Re: [Qemu-ppc] [OpenBIOS] MorphOS 4.x on QEMU

[BALATON Zoltan]

On Tue, 4 Mar 2014, Mark Cave-Ayland wrote:
> These patches basically look okay, although would it be possible to submit 
> them as separate patches? The reason for this is to allow bisection e.g. in 
> the case that renaming the CPU properties suddenly means a guest OS can find 
> them, and it then breaks as a result.

I can split them or you could take the parts and commit them separately.

> - The CPU property renaming patch looks good

This can be taken as is. Do I need to resubmit as a separate patch?

> - The PowerMac model name change is stylistically fine, however I don't know 
> enough about PPC to know whether bumping the model from PowerMac2 to 
> PowerMac3 violates the -M mac99 QEMU machine - Alex Graf is probably the 
> person to ask about this one

Since QEMU now says to emulate a G4 CPU I believe PowerMac3,1 is a better 
match as the PowerMac2,1 had a G3 CPU according to everymac.com. I hope 
Alex or someone who is more knowledgeable about Mac hardware can chime in 
and confirm/correct this. If this is OK this part can be taken as is too.

> - The root node rename is stylistically okay, however it's a pretty stupid 
> thing to do to locate the root node of the tree based upon it's name (which 
> *isn't* given in the spec) - finddevice("/") is your friend.

I agree this looks like a bug or too much assumption in MorphOS but I'm 
not sure they are willing to change and this is simple to correct in 
openbios. What it does is actually call finddevice("/") but then does 
getprop("name") to see if this is called "device-tree" to find out if it 
is running on a Mac where it also gets the "model" property. Otherwise it 
skips this and only tries to get "CODEGEN,vendor" and "revision" 
properties that seem to exist on the bplan boards it runs on apart from 
Macintosh hardware. I've found a device tree dump of a bplan board, here 
it is for comparison:

http://mega-tokyo.com/blog/index.php/site/grins_and_giggles

> Perhaps the best 
> way here is to move the OpenBIOS property to a different name so that it can 
> be detected another way if required?

What would be a good name for it? I'd say "vendor" but I don't know if 
there is any standard or clashes with any other implementations. Shall I 
submit a patch with this or I'm also OK with you modifying it as you see 
fit.

Regards,
BALATON Zoltan