使用NFS前env为：
bootcmd=nand read.i c0008000 8000 500000;bootm c0008000
setenv bootargs noinitrd console=ttySAC0,115200
setenv bootargs noinitrd console=ttySAC0,115200 init=/init root=/dev/nfs rw nfsroot=192.168.0.110:/home/s5-drivers/part4-wenjian/rootfs,proto=tcp,nfsvers=3 ip=192.168.0.80:192.168.0.110:192.168.1.1:255.255.255.0::eth0:off
挂载根目录注意事项
原文：https://www.cnblogs.com/yuxingli/p/8875942.html
