Re: CG14 in 8-bit color

[Michael <macallan%netbsd.org@localhost>]

Hello,

On Sun, 7 Nov 2021 08:31:15 +0100
Malte Dehling <mdehling%gmail.com@localhost> wrote:

> admittedly it doesn't seem that useful, but I run my cg14 in 8-bit color
> to allow for higher resolutions (1920x1200).  "Out of the box" the Xorg
> driver included with NetBSD 9.2 works only in 24-bit color; with a few
> changes to xsrc/external/mit/xf86-video-suncg14/dist/src/cg14_driver.c
> it works in either 8-bit or 24-bit mode.  I've attached a diff.  Simply
> set DefaultDepth in xorg.conf or use the -depth command line parameter.
> 
> Part of the change is to trust the OBP on the VSIMM size instead of
> assuming an 8MB VSIMM for higher resolutions.  I'm not sure if that
> breaks anything?  (Older OBP versions?  The SS10SX?)

That's from Way Back When OBP access didn't work at all on NetBSD ( or
rather, the NetBSD-specific SBus support code in Xorg was rather
horribly broken. No idea how that happened. )
I fixed it a while ago, so this workaround can go away.

> I also have no clue how to fix the acceleration code.  Currently if you
> enable the Accel option, you will see vertical bars on your screen
> (looks like 3 black pixels followed by 1 pixel of the actual image.)

Yeah, the accel code pretty much assumes 32bit colour. I'll fix that.

> With ShadowFB enabled I find the speed acceptable, but of course
> acceleration would be preferable.

SX isn't *that* fast, especially compared to anything halfway modern.
It should be able to shovel data around faster than the CPU alone
though.

have fun
Michael