产品开发阶段：
tftp 0xc2000000 uImage\; tftp 0xc4000000 stm32mp157a-fsmp1a.dtb\; bootm 0xc2000000 - 0xc4000000;
产品部署阶段：
mmc dev 1; mmc read 0xc2000000 0x2000 0x4000; mmc read 0xc4000000 0x10000 0x200; mmc read 0xc5000000 0x21500 0x21500; bootm 0xc2000000 0xc5000000 0xc4000000;