Re: TO DO, was Re: localtalk, pcmcia etc.

[Brad Boyer <flar@allandria.com>]

On Thu, Aug 20, 2020 at 11:15:28AM +1000, Finn Thain wrote:
> On Sat, 15 Aug 2020, I wrote, incorrectly:
> > 
> > I think macfb could be replaced entirely by simplefb and some nubus 
> > drivers, now that nubus has actual drivers under the Linux driver model 
> > (as of Linux v4.16).
> > 
> 
> I was forgetting about palette operations. So macfb is actually required 
> for on-board video hardware.

That's fine, although at least Valkyrie already has a separate driver
as it is also used in some PowerPC models. Would separating them out
like they are there make the code simpler? I know there is also a
separate driver for Control, which is the video chip on the various
PowerMac 7x00 models.

> > As of Linux v5.1 you can configure SCC IOP bypass using /dev/nvram on 
> > 68k Macs. (I wonder whether PRAM reset would enable or disable 
> > bypass...)
> > 
> 
> /dev/nvram functionality works on IIfx but not Quadra 900/950 models 
> because there's no Caboose driver yet. RTC and soft power control 
> functionality are also missing on Quadra 900/950 for the same reason.

That might be a tough one. I've never heard of anyone finding good
documentation on Caboose. This may be one thing that has to be
completely reverse engineered by disassembling the ROM code. Even
on the various IIfx craziness, we still managed to find some basic
information to give us a head start.

The official board diagram for the Q900 shows Caboose connected to
VIA1 instead of directly to the CPU. The MESS hardware information
claims it is a 68HC05 just like Egret and Cuda. Perhaps we should
try the via-cuda driver with ADB disabled and see what happens?

	Brad Boyer
	flar@allandria.com