Skip to main content

Building (the semi-manual way)

This will help you on building kernels from source code (12 or older)

Guide​

Cloning the needed build tools​

To simplify our life, we'll use repo (yes) to clone these.

Clone the manifest, replace <branch> with actual one (e.g. common-android12-5.10), you can find the one you need by searching https://android.googlesource.com/kernel/manifest/+refs

repo init -u https://android.googlesource.com/kernel/manifest -b <branch> --depth 1

Sync the sources

repo sync -c -j$(nproc --all) --no-clone-bundle --no-tags

Cloning the kernel source​

First, we'll remove the common folder which contains the generic kernel.

rm -rf ./common

Then after that, clone the kernel source to the common folder, where <kernel source> would be something like https://github.com/LineageOS/android_kernel_xiaomi_sm8450, and optionally set the branch with -b <branch> in the clone command.

git clone <kernel source> common --depth 1

Set build environment variables​

First, cd to common

cd common

Apply whatever patches you want to your kernel here (e.g. SukiSU), then after that do the following:

To simplify our lives, we'll use environment variables defined by build configs

source build.config.common
source build.config.aarch64

Then export these variables

export ARCH="arm64"
export CC="ccache clang"
export LTO="thin"
export PATH="$(realpath ../build/build-tools/path/linux-x86):$(realpath ../$CLANG_PREBUILT_BIN):$(realpath ../build/build-tools/path/linux-x86):$(realpath ./out/android12-5.10/common/host_tools):$PATH"

Ignore any error you encountered, as long as the kernel builds then it's fine.

Build the kernel itself​

  1. Cleanup

This will cleanup any artifacts from the last old (failed) build. This is required to perform a build.

make O=out LLVM=1 LLVM_IAS=1 mrproper
  1. Apply base defconfig

Typically you'll apply the GKI one, but in case you want to use custom defconfig then you can find (or place it) here: common/arch/arm64/configs/

make O=out LLVM=1 LLVM_IAS=1 gki_defconfig
  1. (Optional) Apply vendor configs

In case you want to apply any vendor changes, apply it here. The example below adds configs for waipio (the base config for SM8450) -> xiaomi (the vendor) -> diting (the device). You can find the .config files in common/arch/arm64/configs/vendor/

make O=out LLVM=1 LLVM_IAS=1 vendor/waipio_GKI.config 
make O=out LLVM=1 LLVM_IAS=1 vendor/xiaomi_GKI.config
make O=out LLVM=1 LLVM_IAS=1 vendor/diting_GKI.config
  1. Compile the kernel
make -j$(nproc --all) O=out LLVM=1 LLVM_IAS=1

This will build a GKI kernel in common/out/arch/arm64/boot/Image