code: def get_boot_device(self):
          
          operation = 'get_boot_device'
          try:
              boot_device = None
              boot_devices = get_children_by_dn(self.__handle, self.__boot_policy_dn)
              if boot_devices:
                  for boot_device_mo in boot_devices:
                      if boot_device_mo.Order == 1:
                          boot_device = boot_device_rn[boot_device_mo.Rn]
                          break
  
              return {'boot_device': boot_device, 'persistent': None}
          except UcsException as ex:
              print "Cisco client exception: %ss." %(ex)
              raise exception.UcsOperationError(operation=operation, error=ex)
docs: Get the current boot device for the node.
  
              Provides the current boot device of the node. Be aware that not
              all drivers support this.
  
              :raises: InvalidParameterValue if any connection parameters are
                  incorrect.
              :raises: MissingParameterValue if a required parameter is missing
              :returns: a dictionary containing:
  
              :boot_device: the boot device, one of
              :mod:`ironic.common.boot_devices` or None if it is unknown.
              :persistent: Whether the boot device will persist to all
                  future boots or not, None if it is unknown.