Mmm.. I have another approach for this in mind now.

Assuming I can locate the kernel source for the RioReceiver, the need for NFS can be almost 100% replaced by simply replacing it in the Receiver kernel with FTPFS instead. Which is tiny, read-only (for 2.2.x kernels), and will work as-is with the existing Hijack KFTPD server. So, no need for NFS at all on the Empeg, no extra code needed even. The only possible issue would be the initial kernel download by the Receiver's firmware -- I don't want to touch the firmware, so the NFS mount/read of zImage will have to be spoofed by Hijack. Probably not too much code for that one special case.

Cheers