603 support

[Greg Alexander]

I'm interested in getting 603 support working.  From posts on the list
it looks like it isn't.

I've been looking at the code in 603.S, and one glaring thing stands out
at me so far:

Why do we believe that r0 gets the ctr after a page table searching
interrupt?  From what I can see in the documentation and in sample code,
this is not a valid assumption.  I'm not saying it isn't, but I don't
see evidence of it anywhere.

Other than the page table searching interrupts (which we make
disappear), what other 603-specific issues are there?  I'd like to check
some of these also.

Thanks,

GREG