anchor.diff:  
   let
   
  -  version = "1.43";
  +  version = "1.43_4";
   
  -  dmgRange = "420107885-421933300"; # the whole download is 1.3GB, this cuts it down to 2MB
   
  +  # Updated according to https://github.com/patjak/bcwc_pcie/pull/81/files
  +  # and https://github.com/patjak/bcwc_pcie/blob/5a7083bd98b38ef3bd223f7ee531d58f4fb0fe7c/firmware/Makefile#L3-L9
  +  # and https://github.com/patjak/bcwc_pcie/blob/5a7083bd98b38ef3bd223f7ee531d58f4fb0fe7c/firmware/extract-firmware.sh
  +
  +  # From the Makefile:
  +  dmgUrl = "https://support.apple.com/downloads/DL1877/en_US/osxupd10.11.5.dmg";
  +  dmgRange = "205261917-208085450"; # the whole download is 1.3GB, this cuts it down to 2MB
  +  # Notes:
  +  # 1. Be sure to update the sha256 below in the fetch_url
  +  # 2. Be sure to update the homepage in the meta
  +
  +  # Also from the Makefile (OS_DRV, OS_DRV_DIR), but seems to not change:
     firmwareIn = "./System/Library/Extensions/AppleCameraInterface.kext/Contents/MacOS/AppleCameraInterface";
     firmwareOut = "firmware.bin";
  -  firmwareOffset = "81920";
  -  firmwareSize = "603715";
  +
  +  # The following are from the extract-firmware.sh
  +  firmwareOffset = "81920"; # Variable: firmw_offsets
  +  firmwareSize = "603715"; # Variable: firmw_sizes
  +
   
     # separated this here as the script will fail without the 'exit 0'
     unpack = pkgs.writeScriptBin "unpack" ''
  
positive.code: stdenv.mkDerivation {
  
    name = "facetimehd-firmware-${version}";
  
    src = fetchurl {
      url = "https://support.apple.com/downloads/DL1849/en_US/osxupd10.11.2.dmg";
      sha256 = "1jw6sy9vj27amfak83cs2c7q856y4mk1wix3rl4q10yvd9bl4k9x";
      curlOpts = "-r ${dmgRange}";
    };
  
  
negative.code: 
    meta = with stdenv.lib; {
      description = "facetimehd firmware";
      homepage = https://support.apple.com/downloads/DL1877;
      license = licenses.unfree;
      maintainers = [ maintainers.womfoo ];
      platforms = platforms.linux;
  