1 Patch the kernel

In this example, we create a patch for Linux GPIO driver. We should do the steps as below:

• 1. Go to the gpio driver folder:

cd tmp/work/<machine>-fsl-linux/linux-s32/5.4-r0/git/drives/gpio

and edit the source file gpio-siul2-s32gen1.c

• 2. Add source that you changed before to git

cd <builddirectory>/tmp/work/<machine>-fsl-linux/linux-s32/5.4-r0/git
git add drivers/gpio/gpio-siul2-s32gen1.c
git commit -s -m <title of your commit>

• 3. Create the patch

git format-patch -1
Check in <builddirectory>/tmp/work/<machine>-fsl-linux/linux-s32/5.4-r0/git folder, there is a patch file created, e.g.
0001-test-gpio-repackage.patch

• 4. Copy the patch file to meta-alb/recipes-kernel/linux/linux-s32 folder
• 5. Edit linux-s32_5.4.bb file in /meta-alb/recipes-kernel/linux to include the patch file, e.g.

SRC_URI += "file://0001-test-gpio-repackage.patch"

• 6. Return to the build directory and run command as below to clean the previous sstate:

source ./SOURCE_THIS
bitbake virtual/kernel -c cleansstate

• 7. Re-build and deploy linux

bitbake virtual/kernel