1.1. About Backstreet Ruby

Backstreet Ruby is a kernel patch for the Linux kernel. It is a back port to linux-2.4 of the Ruby kernel tree, which is developed by the Linux Console Project. The aim of the Linux Console developers is to enhance and reorganise the input, the console and the framebuffer subsystems in the Linux kernel, so they can work independent from each other and to allow multi-desktop operation. All this is done in the Ruby kernel tree which is based on the development linux-2.5 kernel. The new Input subsystem and the new Framebuffer layer are already integrated in linux-2.5 kernel, but as the main developer of the Linux Console Project, James Simmons, is too busy with completing the rewrite of the framebuffer layer in linux-2.5, the multi-desktop operation will not be integrated in the next stable Linux kernel (linux-2.6).

So Backstreet Ruby brings to the current stable Linux kernel (linux-2.4) the enhanced input subsystem and the ability to use multiple graphic cards and multiple keyboards independently, in order to make multiple local XFree users on a single PC system possible.

You can have multiple independent graphic cards and multiple independent mouses, but in order for multiple users to interact with the system, they do need independent keyboards as well. Multiple independent keyboards is the feature that linux-2.4 (and in the future linux-2.6) lacks, and this is what Backstreet Ruby adds to the stable Linux kernel linux-2.4.

The entire work on back porting Ruby to linux-2.4 is done by Aivils Stoss. <Aivils.Stoss (at) unibanka.lv>

Visit his web site for more information on the patch itself, on the current status, how to build a kernel using his patch or how to build modified XFree86 server.

You can find it here: http://startx.times.lv

There are also several mirrors

1. in the United States:

   http://people.debian.org/~andreas/aivils/

2. in Germany:

   http://www.schuldei.org/aivils/

   http://rfhs8012.fh-regensburg.de/~sls35340/aivils/

3. in the United Kingdom:

   http://varna.demon.co.uk/~svetlio/aivils/

The address of the Linux Console Project is: http://linuxconsole.sf.net

1.2. About this document

This document explains how to configure your system for multiple local XFree users using the enchanted console/input subsystem in the Backstreet Ruby kernel .

Currently it is not possible to set up systems for multiple console users.

There are two ways of setting up multiple local XFree users:

1. Modify the kernel to ignore input from USB keyboards and add the handling of USB keyboards to a modified Xserver. This solution was developed by Miguel Freitas. Visit his page on the topic at http://cambuca.ldhs.cetuc.puc-rio.br/multiuser/, for instructions on how to set up such a system.

2. Use the Backstreet Ruby kernel which supports independent keyboards.

I'll concentrate on configuring a system for multiple local XFree users using the Backstreet Ruby kernel, but there are parts which can be used also on a system using the solution from Miguel Freitas.

Note this document is not intended to be a replacement of the existing documentation on the Backstreet Ruby home page (http://startx.times.lv), but rather, this is a smaller HOWTO, explaining the way to a working X multi-user PC system. If you encounter any problems you'll probably need to consult the more detailed information there.

The document is based on the file system layout of the Mandrake-Linux distribution, but I tried to make it distribution-independent by including information about the differences to other mainstream distributions like Debian, Red Hat and SuSE Linux.

1.3. Related Documentation

• The Linux Console Project

  http://linuxconsole.sourceforge.net

• The Backstreet Ruby home page

  http://startx.times.lv/

• XFree with support for the new input layer by Zephaniah Hull

  http://people.debian.org/~warp/evdev/

• Miguel Freitas' page on multiple local XFree users

  http://cambuca.ldhs.cetuc.puc-rio.br/multiuser/

• Russian multi-terminal project Gorinich

  http://www.ctc.msiu.ru/zg/main.html

• Step by step instructions by Jean-Daniel Pauget

  http://disjunkt.com/dualhead/

• Multi-seat XFree solution under Linux with framebuffers, by Frode Trydal

  http://www.itsopen.net/projects/x-hack/

1.4. New versions of this document

You can find the latest version at:

http://varna.demon.co.uk/~svetlio/ruby-contrib/how-to/XFree_local_multi-user-HOWTO/

1.5. Copyright and License

This document, XFree_local_multi-user-HOWTO, is copyrighted (c) 2003 by Svetoslav Slavtchev.

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.1 or any later version published by the Free Software Foundation; with no Invariant Sections, with no Front-Cover Texts, and with no Back-Cover Texts. A copy of the license is available at http://www.gnu.org/copyleft/fdl.html.

Linux is a registered trademark of Linus Torvalds.

NVIDIA is a registered trademark of NVIDIA Corporation.

1.6. Disclaimer

No liability for the contents of this document can be accepted. Use the concepts, examples and information at your own risk. There may be errors and inaccuracies, that could be damaging to your system. Proceed with caution, and although this is highly unlikely, the author(s) do not take any responsibility.

All copyrights are held by their by their respective owners, unless specifically noted otherwise. Use of a term in this document should not be regarded as affecting the validity of any trademark or service mark. Naming of particular products or brands should not be seen as endorsements.

1.7. Credits/Contributors

In this document, I have the pleasure of acknowledging:

• James Simmons <jsimmons (at) transvirtual.com >

  for working so hard on Linux console project, for developing the new framebuffer, VT/console subsystem

• Vojtech Pavlik<vojtech (at) suse.cz>

  for rewriting the input subsystem and working hard on the Linux console project

• Aivils Stoss <Aivils.Stoss (at) unibanka.lv>

  for back porting Ruby to linux-2.4 and providing his back port and experiences to the world

• Andreas Schuldei <andreas (at) schuldei.org>

  for providing Debian packages, comments about Debian

1.8. Feedback

Feedback is most certainly welcome for this document. Send your additions, comments and criticisms to the following email address : <galia (at) st-peter.stw.uni-erlangen.de>.

2.1. XFree configuration files

You should configure each of your video cards to work properly with a single X server, which is actually beyond the scope of this document. You should refer to the documentation that came with your distribution, but some general hints couldn't hurt.

The easiest way would be to use the same kind of monitors & video cards, you could then configure only the first card/monitor pair, make copies of this configuration file for the number of video cards you have, and then only adjust the BusID "PCI:x:xx:x" field in the configuration file. You can do this with the help of lspci, XFree86 -scanpci -verbose , or other similar distribution-specific tools.

You could use a similar approach if you have only monitors or video cards of the same type.

Most modern distributions also have advanced tools for easier configuration of Xinerama. You can use these tools to set up the system for Xinerama and then use this configuration file for generating the configuration files for the different X servers. You can use an example configuration file, replacing video card and monitor section, by the corresponding sections from the Xinerama XFConfig-4 file.

Other useful resources:

• The Linux XFree86 HOWTO

• XFree86 Video Timings HOWTO

• X Window System Architecture Overview HOWTO

• The X Window User HOWTO

2.2. Reusing Xinerama configured XFree

If you have a system configured for Xinerama, you can easily adjust the XFree configuration file so you can use it for multiple users.

This will allow you to easily switch between a multi-user environment and a Xinerama multi-monitor environment.

What is Xinerama and how does the system configured using this HOWTO differ from a system using the Xinerama extensions in XFree?

