OK, received the sheevaPlug yesterday and immediately tried to get NFS root filesystem working. TFTP boot for the kernel image is working fine, but when the kernel tries to mount the NFS root filesystem, it fails with the following sequence:
Looking up port of RPC 100003/2 on 10.0.0.159
eth0: link up, full duplex, speed 100 Mbps
Looking up port of RPC 100005/1 on 10.0.0.159
VFS: Mounted root (nfs filesystem).
Freeing init memory: 104K
Warning: unable to open an initial console.
Failed to execute /bin/bash. Attempting defaults...
Kernel panic - not syncing: No init found. Try passing init= option to kernel.
I changed the kernel boot arguments to use /bin/bash after it kept failing with the default (should be /sbin/init) and specifying "init=/sbin/init".
It appears to mount but cannot access files in the root filesystem. This is the root filesystem provided with the SheevaPlug which is busybox-centric. The NFS server logs an authenticated mount from the SheevaPlug IP address, no errors.
I'm beginning to believe that the root filesystem provided is incomplete. It certainly is missing a console device in /dev.