhash mismatch 2c793438c2d9f8c3681fd5f7bc819efa versus
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be3a89ce7c47178880ba7bf6293d7404 for
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/path/to/esdk/layers/poky/meta/recipes-kernel/linux/linux-yocto_4.10.bb.do_unpack
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</literallayout>
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You can safely ignore these messages.
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The source code is correctly checked out.
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</note>
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</para></listitem>
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<listitem><para>
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<emphasis>Edit the Source Files</emphasis>
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Follow these steps to make some simple changes to the source
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files:
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<orderedlist>
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<listitem><para>
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<emphasis>Change the working directory</emphasis>:
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In the previous step, the output noted where you can find
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the source files (e.g.
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<filename>~/poky_sdk/workspace/sources/linux-yocto</filename>).
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Change to where the kernel source code is before making
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your edits to the <filename>calibrate.c</filename> file:
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<literallayout class='monospaced'>
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$ cd ~/poky_sdk/workspace/sources/linux-yocto
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</literallayout>
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</para></listitem>
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<listitem><para>
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<emphasis>Edit the source file</emphasis>:
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Edit the <filename>init/calibrate.c</filename> file to have
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the following changes:
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<literallayout class='monospaced'>
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You can safely ignore these messages.
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The source code is correctly checked out.
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</note>
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</para></listitem>
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<listitem><para>
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<emphasis>Edit the Source Files</emphasis>
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Follow these steps to make some simple changes to the source
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files:
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<orderedlist>
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<listitem><para>
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<emphasis>Change the working directory</emphasis>:
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In the previous step, the output noted where you can find
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the source files (e.g.
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<filename>~/poky_sdk/workspace/sources/linux-yocto</filename>).
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Change to where the kernel source code is before making
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your edits to the <filename>calibrate.c</filename> file:
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<literallayout class='monospaced'>
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$ cd ~/poky_sdk/workspace/sources/linux-yocto
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</literallayout>
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</para></listitem>
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<listitem><para>
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<emphasis>Edit the source file</emphasis>:
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Edit the <filename>init/calibrate.c</filename> file to have
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the following changes:
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<literallayout class='monospaced'>
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void calibrate_delay(void)
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{
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unsigned long lpj;
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@@ -1085,110 +1077,111 @@
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.
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.
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.
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</literallayout>
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</para></listitem>
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</orderedlist>
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</para></listitem>
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<listitem><para>
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<emphasis>Build the Updated Kernel Source:</emphasis>
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To build the updated kernel source, use
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<filename>devtool</filename>:
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<literallayout class='monospaced'>
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</literallayout>
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</para></listitem>
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</orderedlist>
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</para></listitem>
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<listitem><para>
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<emphasis>Build the Updated Kernel Source:</emphasis>
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To build the updated kernel source, use
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<filename>devtool</filename>:
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<literallayout class='monospaced'>
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$ devtool build linux-yocto
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</literallayout>
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</para></listitem>
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<listitem><para>
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<emphasis>Create the Image With the New Kernel:</emphasis>
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Use the <filename>devtool build-image</filename> command
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to create a new image that has the new kernel.
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<note>
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If the image you originally created resulted in a Wic
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file, you can use an alternate method to create the new
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image with the updated kernel.
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For an example, see the steps in the
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<ulink url='https://wiki.yoctoproject.org/wiki/TipsAndTricks/KernelDevelopmentWithEsdk'>TipsAndTricks/KernelDevelopmentWithEsdk</ulink>
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Wiki Page.
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</note>
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<literallayout class='monospaced'>
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</literallayout>
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</para></listitem>
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<listitem><para>
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<emphasis>Create the Image With the New Kernel:</emphasis>
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Use the <filename>devtool build-image</filename> command
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to create a new image that has the new kernel.
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<note>
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If the image you originally created resulted in a Wic
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file, you can use an alternate method to create the new
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image with the updated kernel.
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For an example, see the steps in the
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<ulink url='https://wiki.yoctoproject.org/wiki/TipsAndTricks/KernelDevelopmentWithEsdk'>TipsAndTricks/KernelDevelopmentWithEsdk</ulink>
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Wiki Page.
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</note>
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<literallayout class='monospaced'>
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$ cd ~
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$ devtool build-image core-image-minimal
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</literallayout>
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</para></listitem>
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<listitem><para>
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<emphasis>Test the New Image:</emphasis>
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For this example, you can run the new image using QEMU
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to verify your changes:
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<orderedlist>
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<listitem><para>
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<emphasis>Boot the image</emphasis>:
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Boot the modified image in the QEMU emulator
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using this command:
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<literallayout class='monospaced'>
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</literallayout>
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</para></listitem>
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<listitem><para>
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<emphasis>Test the New Image:</emphasis>
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For this example, you can run the new image using QEMU
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to verify your changes:
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<orderedlist>
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<listitem><para>
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<emphasis>Boot the image</emphasis>:
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Boot the modified image in the QEMU emulator
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using this command:
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<literallayout class='monospaced'>
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$ runqemu qemux86
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</literallayout>
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</para></listitem>
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<listitem><para>
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<emphasis>Verify the changes</emphasis>:
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Log into the machine using <filename>root</filename>
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with no password and then use the following shell
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command to scroll through the console's boot output.
