OpenBSD Journal

[c2k8]: Accelerated X Support for AMD Geode LX

Contributed by johan on from the can-haz-X11-support dept.

Marc Balmer (mbalmer@) writes about his endeavors into amd-geode graphics that has given us support for the amd-geode-lx gpu in X11.

Marc writes:

Earlier this week I reported that X runs on AMD Geode LX graphics processors using the 'vesa' driver. Well, there is some good news: The accelerated 'geode' driver now works as well and X runs quite a bit faster with it.

Marc continues below...

The accelerated X driver requires access to so-called model specific registers (MSR) found in AMD CPUs. Since these are available in kernel mode only, I first had to write the amdmsr(4) driver which allows a userland process running as root to read or write MSR registers. For security reasons, this is only allowed when 'allowaperture' is set.

For more information on the driver, look at /usr/xenocara/driver/xf86-video-geode/README.

Be aware that the driver still has some rough edges, especially mode selection seems not to work in all cases as desired. In that case, please use the vesa driver instead.

Thanks Marc for taking your time and telling us about this.

(Comments are closed)


  1. By Marc Balmer () on

    I forgot to mention that I got substantial help from Matthieu Herrb and Todd Fries while doing this.

  2. By Jim Razmus II (jim) jtr2-undeadly@bonetruck.org on http://www.bonetruck.org/

    I'd really appreciate hearing about some success using an alix3c3 as a dead quiet OpenBSD desktop. I picture running the thing off cf and then accessing all my real data via nfs. I would run Firefox (privoxy), Evince, and pile of xterms on dwm. Compiling etc. would be done on the machines I ssh into.

    As an alternative, I've also considered picking up an older mac mini (the macppc flavor) for the same purpose.

    Anyone run an Alix in a similar setup?

    Thanks,
    Jim

    1. By Anonymous Coward () on


      > Anyone run an Alix in a similar setup?
      >

      Considering how it's only been possible for the past few days, probably not. You could be the first to tell us how great it is.

    2. By sthen () on

      > I'd really appreciate hearing about some success using an alix3c3 as a dead quiet OpenBSD desktop. I picture running the thing off cf and then accessing all my real data via nfs. I would run Firefox (privoxy), Evince, and pile of xterms on dwm. Compiling etc. would be done on the machines I ssh into.
      >
      > As an alternative, I've also considered picking up an older mac mini (the macppc flavor) for the same purpose.
      >
      > Anyone run an Alix in a similar setup?

      Marc was using an Alix to develop this. They'll use a lot less power than a Mac Mini but of course performance will be lower.

      If someone has an OLPC laptop it would be interesting to know if it works there too. They also use the built-in Geode video (but have no VESA bios).

      1. By Miod Vallat (miod) on

        > If someone has an OLPC laptop it would be interesting to know if it works there too. They also use the built-in Geode video (but have no VESA bios).

        Do OLPC laptops actually work besides for raising venture capital with false promises of them helping children?

        1. By sthen () on

          > > If someone has an OLPC laptop it would be interesting to know if it works there too. They also use the built-in Geode video (but have no VESA bios).
          >
          > Do OLPC laptops actually work besides for raising venture capital with false promises of them helping children?

          Looks like the one on http://radian.org/notebook/sic-transit-gloria-laptopi is doing _something_. They're pretty limited though.

    3. By Marc Balmer () on

      It works surprisingly well as a thin client. I used it using X to access some servers and using rdesktop to access a MS Windows terminal server.

      Even a locally installed firefox browser works nice. Of course you can not expect the performance of a highend graphics workstation...

      I used it in 1280x1024x16 and 1280x1024x24 mode with an IBM T70 TFT display.

      1. By Jim Razmus II (jim) on http://www.bonetruck.org/

        > It works surprisingly well as a thin client. I used it using X to access some servers and using rdesktop to access a MS Windows terminal server.
        >
        > Even a locally installed firefox browser works nice. Of course you can not expect the performance of a highend graphics workstation...
        >
        > I used it in 1280x1024x16 and 1280x1024x24 mode with an IBM T70 TFT display.

        Thanks Mark! That's exactly what I wanted to hear and precisely the usage scenario I intended. I had held off buying one when I saw amdmsr pulled out by Theo. I'm getting out my credit card now that it's back in again.

        BTW, did you run it off compact flash?

        Jim

        1. By Anonymous Coward () on

          Yes, I run the system of a 2 GB SanDisk Extreme II CF card. There are faster cards available, maybe get one of these.

          Of course mounting stuff over NFS works nice as well.

  3. By Matthew Dempsky () on

    I'm looking forward to playing with this some more. Over the weekend I built a snapshot release to play with it on my alix system (the Jun 19 snapshot doesn't have amdmsr compiled into the kernel). Too bad mplayer's complaining about not being fast enough to play h264 video. :(

    1. By Anonymous Coward () on

      The AMD Geode LX graphics processor does support video, so _theoretically_ video support is possible. And well, since one of our uvideo developers lives in my town, it may even happen some day (no promise!)

      1. By Matthew Dempsky () on

        I don't follow. I built an OpenBSD snapshot with the new geode accelerated driver, and confirmed that Xv works. My alix PC has a VGA out that I connected to my TV and it showed up fine (though I haven't figured out the ideal resolution yet).

        The problem is just that the CPU can't decode the 848x480 h264 video I had for testing fast enough. Even using the null video and audio output drivers, mplayer can't decode it in real-time.

        1. By Anonymous Coward () on

          however, since video without sound would be no fun anyway I wrote an audio driver for the amd geode lx...

          1. By Matthew Dempsky () on

            Cool. I hadn't gotten as far as noticing audio support isn't implemented yet. (However, I'll point out the post I replied to spoke only of video, not audio.)

Credits

Copyright © - Daniel Hartmeier. All rights reserved. Articles and comments are copyright their respective authors, submission implies license to publish on this web site. Contents of the archive prior to as well as images and HTML templates were copied from the fabulous original deadly.org with Jose's and Jim's kind permission. This journal runs as CGI with httpd(8) on OpenBSD, the source code is BSD licensed. undeadly \Un*dead"ly\, a. Not subject to death; immortal. [Obs.]