final: prev:
{  magic_rb = prev.magic_rb or {} // {
     uboot-clara-hd = with prev;
       let crossPkgs =
             import prev.src
               { crossSystem.config = "arm-linux-gnueabihf";
               };
       in
       stdenv.mkDerivation {
         pname = "uboot-clara-hd";
         version = "??";
         src = fetchFromGitHub
           { owner = "akemnade";
             repo = "u-boot-fslc";
             rev = "2021.04+fslc";
             sha256 = "sha256-P4aT6BX875sSIRLrk6BKfgkdBGRD8UbIINRf6PdG4hA";
           };
         nativeBuildInputs = [ bison flex crossPkgs.stdenv.cc ];
         makeFlags = "ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- mx6sllclarahd_defconfig";
       };
   };
}