Plan 9 on Sun IPC + cgthree?

[Andrew Lynch lynch@ccigate.cci.de]

Recently I was virtually given a Sun IPC, with 24MB RAM,
cgthree graphics and Sony 19" monitor. I think it would make
a really nice Plan 9 terminal.

I've read the docs ("should work, but..."), also John Kennedy's
"There is Nothing so Simple" guide. Booting the 9ss that is
on the distribution CD, the system counts up the hex numbers to
7ea00 and then freezes (no L1-A, nothing)

I found that although my cgthree is in a lower slot than the
onboard bwtwo the kernel hardcodes bwtwo for SLC and IPC systems,
rather than scanning the slots. Compiled a new kernel with quick
hack: case IPC hardcode my cgthree instead. With this kernel the
numbers go up to 7ec00 but otherwise no change.
My first thought was that it was switching to the bwtwo after
reaching the 7ea00, but the new kernel doesn't help. Any ideas
where else to look?

I've read that only two banks of memory are supported. Might this
inherently mean the banks have to be the same? The 24MB is 16MB in
bank 0 and 4MB each in banks 1 and 2.

I assume the hex numbers come from the ROM receiving the kernel
via tftp. Can I calculate which value should be reached given a
9ss kernel on my PC?
I have booted a Sun3/60 sucessfully with my setup, so for now I
am blaming the Sparc.

Anyone ever had an IPC running Plan 9?

Andrew.

P.S.
SBus slot 0 le esp dma
SBus slot 1
SBus slot 2 cgthree
SBus slot 3 bwtwo