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<TITLE>Mesa fbdev/DRI Environment</TITLE>

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<center><H1>Mesa fbdev/DRI Drivers</H1></center>


<H1>1. Introduction</H1>

<p>
The fbdev/DRI environment supports hardware-accelerated 3D rendering without
the X window system.  This is typically used for embedded applications.
</p>

<p>
Contributors to this project include Jon Smirl, Keith Whitwell and Dave Airlie.
</p>

<p>
Applications in the fbdev/DRI environment use
the <a href="MiniGXL.html"> MiniGLX</a> interface to choose pixel
formats, create rendering contexts, etc.  It's a subset of the GLX and
Xlib interfaces allowing some degree of application portability between
the X and X-less environments.
</p>


<h1>2. Compilation</h1>

<p>
You'll need the DRM and pciaccess libraries.  Check with:
</p>
<pre>
   pkg-config --modversion libdrm
   pkg-config --modversion pciaccess
</pre>

<p>
You can get them from the git repository with:
</p>
<pre>
   git clone git://anongit.freedesktop.org/git/mesa/drm
   git clone git://anongit.freedesktop.org/git/xorg/lib/libpciaccess
</pre>

<p>
See the README files in those projects for build/install instructions.
</p>


<p>
You'll need fbdev header files.  Check with:
</p>
<pre>
   ls -l /usr/include/linux/fb.h
</pre>

<p>
Compile Mesa with the 'linux-solo' configuration:
</p>
<pre>
   make linux-solo
</pre>

<p>
When complete you should have the following:
</p>
<ul>
<li>lib/libGL.so - the GL library which applications link with
<li>lib/*_dri_so - DRI drivers
<li>lib/miniglx.conf - sample MiniGLX config file
<li>progs/miniglx/* - several MiniGLX sample programs
</ul>



<h1>3. Using fbdev/DRI</h1>

<p>
If an X server currently running, exit/stop it so you're working from
the console.
</p>


<h2>3.1 Load Kernel Modules</h2>

<p>
You'll need to load the kernel modules specific to your graphics hardware.
Typically, this consists of the agpgart module, an fbdev driver module
and the DRM kernel module.
</p>
<p>
As root, the kernel modules can be loaded as follows:
</p>

<p>
If you have Intel i915/i945 hardware:
</p>
<pre>
   modprobe agpgart            # the AGP GART module
   modprobe intelfb            # the Intel fbdev driver
   modprobe i915               # the i915/945 DRI kernel module
</pre>

<p>
If you have ATI Radeon/R200 hardware:
</p>
<pre>
   modprobe agpgart            # the AGP GART module
   modprobe radeonfb           # the Radeon fbdev driver
   modprobe radeon             # the Radeon DRI kernel module
</pre>

<p>
If you have ATI Rage 128 hardware:
</p>
<pre>
   modprobe agpgart            # the AGP GART module
   modprobe aty128fb           # the Rage 128 fbdev driver
   modprobe r128               # the Rage 128 DRI kernel module
</pre>

<p>
If you have Matrox G200/G400 hardware:
</p>
<pre>
   modprobe agpgart            # the AGP GART module
   modprobe mgafb              # the Matrox fbdev driver
   modprobe mga                # the Matrox DRI kernel module
</pre>

<p>
To verify that the agpgart, fbdev and drm modules are loaded:
</p>
<pre>
   ls -l /dev/agpgart /dev/fb* /dev/dri
</pre>
<p>
Alternately, use lsmod to inspect the currently installed modules.
If you have problems, look at the output of dmesg.
</p>


<h2>3.2 Configuration File</h2>

<p>
Copy the sample miniglx.conf to /etc/miniglx.conf and review/edit its contents.
Alternately, the MINIGLX_CONF environment variable can be used to
indicate the location of miniglx.conf
</p>

To determine the pciBusID value, run lspci and examine the output.
For example:
</p>
<pre>
   /sbin/lspci:
   00:02.0 VGA compatible controller: Intel Corporation 82915G/GV/910GL Express Chipset Family Graphics Controller (rev 04)
</pre>
<p>
00:02.0 indicates that pciBusID should be PCI:0:2:0
</p>




<h2>3.3 Running fbdev/DRI Programs</h2>

<p>
Make sure your LD_LIBRARY_PATH environment variable is set to the
location of the libGL.so library.  You may need to append other paths
to LD_LIBRARY_PATH if libpciaccess.so is in a non-standard location,
for example.
</p>

<p>
Change to the <code>Mesa/progs/miniglx/</code> directory and
start the sample_server program in the background:
</p>
<pre>
   ./sample_server &amp;
</pre>

<p>
Then try running the <code>miniglxtest</code> program:
</p>
<pre>
   ./miniglxtest
</pre>
<p>
You should see a rotating quadrilateral which changes color as it rotates.
It will exit automatically after a bit.
</p>

<p>
If you run other tests in the miniglx/ directory, you may want to run
them from a remote shell so that you can stop them with ctrl-C.
</p>



<h1>4.0 Troubleshooting</h1>

<ol>
<li>
If you try to run miniglxtest and get the following:
<br>
<pre>
   [miniglx] failed to probe chipset
   connect: Connection refused
   server connection lost
</pre>
It means that the sample_server process is not running.
<br>
<br>
</li>
</ol>


<h1>5.0 Programming Information</h1>

<p>
OpenGL/Mesa is interfaced to fbdev via the <a href="MiniGLX.html">MiniGLX</a>
interface.
MiniGLX is a subset of Xlib and GLX API functions which provides just
enough functionality to setup OpenGL rendering and respond to simple
input events.
</p>

<p>
Since MiniGLX is a subset of the usual Xlib and GLX APIs, programs written
to the MiniGLX API can also be run on full Xlib/GLX implementations.
This allows some degree of flexibility for software development and testing.
</p>

<p>
However, the MiniGLX API is not binary-compatible with full Xlib/GLX.
Some of the structures are different and some macros/functions work
differently.
See the <code>GL/miniglx.h</code> header file for details.
</p>


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