[OpenBIOS] PReP PowerPC "emulation"

[Andreas Färber]

Am 16.09.2010 um 14:50 schrieb Massimo Montecchi:

> So why the QEMU documentation states in this way ?
>
> Use the executable ‘qemu-system-ppc’ to simulate a complete PREP or  
> PowerMac PowerPC system.
>
> QEMU emulates the following PowerMac peripherals:
>
> 	• - UniNorth or Grackle PCI Bridge
> 	• - PCI VGA compatible card with VESA Bochs Extensions
> 	• - 2 PMAC IDE interfaces with hard disk and CD-ROM support
> 	• - NE2000 PCI adapters
> 	• - Non Volatile RAM
> 	• - VIA-CUDA with ADB keyboard and mouse.
> QEMU emulates the following PREP peripherals:
>
> 	• - PCI Bridge
> 	• - PCI VGA compatible card with VESA Bochs Extensions
> 	• - 2 IDE interfaces with hard disk and CD-ROM support
> 	• - Floppy disk
> 	• - NE2000 network adapters
> 	• - Serial port
> 	• - PREP Non Volatile RAM
> 	• - PC compatible keyboard and mouse.
> QEMU uses the Open Hack’Ware Open Firmware Compatible BIOS available  
> at http://perso.magic.fr/l_indien/OpenHackWare/index.htm.
>
> Since version 0.9.1, QEMU uses OpenBIOS http://www.openbios.org/ for  
> the g3beige and mac99 PowerMac machines. OpenBIOS is a free (GPL v2)  
> portable firmware implementation. The goal is to implement a 100%  
> IEEE 1275-1994 (referred to as Open Firmware) compliant firmware.
>
> The following options are specific to the PowerPC emulation:
>
> ‘-g WxH[xDEPTH]’
> Set the initial VGA graphic mode. The default is 800x600x15.
>
> ‘-prom-env string’
> Set OpenBIOS variables in NVRAM, for example:
>
>
> qemu-system-ppc -prom-env 'auto-boot?=false' \
>  -prom-env 'boot-device=hd:2,\yaboot' \
>  -prom-env 'boot-args=conf=hd:2,\yaboot.conf'
> These variables are not used by Open Hack’Ware.
>
> More information is available at http://perso.magic.fr/l_indien/qemu-ppc/ 
> .
>

Source?

I don't spot anything particularly wrong in there, except that OHW no  
longer exists and its URLs are dead.
There are both PReP and PowerMac machines in QEMU (-M prep and g3beige/ 
mac99), the peripherals don't look wrong either, no mention of AIX  
working.
In QEMU's git repository there's still the old OHW ppc_rom.bin file,  
an OpenBIOS openbios-ppc file and we've just used the -prom-env 'auto- 
boot?=false' parameter as described above. The ppc_rom.bin file is 512  
KB but the code obviously expects it to be 1 MB.

You've just filed a bug for it but - as pointed out - nobody has cared  
to fix it for over a year, so posting whatever QEMU documentation you  
may find on OpenBIOS' list (as another top-post btw) is really  
unlikely to solve it.

We've already given you some pointers into the code of both QEMU and  
OpenBIOS. If you find out what's going wrong there and needs to be  
changed, you can submit a patch and have it fixed.

You might find the blame function of the repo.or.cz mirror helpful for  
tracking when and why certain changes were done.
http://repo.or.cz/w/qemu.git/blame/refs/heads/master:/hw/ppc_prep.c

Andreas

> Thanks, sorry and ciao
>
>
> 2010/9/16 Laurent Vivier <Laurent at vivier.eu>
>
> > OK, maybe I make a mistake. It's not a problem.
> > My goals is to run AIX 4.3, 5.1 and 6.1 on QEMU!!!!!.
> > Can you help me? What you suggest?
> > I think there is a lot of confusion ( I also make confusion).
> > How I can run QEMU to "emulate" CHRP platform ?
>
> By default, qemu-system-ppc emulates a CHRP.
>
> To run AIX 4.3 and 5.1 you can use a 32bit machine (qemu-system- 
> ppc), to run AIX 6.1 you need a 64bit machine (qemu-system-ppc64).
>
> But to be able to run AIX, there are some improvements to add:
> - to OpenBIOS: at least RTAS is missing.
> - to qemu: emulate hardware supported by AIX (disk controller,  
> network interface, graphic card, ...)
>
> As said before: patches are welcome...
>
> Regards,
> Laurent
> --
> --------------------- Laurent at vivier.eu  ---------------------
> "Tout ce qui est impossible reste à accomplir"    Jules Verne
> "Things are only impossible until they're not" Jean-Luc Picard
>
> --
> OpenBIOS                 http://openbios.org/
> Mailinglist:  http://lists.openbios.org/mailman/listinfo
> Free your System - May the Forth be with you
>
>
>
> -- 
> Cordiali Saluti/Best Regards
>
> Massimo Montecchi
> Modena - Italy
> -- 
> OpenBIOS                 http://openbios.org/
> Mailinglist:  http://lists.openbios.org/mailman/listinfo
> Free your System - May the Forth be with you