Android Customizing the Linux kernel
From Variscite Wiki
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