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xorg.conf(5)		      File Formats Manual		  xorg.conf(5)



NAME
       xorg.conf, xorg.conf.d - configuration files for Xorg X server

INTRODUCTION
       Xorg  supports several mechanisms for supplying/obtaining configuration
       and run-time parameters: command line options,  environment  variables,
       the  xorg.conf and xorg.conf.d configuration files, auto-detection, and
       fallback defaults. When the same information is supplied in  more  than
       one  way,  the highest precedence mechanism is used. The list of mecha-
       nisms is ordered from highest precedence to lowest. Note that  not  all
       parameters  can be supplied via all methods. The available command line
       options and environment variables (and some defaults) are described  in
       the Xserver(1) and Xorg(1) manual pages. Most configuration file param-
       eters, with their defaults, are described below. Driver and module spe-
       cific  configuration parameters are described in the relevant driver or
       module manual page.

DESCRIPTION
       Xorg uses a configuration file called xorg.conf and files ending in the
       suffix .conf from the directory xorg.conf.d for its initial setup.  The
       xorg.conf configuration file is searched for in	the  following	places
       when the server is started as a normal user:

	   /etc/X11/<cmdline>
	   /usr/etc/X11/<cmdline>
	   /etc/X11/$XORGCONFIG
	   /usr/etc/X11/$XORGCONFIG
	   /etc/X11/xorg.conf
	   /etc/xorg.conf
	   /usr/etc/X11/xorg.conf.<hostname>
	   /usr/etc/X11/xorg.conf
	   /usr/lib/X11/xorg.conf.<hostname>
	   /usr/lib/X11/xorg.conf

       where  <cmdline> is a relative path (with no ".." components) specified
       with the -config command line option, $XORGCONFIG is the relative  path
       (with  no  ".." components) specified by that environment variable, and
       <hostname> is the machine's hostname as reported by gethostname(3).

       When the Xorg server is started by the "root"  user,  the  config  file
       search locations are as follows:

	   <cmdline>
	   /etc/X11/<cmdline>
	   /usr/etc/X11/<cmdline>
	   $XORGCONFIG
	   /etc/X11/$XORGCONFIG
	   /usr/etc/X11/$XORGCONFIG
	   /etc/X11/xorg.conf
	   /etc/xorg.conf
	   /usr/etc/X11/xorg.conf.<hostname>
	   /usr/etc/X11/xorg.conf
	   /usr/lib/X11/xorg.conf.<hostname>
	   /usr/lib/X11/xorg.conf

       where  <cmdline>	 is  the  path specified with the -config command line
       option (which may be absolute or relative),  $XORGCONFIG	 is  the  path
       specified by that environment variable (absolute or relative), $HOME is
       the path specified by  that  environment	 variable  (usually  the  home
       directory),  and	 <hostname>  is	 the machine's hostname as reported by
       gethostname(3).

       Additional configuration files are searched for in the following direc-
       tories when the server is started as a normal user:

	   /etc/X11/<cmdline>
	   /etc/X11/<cmdline>
	   /etc/X11/xorg.conf.d
	   /etc/X11/xorg.conf.d

       where  <cmdline> is a relative path (with no ".." components) specified
       with the -configdir command line option.

       When the Xorg server is started by the "root" user, the	config	direc-
       tory search locations are as follows:

	   <cmdline>
	   /etc/X11/<cmdline>
	   /etc/X11/<cmdline>
	   /etc/X11/xorg.conf.d
	   /etc/X11/xorg.conf.d

       where  <cmdline> is the path specified with the -configdir command line
       option (which may be absolute or relative).

       Finally, configuration files will also be searched for in  a  directory
       reserved	 for system use.  This is to separate configuration files from
       the vendor or 3rd party packages from those  of	local  administration.
       These files are found in the following directory:

	   /usr/share/X11/xorg.conf.d

       The  xorg.conf  and  xorg.conf.d files are composed of a number of sec-
       tions which may be present in any order, or omitted to use default con-
       figuration values.  Each section has the form:

	   Section  "SectionName"
	       SectionEntry
	       ...
	   EndSection

       The section names are:

	   Files	  File pathnames
	   ServerFlags	  Server flags
	   Module	  Dynamic module loading
	   Extensions	  Extension enabling
	   InputDevice	  Input device description
	   InputClass	  Input class description
	   OutputClass	  Output class description
	   Device	  Graphics device description
	   VideoAdaptor	  Xv video adaptor description
	   Monitor	  Monitor description
	   Modes	  Video modes descriptions
	   Screen	  Screen configuration
	   ServerLayout	  Overall layout
	   DRI		  DRI-specific configuration
	   Vendor	  Vendor-specific configuration

       The  following obsolete section names are still recognised for compati-
       bility purposes.	 In new config files, the InputDevice  section	should
       be used instead.

	   Keyboard	  Keyboard configuration
	   Pointer	  Pointer/mouse configuration

       The old XInput section is no longer recognised.

       The ServerLayout sections are at the highest level.  They bind together
       the input and output devices that will be used in a session.  The input
       devices are described in the InputDevice sections.  Output devices usu-
       ally consist of multiple independent components (e.g., a graphics board
       and  a  monitor).   These multiple components are bound together in the
       Screen sections, and it is these that are referenced by the  ServerLay-
       out section.  Each Screen section binds together a graphics board and a
       monitor.	 The graphics boards are described in the Device sections, and
       the monitors are described in the Monitor sections.

       Config  file  keywords  are  case-insensitive,  and  "_" characters are
       ignored.	 Most strings (including Option names) are also	 case-insensi-
       tive, and insensitive to white space and "_" characters.

       Each  config  file  entry  usually  takes up a single line in the file.
       They consist of a keyword, which is possibly followed by	 one  or  more
       arguments,  with the number and types of the arguments depending on the
       keyword.	 The argument types are:

	   Integer     an integer number in decimal, hex or octal
	   Real	       a floating point number
	   String      a string enclosed in double quote marks (")

       Note: hex integer values must be prefixed with "0x", and	 octal	values
       with "0".

       A  special  keyword called Option may be used to provide free-form data
       to various components of the server.  The Option keyword	 takes	either
       one  or	two  string  arguments.	 The first is the option name, and the
       optional second argument is  the	 option	 value.	  Some	commonly  used
       option value types include:

	   Integer     an integer number in decimal, hex or octal
	   Real	       a floating point number
	   String      a sequence of characters
	   Boolean     a boolean value (see below)
	   Frequency   a frequency value (see below)

       Note  that  all	Option	values,	 not just strings, must be enclosed in
       quotes.

       Boolean options may optionally have a value specified.  When  no	 value
       is specified, the option's value is TRUE.  The following boolean option
       values are recognised as TRUE:

	   1, on, true, yes

       and the following boolean option values are recognised as FALSE:

	   0, off, false, no

       If an option name is prefixed with  "No",  then	the  option  value  is
       negated.

