[OpenBIOS] [RFC PATCH 1/2] add power-mgt node under /pci/mac-io/via-cuda

[Programmingkid]

On Feb 25, 2013, at 7:11 PM, Mark Cave-Ayland wrote:

> On 24/02/13 00:24, Amadeusz Sławiński wrote:
> 
>> xnu needs power-mgt node otherwise it panics
>> http://www.opensource.apple.com/source/AppleCore99PE/AppleCore99PE-121.0.2/Core99.cpp
>> 
>> I see two possible locations
>> either /pci/mac-io/power-mgt
>> http://web.archive.org/web/20090107152212/http://penguinppc.org/historical/dev-trees-html/g3bw_350.html
>> or /pci/mac-io/via-cuda/power-mgt
>> http://web.archive.org/web/20090107144433/http://penguinppc.org/historical/dev-trees-html/g3_beige_300.html
>> 
>> also seen it under /pci/pci-bridge/mac-io/via-pmu/power-mgt
>> http://web.archive.org/web/20090107151044/http://penguinppc.org/historical/dev-trees-html/g4_agp_500_2.html
>> 
>> Seems like it is basically used to fake powermanagement
> 
> Agreed - it doesn't seem to matter particularly where the node lies, but I suppose it's a hint for the parent device. I'd compare the OpenBIOS device tree with the historical dev trees ("cd /" followed by "show-devs"), work out which Mac99 model is closest (hence being the model emulated by QEMU) and use that as a baseline.
> 
> 
> HTH,
> 
> Mark.

My own research indicates that the PowerMac1,1 is the model that is most similar to QEMU's model. Here is some information about that model: http://www.everymac.com/ultimate-mac-lookup/?search_keywords=PowerMac1,1

According to Andreas Farber's research, the PowerMac1,1 doesn't have a uni-north node to begin with. It has instead a Grackle node. I suspect Mac OS X reads the incorrect value of PowerMac2,1 and tried to query for a uni-north node.