U-Boot> help
?       - alias for 'help'
base    - print or set address offset
boot    - boot default, i.e., run 'bootcmd'
bootd   - boot default, i.e., run 'bootcmd'
bootm   - boot application image from memory
bootp   - boot image via network using BOOTP/TFTP protocol
cmp     - memory compare
coninfo - print console devices and information
cp      - memory copy
crc32   - checksum calculation
dhcp    - boot image via network using DHCP/TFTP protocol
echo    - echo args to console
erase   - erase FLASH memory
fatinfo - print information about filesystem
fatload - load binary file from a dos filesystem
fatls   - list files in a directory (default /)
flinfo  - print FLASH memory information
go      - start application at address 'addr'
help    - print online help
imxtract- extract a part of a multi-image
itest   - return true/false on integer compare
loadb   - load binary file over serial line (kermit mode)
loady   - load binary file over serial line (ymodem mode)
loop    - infinite loop on address range
md      - memory display
mm      - memory modify (auto-incrementing address)
mtest   - simple RAM read/write test
mw      - memory write (fill)
nand    - NAND sub-system
nboot   - boot from NAND device
nfs     - boot image via network using NFS protocol
nm      - memory modify (constant address)
ping    - send ICMP ECHO_REQUEST to network host
printenv- print environment variables
protect - enable or disable FLASH write protection
rarpboot- boot image via network using RARP/TFTP protocol
reset   - Perform RESET of the CPU
run     - run commands in an environment variable
saveenv - save environment variables to persistent storage
setenv  - set environment variables
sleep   - delay execution for some time
tftpboot- boot image via network using TFTP protocol
usb     - USB sub-system
usbboot - boot from USB device
version - print monitor version
U-Boot> printenv
bootargs=mem=32M console=ttyS0,115200 initrd=0x21900000,5242880 root=/dev/ram0 rw 
bootcmd=nand read 0x21000000 0x100000 0x200000; nand read 0x21900000 0x400000 0x200000; bootm 0x21000000 
bootdelay=1
baudrate=115200
ethaddr=22:33:11:44:55
ipaddr=192.168.1.140
serverip=192.168.1.100
netmask=255.255.255.0
stdin=serial
stdout=serial
stderr=serial
ethact=macb0


Environment size: 360/131067 bytes
posted on 2015-01-13 10:04  醉依危栏听松涛  阅读(244)  评论(0编辑  收藏  举报