       Example: the following option entries are equivalent:

	   Option "Accel"   "Off"
	   Option "NoAccel"
	   Option "NoAccel" "On"
	   Option "Accel"   "false"
	   Option "Accel"   "no"

       Frequency  option  values  consist  of a real number that is optionally
       followed by one of the following frequency units:

	   Hz, k, kHz, M, MHz

       When the unit name is omitted, the correct  units  will	be  determined
       from  the  value	 and  the expectations of the appropriate range of the
       value.  It is recommended that the units always be specified when using
       frequency option values to avoid any errors in determining the value.

FILES SECTION
       The  Files  section  is used to specify some path names required by the
       server.	Some of these paths can also be set from the command line (see
       Xserver(1) and Xorg(1)).	 The command line settings override the values
       specified in the config file.  The Files section is  optional,  as  are
       all of the entries that may appear in it.

       The entries that can appear in this section are:

       FontPath "path"
	      sets  the search path for fonts.	This path is a comma separated
	      list of font path elements which the Xorg	 server	 searches  for
	      font databases.  Multiple FontPath entries may be specified, and
	      they will be concatenated to build up the fontpath used  by  the
	      server.	Font  path  elements  can be absolute directory paths,
	      catalogue directories or a font server identifier.  The  formats
	      of the later two are explained below:

	      Catalogue directories:

		  Catalogue directories can be specified using the prefix cat-
		  alogue: before the directory name. The directory can then be
		  populated  with  symlinks pointing to the real font directo-
		  ries, using the following syntax in the symlink name:

		      <identifier>:[attribute]:pri=<priority>

		  where	  <identifier>	 is   an   alphanumeric	   identifier,
		  [attribute]  is  an  attribute  which	 will be passed to the
		  underlying FPE and <priority> is a number used to order  the
		  fontfile FPEs. Examples:

		      75dpi:unscaled:pri=20 -> /usr/share/X11/fonts/75dpi
		      gscript:pri=60 -> /usr/share/fonts/default/ghostscript
		      misc:unscaled:pri=10 -> /usr/share/X11/fonts/misc

	      Font server identifiers:

		  Font server identifiers have the form:

		      <trans>/<hostname>:<port-number>

		  where <trans> is the transport type to use to connect to the
		  font server (e.g., unix for UNIX-domain sockets or tcp for a
		  TCP/IP  connection),	<hostname>  is	the  hostname  of  the
		  machine running the font server, and	<port-number>  is  the
		  port	number	that  the font server is listening on (usually
		  7100).

	      When this entry is not specified in the config file, the	server
	      falls  back to the compiled-in default font path, which contains
	      the following font path elements (which can be set inside a cat-
	      alogue directory):

		  /usr/share/fonts/X11/misc/
		  /usr/share/fonts/X11/TTF/
		  /usr/share/fonts/X11/OTF/
		  /usr/share/fonts/X11/Type1/
		  /usr/share/fonts/X11/100dpi/
		  /usr/share/fonts/X11/75dpi/

	      Font path elements that are found to be invalid are removed from
	      the font path when the server starts up.

       ModulePath "path"
	      sets the search path for loadable	 Xorg  server  modules.	  This
	      path  is	a  comma  separated list of directories which the Xorg
	      server searches for loadable modules loading in the order speci-
	      fied.   Multiple	ModulePath  entries may be specified, and they
	      will be concatenated to build the module search path used by the
	      server.  The default module path is

		  /usr/lib64/xorg/modules

       XkbDir "path"
	      sets  the base directory for keyboard layout files.  The -xkbdir
	      command line option can be used to override this.	  The  default
	      directory is

		  /usr/share/X11/xkb

SERVERFLAGS SECTION
       In  addition to options specific to this section (described below), the
       ServerFlags section is used to specify some global Xorg server options.
       All  of	the entries in this section are Options, although for compati-
       bility purposes some of the old style  entries  are  still  recognised.
       Those old style entries are not documented here, and using them is dis-
       couraged.  The ServerFlags section is optional, as are the entries that
       may be specified in it.

       Options	specified in this section (with the exception of the "Default-
       ServerLayout" Option) may be overridden by  Options  specified  in  the
       active ServerLayout section.  Options with command line equivalents are
       overridden when their command line equivalent  is  used.	  The  options
       recognised by this section are:

       Option "DefaultServerLayout"  "layout-id"
	      This  specifies  the  default ServerLayout section to use in the
	      absence of the -layout command line option.

       Option "NoTrapSignals"  "boolean"
	      This prevents the Xorg server from trapping  a  range  of	 unex-
	      pected  fatal  signals  and  exiting cleanly.  Instead, the Xorg
	      server will die and drop core where  the	fault  occurred.   The
	      default  behaviour  is  for the Xorg server to exit cleanly, but
	      still drop a core file.  In general you never want to  use  this
	      option  unless you are debugging an Xorg server problem and know
	      how to deal with the consequences.

       Option "UseSIGIO"  "boolean"
	      This controls whether the Xorg server requests that events  from
	      input devices be reported via a SIGIO signal handler (also known
	      as SIGPOLL on some platforms), or only reported via the standard
	      select(3)	 loop.	 The  default  behaviour is platform specific.
	      In general you do not want to use this  option  unless  you  are
	      debugging	 the  Xorg  server,  or	 working around a specific bug
	      until it is fixed, and understand the consequences.

       Option "DontVTSwitch"  "boolean"
	      This disallows the use of the  Ctrl+Alt+Fn  sequence  (where  Fn
	      refers  to one of the numbered function keys).  That sequence is
	      normally used to switch to another "virtual terminal" on operat-
	      ing  systems  that  have	this  feature.	 When  this  option is
	      enabled, that key sequence has no special meaning and is	passed
	      to clients.  Default: off.

       Option "DontZap"	 "boolean"
	      This  disallows the use of the Terminate_Server XKB action (usu-
	      ally on Ctrl+Alt+Backspace, depending  on	 XKB  options).	  This
	      action is normally used to terminate the Xorg server.  When this
	      option is enabled, the action has no effect.  Default: off.

       Option "DontZoom"  "boolean"
	      This  disallows  the  use	 of   the   Ctrl+Alt+Keypad-Plus   and
	      Ctrl+Alt+Keypad-Minus  sequences.	 These sequences allows you to
	      switch between video modes.  When this option is enabled,	 those
	      key sequences have no special meaning and are passed to clients.
	      Default: off.

       Option "DisableVidModeExtension"	 "boolean"
	      This disables the parts of the VidMode  extension	 used  by  the
	      xvidtune	client	that  can  be  used to change the video modes.
	      Default: the VidMode extension is enabled.

       Option "AllowNonLocalXvidtune"  "boolean"
	      This allows the xvidtune client (and other clients that use  the
	      VidMode extension) to connect from another host.	Default: off.

