Re: Panic at boot on 4/330 with cgfour and cgsix

[Julian Coleman <jdc%coris.org.uk@localhost>]

Hi,

> > [...].  When we get to running X,
> 
> "When"?  I was using X on a cg4 back in the '80s.  Match SunOS's mmap
> offsets and I see no reason it wouldn't Just Work now.

Indeed, and the Xsun driver would handle this correctly ...

> Maybe for text console.  But for X, I'd prefer to use the enable plane
> to support both 8bpp and 1bpp at the same time.  It's not difficult; I
> did something very similar for the cg14 (except there it's 24bpp and
> 8bpp rather than 8bpp and 1bpp).

... and probably did this as well - I didn't check the code when I had
a working cg4.  However, looking at the current source tree, we don't
have either Xsun or xf86-video-suncg4 (hmm, did the latter exist?) so
we'll have to put this together ourselves to work with modern X.
 
> Also, my experience is that 1bpp PseudoColor does not work well,
> largely because few clients are prepared to handle it.  Perhaps that's
> improved since the '80s, but perhaps not, too; my experience is that
> over the decades clients have become _less_, not _more_, ready to
> handle the full spectrum of visuals.  I've seen too many that break on
> anything but 24bpp BGR TrueColor (or 24bpp RGB TrueColor, presumably
> depending on which the author's hardware provided).

This sounds like we would probably end up with only using the 8-bit colour
part, even though it is possible to switch between 1-bit and 8-bit.  At
this point in time though, we don't have the console output working, so
I think that when we get that working, we can try the simplest X driver
(e.g. only 8-bit colour) and then extend from that.

Regards,

Julian