我先在mini2440的开发板上烧写了U-boot,，然后用tftp下载内核映象（不包含根文件系统）到开发板成功，想用NFS起根文件系统。总是无法挂载。如果把根文件系统下载到内存或与内核编译在一个映象里都可以正常启动。我把nfs起根文件系统的启动信息贴出来，请大家指教：先谢谢啦
s3c2440-sdi s3c2440-sdi: running at 198kHz (requested: 197kHz).
s3c2440-sdi s3c2440-sdi: running at 198kHz (requested: 197kHz).
s3c2440-sdi s3c2440-sdi: running at 198kHz (requested: 197kHz).
s3c2440-sdi s3c2440-sdi: powered down.
eth0: link down
IP-Config: Guessing netmask 255.255.255.0
IP-Config: Complete:
device=eth0, addr=192.168.0.100, mask=255.255.255.0, gw=255.255.255.255,
host=192.168.0.100, domain=, nis-domain=(none),
bootserver=255.255.255.255, rootserver=192.168.0.110, rootpath=
Looking up port of RPC 100003/2 on 192.168.0.110
eth0: link up, 100Mbps, full-duplex, lpa 0xC5E1
Looking up port of RPC 100005/1 on 192.168.0.110
mount: server 192.168.0.110 not responding, timed out
Root-NFS: Server returned error -5 while mounting /nfsroot/rootfs
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; here are the available partitions:
1f00 384 mtdblock0 (driver?)
1f01 2048 mtdblock1 (driver?)
1f02 259712 mtdblock2 (driver?)
1f03 262144 mtdblock3 (driver?)
Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(2,0)
