Android Customizing the Linux kernel: Difference between revisions

Revision as of 14:32, 31 December 2019

VAR-SOM-MX6 - Android Nougat N7.1.1 - Customizing the Linux kernel

Making changes to kernel configuration

$ cd ~/var_n_711_100/n_711_100_build/vendor/variscite/kernel_imx/
$ make ARCH=arm mrproper
$ make ARCH=arm imx_v7_var_android_defconfig
$ make ARCH=arm menuconfig

Navigate the menu and select the desired kernel functionalities, save the new configuration and exit.
Then, save the new configuration as the new default configuration:

$ make ARCH=arm savedefconfig
$ cp arch/arm/configs/imx_v7_var_android_defconfig arch/arm/configs/imx_v7_var_android_defconfig.orig 
$ cp defconfig arch/arm/configs/

Making changes to the device tree

Edit

VAR-SOM-MX6 : arch/arm/boot/dts/imx6qdl-var-som.dtsi
DART-MX6: arch/arm/boot/dts/imx6qdl-var-dart.dtsi

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_n_711_100/n_711_100_build
$ source build/envsetup.sh
$ lunch -userdebug
$ make bootimage

Flashing the boot image to the target

Run the following to boot the device into fastboot mode and reflash the boot image:

$ adb reboot bootloader
$ fastboot flash bootout/target/product/var_mx6/boot-<setup-name>.img
Replace setup-name as per above table.
$ sudo fastboot reboot

@@ Line 9: / Line 9: @@
   $ make ARCH={{#ifeq: {{#var:HARDWARE_NAME}} |VAR-SOM-MX6|arm|arm64}} {{#var:KERNEL_DEFCONFIG}}
   $ make ARCH={{#ifeq: {{#var:HARDWARE_NAME}} |VAR-SOM-MX6|arm|arm64}} menuconfig
-Navigate the menu and select the desired kernel functionality
+Navigate the menu and select the desired kernel functionalities, save the new configuration and exit.<br>
-Exit the menu and answer "Yes" when asked "Do you wish to save your new configuration?"
+Then, save the new configuration as the new default configuration:<br>
   $ make ARCH={{#ifeq: {{#var:HARDWARE_NAME}} |VAR-SOM-MX6|arm|arm64}} savedefconfig
   $ cp arch/{{#ifeq: {{#var:HARDWARE_NAME}} |VAR-SOM-MX6|arm|arm64}}/configs/{{#var:KERNEL_DEFCONFIG}} arch/{{#ifeq: {{#var:HARDWARE_NAME}} |VAR-SOM-MX6|arm|arm64}}/configs/{{#var:KERNEL_DEFCONFIG}}.orig