       Option "AllowMouseOpenFail"  "boolean"
	      This  tells the mousedrv(4) and vmmouse(4) drivers to not report
	      failure if the mouse device can't be opened/initialised.	It has
	      no effect on the evdev(4) or other drivers.  Default: false.

       Option "BlankTime"  "time"
	      sets  the	 inactivity timeout for the blank phase of the screen-
	      saver.  time is in minutes.  This	 is  equivalent	 to  the  Xorg
	      server's	-s flag, and the value can be changed at run-time with
	      xset(1).	Default: 10 minutes.

       Option "StandbyTime"  "time"
	      sets the inactivity timeout for the standby phase of DPMS	 mode.
	      time  is	in  minutes,  and the value can be changed at run-time
	      with xset(1).  Default: 10 minutes.  This is only	 suitable  for
	      VESA  DPMS  compatible monitors, and may not be supported by all
	      video drivers.  It is only enabled for  screens  that  have  the
	      "DPMS" option set (see the MONITOR section below).

       Option "SuspendTime"  "time"
	      sets  the inactivity timeout for the suspend phase of DPMS mode.
	      time is in minutes, and the value can  be	 changed  at  run-time
	      with  xset(1).   Default: 10 minutes.  This is only suitable for
	      VESA DPMS compatible monitors, and may not be supported  by  all
	      video  drivers.	It  is	only enabled for screens that have the
	      "DPMS" option set (see the MONITOR section below).

       Option "OffTime"	 "time"
	      sets the inactivity timeout for the  off	phase  of  DPMS	 mode.
	      time  is	in  minutes,  and the value can be changed at run-time
	      with xset(1).  Default: 10 minutes.  This is only	 suitable  for
	      VESA  DPMS  compatible monitors, and may not be supported by all
	      video drivers.  It is only enabled for  screens  that  have  the
	      "DPMS" option set (see the MONITOR section below).

       Option "MaxClients"  "integer"
	      Set  the	maximum	 number of clients allowed to connect to the X
	      server.  Acceptable values are 64, 128, 256 or 512.

       Option "Pixmap"	"bpp"
	      This sets the pixmap format to use for depth 24.	Allowed values
	      for  bpp	are  24 and 32.	 Default: 32 unless driver constraints
	      don't allow this (which is  rare).   Note:  some	clients	 don't
	      behave well when this value is set to 24.

       Option "NoPM"  "boolean"
	      Disables something to do with power management events.  Default:
	      PM enabled on platforms that support it.

       Option "Xinerama"  "boolean"
	      enable or disable XINERAMA extension.  Default is disabled.

       Option "AIGLX" "boolean"
	      enable or disable AIGLX. AIGLX is enabled by default.

       Option "IndirectGLX" "boolean"
	      enable or disable indirect GLX contexts. Indirect	 GLX  contexts
	      are enabled by default.

       Option "DRI2" "boolean"
	      enable or disable DRI2. DRI2 is disabled by default.

       Option "GlxVisuals" "string"
	      This  option  controls how many GLX visuals the GLX modules sets
	      up.  The default value is typical, which will setup up a typical
	      subset  of  the GLXFBConfigs provided by the driver as GLX visu-
	      als.  Other options are minimal, which will set up  the  minimal
	      set  allowed  by	the GLX specification and all which will setup
	      GLX visuals for all GLXFBConfigs.

       Option "UseDefaultFontPath" "boolean"
	      Include the default font path even if other paths are  specified
	      in xorg.conf. If enabled, other font paths are included as well.
	      Enabled by default.

       Option "IgnoreABI" "boolean"
	      Allow modules built for a	 different,  potentially  incompatible
	      version of the X server to load. Disabled by default.

       Option "AutoAddDevices" "boolean"
	      If  this	option is disabled, then no devices will be added from
	      the HAL or udev backends. Enabled by default.

       Option "AutoEnableDevices" "boolean"
	      If this option is disabled, then the devices will be added  (and
	      the  DevicePresenceNotify	 event	sent),	but  not enabled, thus
	      leaving policy up to the client.	Enabled by default.

       Option "AutoAddGPU" "boolean"
	      If this option is disabled, then no GPU devices  will  be	 added
	      from  the udev backend. Enabled by default. (May need to be dis-
	      abled to setup Xinerama).

       Option "Log" "string"
	      This option controls whether the log is flushed and/or synced to
	      disk  after  each	 message.   Possible values are flush or sync.
	      Unset by default.

MODULE SECTION
       The Module section is used to specify which Xorg server modules	should
       be  loaded.   This  section is ignored when the Xorg server is built in
       static form.  The type of modules normally loaded in this  section  are
       Xorg  server  extension	modules.   Most	 other module types are loaded
       automatically when they are needed via other  mechanisms.   The	Module
       section is optional, as are all of the entries that may be specified in
       it.

       Entries in this section may be in two forms.  The first and  most  com-
       monly  used  form  is an entry that uses the Load keyword, as described
       here:

       Load  "modulename"
	      This instructs the server to load the module called  modulename.
	      The  module name given should be the module's standard name, not
	      the module file name.  The standard name is case-sensitive,  and
	      does  not	 include  the "lib" or "cyg" prefixes, or the ".so" or
	      ".dll" suffixes.

	      Example: the DRI extension module can be loaded with the follow-
	      ing entry:

		  Load "dri"

       Disable	"modulename"
	      This  instructs the server to not load the module called module-
	      name.  Some modules are loaded by default	 in  the  server,  and
	      this  overrides that default. If a Load instruction is given for
	      the same module, it overrides the Disable	 instruction  and  the
	      module  is  loaded. The module name given should be the module's
	      standard name, not the  module  file  name.  As  with  the  Load
	      instruction,  the	 standard name is case-sensitive, and does not
	      include the "lib" prefix, or the ".a", ".o", or ".so" suffixes.

       The second form of entry is a  SubSection,  with	 the  subsection  name
       being the module name, and the contents of the SubSection being Options
       that are passed to the module when it is loaded.

       Example: the extmod module (which contains  a  miscellaneous  group  of
       server  extensions)  can be loaded, with the XFree86-DGA extension dis-
       abled by using the following entry:

	   SubSection "extmod"
	      Option  "omit XFree86-DGA"
	   EndSubSection

       Modules are searched for in each directory specified in the  ModulePath
       search  path, and in the drivers, extensions, input, internal, and mul-
       timedia subdirectories of each of those directories.   In  addition  to
       this,  operating	 system	 specific  subdirectories of all the above are
       searched first if they exist.

       To see what extension modules are available, check the extensions  sub-
       directory under:

	   /usr/lib64/xorg/modules

       The  "extmod", "dbe", "dri", "dri2", "glx", and "record" extension mod-
       ules are loaded automatically, if they  are  present,  unless  disabled
       with  "Disable"	entries.   It  is  recommended	that at very least the
       "extmod" extension module be loaded.  If it isn't, some	commonly  used
       server extensions (like the SHAPE extension) will not be available.

