[9fans] super-minimal boot for plan 9 on xen; we could use some help.

[9fans] super-minimal boot for plan 9 on xen; we could use some help.

[ron minnich]

Aki and I have a non-working, but close, minimal root image to allow
you to quickly get to plan 9 on xen. Note: this is really quite
different than xen-knoppix. There is a kernel, a VERY minimal root,
and a plan 9 kernel and disk image -- or that is the plan.

The model is this: you boot the disk, which loads xen, and linux. It
drops you into a bash running in a read-only  ext3. There is a simple
script to mount tmpfs on important places (/tmp, /var/log, whatever).
You start a plan 9 domU, then start up Aki's drawterm that runs on
/dev/fb. At that point it looks like a Plan 9.

There are just about no linux binaries, and, since we have this damned
python interpreter, we may replace the few binaries we have (grep,
etc.) with python scripts. There is no /etc/init* stuff. Linux is
always running in runlevel 1.

Note that since we run a drawterm, you always have access to both the
linux file system and the Plan 9 file system. Next step is to have
linux dom0 run an xcpu server, so that Plan 9 can host any/all linux
binaries needed. This is getting interesting: the Linux dom0 will be
entirely subordinate to the Plan 9 domU.

I almost have the PCI control done so that Plan 9 domU can "own" a
hardware device. The Plan 9 PCI "frontend" driver is now making
connections to the dom0 and taking ownership; I still don't have
actual I/O working.

Status is that it the disk image almost works. We could use a little
capable help from those interested and (IMPORTANT!) knowledgable about
Xen. The xen startup is a maze of python and bash stuff, and there is
something we're missing. It would be nice long term to kill the bash
scripts and have just python -- it's a pain in the neck running two
interpreters to just bring up a domain.

So, if you
1. have run xen before
2. understand python and linux somewhat
3. are patient

give me a ring, and we can tell you how to test this thing; you might
even tell us what we got wrong. Aki is done here at LANL and is off to
the Grand Canyon, ... he is Off The Grid; it'd be nice to have
something working for him when he gets back!

thanks

ron