anchor.diff:        description = "Names of supported filesystem types.";
       };
   
  +    boot.specialFileSystems = mkOption {
  +      default = {};
  +      type = types.loaOf (types.submodule coreFileSystemOpts);
  +      internal = true;
  +      description = ''
  +        Special filesystems that are mounted very early during boot.
  +      '';
  +    };
  +
     };
   
   
  
positive.code:         description = "Disable running fsck on this filesystem.";
        };
  
        early = mkOption {
          default = false;
          type = types.bool;
          internal = true;
          description = ''
  	  Mount this filesystem very early during boot. At the moment of
  	  mounting no disks are exposed, so this option is primarily for
            special file systems.
          '';
        };
  
      };
  
      config = {
        mountPoint = mkDefault name;
        device = mkIf (elem config.fsType specialFSTypes) (mkDefault config.fsType);
        options = mkIf config.autoResize [ "x-nixos.autoresize" ];
  
        # -F needed to allow bare block device without partitions
  
negative.code:           "/bigdisk".label = "bigdisk";
          }
        '';
        type = types.loaOf (types.submodule [coreFileSystemOpts fileSystemOpts]);
        description = ''
          The file systems to be mounted.  It must include an entry for
          the root directory (<literal>mountPoint = "/"</literal>).  Each
  