Subject: Re: Building OpenChrome driver
To: Jan Danielsson <>
From: Girish Venkatachalam <>
List: tech-x11
Date: 09/14/2006 19:55:17
On Thu, Sep 14, 2006 at 02:34:22PM +0200, Jan Danielsson wrote:
|   Let me first point out that I am a complete newbie with regards to X
|and its drivers, and related technologies. I'm running (from
|pkgsrc) on NetBSD/amd64 3.0.
|   I have a VIA UniChrome chip on my mother board that I wish to use. I
|currently use the VESA driver, but it's slow and - AFAIK - will only
|allow 1024x768, and 60Hz vertical refresh rate -- which gives me a head
|   After searching around, I found _two_ relevant open source drivers.
|For no other reason than "my instincts tell me to go with this one" I
|chose the OpenChrome driver.
|   The OpenChrome project is located at:
|   Now, I know very little about X, and its related technologies, so I
|would _love_ if someone who knows X could check the OpenChrome home page
|for 60 seconds and search for any potential buzz-words which immediately
|imply "This is Linux specific, so Just Give Up And Don't Even Think
|About Getting It Compiled And Running In NetBSD".
|   What exactly is "xvmc"? On
|I am instructed to compile "openchrome", and then "libxvmc". And there
|are referenced to xvmc support and mplayer, which sound like something
|I'd be interested in. But is "xvmc" required? (The reason I'm asking, is
|because more Linux-oriented friends of mine have informed me that there
|are a bunch of X driver interfaces (DRI, DRM, XGL, etc..) and some of
|these apparently are highly Linux-specific).
|   After editing some source files, and changing to a hardcoded absolute
|path to drm.h in some file, I managed to get a binary compiled.
|The libxvmc, however, I never got so far with. Can I use the
|driver? If, so, how? Do I simply copy it to the relevant directory, and
|edit the xorg.conf to use the "via" driver? (I don't want to run "make
|install" since I'm not sure what it will do with me system).

I will tell you whatever little I know. :-)

XvMc AFAIK is some sort of hardware scaling mechanism. It is absolutely essential for tvtime to work under linux. That is why I fucked with it. I nearly took a month to get it running on my unichrome hardware. It turned out that there was a particular check being made in one of the driver sources for KM400 chipset and it was failing for me. So I just commented out that check, compiled the driver, installed it and voila, I got my mplayer output to -vo Xv and also tvtime working.

Now, all this is really stuff AFAIK and I think u shud be able to get it working for NetBSD too. I did download DirectFB but have no idea what that means. :-)

You have to observe the Xorg.log file to figure out what model of unichrome u have.

X as you are aware I am sure does use some kernel code and the rest of the driver code is in userland. I believe xvmc is in the kernel.


Whenever people agree with me I always feel I am wrong.

    - Oscar Wilde