mirror of
https://github.com/ryan4yin/nixos-and-flakes-book
synced 2024-12-20 09:23:13 +00:00
116 lines
3.5 KiB
Markdown
116 lines
3.5 KiB
Markdown
# Kernel Development
|
|
|
|
> WIP work in progress
|
|
|
|
An example of kernel development with `flake.nix`.
|
|
|
|
```nix
|
|
{
|
|
description = "NixOS running on LicheePi 4A";
|
|
|
|
inputs = {
|
|
nixpkgs.url = "github:nixos/nixpkgs/nixos-23.05-small";
|
|
|
|
# custom kernel's source
|
|
thead-kernel = {
|
|
url = "github:revyos/thead-kernel/lpi4a";
|
|
flake = false;
|
|
};
|
|
};
|
|
|
|
outputs = inputs@{
|
|
self
|
|
,nixpkgs
|
|
,thead-kernel
|
|
,... }:
|
|
let
|
|
pkgsKernel = import nixpkgs {
|
|
localSystem = "x86_64-linux";
|
|
crossSystem = {
|
|
config = "riscv64-unknown-linux-gnu";
|
|
};
|
|
|
|
overlays = [
|
|
(self: super: {
|
|
# use gcc 13 to compile this custom kernel
|
|
linuxPackages_thead = super.linuxPackagesFor (super.callPackage ./pkgs/kernel {
|
|
src = thead-kernel;
|
|
stdenv = super.gcc13Stdenv;
|
|
kernelPatches = with super.kernelPatches; [
|
|
bridge_stp_helper
|
|
request_key_helper
|
|
];
|
|
});
|
|
})
|
|
];
|
|
};
|
|
in
|
|
{
|
|
nixosConfigurations.lp4a = nixpkgs.lib.nixosSystem {
|
|
system = "x86_64-linux";
|
|
|
|
specialArgs = {
|
|
inherit nixpkgs pkgsKernel;
|
|
};
|
|
modules = [
|
|
{
|
|
# cross-compile this flake.
|
|
nixpkgs.crossSystem = {
|
|
system = "riscv64-linux";
|
|
};
|
|
}
|
|
|
|
./modules/licheepi4a.nix
|
|
./modules/sd-image-lp4a.nix
|
|
];
|
|
};
|
|
|
|
# use `nix develop .#kernel` to enter the environment with the custom kernel build environment available.
|
|
# and then use `unpackPhase` to unpack the kernel source code and cd into it.
|
|
# then you can use `make menuconfig` to configure the kernel.
|
|
#
|
|
# problem
|
|
# - using `make menuconfig` - Unable to find the ncurses package.
|
|
devShells.x86_64-linux.kernel = pkgsKernel.linuxPackages_thead.kernel.dev;
|
|
|
|
# use `nix develop .#fhs` to enter the fhs test environment defined here.
|
|
devShells.x86_64-linux.fhs = let
|
|
pkgs = import nixpkgs {
|
|
system = "x86_64-linux";
|
|
};
|
|
in
|
|
# the code here is mainly copied from:
|
|
# https://nixos.wiki/wiki/Linux_kernel#Embedded_Linux_Cross-compile_xconfig_and_menuconfig
|
|
(pkgs.buildFHSUserEnv {
|
|
name = "kernel-build-env";
|
|
targetPkgs = pkgs_: (with pkgs_;
|
|
[
|
|
# we need theses packages to run `make menuconfig` successfully.
|
|
pkgconfig
|
|
ncurses
|
|
|
|
pkgsKernel.gcc13Stdenv.cc
|
|
gcc
|
|
]
|
|
++ pkgs.linux.nativeBuildInputs);
|
|
runScript = pkgs.writeScript "init.sh" ''
|
|
# set the cross-compilation environment variables.
|
|
export CROSS_COMPILE=riscv64-unknown-linux-gnu-
|
|
export ARCH=riscv
|
|
export PKG_CONFIG_PATH="${pkgs.ncurses.dev}/lib/pkgconfig:"
|
|
exec bash
|
|
'';
|
|
}).env;
|
|
};
|
|
}
|
|
```
|
|
|
|
With the above `flake.nix`, I can enter the kernel build environment with `nix develop .#kernel`, and then use `unpackPhase` to unpack the kernel source code and cd into it.
|
|
But I can't use `make menuconfig` to configure the kernel, because the `ncurses` package is missing in this environment.
|
|
|
|
To solve this problem, I add a `fhs` environment to install the `ncurses` package and other necessary packages, and then I can use `nix develop .#fhs` to enter this environment and use `make menuconfig` to configure the kernel.
|
|
|
|
## References
|
|
|
|
- [Linux kernel - NixOS Wiki](https://nixos.wiki/wiki/Linux_kernel)
|
|
- https://github.com/jordanisaacs/kernel-module-flake
|