求助！ qemu通过nfs方式挂载rootfs失败

Question

这几天有点闲功夫，把maxwit linux编译了一下，编译完运行qemu-system-arm却怎么也挂不上文件系统，请帮我看看，谢谢！

具体描述如下：

编译完maxwit linux后，用编好的kernel和rootfs运行qemu,内核启动正常，出现小企鹅，但无法正常挂载rootfs

VFP support v0.3: implementor 41 architecture 1 part 10 variant 9 rev 0
input: AT Raw Set 2 keyboard as /devices/fpga:06/serio0/input/input0
input: ImExPS/2 Generic Explorer Mouse as /devices/fpga:07/serio1/input/input1
eth0: link up
IP-Config: Complete:
     device=eth0, addr=192.168.1.100, mask=255.255.255.0, gw=192.168.1.1,
     host=maxwit, domain=, nis-domain=googlecode.com,
     bootserver=255.255.255.255, rootserver=192.168.1.204, rootpath=
Looking up port of RPC 100003/2 on 192.168.1.204
rpcbind: server 192.168.1.204 not responding, timed out
Root-NFS: Unable to get nfsd port number from server, using default
Looking up port of RPC 100005/1 on 192.168.1.204
rpcbind: server 192.168.1.204 not responding, timed out
Root-NFS: Unable to get mountd port number from server, using default
Root-NFS: Server returned error -5 while mounting /home/chenyq/maxwit/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:
Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(2,0)

qemu启动参数是自己写的，貌似没有什么问题。

qemu启qemu-system-arm -M realview -kernel /home/chenyq/maxwit/build/kernel/linux-2.6.29.4/arch/arm/boot/zImage -net nic -net tap -serial stdio --append "root=/dev/nfs rw nfsroot=192.168.1.204:/home/chenyq/maxwit/rootfs ip=192.168.1.100::192.168.1.1:255.255.255.0:maxwit.googlecode.com:eth0ff console=ttyAMA0"

nfs目录的配置也是正确的。
chenyq@ubuntu:~$ sudo mount -t nfs 192.168.1.204:/home/chenyq/maxwit/rootfs/ /mnt
chenyq@ubuntu:~$ mount
/dev/sda8 on / type ext3 (rw,relatime,errors=remount-ro)
tmpfs on /lib/init/rw type tmpfs (rw,nosuid,mode=0755)
proc on /proc type proc (rw,noexec,nosuid,nodev)
sysfs on /sys type sysfs (rw,noexec,nosuid,nodev)
varrun on /var/run type tmpfs (rw,nosuid,mode=0755)
varlock on /var/lock type tmpfs (rw,noexec,nosuid,nodev,mode=1777)
udev on /dev type tmpfs (rw,mode=0755)
tmpfs on /dev/shm type tmpfs (rw,nosuid,nodev)
devpts on /dev/pts type devpts (rw,noexec,nosuid,gid=5,mode=620)
fusectl on /sys/fs/fuse/connections type fusectl (rw)
lrm on /lib/modules/2.6.28-16-generic/volatile type tmpfs (rw,mode=755)
securityfs on /sys/kernel/security type securityfs (rw)
rpc_pipefs on /var/lib/nfs/rpc_pipefs type rpc_pipefs (rw)
nfsd on /proc/fs/nfsd type nfsd (rw)
binfmt_misc on /proc/sys/fs/binfmt_misc type binfmt_misc (rw,noexec,nosuid,nodev)
gvfs-fuse-daemon on /home/chenyq/.gvfs type fuse.gvfs-fuse-daemon (rw,nosuid,nodev,user=chenyq)
192.168.1.204:/home/chenyq/maxwit/rootfs/ on /mnt type nfs (rw,addr=192.168.1.204)

Answer 1

你用which 查看一下qemu-system-arm 是不是MaxWit linux编译生成的工具？

Answer 2

chenyq@ubuntu:~$ which qemu-system-arm
/usr/bin/qemu-system-arm
确实不是maxwit linux编译出来的，应该是之前用包管理器装的qemu

但是用maxwit linux编出来的qemu,也是一样的结果挂不上rootfs,跟以前的现象一样。
chenyq@ubuntu:~$ sudo ./maxwit/utils/bin/qemu-system-arm -M realview -kernel /home/chenyq/maxwit/build/kernel/linux-2.6.29.4/arch/arm/boot/zImage -net nic -net tap -serial stdio --append "root=/dev/nfs rw nfsroot=192.168.1.204:/home/chenyq/maxwit/rootfs ip=192.168.1.100::192.168.1.1:255.255.255.0:maxwit.googlecode.com:eth0ff console=ttyAMA0"

看看还有什么可能出问题的？
睡觉了，明天还上班呢