EXTENSIONS SECTION
       The Extensions section is used to specify which X11 protocol extensions
       should be enabled or disabled.  The Extensions section is optional,  as
       are all of the entries that may be specified in it.

       Entries	in  this section are listed as Option statements with the name
       of the extension as the first argument, and a boolean value as the sec-
       ond.   The extension name is case-sensitive, and matches the form shown
       in the output of "Xorg -extension ?".

	      Example: the MIT-SHM extension can be disabled with the  follow-
	      ing entry:

		  Section "Extensions"
		      Option "MIT-SHM" "Disable"
		  EndSection

INPUTDEVICE SECTION
       The  config  file  may  have  multiple  InputDevice sections.  Recent X
       servers employ HAL or udev backends for input  device  enumeration  and
       input  hotplugging.  It is usually not necessary to provide InputDevice
       sections in the xorg.conf if hotplugging is in use (i.e. AutoAddDevices
       is  enabled). If hotplugging is enabled, InputDevice sections using the
       mouse, kbd and vmmouse driver will be ignored.

       If hotplugging is disabled, there will normally be at  least  two:  one
       for  the	 core  (primary)  keyboard  and	 one for the core pointer.  If
       either of these two is missing, a default configuration for the missing
       ones will be used. In the absence of an explicitly specified core input
       device, the first InputDevice marked as CorePointer  (or	 CoreKeyboard)
       is  used.   If there is no match there, the first InputDevice that uses
       the "mouse" (or "kbd") driver is used.  The final fallback  is  to  use
       built-in	 default  configurations.  Currently the default configuration
       may not work as expected on all platforms.

       InputDevice sections have the following format:

	   Section "InputDevice"
	       Identifier "name"
	       Driver	  "inputdriver"
	       options
	       ...
	   EndSection

       The Identifier and Driver entries are required in all InputDevice  sec-
       tions.  All other entries are optional.

       The  Identifier	entry specifies the unique name for this input device.
       The Driver entry specifies the name of the driver to use for this input
       device.	 When  using  the  loadable  server,  the  input driver module
       "inputdriver" will be loaded for each active InputDevice	 section.   An
       InputDevice  section  is	 considered  active  if it is referenced by an
       active ServerLayout section, if it is referenced by  the	 -keyboard  or
       -pointer	 command  line options, or if it is selected implicitly as the
       core pointer or keyboard device in the absence of such explicit	refer-
       ences.  The most commonly used input drivers are evdev(4) on Linux sys-
       tems, and kbd(4) and mousedrv(4) on other platforms.

       InputDevice sections recognise some driver-independent  Options,	 which
       are described here.  See the individual input driver manual pages for a
       description of the device-specific options.

       Option "AutoServerLayout"  "boolean"
	      Always add the device to the ServerLayout section used  by  this
	      instance	of the server. This affects implied layouts as well as
	      explicit layouts specified in the configuration  and/or  on  the
	      command line.

       Option "CorePointer"
	      Deprecated, see Floating

       Option "CoreKeyboard"
	      Deprecated, see Floating

       Option "AlwaysCore"  "boolean"
	      Deprecated, see Floating

       Option "SendCoreEvents"	"boolean"
	      Deprecated, see Floating


       Option "Floating"  "boolean"
	      When  enabled,  the input device is set up floating and does not
	      report events through any master device or control a cursor. The
	      device  is only available to clients using the X Input Extension
	      API. This option is disabled  by	default.   The	options	 Core-
	      Pointer,	CoreKeyboard,  AlwaysCore, and SendCoreEvents, are the
	      inverse of option Floating (i.e.	SendCoreEvents "on" is equiva-
	      lent to Floating "off" ).

	      This  option controls the startup behavior only, a device may be
	      reattached or set floating at runtime.

       Option "TransformationMatrix" "a b c d e f g h i"
	      Specifies the  3x3  transformation  matrix  for  absolute	 input
	      devices. The input device will be bound to the area given in the
	      matrix.  In most configurations, "a" and "e" specify  the	 width
	      and  height  of the area the device is bound to, and "c" and "f"
	      specify the x and y offset of the area.  The value range is 0 to
	      1,  where	 1  represents the width or height of all root windows
	      together, 0.5 represents half the area, etc. The	values	repre-
	      sent  a  3x3  matrix,  with the first, second and third group of
	      three values representing the first, second and third row of the
	      matrix,  respectively.   The identity matrix is "1 0 0 0 1 0 0 0
	      1".

   POINTER ACCELERATION
       For pointing devices, the following options control how the pointer  is
       accelerated or decelerated with respect to physical device motion. Most
       of these can be adjusted at runtime, see the  xinput(1)	man  page  for
       details.	 Only  the  most  important acceleration options are discussed
       here.

       Option "AccelerationProfile"  "integer"
	      Select the profile. In layman's terms, the  profile  constitutes
	      the "feeling" of the acceleration. More formally, it defines how
	      the transfer function (actual acceleration as a function of cur-
	      rent  device velocity and acceleration controls) is constructed.
	      This is mainly a matter of personal preference.

	      0	     classic (mostly compatible)
	     -1	     none (only constant deceleration is applied)
	      1	     device-dependent
	      2	     polynomial (polynomial function)
	      3	     smooth linear (soft knee, then linear)
	      4	     simple (normal when slow, otherwise accelerated)
	      5	     power (power function)
	      6	     linear (more speed, more acceleration)
	      7	     limited (like linear, but maxes out at threshold)

       Option "ConstantDeceleration"  "real"
	      Makes the pointer go deceleration times slower than normal. Most
	      useful for high-resolution devices. A value between 0 and 1 will
	      speed up the pointer.

       Option "AdaptiveDeceleration"  "real"
	      Allows to actually decelerate the pointer when  going  slow.  At
	      most,  it	 will  be  adaptive deceleration times slower. Enables
	      precise pointer placement without sacrificing speed.

       Option "AccelerationScheme"  "string"
	      Selects the scheme, which is the underlying algorithm.

	      predictable   default algorithm (behaving more predictable)
	      lightweight   old acceleration code (as specified in the X protocol spec)
	      none	    no acceleration or deceleration

       Option "AccelerationNumerator"  "integer"

       Option "AccelerationDenominator"	 "integer"
	      Set numerator and denominator of the  acceleration  factor.  The
	      acceleration  factor  is a rational which, together with thresh-
	      old, can be used to tweak profiles to suit the users needs.  The
	      simple  and limited profiles use it directly (i.e. they acceler-
	      ate by the factor), for other profiles it	 should	 hold  that  a
	      higher acceleration factor leads to a faster pointer. Typically,
	      1 is unaccelerated and values up to 5 are sensible.

       Option "AccelerationThreshold"  "integer"
	      Set the threshold, which is roughly the velocity (usually device
	      units  per 10 ms) required for acceleration to become effective.
	      The precise effect varies with the profile however.


