uboot 用 yaffs、nfs 引导linux命令行，u-boot，bootargs，arm

yaffs:

setenv bootargs 'mem=64M console=ttyS0,115200n8 noinitrd root=/dev/mtdblock3 rootfstype=yaffs rw'

nfs:

setenv bootargs nfsroot=$serverip:$rootpath " /

"ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname:$netdev:off " /

"root=/dev/nfs rw console=ttyS0,115200n8"

如果flash是nor flash，那么用如下烧写方法：

"tftpflash=tftp $loadaddr $uboot;" /

"protect off " MK_STR(TEXT_BASE) " +$filesize; " /

"erase " MK_STR(TEXT_BASE) " +$filesize; " /

"cp.b $loadaddr " MK_STR(TEXT_BASE) " $filesize; " /

"protect on " MK_STR(TEXT_BASE) " +$filesize; " /

"cmp.b $loadaddr " MK_STR(TEXT_BASE) " $filesize/0" /