How to run dual screen with Intel i810 driver and MergedFB

This is how I configured my laptop with an Intel graphics driver i810 to use my dual screens. I've tested this setup with Ubuntu Hardy. But I guess this configuration could work with other dists too. In my setup I use MergedFB since I had some problems with wrong positioned windows when running wine programs with Xinerama.

I have the following setup: HP laptop (nc6220) in a docking station with two LCD screens (SyncMaster 740T) connected to it. One connected with a VGA cable and the other one with DVI. Sometimes I do not have my laptop in the docking station so I'll also show how I did to switch between the laptop monitor and the dual screens by using different ServerLayouts.

First, to be able to choose ServerLayouts we must start X manually. So we must disable gdm login:

sudo update-rc.d -f gdm remove

Remember to take a backup of your xorg.conf before starting editing it:

sudo cp /etc/X11/xorg.conf /etc/X11/xorg.conf.backup

Ok, so here is the xorg.conf file with all the magic. Store it as xorg.conf in /etc/X11/:

Section "Files"
 FontPath "/usr/share/X11/fonts/misc"
 FontPath "/usr/share/X11/fonts/cyrillic"
 FontPath "/usr/share/X11/fonts/100dpi/:unscaled"
 FontPath "/usr/share/X11/fonts/75dpi/:unscaled"
 FontPath "/usr/share/X11/fonts/Type1"
 FontPath "/usr/share/X11/fonts/100dpi"
 FontPath "/usr/share/X11/fonts/75dpi"
 # path to defoma fonts
 FontPath "/var/lib/defoma/x-ttcidfont-conf.d/dirs/TrueType"
EndSection

Section "Module"
 Load "i2c"
 Load "bitmap"
 Load "ddc"
 Load "dri"
 Load "extmod"
 Load "freetype"
 Load "glx"
 Load "int10"
 Load "type1"
 Load "vbe"
EndSection

Section "InputDevice"
 Identifier "Generic Keyboard"
 Driver  "kbd"
 Option  "CoreKeyboard"
 Option  "XkbRules" "xorg"
 Option  "XkbModel" "pc105"
 Option  "XkbLayout" "se"
EndSection

Section "InputDevice"
 Identifier "Configured Mouse"
 Driver  "mouse"
 Option  "CorePointer"
 Option  "Device"  "/dev/input/mice"
 Option  "Protocol"  "ExplorerPS/2"
 Option  "ZAxisMapping"  "4 5"
 Option  "Emulate3Buttons" "true"
EndSection

Section "InputDevice"
 Identifier "Synaptics Touchpad"
 Driver  "synaptics"
 Option  "SendCoreEvents" "true"
 Option  "Device"  "/dev/psaux"
 Option  "Protocol"  "auto-dev"
 Option  "HorizScrollDelta" "0"
EndSection

Section "InputDevice"
  Driver        "wacom"
  Identifier    "stylus"
  Option        "Device"        "/dev/wacom"     
                                            
                                                      
  Option        "Type"          "stylus"
  Option        "ForceDevice"   "ISDV4"               
EndSection

Section "InputDevice"
  Driver        "wacom"
  Identifier    "eraser"
  Option        "Device"        "/dev/wacom" 
                                                
                                             
  Option        "Type"          "eraser"
  Option        "ForceDevice"   "ISDV4"      
EndSection

Section "InputDevice"
  Driver        "wacom"
  Identifier    "cursor"
  Option        "Device"        "/dev/wacom"    
                                                 
                                              
  Option        "Type"          "cursor"
  Option        "ForceDevice"   "ISDV4"     
EndSection


Section "Device"
  Identifier          "Videocard0"
  Driver                "i810"
  BusID                "PCI:0:2:0"
  Option                "MonitorLayout" "DFP,CRT" #Note: the VGA connected screen must be configured as a CRT monitor
  VideoRam        65536

  Option  "DRI"                           "true"
  Option  "MergedFB"                      "true"
  Option  "SecondPosition"                "RightOf"
  Option  "MetaModes"                     "1280x1024-1280x1024"
  Option  "SecondMonitorHorizSync"        "30-81"
  Option  "SecondMonitorVertRefresh"      "56-75"
EndSection

Section "Device"
 Identifier "laptopdevice"
 Driver  "i810"
 BusID  "PCI:0:2:0"
EndSection

Section "Monitor"
 Identifier "Laptop Monitor"
 Option  "DPMS"
EndSection

#Monitor for dual mode
Section "Monitor"
    Identifier          "Monitor0"
    Option                "DPMS"
    HorizSync   30.0 - 81.0
    VertRefresh 56.0 - 75.0
EndSection

#Screens for dual mode
Section "Screen"
          Identifier      "Screen0"
          Device           "Videocard0"
          Monitor           "Monitor0"
          DefaultDepth      24
          SubSection "Display"
                Depth           24
                Modes           "1280x1024" "1024x768"
          EndSubSection
          SubSection "Display"
                Depth           16
                Modes           "1280x1024" "1024x768"
          EndSubSection
          SubSection "Display"
                Depth           24
                Modes           "1280x1024" "1024x768"
          EndSubSection
EndSection

#laptop screen
Section "Screen"
 Identifier "Laptop Screen"
 Device  "laptopdevice"
 Monitor  "Laptop Monitor"
 DefaultDepth 24
 SubSection "Display"
  Depth  1
  Modes  "1400x1050"
 EndSubSection
 SubSection "Display"
  Depth  4
  Modes  "1400x1050"
 EndSubSection
 SubSection "Display"
  Depth  8
  Modes  "1400x1050"
 EndSubSection
 SubSection "Display"
  Depth  15
  Modes  "1400x1050"
 EndSubSection
 SubSection "Display"
  Depth  16
  Modes  "1400x1050"
 EndSubSection
 SubSection "Display"
  Depth  24
  Modes  "1400x1050"
 EndSubSection
EndSection

# Serverlayout for laptop mode
Section "ServerLayout"
 Identifier "laptop"
 Screen  "Laptop Screen"
 InputDevice "Generic Keyboard"
 InputDevice "Configured Mouse"
 InputDevice     "stylus" "SendCoreEvents"
 InputDevice     "cursor" "SendCoreEvents"
 InputDevice     "eraser" "SendCoreEvents"
 InputDevice "Synaptics Touchpad"
EndSection

# Serverlayout for dual screen mode
Section "ServerLayout"
    Identifier      "dual"
    Screen "Screen0"
    InputDevice      "Generic Keyboard"
    InputDevice      "Configured Mouse"
    InputDevice      "Synaptics Touchpad"
EndSection

# Choose here which one that should be default e.g. when running # startx
Section "ServerFlags"
  # Option "DefaultServerLayout" "laptop"
  Option "DefaultServerLayout" "dual"
EndSection

Section "DRI"
 Mode 0666
EndSection

To start with dual screen setup simply just run:

startx

To use the laptop monitor I've created a simple bashscript:

#!/bin/bash
startx -- -layout laptop