Newbie looking to figure out how to do a port!

Well, I'm not sure I'm a newbie.  I have a very eclectic knowledge base about
kernels and bootstraps.

I would like to run NetBSD on the TAMS 3011:
	http://www.tamsinc.com/3011/index.htm

This is a 405GPr (we support those with evbppc) using RedBoot.

The only RedBoot stuff I've spotted so far is over in ARM land, but it
shouldn't matter.

At this point, my big issue is not being quite sure where to start.
Presumably, the first step would be to clone existing files.*/std.* files
for one of the other evbppc's, and modify them appropriately.  Now, somewhere
in here, there must be some file in arch/evbppc which handles the very
initial setup (finding the PCI bus, knowing which chunks of address space
have memory), and I need to replace the version for whatever the obs405 uses
with some RedBoot code.

But around here I find I don't really know that much about how the very very
early parts of NetBSD's boot process happen.  It seems to me that it's
probably reasonable to just use redboot instead of the native bootloader,
so the kernel can be loaded into memory at whatever address I choose to link
it at, but...

So far as I know, despite my near total ignorance of this part of the kernel,
I'm not actually dumb, I just don't know enough yet to know which questions to
ask.  Assuming that RedBoot can load an ELF kernel and transfer execution
to _start, what should happen next?

-s