Re: SS20 cg14 help

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

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Hello,

On Aug 4, 2009, at 11:34 AM, der Mouse wrote:

> Not quite as nice as it would be if we knew, for example, how to use
> the blitter, but still substantially faster than 24bpp by itself.

The 'blitter' is actually half of a SIMD CPU nailed to the mainboard -  
'half' as in 'no jumps, branches and related stuff'. You're supposed  
to feed it instructions through an IO port, it has a bunch of  
registers, it could probably be used to do stuff like alpha blending  
but we have no docs at all on the actual instruction set.
Since it's onboard we could use it even without a cg14 present but  
apparently nobody at Sun even knows about this thing anymore :/

> > The wsdisplay driver will run the console on the cg14 in 8 bit for
> > speed and switch to 32bit for X, the wsfb driver should know which
> > pixel format to use in both XFree86 and Xorg.
>
> If wsdisplay can't describe both pixel formats - and how to select
> between them - it sounds like a reason to not use wscons X, at least  
> on
> the cg14. :)

This has nothing to do with wsdisplay at all. Again.

> > There is a cg14 driver for XFree86 but all it does is to do the
> > switch between 'native' 8bit and 24bit on its own and to provide a
> > hardware cursor, which wsfb can do as well ( using the appropriate
> > ioctl()s )
>
> I'm a little surprised at the implication that nobody has already done
> a both-depths-on-the-screen-at-once cg14 layer for recent X; If anyone
> is interested in basing one on my dual-depth code, I'm happy to share.

I guess nobody cares enough. Few mainstream graphics chips support  
WIDs and these days pretty much everything wants 24bits anyway.  
Teaching Xorg's cg14 driver to do 8/24 probably isn't really hard, it  
just takes someone who cares enough to do it.

have fun
Michael

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