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kernel-dev: Updates to the kernel patch examples.

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Switching to kernel version 4.12.  Pulled some old commented
stuff out.

(From yocto-docs rev: c0a5c886256d3477ddaf670df4939bec1c73152e)

Signed-off-by: Scott Rifenbark <srifenbark@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
This commit is contained in:
Scott Rifenbark
2017-09-07 16:43:49 -07:00
committed by Richard Purdie
parent db3c4c8557
commit f2d4f77afb
1 changed files with 22 additions and 111 deletions
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133
documentation/kernel-dev/kernel-dev-common.xml
View File

@@ -362,25 +362,26 @@
</para>
<para>
The following command shows how to create a local copy
of the <filename>linux-yocto-4.9</filename> kernel:
The following commands show how to create a local copy
of the <filename>linux-yocto-4.12</filename> kernel:
<literallayout class='monospaced'>
$ git clone git://git.yoctoproject.org/linux-yocto-4.9 linux-yocto-4.9.git
Cloning into 'linux-yocto-4.9.git'...
remote: Counting objects: 5094108, done.
remote: Compressing objects: 100% (765113/765113), done.
remote: Total 5094108 (delta 4294009), reused 5088388 (delta 4288312)
Receiving objects: 100% (5094108/5094108), 1.02 GiB | 7.82 MiB/s, done.
Resolving deltas: 100% (4294009/4294009), done.
$ cd ~
$ git clone git://git.yoctoproject.org/linux-yocto-4.12 linux-yocto-4.12
Cloning into 'linux-yocto-4.12'...
remote: Counting objects: 6097195, done.
remote: Compressing objects: 100% (901026/901026), done.
remote: Total 6097195 (delta 5152604), reused 6096847 (delta 5152256)
Receiving objects: 100% (6097195/6097195), 1.24 GiB | 7.81 MiB/s, done.
Resolving deltas: 100% (5152604/5152604), done.
Checking connectivity... done.
Checking out files: 100% (56233/56233), done.
Checking out files: 100% (59846/59846), done.
</literallayout>
</para></listitem>
</orderedlist>
</para>
<para>
At this point you have set up to start making modifications to
At this point, you are ready to start making modifications to
the kernel using traditional kernel development steps.
For a continued example, see the
"<link linkend='using-traditional-kernel-development-to-patch-the-kernel'>Using Traditional Kernel Development to Patch the Kernel</link>"
@@ -1010,97 +1011,6 @@
$ devtool build linux-yocto
</literallayout>
</para></listitem>
<!--
<listitem><para>
NOTE: This stuff is how it would have been if a *.wic file was created
when the image was built earlier. That is the method used by the
example in the wiki (https://wiki.yoctoproject.org/wiki/TipsAndTricks/KernelDevelopmentWithEsdk).
I am leaving it here for now.
<emphasis>Create the Image With the New Kernel:</emphasis>
Normally, you would create a new image using the
<filename>devtool build-image</filename> command.
However, this method can take some time and alters the
kernel source folder.
A faster option is to use
<ulink url='https://linux.die.net/man/8/kpartx'><filename>kpartx</filename></ulink>
to splice the new kernel into the image you have already built.
<note>
You might have to install <filename>kpartx</filename>
onto your build host.
</note>
Follow these steps to create the image with the new kernel:
<orderedlist>
<listitem><para>
<emphasis>Make a Copy of Your Wic File:</emphasis>
Create a copy of your Wic from into the
<filename>/tmp</filename> directory:
<literallayout class='monospaced'>
$ cp tmp/deploy/images/qemux86/core-image-minimal-qemux86.wic /tmp
</literallayout>
</para></listitem>
<listitem><para>
<emphasis>Create Loopback Devices for Partitions:</emphasis>
Next, create loopback devices for each partition in
the Wic file.
<note>
The first unused loopback device is automatically
allocated.
</note>
In this example, the command's output uses a variable
