boot.nix

{ config, lib, pkgs, ... }:
{
  config = {
    boot = {
      loader = {
        systemd-boot.enable = true;
        efi.canTouchEfiVariables = false;
        grub.device = "nodev";
        grub.efiSupport = true;
      };
      supportedFilesystems = [ "ext4" "ntfs" "nfs" ];
      kernelPackages = let
        linux_rpi5_pkg = { stdenv, lib, buildPackages, fetchFromGitHub, perl, buildLinux, rpiVersion, ... } @ args:

        let
          # NOTE: raspberrypifw & raspberryPiWirelessFirmware should be updated with this
          modDirVersion = "6.6.35";
          tag = "rpi-6.6.y";
        in
        lib.overrideDerivation (buildLinux (args // {
          version = "${modDirVersion}-${tag}";
          inherit modDirVersion;
        
          src = fetchFromGitHub {
            owner = "raspberrypi";
            repo = "linux";
            rev = "c1432b4bae5b6582f4d32ba381459f33c34d1424";
            hash = "sha256-pzjgCWG9FhMU3LCZnvz5N4jYfaaJQDT6Pv5lD/3zsm4=";
          };
          defconfig = {
            "1" = "bcmrpi_defconfig";
            "2" = "bcm2709_defconfig";
            "3" = if stdenv.hostPlatform.isAarch64 then "bcmrpi3_defconfig" else "bcm2709_defconfig";
            "4" = "bcm2711_defconfig";
            "5" = "bcm2712_defconfig";
          }.${toString rpiVersion};
       
          features = {
            efiBootStub = false;
          } // (args.features or {});
       
          makeFlags = [
            "CONFIG_CEPH_LIB=n"
            "CONFIG_CEPH_FS=n"
            "CONFIG_CEPH_FSCACHE=n"
            "CONFIG_CEPH_FS_POSIX_ACL=n"
            "CONFIG_EROFS_FS_XATTR=n"
            "CONFIG_EROFS_FS_POSIX_ACL=n"
            "CONFIG_EROFS_FS_SECURITY=n"
            "CONFIG_EROFS_FS_ZIP=n"
            "CONFIG_SND_SOC_SIMPLE_MUX=n"
          ];
 
          extraMeta = if (rpiVersion < 3) then {
            platforms = with lib.platforms; arm;
            hydraPlatforms = [];
          } else {
            platforms = with lib.platforms; arm ++ aarch64;
            hydraPlatforms = [ "aarch64-linux" ];
          };
        } // (args.argsOverride or {}))) (oldAttrs: {
          postConfigure = ''
            # The v7 defconfig has this set to '-v7' which screws up our modDirVersion.
            sed -i $buildRoot/.config -e 's/^CONFIG_LOCALVERSION=.*/CONFIG_LOCALVERSION=""/'
            sed -i $buildRoot/include/config/auto.conf -e 's/^CONFIG_LOCALVERSION=.*/CONFIG_LOCALVERSION=""/'
          '';
        
          # Make copies of the DTBs named after the upstream names so that U-Boot finds them.
          # This is ugly as heck, but I don't know a better solution so far.
          postFixup = ''
            dtbDir=${if stdenv.isAarch64 then "$out/dtbs/broadcom" else "$out/dtbs"}
            rm $dtbDir/bcm283*.dtb
            copyDTB() {
              cp -v "$dtbDir/$1" "$dtbDir/$2"
            }
          '' + lib.optionalString (lib.elem stdenv.hostPlatform.system ["armv6l-linux"]) ''
            copyDTB bcm2708-rpi-zero-w.dtb bcm2835-rpi-zero.dtb
            copyDTB bcm2708-rpi-zero-w.dtb bcm2835-rpi-zero-w.dtb
            copyDTB bcm2708-rpi-b.dtb bcm2835-rpi-a.dtb
            copyDTB bcm2708-rpi-b.dtb bcm2835-rpi-b.dtb
            copyDTB bcm2708-rpi-b.dtb bcm2835-rpi-b-rev2.dtb
            copyDTB bcm2708-rpi-b-plus.dtb bcm2835-rpi-a-plus.dtb
            copyDTB bcm2708-rpi-b-plus.dtb bcm2835-rpi-b-plus.dtb
            copyDTB bcm2708-rpi-b-plus.dtb bcm2835-rpi-zero.dtb
            copyDTB bcm2708-rpi-cm.dtb bcm2835-rpi-cm.dtb
          '' + lib.optionalString (lib.elem stdenv.hostPlatform.system ["armv7l-linux"]) ''
            copyDTB bcm2709-rpi-2-b.dtb bcm2836-rpi-2-b.dtb
          '' + lib.optionalString (lib.elem stdenv.hostPlatform.system ["armv7l-linux" "aarch64-linux"]) ''
            copyDTB bcm2710-rpi-zero-2.dtb bcm2837-rpi-zero-2.dtb
            copyDTB bcm2710-rpi-3-b.dtb bcm2837-rpi-3-b.dtb
            copyDTB bcm2710-rpi-3-b-plus.dtb bcm2837-rpi-3-a-plus.dtb
            copyDTB bcm2710-rpi-3-b-plus.dtb bcm2837-rpi-3-b-plus.dtb
            copyDTB bcm2710-rpi-cm3.dtb bcm2837-rpi-cm3.dtb
            copyDTB bcm2711-rpi-4-b.dtb bcm2838-rpi-4-b.dtb
          '';
        } // (args.argsOverride or {}));
      linux_rpi5 = pkgs.callPackage linux_rpi5_pkg{
        kernelPatches = with pkgs.kernelPatches; [
          bridge_stp_helper
          request_key_helper
        ];
        rpiVersion = 5;
      };
    in
      pkgs.recurseIntoAttrs (pkgs.linuxPackagesFor linux_rpi5);
      initrd.kernelModules = [ "8821au" ];
      extraModulePackages = with config.boot.kernelPackages; [ rtl8821au ];
      kernelParams = [ "8250.nr_uarts=11" "console=ttyAMA10,9660" "console=tty0" "usbhid.mousepoll=0" ];
      kernelModules = [ "uinput" ];
    };
  };
}