boot net pointer wanted

[labrador]

I've worked a little with PXE boot on x86 (mainly for use with udpcast)
and I'd like to know how to get a minimal boot over the network
for a sparc machine (it being the net boot client).

Obviously I can set up the kernel and place the lib/module stuff in
an initrd file, but are there any packages like busybox available
that allow one to have a little OS in RAM (within the initrd),
for the sparc?

If not that, any pointers on a tool or project site that focuses
on creation of a net boot Linux for the sparc platform would be useful.