[OpenBIOS] [Qemu-ppc] MorphOS 4.x on QEMU
BALATON Zoltan
balaton at eik.bme.hu
Sat Mar 1 01:49:20 CET 2014
On Fri, 28 Feb 2014, BALATON Zoltan wrote:
> On Thu, 27 Feb 2014, Mark Cave-Ayland wrote:
>> FWIW there is a known issue with PPC's next-property iterator being
>> implemented differently to the standard (see Olivier's tentative patch at
>> http://www.openfirmware.info/pipermail/openbios/2014-February/008141.html).
>> It's likely that a broken device tree iteration could be the cause of the
>> MorphOS bootloader not being able to locate a suitable console mode which
>> could be related to your issue.
>
> I think I did not hit this one yet at least the console problem is surely not
> caused by this but by MorphOS only supporting some specific Radeon GPUs that
> are found in the PPC Macs it is supporting. It is looking for them by their
> vendor-id:device-id and fails if not found, but tries to continue anyway.
While the next property iterator is not the cause of the console failed
message it may very well be related to the hang in CPU detection later
that I'm currently facing. I see the following openbios debug output with
DEBUG_CIF enabled in libopenbios/client.c while MorphOS tries to detect
the CPU:
>> finddevice("/cpus") = 0xfff4bbec
>> child(0xfff4bbec) = 0xfff5194c
>> nextprop(0xfff5194c, "", 0x07de7e30) = 1
>> 0x07de7e30 6e __ __ __ __ __ __ __ __ __ __ __ __ __ __ __ n
>> getprop(0xfff5194c, "name", 0x07de7df0, 64) = 11
>> 0x07de7df0 50 6f 77 65 72 50 43 2c 47 34 00 __ __ __ __ __ PowerPC,G4.
>> nextprop(0xfff5194c, "name", 0x07de7e30) = -1
>> child(0xfff5194c) = 0x00000000
and here it gives up and freezes. This is with Olivier's patch applied,
which does not change anything in the above, I'm seeing this with or
without this patch. It seems to be a case of nextprop failing which the
patch does not correct. Any hints how to debug it further? I don't know
how to test or trace forth so I'd need some help with this.
By the way, if it didn't fail to explore the properties of the CPU it
seems to be looking for these on the CPU node:
altivec
bus-frequency
clock-frequency
cpu-version
data-streams
d-cache-block-size
d-cache-line-size
d-cache-sets
d-cache-size
i-cache-block-size
i-cache-line-size
i-cache-sets
i-cache-size
performance-monitor
reservation-granule-size
timebase-frequency
tlb-size
tlb-sets
then it tries to go down the tree and explore l2-cache and l3-cache nodes
(this is the last child call returning NULL in the above). I don't know
which of these are optional and which are critical but looking at what
QEMU provides now:
name "PowerPC,G4"
device_type "cpu"
cpu-version c0209
dcache-size 8000
icache-size 8000
dcache-sets 80
icache-sets 80
dcache-block-size 20
icache-block-size 20
timebase-frequency 3b9aca00
clock-frequency 0
state "running"
reg 00000000
available 00004000 07c54000
07e10000 f80f0000
00000000 ffffffff
translations 00001000 00003000 00001000 00000000
07c58000 001b8000 07c58000 00000000
fff00000 00100000 07f00000 00000000
I expect some problems with these too once we manage to make nextprop
work. For a start frequency entries are missing or seem to be wrong.
Regards,
BALATON Zoltan
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