Efika OF problems

[vi0]

Hi there!

I have a question about openfirmware in Efika. I have big problems with 
calls to OF. The most recent problem is with the instruction that
move a new value to sprg0:

mtspr   r8, sprg0

and in r8 at the moment is zero. The problem is that sometimes it works 
and sometimes does not. I can't actually understand why
does it happend. One function sometimes works perfectly well and just 
after that it crashes. All around the OF, in the very same place.
Could you tell me, does  the Efika's openfirmware use sprg0 for 
something special? Or maybe you have some advice concerning OF in Efika?

Other thing I were wondering is, how to make a memdump. After the crash 
efika is dead, nothing works (deadend). But
the OF supports the mem dump: ldump. Is it possible to get the content 
of the memory after the deadend? For example
by softreset? Is there a control sequence I could send via serial 
console to efika to do it?
(or is there other way to get the crashdump?)

Best regards,
Przemek