The Xinerama extensions were introduced to the XFree86 system in version 4.0. Xinerama is an extension to XFree86 Release 6 Version 4.0 (X4.0) which allows applications and window managers to use the two (or more) physical displays as one large virtual display. In case Xinerama is not used, applications can only reside on one of the displays and can not be moved between the two. Window managers had to be specially written to support the two displays. With Xinerama, window managers and applications don't have to be specially written to support the larger "Virtual Desktop" Xinerama creates.

Just the opposite, the primary goal of a system configured according to this HOWTO is to offer multiple independent displays for several users on a single PC system.

For more information on Xinerama read:

• Xinerama-HOWTO, Using Xinerama to MultiHead XFree86 v.4.0+

2.3. Binary packages

Binary rpms of modified XFree servers are currently available for Mandrake 8.2/ 9/ 9.1, Red Hat 8/ 9, SuSE 8.1 and Debian Sid. If you're running other rpm-based distributions please help me to prepare and rebuild packages, so other users can get pre-compiled binaries. Currently the binary rpm packages are not mirrored and are only available from http://varna.demon.co.uk/~svetlio/ruby-contrib.

Debian packages are also available thanks to Andreas Schuldei at http://www.schuldei.org/debian/bruby, or as apt repository "deb http://www.schuldei.org/debian/bruby ./ ".

3.1. Installing the Backstreet Ruby kernel

Now it's time to install the kernel.

The easiest way would be to pull an already prepared binary kernel; there are packages for some distributions (currently only Mandrake and Debian) or a source package, and rebuild it on your system.

If for some reason you cannot use them or have problems using them you can also build your own kernel with the bruby patch, for more information how to do this visit the Backstreet Ruby page on building and installing the kernel: http://startx.times.lv (or some of the mirrors) -> Documentation -> Quick Kernel.

(If you are new to Linux, reading "The Linux Kernel HOWTO", http://tldp.org/HOWTO/Kernel-HOWTO.html, could be very helpful.)

You can find binary kernel package for Mandrake-9.1 at http://varna.demon.co.uk/~svetlio/ruby-contrib/kernel.html.

Debian binary kernel packages are available at http://www.schuldei.org/debian/bruby, or as apt repository "deb http://www.schuldei.org/debian/bruby ./ "

3.2. Notes on building your own kernel

There are some things I would like to mention, although I won't go in details, as the Backstreet Ruby page on compiling the kernel discusses this topic.

1. You have to follow this order:

   Input support Virtual Terminal support Console drivers

   for all required options to be available/selectable.

2. You have to use built in input support:

   Input device support --> Input core support Input device support --> Mouse support

3. I would suggest you also include at least one keyboard (built in - not as a module). You can also use modules, but I find it safer to be able to use a keyboard instead of trying to find a PC with ssh (or something similar) to load the required modules.

   For AT/PS2 keyboards, turn on (not modules):

   Input device support --> Serial i/o support Input device support --> i8042 PC Keyboard controller Input device support --> Keyboards Input device support --> AT keyboard support

   For a USB keyboard turn on (not modules):

   Input device support --> Keyboards USB support --> support for USB USB support --> USB driver (probably usb-uhci.o) USB support --> USB Human Interface Device (full HID) support USB support --> HID input layer support

4. If you are new to Linux, do not try to patch an already patched kernel (heavily patched kernels like the ones that ship with most distributions). Use a kernel from www.kernel.org, and take a look at the Linux Kernel HOWTO.

Support for frame buffer devices is not back-ported, and is disabled.

As Backstreet Ruby lacks framebuffer support, you will most certainly need separate graphic card for each display. You won't be able to use dual-headed card with single BusID for 2 independent displays, but it might be possible in case the card has different BusId's for the different heads.

3.3. Creating needed device files

If you are not using the devfs file system, you'll have to create several device files needed for the new input sub-system in the Backstreet Ruby kernel:

cd /dev
mkdir input.old
mv mouse js? input.old
mkdir input
cd input
mknod js0 c 13 0
mknod js1 c 13 1
mknod js2 c 13 2
mknod js3 c 13 3
mknod mouse0 c 13 32
mknod mouse1 c 13 33
mknod mouse2 c 13 34
mknod mouse3 c 13 35
mknod mice c 13 63
mknod event0 c 13 64
mknod event1 c 13 65
mknod event2 c 13 66
mknod event3 c 13 67
cd ..
ln -s input/js0 js0
ln -s input/js1 js1
ln -s input/mice mouse
      

If you use devfs, all required devices will be created automatically by devfs.

Mandrake is an example of one distribution that uses devfs. Debian does not use devfs by default, but the kernel supports devfs; in order to activate devfs you have to add "devfs=mount" to the "append" line of your boot loader and install devfsd (the devfs demon). Distributions that do not use devfs are Red Hat and SuSE.

You can check whether devfs is used by issuing the following commands:

• To check whether support for devfs is enabled in your kernel

  cat /proc/filesystems | grep devfs

• To check whether devfs is used/mounted

  mount | grep devfs

If you get an empty string this means that devfs is not used; if you get something like the following output, devfs is activated:

[root@mc contrib]# cat /proc/filesystems | grep devfs
nodev   devfs
nodev   usbdevfs
[root@mc contrib]# mount | grep devfs
none on /proc/bus/usb type usbdevfs (rw)
none on /dev type devfs (rw)
[root@mc contrib]#
      

3.4. Notes on using multiple VT's

As the frame buffer layer is not back-ported to linux-2.4, only the primary graphic card is initialised during the boot process. Secondary graphic cards can only be initialised by an X server, so you will have a single VGA text console on the primary graphic card.

3.5. Keyboard numbering(order of detection)

In the following chapters you will read about 1st keyboard, 2nd keyboard and so on, so here I will explain what is meant by n-th keyboard.

When a keyboard device is found, it is bound to a free VT (given that there are free VT's). The first keyboard found will be bound to VT0 (tty0-tty7), the second to VT1 (tty8-tty15), the third to VT2 (tty16-tty23).

The order of detecting the keyboards depends on the configuration of your kernel :

• If you are using kernel with integrated USB input the USB keyboard devices will be registered first, then the AT/PS2 keyboards will follow when the modules are loaded

• If you are using kernel with integrated PS2 input the AT/PS2 keyboard devices will be registered first, then the USB keyboards will follow when the modules are loaded

• If you are using kernel with integrated PS2 & USB input the AT/PS2 keyboard devices will be registered first, then the USB keyboards will follow

But there are some caveats:

Most USB keyboards represent themselves as more than one keyboard; it is common that the multimedia keys or the number-pad identify themselves as a different keyboard device. So if you are running a kernel with integrated USB input and have one USB keyboard with multimedia keys and one PS2 keyboard, the USB keyboard will be bound to VT0(real keyboard) and VT1(multimedia keys), the PS2 keyboard will be bound to VT2 (in case you have enough DUMB consoles).

There are several ways to work around these issues. Here I'll explain the easiest way to follow. It's definitely not the best one, but the shortest explanation, and I just want to make it clear to you that the problem is not that big. The Better solutions will follow later in their own section.

