core/pkgs/by-name/ke/kernel-headers/default.nix

{
  stdenvNoCC,
  lib,
  buildPackages,
  fetchurl,
  perl,
  elf-header,
  bison,
  flex,
  rsync,
  writeTextFile,
}:

let

  # As part of building a hostPlatform=mips kernel, Linux creates and runs a
  # tiny utility `arch/mips/boot/tools/relocs_main.c` for the buildPlatform.
  # This utility references a glibc-specific header `byteswap.h`.  There is a
  # compatibility header in gnulib for most BSDs, but not for Darwin, so we
  # synthesize one here.
  darwin-endian-h = writeTextFile {
    name = "endian-h";
    text = ''
      #include <byteswap.h>
    '';
    destination = "/include/endian.h";
  };
  darwin-byteswap-h = writeTextFile {
    name = "byteswap-h";
    text = ''
      #pragma once
      #include <libkern/OSByteOrder.h>
      #define bswap_16 OSSwapInt16
      #define bswap_32 OSSwapInt32
      #define bswap_64 OSSwapInt64
    '';
    destination = "/include/byteswap.h";
  };

  makeLinuxHeaders =
    {
      src,
      version,
      patches ? [ ],
    }:
    stdenvNoCC.mkDerivation {
      inherit src;

      pname = "linux-headers";
      inherit version;

      ARCH = stdenvNoCC.hostPlatform.linuxArch;

      strictDeps = true;
      enableParallelBuilding = true;

      # It may look odd that we use `stdenvNoCC`, and yet explicit depend on a cc.
      # We do this so we have a build->build, not build->host, C compiler.
      depsBuildBuild = [ buildPackages.stdenv.cc ];
      # `elf-header` is null when libc provides `elf.h`.
      nativeBuildInputs =
        [
          perl
          elf-header
        ]
        ++ lib.optionals stdenvNoCC.hostPlatform.isAndroid [
          bison
          flex
          rsync
        ]
        ++ lib.optionals (stdenvNoCC.buildPlatform.isDarwin && stdenvNoCC.hostPlatform.isMips) [
          darwin-endian-h
          darwin-byteswap-h
        ];

      extraIncludeDirs = lib.optionals (with stdenvNoCC.hostPlatform; isPower && is32bit && isBigEndian) [
        "ppc"
      ];

      inherit patches;

      hardeningDisable = lib.optional stdenvNoCC.buildPlatform.isDarwin "format";

      makeFlags = [
        "SHELL=bash"
        # Avoid use of runtime build->host compilers for checks. These
        # checks only cared to work around bugs in very old compilers, so
        # these changes should be safe.
        "cc-version:=9999"
        "cc-fullversion:=999999"
        # `$(..)` expanded by make alone
        "HOSTCC:=$(CC_FOR_BUILD)"
        "HOSTCXX:=$(CXX_FOR_BUILD)"
      ];

      # Skip clean on darwin, case-sensitivity issues.
      buildPhase =
        lib.optionalString (!stdenvNoCC.buildPlatform.isDarwin) ''
          make mrproper $makeFlags
        ''
        + (
          if stdenvNoCC.hostPlatform.isAndroid then
            ''
              make defconfig
              make headers_install
            ''
          else
            ''
              make headers $makeFlags
            ''
        );

      checkPhase = ''
        make headers_check $makeFlags
      '';

      # The following command requires rsync:
      #   make headers_install INSTALL_HDR_PATH=$out $makeFlags
      # but rsync depends on popt which does not compile on aarch64 without
      # updateAutotoolsGnuConfigScriptsHook which is not enabled in stage2,
      # so we replicate it with cp. This also reduces bootstrap closure size.
      installPhase =
        ''
          mkdir -p $out
          cp -r usr/include $out
          find $out -type f ! -name '*.h' -delete
        ''
        # Some builds (e.g. KVM) want a kernel.release.
        + ''
          mkdir -p $out/include/config
          echo "${version}-default" > $out/include/config/kernel.release
        '';

      meta = with lib; {
        description = "Header files and scripts for Linux kernel";
        license = licenses.gpl2;
        platforms = platforms.linux;
      };
    };
in
{
  inherit makeLinuxHeaders;

  linuxHeaders =
    let
      version = "6.7";
    in
    makeLinuxHeaders {
      inherit version;
      src = fetchurl {
        url = "mirror://kernel/linux/kernel/v${lib.versions.major version}.x/linux-${version}.tar.xz";
        hash = "sha256-7zEUSiV20IDYwxaY6D7J9mv5fGd/oqrw1bu58zRbEGk=";
      };
      patches = [
        ./no-relocs.patch # for building x86 kernel headers on non-ELF platforms
      ];
    };
}