Re: [Qemu-ppc] [OpenBIOS] Apple's BootX

[Jd Lyons]

> On Jan 30, 2018, at 9:10 AM, BALATON Zoltan <address@hidden> wrote:
> 
> On Mon, 29 Jan 2018, Jd Lyons via OpenBIOS wrote:
>> Ok, with a little help for Paul at the kvm-ppc mailing list, it seems the 
>> issue maybe that the BootX or more likely mach_kernel it trying to write 
>> something to or probe for an L3 cache.
> 
> With kvm could be but on TCG it doesn't seem that way. Enabling some SPR 
> debug options in target/ppc/translate_init.c I see this (with qemu git HEAD 
> without other patches):
> 
> $ ppc-softmmu/qemu-system-ppc -cpu G4 -d int
> Write SPR 272 110 <= 07e00000
> Read SPR 287 11f => 000c0209
> Read SPR 25 019 => 07e00000
> Read SPR 25 019 => 07e00000
> Read SPR 287 11f => 000c0209
> Raise exception at fff08978 => 00000003 (40000000)
> Write SPR 273 111 <= 07df7ff0
> Write SPR 274 112 <= 20000004
> Read SPR 272 110 => 07e00000
> Read SPR 273 111 => 07df7ff0
> Read SPR 274 112 => 20000004
> Read SPR 26 01a => fff08978
> Read SPR 27 01b => 40000030
> 
> $ ppc-softmmu/qemu-system-ppc -cpu 7447a -d int
> Write SPR 272 110 <= 07e00000
> Read SPR 287 11f => 80030102
> Read SPR 25 019 => 07e00000
> Read SPR 25 019 => 07e00000
> Read SPR 287 11f => 80030102
> Raise exception at fff08978 => 0000004e (00)
> 
> So OpenBIOS gets unexpected exception very early right after reading the PVR 
> so maybe it's a problem in OpenBIOS before it gets to what you're describing. 
> Is this already fixed?
> 
> Regards,
> BALATON Zoltan
> 
> -- 
> OpenBIOS                 http://openbios.org/
> Mailinglist:  http://lists.openbios.org/mailman/listinfo
> Free your System - May the Forth be with you

It looks like in TCG mode that it tries to read these invalid spr’s

1018
1011
1016
1012

This doesn’t cause a halt, as the kernel boots.