anchor.diff:    # Map the video driver setting to a driver.
     knownVideoDrivers = {
       nvidia =     { modules = [ kernelPackages.nvidia_x11 ]; };
  +    nvidiaLegacy =     { modules = [ kernelPackages.nvidia_x11_legacy ]; };
       vesa =       { modules = [ xorg.xf86videovesa ]; };
       vga =        { modules = [ xorg.xf86videovga ]; };
       sis =        { modules = [ xorg.xf86videosis ]; };
  
positive.code:         EndSection
  
          Section "Extensions"
            ${optionalString (cfg.videoDriver == "nvidia" || cfg.videoDriver == "i810" || cfg.videoDriver == "ati" || cfg.videoDriver == "radeonhd") ''
              Option "Composite" "Enable"
            ''}
          EndSection
  
negative.code:       };
  
      boot.extraModulePackages =
        optional (cfg.videoDriver == "nvidia") kernelPackages.nvidia_x11 ++ 
        optional (cfg.videoDriver == "nvidiaLegacy") kernelPackages.nvidia_x11_legacy;
  
      environment.etc = optionals cfg.exportConfiguration
        [ { source = "${configFile}";
  