很久远的东西了，启动命令参数，针对uboot，
setenv bootargs console=ttySAC0,115200 root=/dev/nfs nfsroot=10.140.28.13:/nfs/roofs ip= 10.140.28.26 : 10.140.28.10 : 10.140.28.10 :255.255.255.0:mini6410:eth0:off
uboot设置参数
bootcmd=nand read.i c0008000 400000 500000;bootm c0008000
bootdelay=1
baudrate=115200
ethaddr=08:90:90:90:90:90
netmask=255.255.255.0
bootargs=console=ttySAC0,115200
stdin=serial
stdout=serial
stderr=serial
ipaddr=10.140.28.26
gatewayip=10.140.28.1
serverip=10.140.28.26