All you need to do is to start the Backstreet Ruby kernel with dumbcon=n , where n is the sum of your AT/PS2 keyboards plus the sum of your USB keyboards multiplied by 2 (I suppose this is the maximum number of interfaces a USB keyboard registers), so all keyboards will be bound to a VT. Now you should find out which VT's the real keyboards are bound to (the keyboards excluding the multimedia keys) and start X using the appropriate tty ranges. Thanks to the proc interface integrated in Backstreet Ruby, you can easily find the assignment of keyboards to VT's. Each VT creates a file /proc/bus/console/[n]/keyboard (n is the number of the VT, for VT0 n will be 00, for VT1 - 01, ... , for VT11 - 11); reading this file will give you the assigned keyboard.

[root@svetljo root]# cat /proc/bus/console/*/* usb-00:10.1-1.1/input0 usb-00:10.1-1.1/input1 isa0060/serio0/input0

tells us that:

• USB keyboard (real) is bound to VT0

• USB keyboard (multimedia keys) is bound to VT1

• PS2 keyboard is bound to VT2

Now we can start X on the VT's with real keyboards, in this case VT0 and VT2.

Of course in this simple example with only 2 keyboards (one USB and one PS2) the problem could be easily avoided by using a kernel with primary PS2 input support. The PS2 keyboard would be found first and bound to VT0, the USB keyboard would follow and it's real keyboard interface would be bound to VT1, so there is no need for additional dumb consoles (for the multimedia interfaces of USB keyboards).

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.

This can also be done in the kernel, 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

4.2. Creating symbolic links

The symbolic links are needed for properly starting several XFree instances, as well for properly exiting an X session. This applies for both starting X from console and the automatic starting of X by the display manager (kdm, gdm, xdm).

You need to create as many symbolic links to the modified X server binary (or the original X server in case you do not need a modified one), as the number of your video cards/X sessions.

I assume that you will have to use a modified X server, but in case you do not need it, use the following commands to create the links to your original X server:

cd /usr/X11R6/bin/
ln -s XFree[modified] X0
ln -s XFree[modified] X1
ln -s XFree[modified] X2
      

In case you use the provided rpm packages, you'll only need this if you want more than 4 parallel running X servers/X sessions, as the rpm creates 4 symbolic links to the X server binary.

4.3. Using independent keyboards with XFree

Once you install the Backstreet Ruby kernel and start it with dumbcon=n, you get n +1 independent consoles (1VGA + n DUMB). If you have enough keyboards connected to your PC, each of these consoles are associated with a given keyboard. This enables you to start multiple X servers on each of the consoles, using the keyboard associated with the corresponding console for input. Hence you get multiple independent X servers with independent keyboards, which in turn make it possible for one single PC to be used by several local X users simultaneously.

To start X on a given console (using a given independent keyboard) you pass it the argument vt[N], where N is a number from a given tty range.

Under Backstreet Ruby, each console is represented by 8 tty's:

• VGA: tty0 to tty7

• DUMB1: tty8 to tty15

• DUMB2: tty16 to tty23

For the new Preferred Bus ID XFree Server you also have to specify the desired graphic card with parameter "-prefbusid x:x:x", where x:x:x is the Bus ID of the desired graphic card. For AGP cards, something similar to -prefbusid 1:0:0 For PCI cards, something similar to -prefbusid 0:x:0 (x is normally the IRQ number) In the following explanation I will not use this option. If you use the Preferred Bus ID X server just append -prefbusid x:x:x with the correct Bus ID of the card you want to start right before the last argument vt[x] .

If you have 3 video cards, 3 keyboards, and you have started the Backstreet Ruby kernel with dumbcon=2, you can start 3 independent X servers for 3 simultaneous users with the following commands:

For the 1st X server with the 1st keyboard:

$ startx -- /usr/X11R6/bin/X0 :0 -xf86config /etc/X11/XF86Config-4[for your 1st video card] vt7

For the 2nd X server with the 2nd keyboard:

$ startx -- /usr/X11R6/bin/X1 :1 -xf86config /etc/X11/XF86Config-4[for your 2nd video card] vt8

For the 3rd X server with the 3rd keyboard:

$ startx -- /usr/X11R6/bin/X2 :2 -xf86config /etc/X11/XF86Config-4[for your 3rd video card] vt16

For the 1st X server you can skip the -xf86config /etc/X11/XF86Config-4[for your 1st video card] argument. In this case, the default configuration file, /etc/X11/XF86Config-4, will be used.

For SuSE users: the XFree configuration files are normally /etc/X11/XF86Config The same applies for Red Hat users: the XFree configuration files are normally /etc/X11/XF86Config

You can also setup your display manager to start the independent X servers, once everything is properly configured. But don't rush to setup your display manager before the configuration is finished, because this could give you serious problems. When you are ready with the required configurations, you'll reach the section on configuring the display manager.

4.4. Using independent mice with XFree

To use an independent mouse for each of your independent X servers/sessions, you just have to modify the input section of the XFree configuration files to adjust the proper device files.

Use /dev/input/mouse[n], where n is the number of your mouse starting from 0:

• 1st mouse --> /dev/input/mouse0

• 2nd mouse --> /dev/input/mouse1

• 3rd mouse --> /dev/input/mouse2

• 4th mouse --> /dev/input/mouse3

You shouldn't use /dev/input/mice because it merges the input from all mouse devices.

Here is my configuration before modifications:

------------------------------------------------------------------------------------------------

# **********************************************************************
# Pointer section
# **********************************************************************

Section "InputDevice"

    Identifier  "Mouse1"
    Driver      "mouse"
    Option "Protocol"    "IMPS/2"
    Option "Device"      "/dev/psaux"
    Option "ZAxisMapping" "4 5"

# ChordMiddle is an option for some 3-button Logitech mice
    Option "Emulate3Buttons"
#    Option "ChordMiddle"

EndSection

------------------------------------------------------------------------------------------------
      

After modifications for the first X server:

------------------------------------------------------------------------------------------------

# **********************************************************************
# Pointer section
# **********************************************************************

Section "InputDevice"

    Identifier  "Mouse1"
    Driver      "mouse"
    Option "Protocol"    "IMPS/2"
    Option "Device"      "/dev/input/mouse0"
    Option "ZAxisMapping" "4 5"

# ChordMiddle is an option for some 3-button Logitech mice
    Option "Emulate3Buttons"
#    Option "ChordMiddle"

EndSection

-----------------------------------------------------------------------------------------------
      

For the second X server:

-----------------------------------------------------------------------------------------------  
# **********************************************************************
# Pointer section
# **********************************************************************

Section "InputDevice"

    Identifier  "Mouse1"
    Driver      "mouse"
    Option "Protocol"    "IMPS/2"
    Option "Device"      "/dev/input/mouse1"
    Option "ZAxisMapping" "4 5"

# ChordMiddle is an option for some 3-button Logitech mice
    Option "Emulate3Buttons"
#    Option "ChordMiddle"

EndSection
-----------------------------------------------------------------------------------------------
      

and so on ...

4.5. For graphic cards without DRI

(or reusing Xinerama configured XFree)

There could be several reasons for not using DRI:

• As far I know only one graphic card in a system can use DRI.

• The Nvidia closed source driver does not support DRI.

In case one of this reasons applies to your system, you do not need different XFree configuration files for the different displays.

