anchor.diff:    };
   
     ubootNanoPCT4 = buildUBoot rec {
  -    # vanilla u-boot does not work with the nanopc-t4
  -    # so we use this repo with the required patches applied
  -    src = fetchFromGitHub {
  -      owner = "tmountain";
  -      repo = "u-boot-nanopct4";
  -      rev = "23f6f74ec3ba53263ed97ec3cac9979b0ad998bc";
  -      sha256 = "07b3gcizkswld796l502bj6ln0hwz7wcm2rp3knpjmmha5llb5dz";
  +    rkbin = fetchFromGitHub {
  +      owner = "armbian";
  +      repo = "rkbin";
  +      rev = "3bd0321cae5ef881a6005fb470009ad5a5d1462d";
  +      sha256 = "09r4dzxsbs3pff4sh70qnyp30s3rc7pkc46v1m3152s7jqjasp31";
       };
  -
  -    version = "2020.10";
  -    # this provides wrapped rkbin binaries that are patched to work with NixOS
  -    rkbin = callPackage "${src}/rkbin" {};
   
       defconfig = "nanopc-t4-rk3399_defconfig";
   
  
positive.code:       platforms = [ "aarch64-linux" ];
        license = lib.licenses.unfreeRedistributableFirmware;
      };
      filesToInstall = [ "idbloader.bin" "uboot.img" "trust.bin" ];
      postBuild = ''
        ./tools/mkimage -n rk3399 -T rksd -d ${rkbin}/share/rkbin/rk33/rk3399_ddr_800MHz_v1.24.bin idbloader.bin
        cat ${rkbin}/share/rkbin/rk33/rk3399_miniloader_v1.19.bin >> idbloader.bin
        ${rkbin}/bin/trust_merger --replace bl31.elf ${rkbin}/share/rkbin/rk33/rk3399_bl31_v1.30.elf trust.ini
        ${rkbin}/bin/loaderimage --pack --uboot ./u-boot-dtb.bin uboot.img
      '';
    };
  
  
negative.code: { stdenv
  , lib
  , fetchurl
  , fetchpatch
  , fetchFromGitHub
  