anchor.diff:    meta = with lib;
       { description = "Network boot firmware";
         homepage = "https://ipxe.org/";
  -      license = licenses.gpl2;
  +      license = licenses.gpl2Only;
         maintainers = with maintainers; [ ehmry ];
         platforms = platforms.linux;
       };
  
positive.code:   buildFlags = lib.attrNames targets;
  
    installPhase = ''
      mkdir -p $out
      ${lib.concatStringsSep "\n" (lib.mapAttrsToList (from: to:
        if to == null
  
negative.code:     # Some PXE constellations especially with dnsmasq are looking for the file with .0 ending
      # let's provide it as a symlink to be compatible in this case.
      ln -s undionly.kpxe $out/undionly.kpxe.0
  
      runHook postInstall
    '';
  
    enableParallelBuilding = true;
  