#define CMD_PREFIX 0x5a
#define CMD_MD_SEND 0xc1 /* send to MD: addr[3], len[3], data[] */
#define CMD_MD_RECV 0xc2 /* recv from MD: addr[3], len[3], data[] */
#define CMD_PREFIX 0x5a
#define CMD_MD_SEND 0xc1 /* send to MD: addr[3], len[3], data[] */
#define CMD_MD_RECV 0xc2 /* recv from MD: addr[3], len[3], data[] */