"<replaceable>X</replaceable>" to indicate the loopback
device.
The actual output you get when you run the command lists
the actual loopback devices (e.g. "loop0p1", "loop0p2",
and "loop0p3"):
<literallayout class='monospaced'>
$ sudo kpartx -v -a /tmp/core-image-minimal-qemux86.wic
add map loop<replaceable>X</replaceable>p1 (253:6): 0 47446 linear /dev/loopX 2048
add map loop<replaceable>X</replaceable>p2 (253:7): 0 119356 linear /dev/loopX 51200
add map loop<replaceable>X</replaceable>p3 (253:8): 0 90112 linear /dev/loopX 170556
</literallayout>
</para></listitem>
<listitem><para>
<emphasis>Mount the First Device:</emphasis>
The kernel is in the first device, so mount
<filename>/dev/mapper/loop</filename><replaceable>X</replaceable><filename>p1</filename>:
<note>
Be sure to replace the "<replaceable>X</replaceable>"
in "loop<replaceable>X</replaceable>p1" with the
automatically allocated loopback device
(e.g loop0p1).
</note>
<literallayout class='monospaced'>
$ sudo mkdir /mnt/wic-p1
$ sudo mount /dev/mapper/loop<replaceable>X</replaceable>p1 /mnt/wic-p1
</literallayout>
</para></listitem>
<listitem><para>
<emphasis>Copy Over the New Kernel:</emphasis>
Now copy over new kernel using the following:
<literallayout class='monospaced'>
$ sudo cp workspace/sources/linux-yocto/arch/x86/boot/bzImage /mnt/wic-p1
</literallayout>
</para></listitem>
<listitem><para>
Finally, unmount the device and use
<filename>kpartx</filename> to delete the partition
mappings:
<note>
Replace the "<replaceable>X</replaceable>" in
"loop<replaceable>X</replaceable>" with the
automatically allocated loopback device from
earlier (e.g "loop0").
</note>
<literallayout class='monospaced'>
$ sudo umount /mnt/wic-p1
$ sudo kpartx -d /dev/loop<replaceable>X</replaceable>
</literallayout>
</para></listitem>
</orderedlist>
</para></listitem>
-->
<listitem><para>
<emphasis>Create the Image With the New Kernel:</emphasis>
Use the <filename>devtool build-image</filename> command
@@ -1260,9 +1170,9 @@ NOTE: This stuff is how it would have been if a *.wic file was created
"<link linkend='getting-ready-for-traditional-kernel-development'>Getting Ready for Traditional Kernel Development</link>"
section, use the following commands to check out the
<filename>standard/base</filename> branch of the
Linux Yocto 4.9 kernel:
Linux Yocto 4.12 kernel:
<literallayout class='monospaced'>
$ cd ~/linux-yocto-4.9
$ cd ~/linux-yocto-4.12
$ git checkout -b standard/base origin/standard/base
</literallayout>
</para></listitem>
@@ -1278,7 +1188,7 @@ NOTE: This stuff is how it would have been if a *.wic file was created
Change to where the kernel source code is before making
your edits to the <filename>calibrate.c</filename> file:
<literallayout class='monospaced'>
$ cd ~/linux-yocto-4.9/init
$ cd ~/linux-yocto-4.12/init
</literallayout>
</para></listitem>
<listitem><para>
@@ -1326,12 +1236,13 @@ NOTE: This stuff is how it would have been if a *.wic file was created
<filename>local.conf</filename>:
<literallayout class='monospaced'>
$ cd ~/poky/build/conf
<replaceable>Add the following:</replaceable>
SRC_URI_pn-linux-yocto = "git:///$HOME/linux-yocto-4.9;protocol=file;name=machine;branch=standard/base; \
git:///home/scottrif/yocto-kernel-cache;protocol=file;type=kmeta;name=meta;branch=yocto-4.9;destsuffix=${KMETA}"
SRCREV_meta_qemux86 = "${AUTOREV}"
SRCREV_machine_qemux86 = "${AUTOREV}"
</literallayout>
Add the following to the <filename>local.conf</filename>:
<literallayout class='monospaced'>
SRC_URI_pn-linux-yocto = "git:///$HOME/linux-yocto-4.12;protocol=file;name=machine;branch=standard/base; \
git:///home/scottrif/yocto-kernel-cache;protocol=file;type=kmeta;name=meta;branch=yocto-4.12;destsuffix=${KMETA}"
SRCREV_meta_qemux86 = "${AUTOREV}"
SRCREV_machine_qemux86 = "${AUTOREV}"
</literallayout>
You must be sure to specify the correct branch and machine
types.