QEMU nfs kernel panic

[Jack Mitchell <ml@communistcode.co.uk>]

I am using the stock sysroot and arm kernel zImage downloaded from the 
yocto site. When I try to boot QEMU all is well until it tries to mount 
the nfs root filesystem. It can't find it and the kernel panics, I have 
set --debug all on in the runqemu-export-rootfs script but it throws no 
further errors. Does anyone have any idea why it would do this, is it 
possible that there is something wrong with the nfs implementation in 
the kernel and the module is not loaded correctly, or is it more likely 
that the nfs share isn't mounted on my machine and the kernel cannot 
find it.

Screenshot of kernel panic: http://imgur.com/UbPTT

The only thing that jumps out at me is in the kernel boot up the rootfs 
doesn't have a value as can be seen in the screenshot, but I don't know 
if this is normal or not?

Cheers,
Jack.