anchor.diff:            '';
         };
   
  +    virtualisation.emptyDiskImages =
  +      mkOption {
  +        default = [];
  +        type = types.list types.int;
  +        description =
  +          ''
  +            Additional disk images to provide to the VM, the value is a list of
  +            sizes in megabytes the empty disk should be.
  +
  +            These disks are writeable by the VM and will be thrown away
  +            afterwards.
  +          '';
  +      };
  +
       virtualisation.graphics =
         mkOption {
           default = true;
  
positive.code:       "
  
        ${pkgs.vmTools.startSamba}
  
        # Start QEMU.
        # "-boot menu=on" is there, because I don't know how to make qemu boot from 2nd hd.
  
negative.code:             -initrd ${config.system.build.toplevel}/initrd \
              -append "$(cat ${config.system.build.toplevel}/kernel-params) init=${config.system.build.toplevel}/init regInfo=${regInfo} ${kernelConsole} $QEMU_KERNEL_PARAMS" \
            ''} \
            $extraDisks \
            ${qemuGraphics} \
            ${toString config.virtualisation.qemu.options} \
            $QEMU_OPTS
  