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"    /