在hi3520d板子上挂载不了根文件系统

进入uboot命令行模式：输入以下参数 setenv bootargs root=/dev/nfs nfsroot=192.168.1.146:/opt/rootfs ip=192.168.1.10:192.168.1.146:192.168.1.112:255.255.255.0::eth0:on init=zhangsan console=ttySAC0,115200              结果挂载不起来，一直卡在这里，错误提示：## Booting kernel from Legacy Image at 82000000 ...
   Image Name:   Linux-3.0.8
   Image Type:   ARM Linux Kernel Image (uncompressed)
   Data Size:    3195960 Bytes = 3 MiB
   Load Address: 80008000
   Entry Point:  80008000
   Loading Kernel Image ... OK
OK

Starting kernel ...

Uncompressing Linux... done, booting the kernel.