Android Customizing the Linux kernel

DART-MX8M-MINI - Android Pie Android P9.0.0_r30 - Customizing the Linux kernel

Making changes to kernel configuration

$ cd ~/var_imx-p9.0.0_2.0.0-ga/android_build/vendor/variscite/kernel_imx/
$ make ARCH=arm64 mrproper
$ make ARCH=arm64 imx8_var_android_defconfig
$ make ARCH=arm64 menuconfig

Navigate the menu and select the desired kernel functionality Exit the menu and answer "Yes" when asked "Do you wish to save your new configuration?"

$ make ARCH=arm64 savedefconfig
$ cp arch/arm64/configs/imx8_var_android_defconfig arch/arm64/configs/imx8_var_android_defconfig.orig 
$ cp defconfig arch/arm64/configs/

Making changes to the device tree

Edit arch/arm64/boot/dts/freescale/fsl-imx8mm-var-dart.dts
For example we want to make device tree changes for SPI configuration
Refer to: SPI

Build a new boot.img

When you perform changes to the kernel, you may build boot.img solely instead of building the whole Android.

$ cd ~/var_imx-p9.0.0_2.0.0-ga/android_build
$ source build/envsetup.sh
$ lunch dart_mx8mm-userdebug
$ make bootimage

Flashing the boot image to the target

Boot the device into fastboot mode by using below commands:

$ adb reboot bootloader
$ fastboot flash boot_a out/target/product/out/target/product/dart_mx8mm/boot.img
$ sudo flash dtbo_a out/target/product/dart_mx8mm/dtbo-<name>.img
$ sudo flash vbmeta_a out/target/product/dart_mx8mm/vbmeta-<name>.img

Replace <name> with the actual desired setup name according to the table in the "images created by the Android build" section in the .

$ sudo fastboot reboot