INPUTCLASS SECTION
       The config file may have multiple InputClass sections.  These  sections
       are optional and are used to provide configuration for a class of input
       devices as they are automatically added. An input device can match more
       than  one  InputClass  section. Each class can override settings from a
       previous class, so it is best to arrange the  sections  with  the  most
       generic matches first.

       InputClass sections have the following format:

	   Section "InputClass"
	       Identifier  "name"
	       entries
	       ...
	       options
	       ...
	   EndSection

       The Identifier entry is required in all InputClass sections.  All other
       entries are optional.

       The Identifier entry specifies the unique name for  this	 input	class.
       The Driver entry specifies the name of the driver to use for this input
       device.	After all classes have been examined, the "inputdriver" module
       from  the  first	 Driver	 entry will be enabled when using the loadable
       server.

       When an input device is automatically added,  its  characteristics  are
       checked	against	 all  InputClass  sections.  Each  section can contain
       optional entries to narrow the match of	the  class.  If	 none  of  the
       optional	 entries  appear,  the	InputClass section is generic and will
       match any input device. If more than one of these entries appear,  they
       all must match for the configuration to apply.

       There  are  two types of match entries used in InputClass sections. The
       first allows various tokens to be matched  against  attributes  of  the
       device.	An entry can be constructed to match attributes from different
       devices by separating arguments with a '|' character. Multiple  entries
       of the same type may be supplied to add multiple matching conditions on
       the same attribute. For example:

	   Section "InputClass"
	       Identifier   "My Class"
	       # product string must contain example and
	       # either gizmo or gadget
	       MatchProduct "example"
	       MatchProduct "gizmo|gadget"
	       ...
	   EndSection

       MatchProduct  "matchproduct"
	      This entry can be used to check if the substring	"matchproduct"
	      occurs in the device's product name.

       MatchVendor  "matchvendor"
	      This  entry  can be used to check if the substring "matchvendor"
	      occurs in the device's vendor name.

       MatchDevicePath "matchdevice"
	      This entry can be used to check if the device file  matches  the
	      "matchdevice" pathname pattern.

       MatchOS "matchos"
	      This  entry can be used to check if the operating system matches
	      the case-insensitive "matchos" string. This entry is  only  sup-
	      ported on platforms providing the uname(2) system call.

       MatchPnPID "matchpnp"
	      The  device's  Plug and Play (PnP) ID can be checked against the
	      "matchpnp" shell wildcard pattern.

       MatchUSBID "matchusb"
	      The device's USB ID can be checked against the "matchusb"	 shell
	      wildcard pattern. The ID is constructed as lowercase hexadecimal
	      numbers separated by a ':'. This	is  the	 same  format  as  the
	      lsusb(8) program.

       MatchDriver "matchdriver"
	      Check  the  case-sensitive string "matchdriver" against the cur-
	      rently configured driver of the  device.	Ordering  of  sections
	      using this entry is important since it will not match unless the
	      driver has been set by the config backend or a  previous	Input-
	      Class section.

       MatchTag "matchtag"
	      This  entry  can be used to check if tags assigned by the config
	      backend matches the "matchtag" pattern. A match is found	if  at
	      least  one  of the tags given in "matchtag" matches at least one
	      of the tags assigned by the backend.

       MatchLayout "matchlayout"
	      Check the case-sensitive string "matchlayout" against  the  cur-
	      rently  active ServerLayout section. The empty string "" matches
	      an implicit layout which appears if no named  ServerLayout  sec-
	      tions have been found.

       The  second  type of entry is used to match device types. These entries
       take a boolean argument similar to Option entries.

       MatchIsKeyboard	   "bool"

       MatchIsPointer	   "bool"

       MatchIsJoystick	   "bool"

       MatchIsTablet	   "bool"

       MatchIsTouchpad	   "bool"

       MatchIsTouchscreen  "bool"

       When an input device has been matched to the  InputClass	 section,  any
       Option  entries	are  applied  to  the  device. One InputClass specific
       Option is recognized. See the InputDevice section above for a  descrip-
       tion of the remaining Option entries.

       Option "Ignore" "boolean"
	      This  optional entry specifies that the device should be ignored
	      entirely, and not added to the server. This can be  useful  when
	      the  device is handled by another program and no X events should
	      be generated.

OUTPUTCLASS SECTION
       The config file may have multiple OutputClass sections.	These sections
       are  optional and are used to provide configuration for a class of out-
       put devices as they are automatically  added.   An  output  device  can
       match  more than one OutputClass section.  Each class can override set-
       tings from a previous class, so it is best to arrange the sections with
       the most generic matches first.

       OutputClass sections have the following format:

	   Section "OutputClass"
	       Identifier  "name"
	       entries
	       ...
	   EndSection

       The  Identifier	entry  is  required  in all OutputClass sections.  All
       other entries are optional.

       The Identifier entry specifies the unique name for this	output	class.
       The  Driver entry specifies the name of the driver to use for this out-
       put device.  After all classes have been examined,  the	"outputdriver"
       module from the first Driver entry will be enabled when using the load-
       able server.

       When an output device is automatically added, its  characteristics  are
       checked	against	 all  OutputClass  sections.  Each section can contain
       optional entries to narrow the match of the  class.   If	 none  of  the
       optional	 entries  appear,  the OutputClass section is generic and will
       match any output device.	 If more than one  of  these  entries  appear,
       they all must match for the configuration to apply.

       The  following  list of tokens can be matched against attributes of the
       device.	An entry can be constructed to match attributes from different
       devices by separating arguments with a '|' character.

       For example:

	   Section "OutputClass"
	       Identifier   "My Class"
	       # kernel driver must be either foo or bar
	       MatchDriver "foo|bar"
	       ...
	   EndSection

       MatchDriver "matchdriver"
	      Check the case-sensitive string "matchdriver" against the kernel
	      driver of the device.

DEVICE SECTION
       The config file may have multiple Device sections.  There  must	be  at
       least one, for the video card being used.

       Device sections have the following format:

	   Section "Device"
	       Identifier "name"
	       Driver	  "driver"
	       entries
	       ...
	   EndSection

       The  Identifier and Driver entries are required in all Device sections.
       All other entries are optional.

       The Identifier entry  specifies	the  unique  name  for	this  graphics
       device.	 The  Driver entry specifies the name of the driver to use for
       this graphics device.  When using the loadable server, the driver  mod-
       ule  "driver"  will be loaded for each active Device section.  A Device
       section is considered active if it is referenced by  an	active	Screen
       section.

       Device  sections recognise some driver-independent entries and Options,
       which  are  described  here.   Not  all	drivers	 make  use  of	 these
       driver-independent  entries,  and  many	of those that do don't require
       them to be specified because the information is auto-detected.  See the
       individual  graphics  driver manual pages for further information about
       this, and for a description of the device-specific options.  Note  that
       most  of	 the  Options  listed  here (but not the other entries) may be
       specified in the Screen section instead of here in the Device section.