You can configure your system for Xinerama using the tools provided with your distribution and reading The Xinerama-HOWTO, so when the system is used by a single user, he/she could switch to Xinerama desktop and use all available displays for a bigger desktop.

Once configured for Xinerama, only small additions are needed to achieve multiple independent desktops. All you have to do is to add new layouts which use single screen definition and have independent input devices (well, this is actually needed only for the mouse devices, as the keyboard is managed through the vt[n] option).

If you have configured Xinerama in the following way:

Section "ServerLayout"
    Identifier  "Simple Layout"
    Screen "Screen 2"
    Screen "Screen 1" RightOf "Screen 2"
    InputDevice "Mouse1" "CorePointer"
    InputDevice "Keyboard1" "CoreKeyboard"
EndSection

To achieve multiple independent desktops you only have to add layout definitions for a single screen :

Section "ServerLayout"
    Identifier  "first-Xserver"
    Screen "Screen 1"
    InputDevice "Mouse1" "CorePointer"
    InputDevice "Keyboard1" "CoreKeyboard"
EndSection

Section "ServerLayout"
    Identifier  "second-Xserver"
    Screen "Screen 2"
    InputDevice "Mouse2" "CorePointer"
    InputDevice "Keyboard1" "CoreKeyboard"
EndSection

Which should result in these layout definitions:

Section "ServerLayout"
    Identifier  "Xinerama"
    Screen "Screen 2"
    Screen "Screen 1" RightOf "Screen 2"
    InputDevice "Mouse1" "CorePointer"
    InputDevice "Keyboard1" "CoreKeyboard"
EndSection

Section "ServerLayout"
    Identifier  "first-Xserver"
    Screen "Screen 1"
    InputDevice "Mouse1" "CorePointer"
    InputDevice "Keyboard1" "CoreKeyboard"
EndSection

Section "ServerLayout"
    Identifier  "second-Xserver"
    Screen "Screen 2"
    InputDevice "Mouse2" "CorePointer"
    InputDevice "Keyboard1" "CoreKeyboard"
EndSection

Now you can start a single X server with option -layout Xinerama and enjoy the Xinerama desktop, or

You can start 2 independent X servers using -layout first-Xserver for the first, and -layout second-Xserver for the second.

Since you will use a single XFree configuration file for all X servers,

1. in order to use independent keyboards you have to use following command:

   For 1st X server with the 1st keyboard:

   $ startx -- /usr/X11R6/bin/X0 :0 -layout first-Xserver vt7

   For 2nd X server with the 2nd keyboard:

   $ startx -- /usr/X11R6/bin/X1 :1 -layout second-Xserver vt8

   and if you want to use Xinerama:

   $ startx -- /usr/X11R6/bin/X -layout Xinerama vt7

2. also the mice must have different identifiers:

   ------------------------------------------------------------------------------------------------ # ********************************************************************** # Pointer section # ********************************************************************** Section "InputDevice" Identifier "Mouse1" Driver "mouse" Option "Protocol" "IMPS/2" Option "Device" "/dev/input/mouse0" Option "ZAxisMapping" "4 5" # ChordMiddle is an option for some 3-button Logitech mice Option "Emulate3Buttons" # Option "ChordMiddle" EndSection Section "InputDevice" Identifier "Mouse2" Driver "mouse" Option "Protocol" "IMPS/2" Option "Device" "/dev/input/mouse1" Option "ZAxisMapping" "4 5" # ChordMiddle is an option for some 3-button Logitech mice Option "Emulate3Buttons" # Option "ChordMiddle" EndSection -----------------------------------------------------------------------------------------------

4.6. Nvidia GLX & DRI

Here you will learn how to configure your system for parallel use of Nvidia's GLX and XFree's DRI. If you do not have Nvidia cards, or you have only Nvidia cards, you do not need to read this section. In the first case you do not need the Nvidia GLX at all, and in the second, you can use the standard procedure for installing GLX.

Why Nvidia? Why closed source drivers?

A bit of a mixed up answer:

1. With the open source driver it's almost impossible to bring up a secondary card, so we should use the closed source driver.

2. Why the Nvidia card? Currently these are the only available, affordable PCI video cards with some acceleration.

3. I tried to use DRI on 2 parallel X servers, but it didn't work. I posted emails to XFree, DRI and lkml list, but I only got a single answer with no valuable information on my problem. I tried to run DRI on a Matrox G550 DH AGP & SiS63xx PCI, but when enabled for both cards, I got AGP errors. When enabled only for one of the cards, I got DRI up and running. Please, someone confirm or prove me wrong!

I'll explain several ways to get configuration working for both Nvidia GLX and XFree86 DRI. There are probably a lot of other possibilities, and maybe these are not the simplest, but they are the ones I know to work.

The reasons why this is needed:

1. Nvidia should use a different module path for xf86: the glx extension module from Nvidia is incompatible with the one from XFree86.

2. Nvidia should use a different XF86Config file: because DRI should be disabled for Nvidia and enabled for others.

If you find a simpler way, please email it me and I'll include it.

This can not be used as-is on SuSE Linux. In order to make it easy for the user to switch between Mesa, XFree and Nvidia GL libraries, SuSE uses a very complicated setup for the GL libraries. To use this setup you have to switch your configuration to XFree86's GL libraries.

cp XNV /usr/X11R6/bin
cd /usr/X11R6/bin
ln -s XNV Xnv0
ln -s XNV Xnv1
ln -s XNV Xnv2
        

5.1. Finding the real devices

We will need this information later on, to be able to assign a given keyboard/mouse to a given X-server/Display.

To find the PHYS ID's (the addresses) or the name(quite oft it differs from the one labeled on the device) of your input devices you have to read the file /proc/bus/input/devices.

Here is what I have:

[svetljo@svetljo How-To]# cat /proc/bus/input/devices 
I: Bus=0011 Vendor=0002 Product=0002 Version=0034
N: Name="PS2++ Logitech Wheel Mouse"
P: Phys=isa0060/serio1/input0
H: Handlers=mouse0 ts0 
B: EV=7 
B: KEY=f0000 0 0 0 0 0 0 0 0 
B: REL=103 

I: Bus=0011 Vendor=0001 Product=0002 Version=ab02
N: Name="AT Set 2 keyboard"
P: Phys=isa0060/serio0/input0
H: Handlers=kbd 
B: EV=120003 
B: KEY=4 2000000 8061f9 fbc9d621 efdfffdf ffefffff ffffffff fffffffe 
B: LED=7 

I: Bus=0003 Vendor=046d Product=c303 Version=0700
N: Name="Logitech    USB Keyboard"
P: Phys=usb-00:10.1-1.1/input0
H: Handlers=kbd 
B: EV=120003 
B: KEY=10000 7f ffe00000 7ff ffbeffdf ffffffff ffffffff fffffffe 
B: LED=7 

I: Bus=0003 Vendor=046d Product=c303 Version=0700
N: Name="Logitech    USB Keyboard"
P: Phys=usb-00:10.1-1.1/input1
H: Handlers=kbd 
B: EV=100003 
B: KEY=1078 1800d100 1e0000 0 0 0 

I: Bus=0003 Vendor=05fe Product=0011 Version=0000
N: Name="Cypress Sem. PS2/USB Browser Combo Mouse"
P: Phys=usb-00:10.1-1.2/input0
H: Handlers=mouse1 ts1 
B: EV=7 
B: KEY=1f0000 0 0 0 0 0 0 0 0 
B: REL=103 

/proc/bus/input/devices will provide the needed information for all devices except USB multimedia/office keyboards. For such USB multimedia/office keyboards you will have to gather additional information, for example with the help of lsusb.

