anchor.diff:        ]
         ++ optional (videoDriver == "nvidia") kernelPackages.nvidia_x11
         ++ optional (videoDriver == "nvidiaLegacy") kernelPackages.nvidia_x11_legacy;
  -
  +      
       environment.systemPackages = config.environment.x11Packages;
       
       services.hal.packages = halConfigFiles;
  
positive.code:     openchrome = { modules = [ xorg.xf86videoopenchrome ]; };
      cirrus =     { modules = [ xorg.xf86videocirrus ]; };
      vmware =     { modules = [ xorg.xf86videovmware ]; };
    };
  
    videoDriver = cfg.videoDriver;
  
negative.code: 
      boot.extraModulePackages =
        optional (cfg.videoDriver == "nvidia") kernelPackages.nvidia_x11 ++ 
        optional (cfg.videoDriver == "nvidiaLegacy") kernelPackages.nvidia_x11_legacy ++
        optional (cfg.videoDriver == "vboxvideo") kernelPackages.virtualboxGuestAdditions;
  
      environment.etc = optionals cfg.exportConfiguration
        [ { source = "${configFile}";
  