From: John P . Looney (valen at domain tuatha.org)
Date: Thu 23 Sep 1999 - 10:58:10 IST
On Thu, Sep 23, 1999 at 10:47:24AM +0100, Jakma, Paul mentioned:
> > Well, that's an exaggeration. Some of the video drivers are in the
> > kernel. The Linux Kernel has /dev/fb as well as the recent DRI
> > (Direct Rendering Interface) stuff, for 3D acceleration for
> > X/Mesa/GLX.
> but fb is nothing more than a safe way of exporting the graphics hardware to
> userspace. all the fancy stuff still has to be done in userspace. eg the
> matrox fb driver knows how to get the card into fancy text modes and how to
> get back to them. Accel still has to be done by userspace mmap'ing /dev/fbx
> and tweaking the right bits of memory.
Do you think that NT has all the rendering stuff in ring0 too ? No it
doesn't - it has a little more than Linux does these days. There isn't much
there, but what there is, apparently speeds stuff up a lot. Of course,
Linux doesn't have multiple rings - it's in or out, so it has a small bit
in the kernel, most of the stuff in userspace, which is a small
difference..
> (there was something on glx-dev about this the other day).
>
> Don't know about DRI, but as it's in the kernel i guess it does no more than
> the bare minimum for safe concurrent access to graphics hardware.
> (arbitration i guess).
Nice piccie of what it's all supposed to do..
http://www.precisioninsight.com/dr/mini_poster.jpg
Is it just me, or are there parallels between Corels "Closed" beta test
program, and XFree86's closed source-until-release program ?
Kate
-- Microsoft. The best reason in the world to drink beer.
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