• First we have to find the address of the USB keyboard:

  [root@svetljo How-To]# lsusb Bus 004 Device 001: ID 0000:0000 Bus 003 Device 001: ID 0000:0000 Bus 003 Device 002: ID 0409:55ab NEC Corp. Hub [iMac kbd] Bus 003 Device 003: ID 046d:c303 Logitech, Inc. Bus 003 Device 004: ID 05fe:0011 Chic Technology Corp. Browser Mouse Bus 002 Device 001: ID 0000:0000 Bus 001 Device 001: ID 0000:0000

  Here, my USB Logitech keyboard is Device 003 on Bus 003.

• Now we run lsusb with arguments -v -s [your USB keyboard device id in form Bus:Device], in my case, lsusb -v -s 003:003.

  ........ Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 0 bAlternateSetting 0 bNumEndpoints 1 bInterfaceClass 3 Human Interface Devices bInterfaceSubClass 1 Boot Interface Subclass bInterfaceProtocol 1 Keyboard iInterface 0 ........ Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 1 bAlternateSetting 0 bNumEndpoints 1 bInterfaceClass 3 Human Interface Devices bInterfaceSubClass 0 No Subclass bInterfaceProtocol 0 None iInterface 0 ........

So my USB keyboard has two interfaces (see bInterfaceNumber); the first one is the real keyboard (bInterfaceProtocol 1 Keyboard), the second (bInterfaceProtocol 0 None) - the additional keys. Hence the real USB keyboard is:

.....
N: Name="Logitech    USB Keyboard"
P: Phys=usb-00:10.1-1.1/input0
H: Handlers=kbd 
.....

The "P: Phys=" field (the physical descriptor/address) consorts of:

1. Bus type: "usb"

2. PCI function of the USB controller: "00:10.1"

3. USB device id: "1.1"

4. The string: "/input"

5. Interface number: "0"

5.2. Using hotplug with input.agent

Using the input agent will allow you to manage input devices based on their PHYS ID.

The input agent uses 3 configuration files:

• /etc/hotplug/kbd.conf

• /etc/hotplug/mouse.conf

• /etc/hotplug/event.conf

To configure the keyboards you have to adjust /etc/hotplug/kbd.conf

If I wanted to use the PS2 keyboard for the primary Display and for the VGA console, I would have:

#
# keyboard configuration
#
# vt_name device_physicaly_location

VT0	isa0060/serio0/input0
VT1	usb-00:10.1-1.1/input0
        

Or, if I want to use the USB keyboard for the primary Display and for the VGA console:

#
# keyboard configuration
#
# vt_name device_physicaly_location

VT0	usb-00:10.1-1.1/input0
VT1	isa0060/serio0/input0
        

you could also use "*.*" instead of the pci function of the USB controller:

#
# keyboard configuration
#
# vt_name device_physicaly_location

VT0	usb-*.*-1.1/input0
VT1	isa0060/serio0/input0
      

For mouse devices you have to edit /etc/hotplug/mouse.conf

#
# mouse device configuration
#
# sym_link device_physicaly_location
mouse0br	usb-00:10.1-1.2/input0
mouse1br	usb-*.*-2.7.*/input0
mouse2br	isa0060/serio1/*
        

and adjust the XFree configuration file.

For the first mouse change

......
    Option "Protocol"    "IMPS/2"
    Option "Device"      "/dev/input/mouse0"
    Option "ZAxisMapping" "4 5"
......
      

to :

......
    Option "Protocol"    "IMPS/2"
    Option "Device"      "/dev/input/mouse0br"
    Option "ZAxisMapping" "4 5"
......
      

For the second mouse change

......
    Option "Protocol"    "IMPS/2"
    Option "Device"      "/dev/input/mouse1"
    Option "ZAxisMapping" "4 5"
......
      

to :

......
    Option "Protocol"    "IMPS/2"
    Option "Device"      "/dev/input/mouse1br"
    Option "ZAxisMapping" "4 5"
......
      

and so on.

For Event devices edit /etc/hotplug/event.conf

#
# input event device config file
#
# symbolic_link device_physicaly_location
event0br	isa0060/serio0/*
event1br	isa0060/serio1/input0
event2br	usb-*.*-3/input0
      

and configure the applications which use them to use the symbolic links instead of the real devices

5.3. Using XFree with event interface support

This will allow you:

• if you have input devices with different names, to use them with the same Xserver/screen wherever you plug or re-plug them.

• if you have input devices with the same names, to use them with the same Xserver/screen according to the USB port where you plug or re-plug them.

• the ability to use wild cards such as "*" and "?".

Currently hot-plugging doesn't seems to work properly. I have reports that it works when using the "Dev Name" option, but my primary purpose was to get it working with "Dev Phys" and this does not currently seem to work. "Why "Dev Phys"?" - because if one wants to setup a single system for 4,5 or more users it would be easier to get 4,5 or more pieces of the same keyboard/ mouse then to find the same number keyboards or mice but from different manufacturer or with different names, and i find configuring XFree for such number users is simpler when "Dev Phys" is used.

For this to work you will have to use XFree with the patches for event interface support, developed by Zephaniah Hull. You can find them at the following url: http://people.debian.org/~warp/evdev/.

To build from source you will need the following patches :

• 029_lnx_evdev.diff : The evdev core patch.

• 030_lnx_evdev_mouse.diff : The mouse side of the patch.

• 031_lnx_evdev_keyboard.diff : The keyboard side of the patch.

The binaries for Debian include these patches. Mandrake-9.1 rpms are also available.

For hot-plugging you will also need the /etc/hotplug/input.agent , which you can find under the above address and in Appendix Scripts

Then you have to configure XFree to use the event devices.

The configuration section for a mouse should look something like this:

Section "InputDevice"
    Identifier  "Mouse1"
    Driver      "mouse"
    Option      "Protocol"      "evdev"
    Option      "Dev Name"      "A4Tech USB Optical Mouse"
    Option      "Dev Phys"      "usb-*/input0"
    Option      "Buttons"       "9"

    Option      "ZAxisMapping"  "6 7 8 9"
EndSection

The configuration section for a keyboard should look something like this:

Section "InputDevice"
    Identifier  "Keyboard1"
    Driver      "kbd"
    Option      "Protocol"      "evdev"
    Option      "Dev Name"      "SILITEK USB Keyboard"
    Option      "Dev Phys"      "usb-*/input0"
    Option      "AutoRepeat"    "250 30"
    Option      "XkbRules"      "xfree86"
    Option      "XkbModel"      "pc101"
    Option      "XkbLayout"     "dvorak"
EndSection

For Dev Name and Dev Phys, the wildcats "?" and "*" work, you MUST have at least one of the two, if you have both then the device must match on both, a non-existent entry is the same as one consisting of "*".

