> that is, blackice II will not start? I think it should be possible to add an MMU to a small RISC-V core (eg picorv32) to fit on BlackIce II or MX, but I haven't tried it myself.
You would also need some external RAM. I've been experimenting with an 8MB hyperram chip, which is enough for bootstrapping the C compiler in a "bare metal" setting, but a full Plan 9 would need lots more.