您好，我是嵌入式Linux的新手，我正在按照本教程（https://e2e.ti.com/support/arm/sitara_arm/f/791/p/344528/1206203）进行eMMC引导beaglebone black的开发。但是我遇到了一个错误：bootcmd_nand0未定义。
这是我的cmd
Booting from microSD ...
Card did not respond to voltage select!
** Bad device mmc 0 **
Card did not respond to voltage select!
** Bad device mmc 0 **
Wrong Image Format for bootm command
ERROR: can't get kernel image!
Checking if client_ip is set ...
Checking for: /boot.scr ...
Checking for: /boot/boot.scr ...
Checking for: /boot/uEnv.txt ...
** Invalid partition 3 **
** Invalid partition 4 **
** Invalid partition 5 **
** Invalid partition 6 **
** Invalid partition 7 **
## Error: "bootcmd_nand0" not defined
link up on port 0, speed 100, full duplex
我将“ uImage，zImage，u-boot.img，MLO，am335x-boneblack.dtb”和uEnv.txt安装到了mmcblk1p1
然后我将“ bin，dev，home，lost + found，mnt，run，sys，usr，boot，etc，lib，media，proc，sbin，tmp，var”安装到mmcblk1p2
对不起，我的英语不好。有人对我做错了什么还是错过了什么有所了解吗？