5.4. Using the "Phys" descriptor and USB devices

Using the "Phys" descriptor of input devices simplifies a lot the configuration of input devices in XFree, especially when a bigger number of displays are used.

As USB devices are connecting in a tree form, you can really easy specify the way keyboard and mice devices are bound to a specified X display. You have to use one USB hub with number of ports equal(or bigger) to the number of the X displays, to this hub are connected smaller (2-4 port) hubs (or keyboards with integrated hub). To the first port of the smaller (integrated) hub are connected the keyboards, to the second the mice (in case there are free ports you can connect usb-audio devices to them :) ). This results in the following layout of the usb-id's in case the primary USB hub is the first USB device :

In the following explanations and examples I use for first device on the secondary(integrated) hub keyboard device because my keyboard is internally connected to the 1st port of the integrated hub. I assume this will apply for most of the keyboards with integrated hub, but in case the one you own uses different port you will have to make small adjustments.

• on the 1st port of the primary hub

  • 1.1 USB hub (integrated)

  • 1.1.1 USB keyboard

  • 1.1.2 USB mouse

  • (1.1.3 usb-audio/other usb device)

• on the 2nd port

  • 1.2 USB hub (integrated)

  • 1.2.1 USB keyboard

  • 1.2.2 USB mouse

  • (1.2.3 usb-audio/other usb device)

• on the 3rd port

  • 1.3 USB hub (integrated)

  • 1.3.1 USB keyboard

  • 1.3.2 USB mouse

  • (1.3.3 usb-audio/other usb device)

• on the 4th port

  • 1.4 USB hub (integrated)

  • 1.4.1 USB keyboard

  • 1.4.2 USB mouse

  • (1.4.3 usb-audio/other usb device)

Based on this we can bind all devices connected to a specified USB port to a given X server.

#
# keyboard configuration
#
# vt_name device_physicaly_location

VT0	usb-*.*-1.1.1/input0
VT1	usb-*.*-1.2.1/input0
VT2	usb-*.*-1.3.1/input0
VT3	usb-*.*-1.4.1/input0
      

#
# mouse device configuration
#
# sym_link device_physicaly_location
mouse0br	usb-*.*-1.1.2/input0
mouse1br	usb-*.*-1.2.2/input0
mouse2br	usb-*.*-1.3.2/input0
mouse3br	usb-*.*-1.4.2/input0
        

......
# **********************************************************************
# Pointer section
# **********************************************************************

Section "InputDevice"

    Identifier  "Mouse1"
    Driver      "mouse"
    Option "Protocol"    "IMPS/2"
    Option "Device"      "/dev/input/mouse0br"
    Option "ZAxisMapping" "4 5"

# ChordMiddle is an option for some 3-button Logitech mice
    Option "Emulate3Buttons"
#    Option "ChordMiddle"

EndSection
......
      

......
# **********************************************************************
# Pointer section
# **********************************************************************

Section "InputDevice"

    Identifier  "Mouse1"
    Driver      "mouse"
    Option "Protocol"    "IMPS/2"
    Option "Device"      "/dev/input/mouse1br"
    Option "ZAxisMapping" "4 5"

# ChordMiddle is an option for some 3-button Logitech mice
    Option "Emulate3Buttons"
#    Option "ChordMiddle"

EndSection
......
      

......
# **********************************************************************
# Pointer section
# **********************************************************************

Section "InputDevice"

    Identifier  "Mouse1"
    Driver      "mouse"
    Option "Protocol"    "IMPS/2"
    Option "Device"      "/dev/input/mouse0br"
    Option "ZAxisMapping" "4 5"

# ChordMiddle is an option for some 3-button Logitech mice
    Option "Emulate3Buttons"
#    Option "ChordMiddle"

EndSection
Section "InputDevice"

    Identifier  "Mouse2"
    Driver      "mouse"
    Option "Protocol"    "IMPS/2"
    Option "Device"      "/dev/input/mouse1br"
    Option "ZAxisMapping" "4 5"

# ChordMiddle is an option for some 3-button Logitech mice
    Option "Emulate3Buttons"
#    Option "ChordMiddle"

EndSection
......
      

---

5.4.2. ... with XFree with event interface support

Using the "Dev Phys" option of XFree with event device support and USB input devices enables us to use almost identical configuration of the input devices for all X servers. The only difference will be in the part of the usb-id, which reflects the port of the primary USB hub.

The examples below are for multiple XFree configuration files, if you use a single XFree configuration file you have to adjust the identifiers.

The configuration for the input devices for the 1st display would look something like this:

Section "InputDevice" Identifier "Keyboard1" Driver "kbd" Option "Protocol" "evdev" Option "Dev Phys" "usb-*-1.1.1/input0" Option "AutoRepeat" "250 30" Option "XkbRules" "xfree86" Option "XkbModel" "pc101" Option "XkbLayout" "dvorak" EndSection Section "InputDevice" Identifier "Mouse1" Driver "mouse" Option "Protocol" "evdev" Option "Dev Phys" "usb-*-1.1.2/input0" Option "ZAxisMapping" "4 5" EndSection

For the 2nd display something like this:

Section "InputDevice" Identifier "Keyboard1" Driver "kbd" Option "Protocol" "evdev" Option "Dev Phys" "usb-*-1.2.1/input0" Option "AutoRepeat" "250 30" Option "XkbRules" "xfree86" Option "XkbModel" "pc101" Option "XkbLayout" "dvorak" EndSection Section "InputDevice" Identifier "Mouse1" Driver "mouse" Option "Protocol" "evdev" Option "Dev Phys" "usb-*-1.2.2/input0" Option "ZAxisMapping" "4 5" EndSection

For the 3rd display something like this:

Section "InputDevice" Identifier "Keyboard1" Driver "kbd" Option "Protocol" "evdev" Option "Dev Phys" "usb-*-1.3.1/input0" Option "AutoRepeat" "250 30" Option "XkbRules" "xfree86" Option "XkbModel" "pc101" Option "XkbLayout" "dvorak" EndSection Section "InputDevice" Identifier "Mouse1" Driver "mouse" Option "Protocol" "evdev" Option "Dev Phys" "usb-*-1.3.2/input0" Option "ZAxisMapping" "4 5" EndSection

and so on.

You could also use the "?", so wherever you plug the primary hub, all displays will still have the desired configuration.

Section "InputDevice" Identifier "Keyboard1" Driver "kbd" Option "Protocol" "evdev" Option "Dev Phys" "usb-*-?.1.1/input0" Option "AutoRepeat" "250 30" Option "XkbRules" "xfree86" Option "XkbModel" "pc101" Option "XkbLayout" "dvorak" EndSection Section "InputDevice" Identifier "Mouse1" Driver "mouse" Option "Protocol" "evdev" Option "Dev Phys" "usb-*-?.1.2/input0" Option "ZAxisMapping" "4 5" EndSection

6.1. Configuring xdm and kdm

If everything is working now, it's time to setup the automatic starting of X on all displays. For xdm and kdm you have to modify one single file. For a Red Hat-like system this would be /etc/X11/xdm/Xservers; for other distributions check whether this file exists. If not, find your XFree86 configuration directory, and in it you'll find xdm/Xservers.

