[OpenBIOS] [PATCH 4/5] pci: enable AAPL, address property for all Apple PPC machines

BALATON Zoltan balaton at eik.bme.hu
Mon Jan 4 12:14:32 CET 2016

On Mon, 4 Jan 2016, Mark Cave-Ayland wrote:
> On 04/01/16 08:20, Alexander Graf wrote:
>> On 04.01.16 02:57, BALATON Zoltan wrote:
>>> On Sun, 3 Jan 2016, Mark Cave-Ayland wrote:
>>>> Actually this may be a red herring, since the AAPL,address properties
>>>> are present in the G4 AGP device trees but not the G4 PCI device trees.
>>>> So unless G4 AGP are old world then this patch might be a red herring.
>>>> Alex?
>>> I think all G4 Macs are New World as it started somewhere around G3 and
>>> all later models had New World ROM (that is OpenFirmware without
>>> Toolbox). So I'm not sure why you don't see these in G4 PCI or if you do
>>> it's not because of Old World ROM.
>>> The model id we have now (PowerMac3,1) is corresponding to the G4 AGP
>>> and I've picked this because it is the minimum required by MorphOS.
>>> Previously it was probably some PCI model but the set of devices
>>> currently emulated by QEMU may not really correspond to any of these
>>> real machines.
>> Yeah, my guess is that they left the legacy AAPL, bits in for Mac OS 9
>> compatibility in systems where they cared about it. Since it is present
>> in real world DTs, I think it's perfectly valid to expose it in OpenBIOS
>> as well.
> In the examples I've looked at, AAPL,address isn't included in all
> devices on the G4 PCI so I suspect it may be generated by older FCode
> ROMs for cards that can work on both old world and new world Macs.

The device tree I've seen here:

only contains APPL,address properties for i2c nodes that lack the 
assigned-addresses property so I think it may have been added as an 
extension or were used before assigned-addresses was standardised and only 
retained for those devices where no standard property exists so having 
both of these on the same node may not make sense.

There's also AAPL,address-step that seems to appear together but I'm not 
sure what would be the standard property for that. Maybe #address-cells?


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