1. help---------to list all instructions

2. help--------- help usb --------- to get the help information for using USB function

3. ping---------used only for the development board to PING other machines

4. setenv--------- to set inter-environment variables

5. setenv serverip 192.168.0.1

6. setenv ipaddr 192.168.0.56

7. setenv bootcmd ‘tftp 32000000 vmlinux;
    kgo 32000000’

8. saveenv--------- to save environment variables after setting them

9. tftp: tftp 32000000 vmlinux---------to read the “vmlinux” under "/tftpdroot/” in the “server（IP= serverip in the environment variables）to the address 0x32000000 in the physical memory via TFTP protocol.

10. kgo--------- to start the uncompressed Linux kernel，
      kgo 32000000

11. bootm-------- to start the compressed LINUX kernel that made by UBOOT TOOLS,
      bootm 3200000

12. protect--------- to enable/disable Flash writing protection.
      protect on 1:0-3---------to protect the 1st to 3rd sectors in the first Flash
      protect off 1:0-3--------- to disable the writing protection

13. erase--------- to erase FLASH sectors，
     erase 1:0-2--------- to erase the 0 to 2 sector in every Flash