Re: [Qemu-devel] Multiple pci buses

["Andreas Färber" <afaerber@suse.de>]

Hi,

Am 15.03.2014 22:21, schrieb BALATON Zoltan:
> I'm trying to change hw/ppc/mac_newworld.c and hw/pci-host/uninorth.c to
> bring the mac99 machine type closer to what's seen in these dumps:
> 
> https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=604134
> http://nandra.segv.jp/NetBSD/G4.dump-device-tree.txt
> http://raveland.org/ports/eeprom.txt
> http://mail-index.netbsd.org/port-macppc/2007/10/24/0000.html
> 
> This machine seems to have 3 pci busses but the third is not important
> just the other two:
> 
> ff8721c0: /pci@f0000000
> ff898cd0:   /uni-north-agp@b
> ff898f40:   /ATY,Rage128Ps@10
> ff873268: /pci@f2000000
> ff8742d8:   /pci-bridge@d
> ff876368:     /mac-io@7
> 
> The first is actually an AGP bus with the onboard graphics card and the
> second is where other devices are. It would be enough to create an empty
> bus without the AGP graphics card for now and have the devices on the
> second bus. The pci_pmac_init function in uninorth.c seems to have some
> commented out code to try to model this but that does not work. Can
> someone who understands this better please explain what should be done
> to model the above? How to create two pci buses and connect them to
> separate memory regions?

In earlier times QEMU did not properly support multiple PCI bus domains.
Some code in
http://git.qemu.org/?p=qemu.git;a=blob;f=hw/pci-host/uninorth.c;h=e72fe2a70b954bf5675ad0c8735fea6bad665be6;hb=HEAD
is #if 0'ed out that you should take a look at.

I had investigated that some time ago based on a G4 in our office and
might be able to revive some patches... Please keep me CC'ed.

Cheers,
Andreas

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