[OpenBIOS] [Qemu-ppc] FreeBSD powerpc issue

Andreas Tobler andreast at fgznet.ch
Sun Aug 26 20:38:58 CEST 2012

On 26.08.12 19:02, Segher Boessenkool wrote:
>>> Now I have to find out about why the OpwnBIOS area is not mapped.
>>> Is it the case that the 'of' code on Apple HW is located
>>> elsewhere, not on such high address like 0xfff00000?
> Apple OF normally sits at the top of the address space, too.

Thanks for clarification!

>>> Or should that not matter?
>> Phew. I honestly have no idea how this would work at all even on
>> Apple HW. Linux simply handles everything from real mode (disable
>> paging) when going into anything firmware related. I have no idea
>> what OpenBSD does. If you could try to find out and summarize it, I
>> might be able to reconstruct how it could work :).
> Perhaps the OpenBSD code did not flush the TLB yet?  Or does QEMU
> emulate the TLB properly?  I seriously doubt that :-)

Hm, s/OpenBSD/FreeBSD. :)

How do I flush the TLB? Then I can look up in the code and see where it 
is done. I guess we do that but the place/time might be the question.
(Otherwise it wouldn't work on real HW, right?)

> The logs do not show whether segment x'f is still mapped in the
> SRs (or I missed it).  Is it?

How can I enable this log or make it visible?

And sorry for not being subscribed to the OPenBIOS list. Now I am and 
everybody should see all my posts to this list too.


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