Linux NFS root file system

1. Install
sudo apt-get install nfs-common nfs-kernel-server
(if you can not find the package, please update /etc/apt/sources.list)

2. Setup
sudo vi /etc/exports
/nfsroot *(rw,async,no_root_squash)
[NOTE] no space after *

3. Restart NFS Server
sudo /etc/init.d/nfs-kernel-server start

4. Using Uboot set Linux Kernel argument
setenv bootargs 'root=dev/nfs nfsroot=192.168.1.100:/nfsroot'
setenv nfsserver 192.168.1.100
setenv netmask 255.255.255.0
saveenv

Reference
Checko' Blog