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<literallayout class='monospaced'>
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</literallayout>
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</para></listitem>
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<listitem><para>
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<emphasis>Verify the changes</emphasis>:
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Log into the machine using <filename>root</filename>
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with no password and then use the following shell
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command to scroll through the console's boot output.
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<literallayout class='monospaced'>
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# dmesg | less
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</literallayout>
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You should see the results of your
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<filename>printk</filename> statements
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as part of the output when you scroll down the
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console window.
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</para></listitem>
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</orderedlist>
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</para></listitem>
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<listitem><para>
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<emphasis>Stage and commit your changes</emphasis>:
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Within your eSDK terminal, change your working directory to
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where you modified the <filename>calibrate.c</filename>
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file and use these Git commands to stage and commit your
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changes:
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<literallayout class='monospaced'>
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</literallayout>
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You should see the results of your
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<filename>printk</filename> statements
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as part of the output when you scroll down the
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console window.
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</para></listitem>
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</orderedlist>
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</para></listitem>
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<listitem><para>
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<emphasis>Stage and commit your changes</emphasis>:
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Within your eSDK terminal, change your working directory to
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where you modified the <filename>calibrate.c</filename>
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file and use these Git commands to stage and commit your
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changes:
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<literallayout class='monospaced'>
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$ cd ~/poky_sdk/workspace/sources/linux-yocto
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$ git status
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$ git add init/calibrate.c
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$ git commit -m "calibrate: Add printk example"
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</literallayout>
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</para></listitem>
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<listitem><para>
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<emphasis>Export the Patches and Create a <filename>.bbappend</filename>:</emphasis>
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To export your commits as patches and create a
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<filename>.bbappend</filename> file, use the following
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command in the terminal used to work with the extensible
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SDK.
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This example uses the previously established layer named
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<filename>meta-mylayer</filename>.
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<note>
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See Step 3 of the
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"<link linkend='getting-ready-to-develop-using-devtool'>Getting Ready to Develop using devtool</link>"
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section for information on setting up this layer.
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</note>
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<literallayout class='monospaced'>
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$ devtool finish linux-yocto /path/to/meta-mylayer
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</literallayout>
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Once the command finishes, the patches and the
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<filename>.bbappend</filename> file are located in the
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<filename>~/meta-mylayer/recipes-kernel/linux</filename>
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directory.
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</para></listitem>
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<listitem><para>
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<emphasis>Build the Image With Your Modified Kernel:</emphasis>
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You can now build an image that includes your kernel
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patches.
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Execute the following command from your
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<ulink url='&YOCTO_DOCS_REF_URL;#build-directory'>Build Directory</ulink>
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in the terminal set up to run BitBake:
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<literallayout class='monospaced'>
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</literallayout>
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</para></listitem>
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<listitem><para>
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<emphasis>Export the Patches and Create an Append File:</emphasis>
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To export your commits as patches and create a
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<filename>.bbappend</filename> file, use the following
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command in the terminal used to work with the extensible
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SDK.
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This example uses the previously established layer named
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<filename>meta-mylayer</filename>.
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<note>
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See Step 3 of the
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"<link linkend='getting-ready-to-develop-using-devtool'>Getting Ready to Develop using devtool</link>"
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section for information on setting up this layer.
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</note>
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<literallayout class='monospaced'>
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$ devtool finish linux-yocto ~/meta-mylayer
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</literallayout>
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Once the command finishes, the patches and the
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<filename>.bbappend</filename> file are located in the
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<filename>~/meta-mylayer/recipes-kernel/linux</filename>
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directory.
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</para></listitem>
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<listitem><para>
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<emphasis>Build the Image With Your Modified Kernel:</emphasis>
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You can now build an image that includes your kernel
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patches.
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Execute the following command from your
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<ulink url='&YOCTO_DOCS_REF_URL;#build-directory'>Build Directory</ulink>
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in the terminal set up to run BitBake:
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<literallayout class='monospaced'>
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$ cd ~/poky/build
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$ bitbake core-image-minimal
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</literallayout>
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</para></listitem>
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</orderedlist>
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</literallayout>
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</para></listitem>
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</orderedlist>
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</para>
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</section>
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<section id="using-traditional-kernel-development-to-patch-the-kernel">
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@@ -1441,8 +1434,8 @@
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following sequence of commands:
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<literallayout class='monospaced'>
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$ cd ~/poky/build
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$ cd bitbake -c cleanall yocto-linux
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$ cd bitbake core-image-minimal -c cleanall
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$ bitbake -c cleanall yocto-linux
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$ bitbake core-image-minimal -c cleanall
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$ bitbake core-image-minimal
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$ runqemu qemux86
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</literallayout>
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Reference in New Issue
Block a user