       BusID  "bus-id"
	      This specifies the bus  location	of  the	 graphics  card.   For
	      PCI/AGP	 cards,	   the	  bus-id    string    has   the	  form
	      PCI:bus:device:function (e.g., "PCI:1:0:0" might be  appropriate
	      for an AGP card).	 This field is usually optional in single-head
	      configurations when using the primary graphics card.  In	multi-
	      head  configurations, or when using a secondary graphics card in
	      a single-head configuration, this entry is mandatory.  Its  main
	      purpose  is to make an unambiguous connection between the device
	      section and the hardware it is representing.   This  information
	      can usually be found by running the pciaccess tool scanpci.

       Screen  number
	      This option is mandatory for cards where a single PCI entity can
	      drive more than one display (i.e., multiple CRTCs sharing a sin-
	      gle  graphics accelerator and video memory).  One Device section
	      is required for each head, and this parameter  determines	 which
	      head  each  of the Device sections applies to.  The legal values
	      of number range from 0 to one less  than	the  total  number  of
	      heads  per entity.  Most drivers require that the primary screen
	      (0) be present.

       Chipset	"chipset"
	      This usually optional entry specifies the chipset	 used  on  the
	      graphics	board.	 In  most  cases  this	entry  is not required
	      because the drivers will probe the  hardware  to	determine  the
	      chipset type.  Don't specify it unless the driver-specific docu-
	      mentation recommends that you do.

       Ramdac  "ramdac-type"
	      This optional entry specifies the type of	 RAMDAC	 used  on  the
	      graphics	board.	This is only used by a few of the drivers, and
	      in most cases it is not required because the drivers will	 probe
	      the hardware to determine the RAMDAC type where possible.	 Don't
	      specify it unless the driver-specific  documentation  recommends
	      that you do.

       DacSpeed	 speed

       DacSpeed	 speed-8 speed-16 speed-24 speed-32
	      This  optional entry specifies the RAMDAC speed rating (which is
	      usually printed on the RAMDAC chip).  The speed is in MHz.  When
	      one  value  is given, it applies to all framebuffer pixel sizes.
	      When multiple values are given, they apply  to  the  framebuffer
	      pixel  sizes 8, 16, 24 and 32 respectively.  This is not used by
	      many drivers, and only needs to be specified when the speed rat-
	      ing  of  the  RAMDAC  is different from the defaults built in to
	      driver,  or  when	 the  driver  can't  auto-detect  the  correct
	      defaults.	  Don't specify it unless the driver-specific documen-
	      tation recommends that you do.

       Clocks  clock ...
	      specifies the pixel that are on your graphics board.  The clocks
	      are  in  MHz,  and  may be specified as a floating point number.
	      The value is stored internally to the nearest kHz.  The ordering
	      of  the  clocks  is important.  It must match the order in which
	      they are selected on the graphics board.	Multiple Clocks	 lines
	      may  be  specified,  and	each is concatenated to form the list.
	      Most drivers do not use this entry, and it is only required  for
	      some  older  boards with non-programmable clocks.	 Don't specify
	      this entry unless the driver-specific  documentation  explicitly
	      recommends that you do.

       ClockChip  "clockchip-type"
	      This  optional  entry  is used to specify the clock chip type on
	      graphics boards which have a programmable clock generator.  Only
	      a	 few  Xorg  drivers  support  programmable  clock  chips.  For
	      details, see the appropriate driver manual page.

       VideoRam	 mem
	      This optional entry specifies the amount of video	 ram  that  is
	      installed	 on  the  graphics board.  This is measured in kBytes.
	      In most cases this is  not  required  because  the  Xorg	server
	      probes  the  graphics  board  to	determine  this quantity.  The
	      driver-specific documentation should indicate when it  might  be
	      needed.

       BiosBase	 baseaddress
	      This optional entry specifies the base address of the video BIOS
	      for the VGA board.  This address is normally auto-detected,  and
	      should  only  be	specified if the driver-specific documentation
	      recommends it.

       MemBase	baseaddress
	      This optional entry specifies  the  memory  base	address	 of  a
	      graphics board's linear frame buffer.  This entry is not used by
	      many drivers, and it should only be specified if the driver-spe-
	      cific documentation recommends it.

       IOBase  baseaddress
	      This  optional  entry specifies the IO base address.  This entry
	      is not used by many drivers, and it should only be specified  if
	      the driver-specific documentation recommends it.

       ChipID  id
	      This  optional  entry  specifies a numerical ID representing the
	      chip type.  For PCI cards, it is usually the  device  ID.	  This
	      can be used to override the auto-detection, but that should only
	      be done when the driver-specific documentation recommends it.

       ChipRev	rev
	      This optional entry specifies the chip  revision	number.	  This
	      can be used to override the auto-detection, but that should only
	      be done when the driver-specific documentation recommends it.

       MatchSeat  seat-id
	      Only apply this Device section if	 X  server  was	 started  with
	      -seat seat-id option.

       Option "ModeDebug" "boolean"
	      Enable  printing of additional debugging information about mode-
	      setting to the server log.

       Options
	      Option flags may be specified in	the  Device  sections.	 These
	      include  driver-specific options and driver-independent options.
	      The former are described in the  driver-specific	documentation.
	      Some  of the latter are described below in the section about the
	      Screen section, and they may also be included here.


VIDEOADAPTOR SECTION
       Nobody wants to say how this works.  Maybe nobody knows ...


MONITOR SECTION
       The config file may have multiple Monitor sections.  There should  nor-
       mally  be  at least one, for the monitor being used, but a default con-
       figuration will be created when one isn't specified.

       Monitor sections have the following format:

	   Section "Monitor"
	       Identifier "name"
	       entries
	       ...
	   EndSection

       The only mandatory entry in a Monitor section is the Identifier entry.

       The Identifier entry specifies the unique name for this	monitor.   The
       Monitor section may be used to provide information about the specifica-
       tions of the monitor, monitor-specific Options, and  information	 about
       the video modes to use with the monitor.

       With  RandR  1.2-enabled	 drivers, monitor sections may be tied to spe-
       cific outputs of the video card.	 Using the name of the output  defined
       by the video driver plus the identifier of a monitor section, one asso-
       ciates a monitor section with an output by  adding  an  option  to  the
       Device section in the following format:

       Option "Monitor-outputname" "monitorsection"

       (for example, Option "Monitor-VGA" "VGA monitor" for a VGA output)

       In  the absence of specific association of monitor sections to outputs,
       if a monitor section is present the server will associate  it  with  an
       output  to  preserve  compatibility for previous single-head configura-
       tions.

