u-boot 命令使用

=> print    //打印配置信息                      
bootcmd=setenv bootargs root=/dev/ram rw console=$consoledev,$baudrate $othbootargs;tftp $ramdiskaddr $ramdiskfile;tftp $loadaddr $bootfile;tftp $fdtadd
r $fdtfile;bootm $loadaddr $ramdiskaddr $fdtaddr
ramboot=setenv bootargs root=/dev/ram rw console=$consoledev,$baudrate $othbootargs;tftp $ramdiskaddr $ramdiskfile;tftp $loadaddr $bootfile;tftp $fdtadd
r $fdtfile;bootm $loadaddr $ramdiskaddr $fdtaddr
nfsboot=setenv bootargs root=/dev/nfs rw nfsroot=$serverip:$rootpath ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname:$netdev:off console=$consoledev,
$baudrate $othbootargs;tftp $loadaddr $bootfile;tftp $fdtaddr $fdtfile;bootm $loadaddr - $fdtaddr
bootdelay=10
baudrate=115200
loads_echo=1
ethaddr=02:E0:0C:00:00:FD
eth1addr=02:E0:0C:00:01:FD
rootpath=/opt/eldk/ppc_85xx
netmask=255.255.255.0
hostname=sbc8548
bootfile=/uImage
loadaddr=1000000
netdev=eth0
uboot=/u-boot.bin
tftpflash=tftpboot $loadaddr $uboot; protect off 0xfffa0000 +$filesize; erase 0xfffa0000 +$filesize; cp.b $loadaddr 0xfffa0000 $filesize; protect on 0xf
ffa0000 +$filesize; cmp.b $loadaddr 0xfffa0000 $filesize
consoledev=ttyS0
ramdiskaddr=2000000
ramdiskfile=uRamdisk
fdtaddr=c00000
fdtfile=sbc8548.dtb
stdin=serial
stdout=serial
stderr=serial
serverip=128.224.156.117
ipaddr=128.224.156.173
gatewayip=128.224.156.1
ethact=eTSEC1

Environment size: 1307/8188 bytes

修改配置，启动参数等：

setenv bootcmd "setenv bootargs root=/dev/ram rw console=$consoledev,$baudrate $othbootargs;tftp $loadaddr $bootfile;tftp $fdtaddr $fdtfile;bootm $loadaddr $fdtaddr"

setenv bootcmd "setenv bootargs root=/dev/ram rw console=$consoledev,$baudrate $othbootargs;tftp $loadaddr $bootfile;tftp $fdtaddr $fdtfile;bootm $loadaddr - $fdtaddr"

setenv bootcmd 'setenv bootargs root=/dev/nfs rw nfsroot=$serverip:$rootpath ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname:$netdev:off console=$consoledev,$baudrate$othbootargs;tftp $loadaddr $bootfile;tftp $fdtaddr $fdtfile;bootm $loadaddr - $fdtaddr'

setenv rootpath /home/wr43/WindRiver/workspace/pure_prj/export/dist/

setenv serverip 128.224.156.117

saveenv    //保存修改

boot  //启动bootcmd

也可以

run nfsboot  //启动nfsboot