{
  lib,
  stdenvNoCC,
  namespace,
  pkgs,
}:
let
  inherit (lib.trivial) importJSON;
  inherit (lib.${namespace}) selectVariant mkAllSources;

  versionSpec = importJSON ./version.json;
  selected = selectVariant versionSpec null null;
  vars = selected.variables or { };
  sources = mkAllSources pkgs selected;

  defaultConfig = ''
    EOF
    armstub=RPI_EFI.fd
    # device_tree_address=0x3e0000
    # device_tree_end=0x400000
    device_tree_address=0x1f0000
    device_tree_end=0x210000

    # Force 32 bpp framebuffer allocation.
    framebuffer_depth=32

    # Disable compensation for displays with overscan.
    disable_overscan=1

    # Force maximum USB power regardless of the power supply.
    usb_max_current_enable=1

    # Force maximum CPU speed.
    force_turbo=1

    dtoverlay=vc4-kms-v3d-pi5.dtbo
    dtoverlay=i2c0-pi5.dtbo
    dtoverlay=i2c1-pi5.dtbo
    dtoverlay=i2c2-pi5.dtbo
    dtoverlay=i2c3-pi5.dtbo
    dtoverlay=pisound-pi5.dtbo
    dtoverlay=sdio-pi5.dtbo

    dtoverlay=disable-wifi-pi5.dtbo

    EOF
  '';

  nvram = ./nvram-block.bin;
in
stdenvNoCC.mkDerivation rec {
  pname = "uefi-rpi5";
  version = vars.version;

  src = sources.firmware;

  sourceRoot = ".";

  dontUnpack = true;

  dontBuild = true;
  # Firmware blobs do not need fixing and should not be modified
  dontFixup = true;
  # fixupPhase = ''
  #   runHook preFixup

  #   dd if=${nvram} of="$src/RPI_EFI.fd" \
  #    bs=1 seek=$((0x1d0060)) count=$((0x11c0)) conv=notrunc

  #   runHook postFixup
  # '';

  installPhase = ''
    runHook preInstall
    mkdir -p "$out"

    cp ${src} .

    dd if=${nvram} of=./RPI_EFI.fd \
     bs=1 seek=$((0x1d0060)) count=$((0x11c0)) conv=notrunc

    cp -v ./RPI_EFI.fd "$out/RPI_EFI.fd"

    # cp ${src} "$out/RPI_EFI.fd"

    cat > "$out/config.txt" << ${defaultConfig}

    runHook postInstall
  '';

  meta = with lib; {
    description = "RPI5 UEFI firmware";
    homepage = "https://github.com/NumberOneGit/rpi5-uefi";
    platforms = platforms.linux;
    maintainers = [ ];
  };
}