       Specifying video modes is optional because the server will use the  DDC
       or other information provided by the monitor to automatically configure
       the list of modes available.  When modes are  specified	explicitly  in
       the  Monitor  section  (with the Mode, ModeLine, or UseModes keywords),
       built-in modes with the same names are not  included.   Built-in	 modes
       with different names are, however, still implicitly included, when they
       meet the requirements of the monitor.

       The entries that may be used in Monitor sections are described below.

       VendorName  "vendor"
	      This optional entry specifies the monitor's manufacturer.

       ModelName  "model"
	      This optional entry specifies the monitor's model.

       HorizSync  horizsync-range
	      gives the range(s) of horizontal sync frequencies	 supported  by
	      the  monitor.   horizsync-range may be a comma separated list of
	      either discrete values or ranges of values.  A range  of	values
	      is two values separated by a dash.  By default the values are in
	      units of kHz.  They may be specified in MHz or Hz if MHz	or  Hz
	      is added to the end of the line.	The data given here is used by
	      the Xorg server to determine if video modes are within the spec-
	      ifications of the monitor.  This information should be available
	      in the monitor's handbook.  If this entry is omitted, a  default
	      range of 28-33kHz is used.

       VertRefresh  vertrefresh-range
	      gives  the range(s) of vertical refresh frequencies supported by
	      the monitor.  vertrefresh-range may be a comma separated list of
	      either  discrete	values or ranges of values.  A range of values
	      is two values separated by a dash.  By default the values are in
	      units  of Hz.  They may be specified in MHz or kHz if MHz or kHz
	      is added to the end of the line.	The data given here is used by
	      the Xorg server to determine if video modes are within the spec-
	      ifications of the monitor.  This information should be available
	      in  the monitor's handbook.  If this entry is omitted, a default
	      range of 43-72Hz is used.

       DisplaySize  width height
	      This optional entry gives the width and height, in  millimetres,
	      of  the  picture	area of the monitor.  If given this is used to
	      calculate the horizontal and vertical pitch (DPI) of the screen.

       Gamma  gamma-value

       Gamma  red-gamma green-gamma blue-gamma
	      This is an optional entry that can be used to specify the	 gamma
	      correction  for  the  monitor.   It may be specified as either a
	      single value or as three separate RGB values.  The values should
	      be  in  the  range 0.1 to 10.0, and the default is 1.0.  Not all
	      drivers are capable of using this information.

       UseModes	 "modesection-id"
	      Include the set of modes listed in the Modes section called mod-
	      esection-id.   This  makes all of the modes defined in that sec-
	      tion available for use by this monitor.

       Mode  "name"
	      This is an optional multi-line entry that can be used to provide
	      definitions for video modes for the monitor.  In most cases this
	      isn't necessary because the built-in set of VESA standard	 modes
	      will  be	sufficient.  The Mode keyword indicates the start of a
	      multi-line video mode description.  The mode description is ter-
	      minated with the EndMode keyword.	 The mode description consists
	      of the following entries:

	      DotClock	clock
		  is the dot (pixel) clock rate to be used for the mode.

	      HTimings	hdisp hsyncstart hsyncend htotal
		  specifies the horizontal timings for the mode.

	      VTimings	vdisp vsyncstart vsyncend vtotal
		  specifies the vertical timings for the mode.

	      Flags  "flag" ...
		  specifies an optional set of mode flags, each of which is  a
		  separate  string  in	double	quotes.	 "Interlace" indicates
		  that the mode is interlaced.	"DoubleScan" indicates a  mode
		  where	 each  scanline is doubled.  "+HSync" and "-HSync" can
		  be  used  to	select	the  polarity  of  the	HSync  signal.
		  "+VSync"  and "-VSync" can be used to select the polarity of
		  the VSync signal.  "Composite" can be used to	 specify  com-
		  posite  sync on hardware where this is supported.  Addition-
		  ally, on some hardware, "+CSync" and "-CSync" may be used to
		  select the composite sync polarity.

	      HSkew  hskew
		  specifies  the  number  of pixels (towards the right edge of
		  the screen) by which the display  enable  signal  is	to  be
		  skewed.   Not all drivers use this information.  This option
		  might become necessary to override the  default  value  sup-
		  plied	 by  the  server  (if any).  "Roving" horizontal lines
		  indicate this value needs to be increased.  If the last  few
		  pixels on a scan line appear on the left of the screen, this
		  value should be decreased.

	      VScan  vscan
		  specifies the number of times each scanline  is  painted  on
		  the  screen.	 Not all drivers use this information.	Values
		  less than 1 are treated as 1, which is the default.	Gener-
		  ally,	 the  "DoubleScan"  Flag  mentioned above doubles this
		  value.

       ModeLine	 "name" mode-description
	      This entry is a more compact version of the Mode entry,  and  it
	      also  can	 be used to specify video modes for the monitor.  This
	      is a single line format for specifying  video  modes.   In  most
	      cases  this  isn't  necessary  because  the built-in set of VESA
	      standard modes will be sufficient.

	      The mode-description is in four sections,	 the  first  three  of
	      which  are mandatory.  The first is the dot (pixel) clock.  This
	      is a single number specifying the pixel clock rate for the  mode
	      in MHz.  The second section is a list of four numbers specifying
	      the horizontal timings.  These numbers  are  the	hdisp,	hsync-
	      start, hsyncend, and htotal values.  The third section is a list
	      of four numbers specifying the vertical timings.	These  numbers
	      are  the	vdisp,	vsyncstart,  vsyncend, and vtotal values.  The
	      final section is a list of flags specifying  other  characteris-
	      tics  of	the mode.  Interlace indicates that the mode is inter-
	      laced.  DoubleScan indicates a mode where each scanline is  dou-
	      bled.   +HSync  and -HSync can be used to select the polarity of
	      the HSync signal.	 +VSync and -VSync can be used to  select  the
	      polarity	of the VSync signal.  Composite can be used to specify
	      composite sync on hardware where this is	supported.   Addition-
	      ally,  on some hardware, +CSync and -CSync may be used to select
	      the composite sync polarity.  The HSkew and VScan	 options  men-
	      tioned  above  in	 the  Mode  entry description can also be used
	      here.

       Option "DPMS" "bool"
	      This option controls whether the server should enable  the  DPMS
	      extension	 for power management for this screen.	The default is
	      to enable the extension.

       Option "SyncOnGreen" "bool"
	      This option controls whether the video  card  should  drive  the
	      sync  signal on the green color pin.  Not all cards support this
	      option, and most monitors do not require	it.   The  default  is
	      off.

