Xegl lives!

Jon Smirl jonsmirl at gmail.com
Sat May 28 08:25:43 PDT 2005


On 5/28/05, Eric Anholt <eta at lclark.edu> wrote:
> Nothing.  What's linux-centric is Xegl's requirement of Linux fbdev.

That is only a requirement of the current Linux base XGL
implementation. There is nothing in the EGL spec requiring fbdev.

EGL provides a user space API for mode setting. It is up to the
implementer to pick you to implement it. In my case I am trying to fix
the Xserver to not run as root. So I pushed mode setting down into a
device driver.

Someone else may chose to implement mode setting in the user library.
Since setting a mode requires root priv this implies that your server
will have to run as root.

> I don't see how we're going have our future X server usable on multiple
> platforms (as Xorg is now) without shared code (in userland, I believe)
> for mode setting.  All I've heard from anyone involved with Xgl is "mode
> setting goes in your kernel fbdev driver."  Mode setting, by far the
> most complicated part of X driver writing including Render acceleration,
> implemented per-kernel sounds even worse than the current multiple
> implementations of rendering.

DRM has shared kernel space code with BSD right now. Why can't the
modesetting code be shared in the same way?

> hardware.  Not to put down the Linux ATI fbdev developers (benh rocks),
> but pretending that all of our OSes will just sprout quality mode
> setting on their own is absurd.  It's nasty stuff.

If you want a quick short term fix move the user space mode code from
XAA to the user space EGL library on your target platform. Then over
time push it into a device driver to remove the requirement for the
server to run as root.

-- 
Jon Smirl
jonsmirl at gmail.com



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