Nix-based KernelSU Android Boot Image Builder

A set of nix packages (derivations) to build Android boot.img and AnyKernel installation zip files for given kernel source code.

Packages

Currently I build boot images for 3 devices:

• .#amazon-fire-hd-karnak: Amazon Fire HD 8 2018. Kernel compiles, but KernelSU doesn't work for lack of 32-bit userland app.
• .#moto-rtwo-lineageos-21: Motorola Edge+ 2023, unofficial LineageOS 21. Working perfectly.
• .#oneplus-8t-blu-spark: OnePlus 8T, Blu_spark kernel for LineageOS 21. Working perfectly.

How to add my own device

See kernels.nix for definitions of pipelines (builds for different devices).

Each kernel definition takes these arguments:

• arch: Kernel architecture, usually arm64.

• anyKernelVariant: Variant of AnyKernel used during packaging. Can have two values:

  • osm0sis: Official version. Works with devices before Android Generic Kernel Image (GKI).
  • kernelsu: Modified by KernelSU team. Works with devices using GKI.

• clangVersion: Version of clang used in kernel build.

  • Can be set to any version present in nixpkgs. Currently the value can be 8 to 17.
  • If set to latest, will use the latest clang in nixpkgs. Recommended.
  • If set to null, uses Google's GCC 4.9 toolchain instead.

• kernelSU.enable: Whether to apply KernelSU patch.

• kernelSU.variant: Variant of KernelSU to use. Can be official, next or custom.

• kernelSU.src: If kernelSU.variant is custom, specify the source of KernelSU patches.

• kernelSU.revision: If kernelSU.variant is custom, specify the revision number of KernelSU patches.

• kernelSU.subdirectory: If kernelSU.variant is custom, specify the directory where KernelSU patches will be extracted to.

• susfs.enable: Whether to apply SusFS patch.

• susfs.src: Source of SusFS patches. Since SusFS has too many different branches, we do not provide default variants.

• susfs.kernelPatch: Path to SusFS's kernel patch. If set, will override the patch used. Useful for overriding patch to adapt to different kernel versions.

• susfs.kernelsuPatch: Path to SusFS's KernelSU patch. If set, will override the patch used. Used for overriding patch to adapt to different KernelSU versions.

• kernelConfig: Additional kernel config to be applied during build.

• kernelDefconfigs: List of kernel config files applied during build.

  • Older kernels usually have a single _defconfig file. Newer devices may have several.
  • If you're building for a open source third party ROM, check the android_device_[Codename of your device] repo and android_device_[Codename of your device]_common repo, take a look at the BoardConfig.mk and BoardConfigCommon.mk, and take note of all config files in TARGET_KERNEL_CONFIG variable.
  • If you do not have access to such repos, you will need to do some guesswork.

• kernelImageName: Generated kernel image name at end of compilation process. Usually Image. If you are unsure, again check the BoardConfig.mk or BoardConfigCommon.mk, and look for BOARD_KERNEL_IMAGE_NAME.

• kernelMakeFlags: Additional make flags passed to kernel build process. Can be used to ignore some compiler warnings.

• kernelPatches: List of patch files to be applied to kernel.

• kernelSrc: Source code of the kernel. Can be supplied with fetchgit, fetchGitHub or alike, or provided with nvfetcher, which is already set up in this repo.

• oemBootImg: Optional, a working boot image for your device, either from official OS or a third party OS (like LineageOS). If this is provided, a boot.img will be generated, which can be directly flashed onto your device.

Use as Flake.parts module

If you want to build Android kernels in your own flake, you can import this repo as a Flake.parts module:

{
  inputs = {
    flake-parts.url = "github:hercules-ci/flake-parts";
    nix-kernelsu-builder.url = "github:xddxdd/nix-kernelsu-builder";
  };
  outputs =
    { flake-parts, ... }@inputs:
    flake-parts.lib.mkFlake { inherit inputs; } {
      imports = [
        inputs.nix-kernelsu-builder.flakeModules.default
      ];
      systems = [ "x86_64-linux" ];
      perSystem =
        { pkgs, ... }:
        {
          kernelsu = {
            # Add your own kernel definition here
            example-kernel = {
              anyKernelVariant = "kernelsu";
              clangVersion = "latest";

              kernelSU.variant = "next";
              susfs = {
                enable = true;
                src = path/to/sufs/source;
                kernelsuPatch = ./patches/susfs-for-kernelsu-next.patch;
              };

              kernelDefconfigs = [
                "gki_defconfig"
                "vendor/kalama_GKI.config"
                "vendor/ext_config/moto-kalama.config"
                "vendor/ext_config/moto-kalama-gki.config"
                "vendor/ext_config/moto-kalama-rtwo.config"
              ];
              kernelImageName = "Image";
              kernelMakeFlags = [
                "KCFLAGS=\"-w\""
                "KCPPFLAGS=\"-w\""
              ];
              kernelSrc = path/to/kernel/source;
            };
          };
        };
    };
}

License

GPLv3.