anchor.diff: -{ stdenv, fetchurl }:
  +{ stdenv, fetchurl, dpkg }:
   
   stdenv.mkDerivation rec {
     name = "raspberrypi-wireless-firmware-${version}";
  
positive.code:     cp broadcom/*.hcd "$out/lib/firmware/brcm"
    '';
  
    meta = with stdenv.lib; {
      description = "Firmware for builtin Wifi/Bluetooth devices in the Raspberry Pi 3 and Zero W";
      homepage = https://archive.raspberrypi.org/debian/pool/main/f/firmware-nonfree/;
  
negative.code:   # Firmware blobs do not need fixing and should not be modified
    dontFixup = true;
  
  
    # Unpack the debian package
    nativeBuildInputs = [ dpkg ];
    unpackCmd = ''
      if ! [[ "$curSrc" =~ \.deb$ ]]; then return 1; fi
      dpkg -x "$curSrc" .
    '';
  
    installPhase = ''
  