一、help
1、help
列出当前uboot所有支持的命令
2、help 命令
查看指定命令的帮助
示例：
hisilicon # help setenv setenv - set environment variables Usage: setenv [-f] name value ... - [forcibly] set environment variable ‘name‘ to ‘value ...‘ setenv [-f] name - [forcibly] delete environment variable ‘name‘
二、reset
重启uboot
三、boot/bootm
1、boot
默认从bootcmd中启动内核
2、bootm
从内存中启动内核
示例：
sf probe 0 sf read 0x42000000 0x100000 0x500000 bootm 0x42000000
四、printenv/setenv/saveenv
1、printenv
打印所有环境变量的值
2、setenv
设置/修改/删除环境变量的值
3、saveenv
保存环境变量，环境变量修改过后必须执行此命令才可以保存起来，否则重启后环境变量就恢复了
示例：
setenv bootargs ‘mem=256M console=ttyAMA0,115200 root=/dev/mtdblock2 rw rootfstype=jffs2 mtdparts=hi_sfc:1M(boot),5M(kernel),26M(rootfs)‘ setenv bootcmd ‘sf probe 0;sf read 0x42000000 0x100000 0x500000;bootm 0x42000000‘
五、loadb/loadx/loady
1、loadb
从串口下载二进制文件（kermit mode）
2、loadx
从串口下载二进制文件（xmodem mode）
3、loady
从串口下载二进制文件（ymodem mode）
示例：
嵌入式设备端
hisilicon # loady 42000000 ## Ready for binary (ymodem) download to 0x42000000 at 115200 bps... Starting ymodem transfer. Press Ctrl+C to cancel. Transferring u-boot-hi3521dv200.bin... 100% 202 KB 3 KB/sec 00:00:56 1 Errors ## Total Size = 0x00032962 = 207202 Bytes
win10端
SecureCRT -> Transfer -> Send Ymodem -> 下载文件 -> 确定
六、mw/md
1、mw（mw.b、mw.w、mw.l）
用于修改内存地址上的值
2、md（md.b、md.w、md.l）
用于查看内存地址上的值
示例：
hisilicon # mw.b 42000000 55 100000 hisilicon # md.b 42000000 100 42000000: 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 UUUUUUUUUUUUUUUU 42000010: 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 UUUUUUUUUUUUUUUU 42000020: 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 UUUUUUUUUUUUUUUU 42000030: 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 UUUUUUUUUUUUUUUU 42000040: 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 UUUUUUUUUUUUUUUU 42000050: 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 UUUUUUUUUUUUUUUU 42000060: 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 UUUUUUUUUUUUUUUU 42000070: 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 UUUUUUUUUUUUUUUU 42000080: 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 UUUUUUUUUUUUUUUU 42000090: 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 UUUUUUUUUUUUUUUU 420000a0: 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 UUUUUUUUUUUUUUUU 420000b0: 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 UUUUUUUUUUUUUUUU 420000c0: 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 UUUUUUUUUUUUUUUU 420000d0: 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 UUUUUUUUUUUUUUUU 420000e0: 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 UUUUUUUUUUUUUUUU 420000f0: 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 UUUUUUUUUUUUUUUU
七、tftp
通过网口下载文件到设备
示例：
hisilicon # mw.b 42000000 ff 100000 hisilicon # tftp 42000000 u-boot-hi3521dv200.bin Hisilicon ETH net controler eth0 : phy status change : LINK=UP : DUPLEX=FULL : SPEED=100M Using eth0 device TFTP from server 172.16.80.91; our IP address is 172.16.80.99 Filename ‘u-boot-hi3521dv200.bin‘. Load address: 0x42000000 Loading: ############### 1.8 MiB/s done Bytes transferred = 207166 (3293e hex)
八、ping
测试网络是否正常通信
示例：
hisilicon # ping 172.16.80.91 Hisilicon ETH net controler eth0 : phy status change : LINK=UP : DUPLEX=FULL : SPEED=100M Using eth0 device host 172.16.80.91 is alive
九、nand
1、nand info
2、nand erase
3、nand read
4、nand write
示例：
mw.b 42000000 ff 100000 tftp 42000000 u-boot-hi3521dv200.bin nand erase 0 100000 nand write 42000000 0 100000
原文：https://www.cnblogs.com/wmate/p/13596921.html