This article explains how to build the kernel binaries (including the kernel image, the modules and the device trees). It is intended for Distribution Package users.
The Android Linux Common kernel is used in the distribution package.
1. Prerequisites[edit source]
The environment must be installed using the Distribution Package adapted to your selected microprocessor device. See the list of Android Distribution Package.
To be able to execute following instructions you need to work from your distribution root directory and initialise your environment:
source build/envsetup.sh
bspsetup
lunch aosp-<BoardId>-userdebug
The distribution includes prebuilt kernel binaries used to generate the partition images (boot
, dt
and vendor
). These binaries are available in the device/stm/<STM32Series>-kernel/prebuilt
directory.
2. Partition layout[edit source]
The Linux kernel binary is part of the boot
partition.
The Linux kernel drivers built as loadable modules (.ko
files) are part of the vendor
partition.
The device tree binary file is part of the dt
partition.
For more information on the complete partition layout depending on your development platform, refer to the corresponding Flash mapping article named Your_development_platform Flash mapping for Android. Example: STM32MP15 Flash mapping for Android for the STM32MP15 boards.
All Flash mapping for Android articles belong to the Category:Flash mapping for Android.
3. Load the kernel sources[edit source]
By default, the kernel sources are not part of the STM32MPU distribution for Android. To load the sources, execute the following command:
load_kernel
This will load the Android™ Linux common kernel sources. These can then be found in the device/stm/<STM32Series>-kernel/linux-<STM32Series>
directory.
4. Build the kernel[edit source]
After retrieving the kernel sources you can build it using:
build_kernel
The output can be found in: out-bsp/<STM32Series>/KERNEL_OBJ
This command generate kernel, DT and gpu module. It is possible to generate them one by one:
build_kernel dtb build_kernel gpu build_kernel vmlinux
For more details please check the command helper:
build_kernel --help
Usage: build_kernel [Options] [Command] This script allows building the Linux kernel source Options: -h/--help: print this message -i/--install: update prebuilt images -v/--version: get script version --verbose: enable verbosity Command: only one command at a time supported dtb: build only device-tree binaries gpu: build only gpu module (kernel is build if not already performed) defaultconfig: build only .config based on default defconfig files and fragments menuconfig: display standard Linux kernel menuconfig interface modules: build only kernel modules binaries (kernel is build if not already performed) mrproper: execute make mrproper on targeted kernel vmlinux: build only kernel vmlinux binary
5. Integrate the kernel[edit source]
To integrate the new kernel, modules or/and device tree within your distribution, you have first to update the prebuilt images:
build_kernel -i
or
build_kernel -i dtb build_kernel -i modules build_kernel -i vmlinux
And then build the distribution to generate output images.
make -j
Then you can update associated partitions on your device. Please refer to How to populate boards for Android
6. Customize the kernel[edit source]
If you want to change the kernel configuration, please refer to How to customize kernel for Android page.