SuSE uses: /etc/X11/XF86Config /etc/X11/xdm/Xservers for xdm /etc/opt/kde3/share/config/kdm/Xservers for kdm you can make a backup copy of /etc/opt/.../kdm/Xservers and make a symbolic link from /etc/X11/xdm/Xservers to /etc/opt/../kdm/Xservers, in order to use the same configuration file for xdm and kdm.

Debian uses: /etc/kde3/kdm/Xservers for kdm you can make a backup copy of /etc/kde3/kdm/Xservers and make a symbolic link from /etc/X11/xdm/Xservers to /etc/kde3/kdm/Xservers, in order to use the same configuration file for xdm and kdm.

Red Hat uses: /etc/X11/XF86Config

For every additional X server you should add a single line. You can copy the existing line, change the X server binary and display number, and append -xf86config [your configuration file]. My original xdm/Xservers:

##################################################################### # $XConsortium: Xserv.ws.cpp,v 1.3 93/09/28 14:30:30 gildea Exp $ # # # $XFree86: xc/programs/xdm/config/Xserv.ws.cpp,v 1.1.1.1.12.2 1998/10/04 15:23:14 hohndel Exp $ # # Xservers file, workstation prototype # # This file should contain an entry to start the server on the # local display; if you have more than one display (not screen), # you can add entries to the list (one per line). If you also # have some X terminals connected which do not support XDMCP, # you can add them here as well. Each X terminal line should # look like: # XTerminalName:0 foreign # :0 local /bin/nice -n -10 /usr/X11R6/bin/X :0 -deferglyphs 16 vt7 ######################################################################

and the modified version:

###################################################################### # $XConsortium: Xserv.ws.cpp,v 1.3 93/09/28 14:30:30 gildea Exp $ # # # $XFree86: xc/programs/xdm/config/Xserv.ws.cpp,v 1.1.1.1.12.2 1998/10/04 15:23:14 hohndel Exp $ # # Xservers file, workstation prototype # # This file should contain an entry to start the server on the # local display; if you have more than one display (not screen), # you can add entries to the list (one per line). If you also # have some X terminals connected which do not support XDMCP, # you can add them here as well. Each X terminal line should # look like: # XTerminalName:0 foreign # :0 local /bin/nice -n -10 /usr/X11R6/bin/X0 :0 -deferglyphs 16 vt7 :1 local /bin/nice -n -10 /usr/X11R6/bin/X1 :1 -xf86config /etc/X11/XF86Config-4.TNT2 vt9 #######################################################################

If you have more video cards just add more lines:

:2 local /bin/nice -n -10 /usr/X11R6/bin/X2 :2 -xf86config /etc/X11/XF86Config-4.[your 3rd card] vt16
:3 local .....
      

If you use a single XFree configuration file :

###################################################################### # $XConsortium: Xserv.ws.cpp,v 1.3 93/09/28 14:30:30 gildea Exp $ # # # $XFree86: xc/programs/xdm/config/Xserv.ws.cpp,v 1.1.1.1.12.2 1998/10/04 15:23:14 hohndel Exp $ # # Xservers file, workstation prototype # # This file should contain an entry to start the server on the # local display; if you have more than one display (not screen), # you can add entries to the list (one per line). If you also # have some X terminals connected which do not support XDMCP, # you can add them here as well. Each X terminal line should # look like: # XTerminalName:0 foreign # :0 local /bin/nice -n -10 /usr/X11R6/bin/X0 :0 -layout first-Xserver -deferglyphs 16 vt7 :1 local /bin/nice -n -10 /usr/X11R6/bin/X1 :1 -layout second-Xserver vt9 #######################################################################

6.2. Configuring gdm

gdm, as a complete rewrite of xdm, uses its own configuration file, /etc/X11/gdm/gdm.conf. You should locate the definitions of the local X servers and add additional X servers for the number of cards you have.

SuSE uses: /etc/X11/XF86Config /etc/opt/gnome2/gdm/gdm.conf for gdm2

Debian uses: /etc/gdm/gdm.conf for gdm /etc/X11/gdm/ is a symbolic link to /etc/gdm/, so you can use both paths.

Red Hat uses: /etc/X11/XF86Config

Modifications:

7.1. Using independent sound cards

In case you do not use devfs, you may need to create additional device files. Take a look at The Linux Sound HOWTO, for information on how to setup additional sound cards.

real_display=`echo $DISPLAY | sed "s/://" | sed "s/\..*//"`
case "$real_display" in
        0)
        artsd -F 10 -S 4096 -D /dev/dsp -s 5 -m artsmessage -l 3 -f &
        ;;
        1)
        artsd -F 10 -S 4096 -D /dev/dsp1 -s 5 -m artsmessage -l 3 -f &
        ;;
        2)
        artsd -F 10 -S 4096 -a alsa -D hw:4,0 -s 5 -m artsmessage -l 3 -f &
        ;;
esac
        

artsshell -q terminate

#!/bin/sh
#   License: GPL

real_display=`echo $DISPLAY | sed "s/://" | sed "s/\..*//"`
case "$real_display" in
        0)
        artsd -F 10 -S 4096 -D /dev/dsp -s 5 -m artsmessage -l 3 -f &
        ;;
        1)
        artsd -F 10 -S 4096 -D /dev/dsp1 -s 5 -m artsmessage -l 3 -f &
        ;;
        2)
        artsd -F 10 -S 4096 -a alsa -D hw:2,0 -s 5 -m artsmessage -l 3 -f &
        ;;
esac

/usr/X11R6/bin/enlightenment
artsshell -q terminate
        

7.2. Customising the login screen

7.3. 1st X server configuration file

A small part of the Mandrake init scripts (you can append it to yours if you are missing something similar):

-----------------------------------------------------------------------------------
# (pixel) a kind of profile for XF86Config
# if no XFree=XXX given on kernel command-line, restore XF86Config.standard
for i in XF86Config XF86Config-4; do
    if [ -L "/etc/X11/$i" ]; then
        XFree=`sed -n 's/.*XFree=\(\w*\).*/\1/p' /proc/cmdline`
        [ -n "$XFree" ] || XFree=standard
        [ -r "/etc/X11/$i.$XFree" ] && ln -sf "$i.$XFree" "/etc/X11/$i"
    fi
done
-----------------------------------------------------------------------------------
      

Move your XF86Config-4 file (the one for standard kernel) to XF86Config-4.standard, create a symbolic link from it to XF86Config-4, and move the XF86Config-4 file (the one for Backstreet Ruby) to XF86Config-4.bruby. For Ruby/Backstreet Ruby kernels, add to the append line in /etc/lilo.conf, or on boot prompt "XFree=bruby", leave the standard kernel as is.

Results:

Booting with "XFree=standard" or without "XFree=" (boot prompt or lilo.conf) will result in linking XF86Config-4.standard to XF86Config-4; booting with "XFree=bruby" will link XF86Config-4.bruby to XF86Config-4, so in both scenarios XFree can be started with the proper configuration file for the first X server.

And what about the other X servers?

Under a standard kernel you cannot use several independent X servers, so you should use the other XFree configuration files only under Ruby/Backstreet Ruby - there is no need for different configuration files under standard & bruby kernels.

