I am using AU1200 board and trying to boot through NFS.Kernel boots but shows a panic after some time..

TCP: Hash tables configured (established 2048 bind 2048)
NET: Registered protocol family 1
NET: Registered protocol family 17
NET: Registered protocol family 15
Root-NFS: No NFS server available, giving up.
VFS: Unable to mount root fs via NFS, trying floppy.
VFS: Cannot open root device "nfs" or unknown-block(2,0)
Please append a correct "root=" boot option
Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(2,0)