4.1. Installing modified X server

For some video cards you can skip this part. Before installing the modified X server check the Video Compatibility list to determine whether you need one. Currently there are reports for working configurations without using a modified X server for Voodoo Graphics as primary and Voodoo3 or Nvidia TNT2 as secondary.

"Why should a modified X server be used?" - The reason is that XFree is designed to serve a single user and this design requires a single X server to drive all available graphic cards. So when an unmodified X server starts, it disables access to graphic cards for other X servers. Hence we have to modify XFree to make it possible more then one X server to run at the same time.

You probably only need already-built binaries. If there are packages for your distribution you can install them. If not, you have 3 more possibilities:

1. Install an already built, but not packaged, modified X server and create the necessary symbolic links. You can get such binaries from the Backstreet Ruby home page, at http://startx.times.lv.

2. Help us (as well other people using your distribution) in building an rpm for your distribution (we lack systems installed with all available distributions, so we are not able to build packages for every distribution).

3. To patch and rebuild XFree from source using the instructions at the Backstreet Ruby page go to the Documentation section, at http://startx.times.lv (or some of the mirrors) -> Documentation -> Quick XFree.

Note that currently there are two different modifications of the X server:

1. XFree86-4.3 prefbusid (Preferred Bus ID), the new recommended patch/ binary.

2. Just the XFree-4.3/ XFree-4.3.patch, which is the older one (in the rpm section *server-concurrent.*rpm).

The new patch solves major problems for a number of graphic cards. Check the Video Compatibility list for details.

The older aproach(disabling the pci_disable functions in XFree) can also be done in kernel space, so the user doesn't need a modified X server, but rather can use the XFree packages that shipped with his distribution. The latest bruby patch includes the needed changes to the linux kernel.

To enable this feature you have to add this to your XFree configuration file:

Section "ServerFlags"
...
Option "PciOsConfig" "1"
 ...
EndSection 
      

and to inform the kernel to filter unnecessary PCI commands:

[root@mc contrib]#echo  "1"> /proc/bus/pci/hackvideo

If you want to disable this functionality you have to:

[root@mc contrib]# echo "0"> /proc/bus/pci/hackvideo

This addition to Bruby is equal to the old XFree modification, so if your system freezes on restarting the first X server, it is recommended to install the Preferred Bus ID X server.