typedef int(* libmem_driver_unlock_fn_t)(libmem_driver_handle_t *h, uint8_t *start, size_t size)
  | A function pointer to a LIBMEM driver's unlock function. Parameters:
  | h | A pointer to the handle of the LIBMEM driver.
  | start | A pointer to the initial memory address in memory range handled by driver to unlock.
  | size | The number of bytes to unlock.
Returns: The LIBMEM status result. The driver's unlock function should unlock size bytes of the memory range handled by the LIBMEM driver pointed to by start. If this operation is not required the function should return LIBMEM_STATUS_SUCCESS.