XFree86

16-Sep-00
Stefan Jeglinski

stopping X
upgrading XFree86
configuring XFree86
tips for 3.x
tips for 4.x
starting X
tips
Xpmac
more resources (including fix for font errors at X startup)
return to the home page

stopping X

Depending on how the Linux distribution was constructed, the system may be configured to launch an X login at boot (runlevel 5). But unless you had a flawless install, this may not work. For example, your Xconfigurator or Xautoconfig step may have failed during installation. Or, you may suffer a symptom commonly reported on mailing lists: a blinking monitor, a repeating message to the effect that gdm was running but was murdered mysteriously, and finally a message that respawning is too fast, disabling for 5 minutes. The solution to these problems is to start in run-level 3.
To start in run-level 3, edit the /etc/inittab file, using emacs for example. Change the id line from id:5:initdefault to id:3:initdefault. This will cause the kernel to boot into runlevel 3, standard for a console login.

upgrading XFree86

Recent distributions of Linux/PPC install a selected version of XFree86 3.3.x. Upcoming distributions of Linux/PPC will very likely install a selected version of XFree86 4.x. To update to the latest version of either, find and download the desired updates. Possible download locations for 3.3.x rpms are subdirectories at ftp://ftp.linuxppc.org/ or ftp://ftp.yellowdoglinux.com/pub/. The current best location for XFree86 4.x rpms is ftp://ftp.linuxppc.org/users/kfukui.
Collect all the XFree86 rpms, gather them in one directory and su to root.
kill `/sbin/pidof xfs` or find the pid of xfs using ps and kill it.
if you are upgrading from 3.x to 4.x ONLY, remove the 3.x rpms:
- rpm -qa |grep XFree86* |xargs rpm -e --nodeps
- the --nodeps switch is mandatory, since the system otherwise thinks
  you are stripping it of libraries etc that it will not get back.
- there will be quite a few messages about directories that cannot be
  removed; while these can be removed by hand, the justification of the
  effort required is questionable. It seems safe to ignore the errors.
From the directory with the new XFree86 rpms, test the upgrade with rpm -Uhv --test XFree86*. A number of errors may be generated, usually referring to broken dependencies. The list of errors will provide clues to other packages that must be installed or updated. Those other packages should be collected and updated before proceeding (consider running rpm -Uhv --test XFree86* occasionally to review the [presumably] diminishing list of problems - patient analysis will eventually yield no errors). When satisfied that there are no errors left, remove the --test switch to proceed with the actual installation.
There may be some errors that just do not go away. While less than optimum, there is no general analysis of this situation. In this case, use the additional switches --nodeps to overcome dependency issues and/or --force to overcome conflicts.
Dependency issues while upgrading may include mouseconfig, kbdconfig, pam, and Xautoconfig. XFree86 4.x additionally may need a newer freetype, xinitrc, initscripts, procps, setup, and modutils.
After the upgrade, restart the font server: xfs & or as at startup: xfs -droppriv -daemon &

configuring XFree86

It is possible to configure XFree86 by hand, but the process is made much easier by using Xautoconfig, or the [deprecated for ppc] Xconfigurator.
Xconfigurator automatically probes the monitor to discover its operating modes and inserts this information in the config file. Although this all works in principle, in practice many have reported problems.
Xautoconfig probes the current monitor mode and creates a default config file. This procedure differs for the two versions of X:
- 3.x: run Xautoconfig3 to create /etc/X11/XF86Config
- 4.x: run Xautoconfig4 to create /etc/X11/XF86Config-4
versions 3.3.x and 4.x differ in the link to the server binary executable file; this link may or may not be updated properly. Check that the following links are in place:
- 3.x: /etc/X11/X->/usr/X11R6/bin/XF68_FBDev
- 4.x: /etc/X11/X->/usr/X11R6/bin/XFree86

tips for 3.x

the first key to understanding the XF86Config configuration file is that the depth and resolution are determined by the Screen section at the very end of the file and reads similar to (example for a Multiscan monitor on a 6500):
```
Section "Screen"
    Driver      "fbdev"
    Device      "ATY Mach64"
    Monitor     "Apple Multiple Scan 1705 Display"
    Subsection  "Display"
        Depth       15
        Modes       "1024x768"
        ViewPort    0 0
        Virtual     1024 768
    EndSubsection
EndSection
		
