Applying PREEMPT RT Patches dunfell l4t r32.4.3

1. Find which git has your meta-tegra is currently using

   user@pc:~/meta-tegra$ cat recipes-kernel/linux/linux-tegra_4.9.bb | grep -n SRCREV -A5 -B5
   13-
   14-LINUX_VERSION_EXTENSION ?= "-l4t-r${@'.'.join(d.getVar('L4T_VERSION').split('.')[:2])}"
   15-SCMVERSION ??= "y"
   16-
   17-SRCBRANCH = "patches${LINUX_VERSION_EXTENSION}"
   18:SRCREV = "0be1a57448010ae60505acf4e2153638455cee7c"
   19-KBRANCH = "${SRCBRANCH}"
   20-SRC_REPO = "github.com/OE4T/linux-tegra-4.9"
   21-KERNEL_REPO = "${SRC_REPO}"
   22-SRC_URI = "git://${KERNEL_REPO};name=machine;branch=${KBRANCH} \
   23-	   ${@'file://localversion_auto.cfg' if d.getVar('SCMVERSION') == 'y' else ''} \

2. Fork https://github.com/OE4T/linux-tegra-4.9

3. git clone https://github.com/you/linux-tegra-4.9

4. cd linux-tegra-4.9

5. git checkout -b patches-l4t-r32.4-rt patches-l4t-r32.4 (or specify the git hash from the SRCREV setting in the recipe)

6. cd scripts

7. ./rt-patch.sh apply-patches

8. cd ..

9. git add .

10. git commit -m "Applied PREEMPT RT Patch to kernel"

11. git push --set-upstream origin patches-l4t-r32.4-rt

12. git log to find the commit hash for your rt patched kernel source

13. Now go back to your meta-tegra folder

14. touch recipes-kernel/linux/linux-tegra_4.9.bbappend

15. put the below in your linux-tegra_4.9.bbappend

SRCBRANCH = "patches${LINUX_VERSION_EXTENSION}-rt"
SRCREV = "##YOUR_HASH###"
KBRANCH = "${SRCBRANCH}"
SRC_REPO = "##YOUR_FORK###"
KERNEL_REPO = "${SRC_REPO}"
SRC_URI = "git://${KERNEL_REPO};name=machine;branch=${KBRANCH};protocol=ssh \
           ${@'file://localversion_auto.cfg' if d.getVar('SCMVERSION') == 'y' else ''} \
"