On Oct 1, 2016, at 9:05 PM, Tarl Neustaedter wrote:
On 2016-Oct-1 20:47 , G 3 wrote:
Actually the Mac OS gets all its information from the VGA driver. It would be the VGA driver that would read the list in OpenBIOS. Currently the VGA driver needs the list to an array of integers.
O.k. - misunderstood. The new VGA driver is a MacOS driver, not a OpenBIOS driver. So we aren't booting standard MacOS, but a modified version.
Actually we are booting a standard (unmodified) Mac OS.
The traditional way information is passed (for IEEE1275 in Sun/Oracle style) from the outside world into drivers/operating systems is with properties in either /chosen or /options. Properties in /options mimic NVRAM variables, looking like they might have been set by the previous iteration of an operating system - that's probably not ideal, it might appear that the client OS could set them, which wouldn't be the case. Properties in /chosen are places where firmware stores anything it determines at startup for use by later clients.
I would suggest in this case that /chosen would be your better location than a device node.
I so wanted to use the /options node, but there is some bug between OpenBIOS, QEMU, or Mac OS X that prevents Mac OS X from seeing anything in the NVRAM. When Mac OS 9 boots it always displays this error message pertaining to the NVRAM. So far no one knows how to fix this problem, so using a property in the QEMU,VGA node is what works.