[OpenBIOS] [Qemu-ppc] FreeBSD powerpc issue
agraf at suse.de
Mon Aug 27 08:10:57 CEST 2012
On 26.08.2012, at 12:09, Segher Boessenkool <segher at kernel.crashing.org> wrote:
>>>> 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. :)
> I have no idea :-)
>> How do I flush the TLB?
> tlbie, and perhaps tlbsync.
The QEMU TLB only caches existing translations, never misses.
>> 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?)
> That is my theory, yes.
>>> 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?
> I have no idea.
More information about the OpenBIOS