anchor.diff:      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-3-b.dtb bcm2837-rpi-3-b.dtb
       copyDTB bcm2710-rpi-3-b-plus.dtb bcm2837-rpi-3-b-plus.dtb
       copyDTB bcm2710-rpi-cm3.dtb bcm2837-rpi-cm3.dtb
  
positive.code: 
    # 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 = if stdenv.hostPlatform.system == "aarch64-linux" then ''
      rm $out/dtbs/broadcom/bcm283*.dtb
      copyDTB() {
        cp -v "$out/dtbs/broadcom/$1" "$out/dtbs/broadcom/$2"
      }
  
      copyDTB bcm2710-rpi-3-b.dtb bcm2837-rpi-3-b.dtb
      copyDTB bcm2710-rpi-3-b-plus.dtb bcm2837-rpi-3-b-plus.dtb
    '' else ''
      rm $out/dtbs/bcm283*.dtb
      copyDTB() {
        cp -v "$out/dtbs/$1" "$out/dtbs/$2"
      }
  
      copyDTB bcm2708-rpi-0-w.dtb bcm2835-rpi-zero.dtb
      copyDTB bcm2708-rpi-0-w.dtb bcm2835-rpi-zero-w.dtb
      copyDTB bcm2708-rpi-b.dtb bcm2835-rpi-a.dtb
  
negative.code: { stdenv, lib, buildPackages, fetchFromGitHub, perl, buildLinux, ... } @ args:
  
  let
    modDirVersion = "4.14.62";
    tag = "1.20180817";
  in
  lib.overrideDerivation (buildLinux (args // rec {
    version = "${modDirVersion}-${tag}";
    inherit modDirVersion;
  
  