Re: [Linux-fbdev-devel] Proper handling of setcolorreg

[Geert U. <ge...@li...>]

On Thu, 22 Nov 2001, Benjamin Herrenschmidt wrote:
> >In directcolor mode, there are two possible approaches to emulate console
> >colors:
> >  - Use a linear ramp as colormap, and write the RGB triplets
> corresponding to
> >    the console colors into the pixel values.
> >  - Store the RGB triples corresponding to the console colors in the
> colormap,
> >    and set all of R, G and B in the pixel value to the console color index
> >    (i.e. the value you'd use in pseudocolor mode).
> >
> >The second approach has the advantage that you can change the console palette
> >without having to redraw the screen, so atyfb uses that.
> 
> Ok, so I'm trying to mimmic what atyfb does. Everything seem to work fine
> with console and MOL well except 16bpp but I think I know how I broke that),
> however, XFree (4.1.0 from latest debian sid) using fbdev seem to never set
> the colormap. If I have a console at 8 bpp, X at 24 and MOL at 24, switching
> from the console to X gives me an ugly X with what look like console colors
> (wrong gamma ramp), but switching from MOL to X gives me correct display
> (MOL properly sets it's own cmap). It looks like if X fbdevhw is not touching
> the cmap at all like if it expected me to be TRUECOLOR.

I don't know whether XFree86 4.x supports directcolor these days, or treats it
like truecolor (with optional gamma table). In the latter case, make sure the X
server sets the ramped colormap.

I remember adding the code for setting the ramped colormap on directcolor to
3.x XF68_FBDev.

Gr{oetje,eeting}s,

						Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- ge...@li...

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
							    -- Linus Torvalds