kernel dumps on powerpc/pmap questions

[Andreas Tobler]

Hello all,

to investigate a system lockup I need to implement kerneldumps on 
powerpc. Well, exactly on PowerMacs. The booke should already support 
this feature.

Right now I'm at the point where I can dump something, means the 
mechanism to be able to get a (core) dump for example via 'call doadump' 
in db works. I can restore the dump via savecore.

I took the approach from booke and implemented the necessary functions 
for PowerMacs. But here I'm offline.

I do not understand what I want to dump, means which part of the memory.
Once I know what to dump, where do I find the information, which addresses?

How can I get a picture of the memory organization form powermacs?
Is there a pointer available about pmap in the kernel to find out a bit 
more on this topic?

What is really needed to be able to run kgdb on a core file to be able 
to find where the kernel crashed?

I know the questions are a bit vague, but I need an entry point.

I appreciate any pointer to implement this feature.

Tia,
Andreas