Android Customizing the Linux kernel: Difference between revisions

Latest revision as of 21:59, 12 September 2023

VAR-SOM-MX6 - 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 through the menu, and select the desired kernel functionalities, save the new configuration, and exit.
Then, save the new configuration as the 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/imx_v7_var_android_defconfig

Making changes to the device tree

For example, edit the following file:

VAR-SOM-MX6 : ~/var_n_711_100/n_711_100_build/vendor/variscite/kernel_imx/arch/arm/boot/dts/imx6qdl-var-som.dtsi
DART-MX6: ~/var_n_711_100/n_711_100_build/vendor/variscite/kernel_imx/arch/arm/boot/dts/imx6qdl-var-dart.dtsi

For example, if you want to make changes related to the SPI configuration you can 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
$ sudo `which fastboot` flash bootout/target/product/var_mx6/boot-<setup-name>.img
Replace setup-name as per above table.
$ sudo `which fastboot` reboot

@@ Line 2: / Line 2: @@
 --> {{#vardefine:RELEASE_PARAM|{{#urlget:release}}}} <!--
 --> {{#lst:Android_Platform_Customization|{{#var:RELEASE_PARAM|RELEASE_N7.1.1_1.0.0_VAR-SOM-MX6}}}} <!--
---> {{PageHeader|{{#var:HARDWARE_NAME}} - Android {{#var:ANDROID_NAME}} {{#var:ANDROID_VERSION}} Developer Guide}} {{DocImage|category1={{#var:HARDWARE_NAME}}|category2=Android}} __toc__
+--> {{PageHeader|{{#var:HARDWARE_NAME}} - {{#var:ANDROID_VERSION}} - Customizing the Linux kernel}} {{DocImage|category1=Android|category2={{#var:HARDWARE_NAME}}}} __toc__
-== Manual build and customizing Android Linux Kernel ==
 == Making changes to kernel configuration ==
@@ Line 11: / 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 through 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 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
-  $ cp defconfig arch/{{#ifeq: {{#var:HARDWARE_NAME}} |VAR-SOM-MX6|arm|arm64}}/configs/
+  $ cp defconfig arch/{{#ifeq: {{#var:HARDWARE_NAME}} |VAR-SOM-MX6|arm|arm64}}/configs/{{#var:KERNEL_DEFCONFIG}}
-== Making changes to device tree ==
+== Making changes to the device tree ==
-Edit {{#ifeq: {{#var:HARDWARE_NAME}}|VAR-SOM-MX6| * VAR-SOM-MX6 : arch/arm/boot/dts/imx6qdl-var-som.dtsi <br>
+For example, edit the following file: {{#ifeq: {{#var:HARDWARE_NAME}}|VAR-SOM-MX6| * VAR-SOM-MX6 : {{#var:BUILD_FOLDER}}/{{#var:BUILD_FOLDER_ANDROID}}/vendor/variscite/kernel_imx/arch/arm/boot/dts/imx6qdl-var-som.dtsi <br>
-*DART-MX6: arch/arm/boot/dts/imx6qdl-var-dart.dtsi| arch/arm64/boot/dts/{{#ifeq: {{#var:HARDWARE_NAME}} | DART-MX8M |freescale/fsl-imx8mq-var-dart-common.dtsi | freescale/fsl-imx8mm-var-dart.dts}}}} <br>
+*DART-MX6: {{#var:BUILD_FOLDER}}/{{#var:BUILD_FOLDER_ANDROID}}/vendor/variscite/kernel_imx/arch/arm/boot/dts/imx6qdl-var-dart.dtsi| {{#var:BUILD_FOLDER}}/{{#var:BUILD_FOLDER_ANDROID}}/vendor/variscite/kernel_imx/arch/arm64/boot/dts/{{#ifeq: {{#var:HARDWARE_NAME}} | DART-MX8M |freescale/fsl-imx8mq-var-dart-common.dtsi | freescale/fsl-imx8mm-var-dart.dts}}}} <br>
-For example we want to make device tree changes for SPI configuration <br>
+For example, if you want to make changes related to the SPI configuration you can refer to: {{#ifeq: {{#var:HARDWARE_NAME}}|VAR-SOM-MX6 |[[{{#var:HARDWARE_NAME}} SPI|SPI]]|{{Varlink|DART-MX8M SPI|{{#var:RELEASE_LINK}}|SPI}}}}
-Refer to: {{#ifeq: {{#var:HARDWARE_NAME}}|VAR-SOM-MX6 |[[{{#var:HARDWARE_NAME}} SPI|SPI]]|{{Varlink|DART-MX8M SPI|{{#var:RELEASE_LINK}}|SPI}}}}
-== Build New boot.img ==
+== 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:BUILD_FOLDER}}/{{#var:BUILD_FOLDER_ANDROID}}
   $ source build/envsetup.sh
   $ lunch {{#var:ANDROID_MACHINE_NAME}}-userdebug
+ {{#ifeq: {{#var:HARDWARE_NAME}} | VAR-SOM-MX6 |
+ $ make bootimage
+ |
   $ make bootimage
+ $ make dtboimage
+ }}
-== Flashing bootimage to target ==
+== Flashing the boot image to the target ==
-Make sure device is in the fastboot mode if not , reboot in fastboot mode by using below commands. <br>
+Run the following to boot the device into fastboot mode and reflash the boot image:<br>
+ $ adb reboot bootloader
+ $ sudo `which fastboot` flash boot{{#ifeq: {{#var:HARDWARE_NAME}} | VAR-SOM-MX6 | out/target/product/var_mx6/boot-<setup-name>.img |_a out/target/product/{{#var:ANDROID_MACHINE_NAME}}/boot.img }}
+ {{#ifeq: {{#var:HARDWARE_NAME}} | VAR-SOM-MX6 |
- $ adb reboot bootloader
- $ fastboot flash boot{{#ifeq: {{#var:HARDWARE_NAME}} | VAR-SOM-MX6 | boot-<setup-name>.img |_a boot.img }}
 Replace setup-name as per above table.
+ |
+ $ sudo `which fastboot` flash dtbo_a out/target/product/{{#var:ANDROID_MACHINE_NAME}}/dtbo-<name>.img
+ $ sudo `which fastboot` flash vbmeta_a out/target/product/{{#var:ANDROID_MACHINE_NAME}}/vbmeta-<name>.img
+Replace <name> with the actual desired setup name according to the table in the {{Varlink|Android_NXP_Guide#Images_created_by_the_Android_build|{{#var:RELEASE_LINK}}|"images created by the Android build" section}} in the "Build Android from source code" page.
+}}
+ $ sudo `which fastboot` reboot
+{{#ifeq: {{#var:HARDWARE_NAME}} | VAR-SOM-MX6 ||
+*Note: While flashing if you encouter like below <br>
+ $ sudo `which fastboot` flash boot_a out/target/product/{{#var:ANDROID_MACHINE_NAME}}/boot.img <br>
+ target reported max download size of 1073741824 bytes
+ Sending 'boot_a' (49152 KB)...
+ OKAY [  1.740s]
+ Writing 'boot_a'...
+ FAILED (remote:  device is locked.)
+ Finished. Total time: 1.772s
+Make sure you unlock your device following<br>
+{{Varlink|Fastboot Unlock|{{#var:RELEASE_LINK}}|Fastboot Unlock}} and then follow the steps above
+}}