> I spec'd one out a long time ago for Cygnus/Red Hat, but we never > pursued the port. The register model on the z80 will be problematical, > though some of the lessons from the rl78 port would probably be useful.
The RL78 is very much a modern decendent of the Z80 architecture so might serve as a good starting point. But yeah, it's a messy port because gcc doesn't like the weird addressing model. I ended up using a virtual ISA that gcc could deal with, then converted that to real instructions after reload.