```
according to documentation, possible depths are 8, 15, 16, 24, and 32. I don't know what 15 actually is, but it implies 5 bits for each primary color, and that's the one that some monitors want. Xconfigurator and/or Xautoconfig will likely create multiple Display subsections, each of which has multiple modes. For simplicity, one can delete all but the one desired (1024x768 in the example above).
the second key to understanding the configuration is that the Monitor subsection in the Screen section (above) needs to find monitor modes in the Monitor section (below). Xconfigurator creates many lines of mode information that are either irrelevant or unneeded for a particular monitor. Xautoconfig adds some default modes and the currernt console video mode. If the only mode desired is 1024x768, all other modes not at this resolution can be commented out (red) to read:
```
Section "Monitor"

    Identifier  "Apple Multiple Scan 1705 Display"
    VendorName  "Unknown"
    ModelName   "Unknown"

    HorizSync   30-65
    VertRefresh 50-120


# 1024x768 @ 60 Hz, 48.4 kHz hsync
#Modeline "1024x768"    65    1024 1032 1176 1344   768  771  777  806 -hsync -vsync
# 1024x768 @ 70 Hz, 56.5 kHz hsync
#Modeline "1024x768"    75    1024 1048 1184 1328   768  771  777  806 -hsync -vsync
# 1024x768 @ 76 Hz, 62.5 kHz hsync
Modeline "1024x768"    85    1024 1032 1152 1360   768  784  787  823
# 1024x768 @ 85 Hz, 70.24 kHz hsync
#Modeline "1024x768"   98.9  1024 1056 1216 1408   768 782 788 822 -HSync -VSync

EndSection
		
```
experimentation shows which rates work on a particular monitor under Linux. For example, if 60, 70, 76, and 85 all work but only 76 gives the best visual experience, that one single mode can be uncommented as shown above.

tips for 4.x

If there are any font problems (including preventing X from starting), uncomment all the font paths.

X depends on the correct keyboard and mouse drivers. With the input layer properly installed, the mouse protocol must be IMPS/2. The choice of keyboard settings shouldn't prevent X from starting, but will determine whether the keyboard map is correct. Run kbdconfig before Xautoconfig4.


Section "InputDevice"
        Identifier      "Keyboard0"
        Driver          "keyboard"
# Uncomment this if your keyboard no longer works in X
        #Option         "XkbModel"      "macintosh_old"
        Option          "XkbLayout"     "us"
EndSection

Section "InputDevice"
        Identifier      "Mouse0"
        Driver          "mouse"
        #Option         "ZAxisMapping"  "4 5"
        Option          "Protocol"      "IMPS/2"
        Option          "Device"        "/dev/mouse"
EndSection

The Modes section works the same as the Monitor section in 3.x.
The most important key to understanding X 4.x is the video card device.
```
		
```

starting X

refer to Switching between KDE, Afterstep, and Gnome

tips

some users report a shift in the display borders when switching from console mode to X and back. Switching to Xpmac may eliminate this. Alternately, after X starts, executing fbset -move [right][left] -step NN from a terminal shifts the display right or left by NN pixels.
a stable build of XFree86 is version 3.3.6-11.2, available at the YDL repository.

Xpmac

to switch from XFree86 to Xpmac, the symbolic link in /etc/X11 must be changed
from X -> /usr/X11R6/bin/XF68_FBDev to X -> /usr/X11R6/bin/Xpmac
all versions of XFree86 include an Xpmac; however, I've never gotten any 3.x XFree86-Xpmac to work (didn't try hard though).
the accelerated Xpmac is a moving target. Consult the mailing list archives for its latest location; as of this date, download the latest version (rev10) from
http://download.sourceforge.net/pub/suse/projects/xpmac
steps to install the new Xpmac:
gunzip Xpmac.rev10.gz (unpack the file)
mv Xpmac.rev10 /usr/X11R6/bin (place file where it belongs)
cd /usr/X11R6/bin (change directories)
chmod 755 Xpmac.rev10 (set permissions identical to Xpmac)
cd /etc/X11 (change directories)
rm X (remove the default X-> symbolic link)
ln -s /usr/X11R6/bin/Xpmac.rev10 X (create new symbolic link for X)
startx (launch the X server)
to specify the video mode for Xpmac, execute startx -- -mode NN -depth MM
where NN and MM are the video mode and color depth, respectively.
Usage Notes for rev9 (haven't evaluated rev10):
- seems to work fine but doesn't seem to be any faster really than XFree86 :-(
- does not seem much faster (if at all) than xpmac_mga on R4

more resources (including fix for font errors at X startup)

http://www.members.home.net/njolly/xppc/index.htm

rapierbit