On 08.11.2013, at 23:18, Mark Cave-Ayland <mark.cave-ayl...@ilande.co.uk> wrote:
> On 08/11/13 03:20, Alexander Graf wrote: > >> On 11.10.2013, at 12:53, Mark Cave-Ayland<mark.cave-ayl...@ilande.co.uk> >> wrote: >> >>> OpenBIOS prior to SVN r1225 had a horrible bug when accessing PCI >>> configuration space for PPC Mac architectures - instead of writing the PCI >>> configuration data value to the data register address, it would instead >>> write >>> it to the data register address plus the PCI configuration address. >>> >>> For this reason, the MemoryRegions for the PCI data register for >>> grackle/uninorth were extremely large in order to accomodate the entire PCI >>> configuration space being accessed during OpenBIOS PCI bus enumeration. Now >>> that the OpenBIOS images have been updated, reduce the MemoryRegion sizes >>> down >>> to a single 32-bit register as intended. >>> >>> Signed-off-by: Mark Cave-Ayland<mark.cave-ayl...@ilande.co.uk> >>> CC: Hervé Poussineau<hpous...@reactos.org> >>> CC: Andreas Färber<afaer...@suse.de> >>> CC: Alexander Graf<ag...@suse.de> >> >> With this patch applied, mac99 emulation seems to break: >> >> >> http://award.ath.cx/results/288-alex/x86/kvm.qemu-git-tcg.ppc-debian.mac99-G4.etch.e1000.reboot/debug/serial-vm1.log >> >> >> Alex > > Hi Alex, > > Thanks for the heads-up - with the information above I was able to reproduce > this fairly easily. I had look at some of the uninorth drivers, and while > it's not particularly apparent from Linux that the PCI configuration data is > accessed via MMIO rather than ioport access, FreeBSD seems to suggest that > this is the case: > http://code.google.com/p/freebsd-head/source/browse/sys/powerpc/powermac/uninorth.c?spec=svnc6989e24706228678e454517dad4ad465a36e556&r=c6989e24706228678e454517dad4ad465a36e556#274. > > The key is that the QEMU uninorth host bridge contains a hack to allow PCI > configuration mechanism #1 as used by OpenBIOS to work at all (see > unin_get_config_reg() in hw/pci-host/uninorth.c) which is why I didn't notice > it in my OpenBIOS boot tests; and in fact, the name of the uninorth PCI > configuration data MemoryRegions have a "-data" rather than a "-idx" suffix > is also a big clue. > > Hence please find a revised version of the patch which is unaltered for > grackle, and only changes the MemoryRegion size for the PCI configuration > address register for uninorth so that the PCI configuration data space is > still accessible using MMIO. This resolves the issue for me, so if you're > satisifed that it works for you then I'll post a revised version to the list. Hrm. Are you 100% sure this correct? This UniNorth is a real headache. The closest thing to a spec for it is the U4 spec which is generations ahead: http://www.datasheetarchive.com/dl/Datasheets-SW3/DSASW0048084.pdf On that at page 109 you can see that you do indeed have a range of registers and a few fancy modes that can even be used to directly access config space registers without the usual index/data cycle. Ben, do you have any more insight into how the original Uninorth worked? Alex
