nfs mount failed

hi,all

i used u-boot to boot uImage from ram, and the kernel boot successed and mounted nfs fs!
and i wanted to boot uImage from falsh, and did:
1. tftp 0x10000000 (0x10000000 is ram address)
2. erase 0x100000 0x3fffff (0x100000--0x3fffff is flash room)
3. cp.b 0x10000000 0x100000 $(fileszie)
4. bootm 0x100000

the kernel boot successed and mounted nfs fs!(i used tcpdump on server and found packages from my board) but if i rebooted, and "bootm 0x100000", the kernel stoped when mounted nfsroot fs.
the boot information was:
..............................
<6>Freeing initrd memory: 4096K
Freeing initrd memory: 4096K
<5>Looking up port of RPC 100003/2 on 172.16.6.79
Looking up port of RPC 100003/2 on 172.16.6.79

(172.16.6.79 is nfsroot server)

i used tcpdump on my nfsroot server, and found no package from my board

so, what's wrong with it?

thank you!

-------------------------------------------------------
This SF.Net email is sponsored by: NEC IT Guy Games.
Get your fingers limbered up and give it your best shot. 4 great events, 4 opportunities to win big! Highest score wins.NEC IT Guy Games. Play to win an NEC 61 plasma display. Visit http://www.necitguy.com/?r=20
_______________________________________________
NFS maillist - [email protected]
https://lists.sourceforge.net/lists/listinfo/nfs