10 请大家帮忙看下邮箱通信rt_mb_recv函数报警是怎么回事

warning: passing argument 2 of 'rt_mb_recv' from incompatible pointer type [-Wincompatible-pointer-types]
             if (rt_mb_recv(&mb, (rt_uint32_t *)&str, RT_WAITING_FOREVER) == RT_EOK)
                                 ^
In file included from ../applications/my_thread.c:1:0:
C:\G070\rt-thread\include/rtthread.h:363:10: note: expected 'rt_ubase_t * {aka long unsigned int *}' but argument is of type 'rt_uint32_t * {aka unsigned int *}'
 rt_err_t rt_mb_recv(rt_mailbox_t mb, rt_ubase_t *value, rt_int32_t timeout);