anchor.diff:  
       virtualisation.xen.bootParams =
         mkOption {
  -        default = "";
  +        default = [];
  +        type = types.listOf types.str;
           description =
             ''
               Parameters passed to the Xen hypervisor at boot time.
  
positive.code:       mkOption {
          default = 0;
          example = 512;
          description =
            ''
              Amount of memory (in MiB) allocated to Domain 0 on boot.
  
negative.code:     virtualisation.xen.bridge = {
          name = mkOption {
            default = "xenbr0";
            type = types.str;
            description = ''
                Name of bridge the Xen domUs connect to.
              '';
  