7.4. Number X servers started by Display managers

Here is a modified version of the previous approach. Add this to your init scripts (I bet it's missing!):

---------------------------------------------------------------------------------------
#
#the same like XF86Config but for gdm.conf & Xservers
#
for i in xdm/Xservers gdm/gdm.conf; do
    if [ -L "/etc/X11/$i" ]; then
        DumbCon=`sed -n 's/.*dumbcon=\([0-9]*\).*/\1/p' /proc/cmdline`
        [ -n "$DumbCon" ] || DumbCon=0
        [ -r "/etc/X11/$i.$DumbCon" ] && ln -sf "/etc/X11/$i.$DumbCon" "/etc/X11/$i"
    fi
done
echo "Setting up display managers for `expr $DumbCon + 1` Xservers"
---------------------------------------------------------------------------------------
      

This will adjust the proper /etc/X11/xdm/Xservers and /etc/X11/gdm/gdm.config according to the boot line argument dumbcon=n (remember n+1= number of X users/sessions).

You have to create the configuration files following these assumptions:

"i" only stands for /etc/X11/xdm/Xserver and /etc/X11/gdm/gdm.conf.

• "i.0" is used for a single X server, when dumbcon=n is not specified, or dumbcon=0.

• "i.1" is used by the display manager when dumbcon=1 is specified.

• "i.2" is used by the display manager when dumbcon=2 is specified.

• "i.3" is used by the display manager when dumbcon=3 is specified.

...and so on.

Therefore:

• "i.0" should contain the definition only of your original standard X server.

• "i.1" should contain the definitions for 2 X servers.

• "i.2" should contain the definitions for 3 X servers.

• ...and so on.

If you boot without dumbcon=n or with dumbcon=0 (for example a standard kernel), your display manager will start a single X server with the corresponding XF86Config file.

If you start with dumbcon=1 the display manager will automatically start 2 X servers.

If you start with dumbcon=2, when booting is finished you'll get 3 login prompts on your 3 displays.

Keep in mind that each X server should have it's own configuration file, and it should be specified in the display manager configuration file properly. Take a look at the configuration files before restarting with an activated display manager and this addition to your init scripts.

This can also be used if you have a single XFree configuration file (see Section 4.5, "For graphic cards without DRI"). In this case you will have to specify the correct layout instead of the correct XFree configuration file.

7.5. Dynamically switching the number of X servers

There is a very experimental GUI/CLI for dynamically switching the number of running X servers. It uses the automatic configuration of the display managers (mentioned in Section 7.1), Python, dialog for the CLI, and Xdialog for the GUI.

Once it is more tested and bug-free, you could, for example, use it under Backstreet Ruby to switch between 2, 3 or more X servers and a single X server using Xinerama. So when your PC isn't used by more then one user, you could use the other monitors under Xinerama. Or one more funny example: you're simulating net gaming with a number of friends on your bruby Linux PC, you have invested a bit more in an additional graphic card which is already configured, but you don't have enough money right now to buy one more monitor and keyboard/mouse pair. One friend of yours comes and says, "Hey guys, that's cool. Can I join?" What would you answer? Using the GUI could result in the following answer from your side: "No problem, just bring your monitor,keyboard and mouse."

If you are feeling like a hacker and want to try out this BUGGY GUI/CLI, check the current status at http://varna.demon.co.uk/~svetlio/ruby-contrib/bruby-python/. But remember, it's not very tested, and if not configured properly it can cause you serious troubles. Please wait until it is more stable if you are not that familiar with Linux. If you feel comfortable enough under Linux, and think of yourself as a hacker, please help in testing it and making it better, bug-free and easy to configure.

8.1. Hardware problems

While not exactly problems, some graphic cards do not work well, or even at all in multi-user environments.

If you are building such a system from the beginning, check the Video Compatibility list before buying video hardware.

8.2. Software problems

For details on solving software problems see Chapter 9, "Special notes on some distributions."

9.1. Mandrake

Almost everything is easy to accomplish (probably because I've used it for 2-3 years, at least).

1. Just a small tweak in /etc/init.d/numlock:

   --- /etc/init.d/numlock.orig 2003-04-11 00:58:55.000000000 +0200 +++ /etc/init.d/numlock 2003-03-19 13:03:30.000000000 +0100 @@ -21,14 +21,14 @@ echo touch $SYSCONF_FILE - for tty in /dev/tty[0-8]; do + for tty in /dev/tty[0-7]; do setleds -D +num < $tty done ;; stop) gprintf "Disabling numlocks on ttys: " - for tty in /dev/tty[0-8]; do + for tty in /dev/tty[0-7]; do setleds -D -num < $tty done echo_success

9.2. Red Hat

1. Replacing sysfont with consolechars.

   < needs to be written >

   Rebuild console-tools-19990829-40.src.rpm using rpmbuild --rebuild console-tools-19990829-40.src.rpm. You can find the source rpm on http://www.rpmfind.net).

   Then install it:

   rpm -Uvh /usr/src/redhat/RPMS/i386/console-tools-19990829-40.i386.rpm

   I still seem to have some kind of problem, because on the console I always get:

   findfont no such file or directory unable to setfont xxx

   But everything else seems okay.

9.3. Debian

There are no known problems.

9.4. SuSE

1. In /etc/init.d/kbd, add this line in the very beginning of the file:

   KBD_TTY="tty0 tty2 tty3 tty4 tty5 tty6 tty7"

   After modifications:

   #! /bin/sh # Copyright (c) 1995-2001 SuSE GmbH Nuernberg, Germany. # # Author: Burchard Steinbild <bs@suse.de> # Werner Fink <werner@suse.de> # # /etc/init.d/kbd # # and symbolic its link # # /sbin/rckbd # ### BEGIN INIT INFO # Provides: kbd # Required-Start: $remote_fs # Required-Stop: # X-SuSE-Should-Start: fbset serial # X-SuSE-Should-Stop: # Default-Start: 1 2 3 5 S # Default-Stop: # Description: Keyboard settings (don't disable!) ### END INIT INFO . /etc/rc.status . /etc/sysconfig/console . /etc/sysconfig/keyboard MACHINE=`/bin/uname -m 2> /dev/null` if [ "$MACHINE" = "sparc" -o "$MACHINE" = "sparc64" ]; then # Test if we have a serial console. (test -c /dev/tty1 && > /dev/tty1 ) > /dev/null 2>&1 || exit 0 fi # The variable NON_SUSE_KERNEL determines whether we need to chvt # to a console before some console settings apply. # We have no magic to find out about this (at boot time), so we # leave it to the user to read this comment and put NON_SUSE_KERNEL="yes" # into /etc/sysconfig/console KBDBASE="/usr/share/kbd" KBD_TTY="tty0 tty2 tty3 tty4 tty5 tty6 tty7" KTABLE=${KEYTABLE%.map*} KTABLE=${KTABLE##*/} # # first search the wanted keytable. # if [ $MACHINE = ppc -o $MACHINE = ppc64 ]; then test -f /proc/cpuinfo || mount -n -t proc proc /proc 2>/dev/null while read line; do ...... ......

2. Hardware scans sometimes cause problems.

   Recommended: disable. If you have to install new hardware and want to use this service, boot with standard kernel and start it manually.