<filename>calibrate.c</filename> source code file.
Applying the patch and booting the modified image causes the added
messages to appear on the emulator's console.
- </para>
+ </para>
+
+ <para>
+ The example assumes a clean build exists for the <filename>x86qemu</filename>
+ machine in a Source Directory named <filename>poky</filename>.
+ Furthermore, the <link linkend='build-directory'>Build Directory</link> is
+ <filename>build</filename> and is located in <filename>poky</filename> and
+ the kernel is based on the Linux 3.4 kernel.
+ </para>
<section id='create-a-layer-for-your-changes'>
<title>Create a Layer for your Changes</title>
$mkdir meta-mylayer
</literallayout>
Creating a directory that follows the Yocto Project layer naming
- conventions sets up the area for your layer.
+ conventions sets up the area for your changes.
The layer is where you place your configuration files, append
files, and patch files.
To learn more about creating a layer and filling it with the
<literallayout class='monospaced'>
${TMPDIR}/work/${MACHINE}-poky-${TARGET_OS}/${PN}-${PV}-${PR}
</literallayout>
- Assuming a recent build for the <filename>qemux86</filename> machine
- based on the Linux 3.4 kernel, a
- <link linkend='source-directory'>Source Directory</link> named <filename>poky</filename>, and
- the existence of a default <filename>build</filename> directory, the directory that
- holds the temporary source code would be here:
+ For this example, the directory that
+ holds the temporary source code is here:
<literallayout class='monospaced'>
~/poky/build/tmp/work/qemux86-poky-linux/linux-yocto-3.4.11+git1+5bdc...85f-r4.3
</literallayout>
- Within the <filename>linux</filename> directory, you find the source directories.
+ Within the <filename>linux</filename> directory, you find directories for
+ the source.
</para>
<para>
For this example, we are going to patch the <filename>init/calibrate.c</filename> file
- and add some simple console <filename>printk</filename> statements that we can
+ by adding some simple console <filename>printk</filename> statements that we can
see when we boot the image using QEMU.
</para>
</section>
</para>
<para>
- To create the patch for the <filename>calibrate.c</filename>, follow the steps
- outlined in the
+ To create the patch for the <filename>calibrate.c</filename>, follow steps
+ 3 through 12 outlined in the
"<link linkend='using-a-git-workflow'>Using a Git Workflow</link>"
section.
- For the steps used to edit the source file, do the following:
+ For step 6 (Edit the Files), do the following:
</para>
<para>
<title>Get Your Layer Setup for the Build</title>
<para>
- At this point, you have a patch file in the same directory as your original
- <filename>calibrate.c</filename>.
- Move it to your layer and place it in a separate folder having the same
- name as the recipe, which is <filename>linux-yocto</filename> in this case.
+ At this point, you have a patch file in the kernel's source code directory.
+ The patch file is named according to the commit's summary line and ends
+ with <filename>.patch</filename>.
+ For this example, it is named <filename>0001-calibrate.c.patch</filename>.
+ </para>
+
+ <para>
+ You need to move the patch file to your layer next.
+ The patch file needs to reside in the
+ <filename>meta-mylayer/recipes-kernel/linux/linux-yocto</filename> directory.
+ Create this directory path within your layer and move the patch file.
+ This directory path mirrors that used by the main kernel recipe in
+ the Source Directory (<filename>poky</filename>).
+ <literallayout class='monospaced'>
+ $ cd ~/poky/meta-mylayer
+ $ mkdir recipes-kernel
+ $ mkdir recipes-kernel/linux
+ $ mkdir recipes-kernel/linux/linux-yocto
+ </literallayout>
</para>
<para>
- Next, you need to set up your <filename>conf</filename> directory in your layer.
- Create the <filename>conf</filename> and create the <filename>layer.conf</filename>
- file.
+ Next, you need to create a <filename>conf</filename> directory in your layer
+ and within it create the <filename>layer.conf</filename> file.
You can find information on this in the
"<link linkend='creating-your-own-layer'>Creating Your Own Layer</link>"
section.
/home/scottrif/poky/meta-mylayer \
"
</literallayout></para></listitem>
- <listitem><para><emphasis>Create a bbappend File:</emphasis> You need to have
- an append file to the main 3.4 kernel recipe.
- Locate the append file in your <filename>meta-mylayer</filename> layer.
- It needs to be in a <filename>meta-mylayer/recipes-kernel/linux</filename> directory.
- Create the directory and use the following for the append file.
- This example assumes patch file is named <filename>0001-documentation-calibrate.c.patch</filename>:
+ <listitem><para><emphasis>Create a bbappend File:</emphasis> You need to create
+ an append file for the main 3.4 kernel recipe.
+ Create the append file in the <filename>linux</filename> directory you
+ created earlier within your layer.
+ Assuming the patch file is named
+ <filename>0001-documentation-calibrate.c.patch</filename>, your append
+ file, which must be named <filename>linux-yocto_3.4.bbappend</filename>,
+ has these statements:
<literallayout class='monospaced'>
FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}:"
projects / thirdparty / openembedded / openembedded-core-contrib.git / commitdiff
