pkgs.linuxConfig

The following is the current implementation of this function.

linuxConfig = {
    src,
    kernelPatches ? [],
    version ? (builtins.parseDrvName src.name).version,
    makeTarget ? "defconfig",
    name ? "kernel.config",
  }: stdenvNoCC.mkDerivation {
    inherit name src;
    depsBuildBuild = [ buildPackages.stdenv.cc ]
      ++ lib.optionals (lib.versionAtLeast version "4.16") [ buildPackages.bison buildPackages.flex ];
    patches = map (p: p.patch) kernelPatches;  # Patches may include new configs.
    postPatch = ''
      patchShebangs scripts/
    '';
    buildPhase = ''
      set -x
      make \
        ARCH=${stdenv.hostPlatform.linuxArch} \
        HOSTCC=${buildPackages.stdenv.cc.targetPrefix}gcc \
        ${makeTarget}
    '';
    installPhase = ''
      cp .config $out
    '';
  };