Re: SPR implementation request.

[BALATON Zoltan]

On Sun, 21 Jun 2020, BALATON Zoltan wrote:
> On Sun, 21 Jun 2020, Jd Lyons wrote:
> > Would some knowledgeable person implement a few SPR’s to get OS X booting 
> > on our emulated G5 CPU’s
> >
> > qemu-system-ppc64 -M mac99 -m 1024 -hda ~/Leopard.img -serial stdio  -d 
> > guest_errors
> >
> > > > =============================================================
> > > > OpenBIOS 1.1 [Oct 28 2019 17:09]
> > > > Configuration device id QEMU version 1 machine id 3
> > > > CPUs: 1
> > > > Memory: 1024M
> > > > UUID: 00000000-0000-0000-0000-000000000000
> > > > CPU type PowerPC,970FX
> > milliseconds isn't unique.
> > > > switching to new context:
> > > > call-method slw_update_keymap failed with error ffffffdf
> > > > call-method slw_update_keymap failed with error ffffffdf
> > Trying to write invalid spr 276 (0x114) at 00000000000b6db4
> > Trying to read invalid spr 277 (0x115) at 00000000000b6db8
> > Trying to read invalid spr 276 (0x114) at 00000000000b6dbc
> > Trying to write invalid spr 277 (0x115) at 00000000000b6dd8
> > Trying to write invalid spr 276 (0x114) at 00000000000b6ddc
> > Trying to read invalid spr 276 (0x114) at 00000000000b6de0
> > Trying to write invalid spr 277 (0x115) at 00000000000b6e8c
> > Trying to write invalid spr 276 (0x114) at 00000000000b6e90
> > Trying to read invalid spr 276 (0x114) at 00000000000b6e94
>
> This:
>
> http://fxr.watson.org/fxr/source/powerpc/include/spr.h
>
> says:
>
> 148 #define SPR_SCOMC               0x114   /* ... SCOM Address Register (970) 
> */
> 149 #define SPR_SCOMD               0x115   /* ... SCOM Data Register (970) */

Also searching for this turns up that there's some documentation on what 
Mac OS X uses these for in the book "Mac OS X Internals: A Systems 
Approach" so you could read that or the XNU kernel is also open source so 
you could be able to identify what part it fails and check in the source 
what it does if it's still crashes during kernel init. Those are probably 
the best sources to make sense of the in_asm log and what you see on QEMU.

Regards,
BALATON Zoltan