       Option "Primary" "bool"
	      This optional entry specifies that the monitor should be treated
	      as the primary monitor. (RandR 1.2-supporting drivers only)

       Option "PreferredMode" "name"
	      This optional entry specifies a mode to be marked	 as  the  pre-
	      ferred initial mode of the monitor.  (RandR 1.2-supporting driv-
	      ers only)

       Option "ZoomModes" "name name ..."
	      This optional entry specifies modes to be marked as zoom	modes.
	      It  is  possible	to  switch  to	the next and previous mode via
	      Ctrl+Alt+Keypad-Plus and Ctrl+Alt+Keypad-Minus.  All these  key-
	      pad  available  modes  are  selected  from the screen mode list.
	      This list is a copy of the  compatibility	 output	 monitor  mode
	      list.   Since  this output is the output connected to the lowest
	      dot-area monitor, as determined from its largest size mode, that
	      monitor defines the available zoom modes.	 (RandR 1.2-supporting
	      drivers only)

       Option "Position" "x y"
	      This optional entry specifies the position of the monitor within
	      the X screen.  (RandR 1.2-supporting drivers only)

       Option "LeftOf" "output"
	      This  optional  entry specifies that the monitor should be posi-
	      tioned to the left of the output	(not  monitor)	of  the	 given
	      name.  (RandR 1.2-supporting drivers only)

       Option "RightOf" "output"
	      This  optional  entry specifies that the monitor should be posi-
	      tioned to the right of the output (not  monitor)	of  the	 given
	      name.  (RandR 1.2-supporting drivers only)

       Option "Above" "output"
	      This  optional  entry specifies that the monitor should be posi-
	      tioned above the output (not monitor) of the given name.	(RandR
	      1.2-supporting drivers only)

       Option "Below" "output"
	      This  optional  entry specifies that the monitor should be posi-
	      tioned below the output (not monitor) of the given name.	(RandR
	      1.2-supporting drivers only)

       Option "Enable" "bool"
	      This  optional  entry  specifies	whether	 the monitor should be
	      turned on at startup.  By default, the server  will  attempt  to
	      enable  all  connected  monitors.	 (RandR 1.2-supporting drivers
	      only)

       Option "DefaultModes" "bool"
	      This optional entry specifies whether the server should add sup-
	      ported  default modes to the list of modes offered on this moni-
	      tor. By default, the server will add default modes;  you	should
	      only  disable this if you can guarantee that EDID will be avail-
	      able at all times, or if you have added custom  modelines	 which
	      the server can use.  (RandR 1.2-supporting drivers only)

       Option "MinClock" "frequency"
	      This  optional  entry  specifies	the minimum dot clock, in kHz,
	      that is supported by the monitor.

       Option "MaxClock" "frequency"
	      This optional entry specifies the maximum	 dot  clock,  in  kHz,
	      that is supported by the monitor.

       Option "Ignore" "bool"
	      This optional entry specifies that the monitor should be ignored
	      entirely, and not reported through RandR.	 This is useful if the
	      hardware	reports	 the  presence	of  outputs  that don't exist.
	      (RandR 1.2-supporting drivers only)

       Option "Rotate" "rotation"
	      This optional entry specifies the initial rotation of the	 given
	      monitor.	 Valid	values	for  rotation  are  "normal",  "left",
	      "right", and "inverted".	(RandR 1.2-supporting drivers only)


MODES SECTION
       The config file may have multiple Modes sections, or none.  These  sec-
       tions  provide  a  way of defining sets of video modes independently of
       the Monitor sections.  Monitor sections	may  include  the  definitions
       provided	 in  these  sections  by  using the UseModes keyword.  In most
       cases the Modes sections are not necessary because the built-in set  of
       VESA standard modes will be sufficient.

       Modes sections have the following format:

	   Section "Modes"
	       Identifier "name"
	       entries
	       ...
	   EndSection

       The  Identifier	entry  specifies  the unique name for this set of mode
       descriptions.  The other entries permitted in Modes  sections  are  the
       Mode  and ModeLine entries that are described above in the Monitor sec-
       tion.

SCREEN SECTION
       The config file may have multiple Screen sections.  There  must	be  at
       least  one,  for	 the  "screen"	being used.  A "screen" represents the
       binding of a graphics device (Device section) and  a  monitor  (Monitor
       section).   A Screen section is considered "active" if it is referenced
       by an active ServerLayout  section  or  by  the	-screen	 command  line
       option.	If neither of those is present, the first Screen section found
       in the config file is considered the active one.

       Screen sections have the following format:

	   Section "Screen"
	       Identifier "name"
	       Device	  "devid"
	       Monitor	  "monid"
	       entries
	       ...
	       SubSection "Display"
		  entries
		  ...
	       EndSubSection
	       ...
	   EndSection

       The Identifier entry is mandatory.  All others are optional.

       The Identifier entry specifies the unique name for  this	 screen.   The
       Screen  section	provides  information  specific	 to  the whole screen,
       including screen-specific Options.  In multi-head configurations, there
       will  be	 multiple  active  Screen  sections,  one  for each head.  The
       entries available for this section are:

       Device  "device-id"
	      This entry specifies the Device section  to  be  used  for  this
	      screen.	When multiple graphics cards are present, this is what
	      ties a specific card to a screen.	 The device-id must match  the
	      Identifier of a Device section in the config file.

       Monitor	"monitor-id"
	      specifies	 which	monitor	 description  is  to  be used for this
	      screen.  If a Monitor name is not specified, a default  configu-
	      ration  is  used.	  Currently  the default configuration may not
	      function as expected on all platforms.

       VideoAdaptor  "xv-id"
	      specifies an optional Xv video adaptor description  to  be  used
	      with this screen.

       DefaultDepth  depth
	      specifies	 which	color  depth the server should use by default.
	      The -depth command line option can be used to override this.  If
	      neither  is specified, the default depth is driver-specific, but
	      in most cases is 8.

       DefaultFbBpp  bpp
	      specifies which framebuffer  layout  to  use  by	default.   The
	      -fbbpp  command  line  option  can be used to override this.  In
	      most cases the driver will chose	the  best  default  value  for
	      this.   The only case where there is even a choice in this value
	      is for depth 24, where some hardware supports both a  packed  24
	      bit framebuffer layout and a sparse 32 bit framebuffer layout.

       MatchSeat  seat-id
	      Only  apply  this	 Screen	 section  if X server was started with
	      -seat seat-id option.

       Options
	      Various Option flags may be specified  in	 the  Screen  section.
	      Some  are	 driver-specific and are described in the driver docu-
	      mentation.  Others are driver-independent, and  will  eventually
	      be described here.

       Option "Accel"
	      Enables 2D hardware acceleration.	 This option is on by default,
	      but it may be necessary to turn it off if there are bugs in  the
	      driver.	There are many options to disable specific accelerated
	      operations, listed below.	 Note that disabling an operation will
	      have  no effect if the operation is not accelerated (whether due
	      to lack of support in the hardware or in the driver).

       Option "InitPrimary" "boolean"
	      Use the Int10 module to initialize the  primary  graphics	 card.
	      Normally,	 only  secondary cards are soft-booted using the Int10
	      module, as the primary card has already been initialized by  the
	      BIOS at boot time.  Default: false.

       Option "NoInt10" "boolean"
	      Disables	the Int10 module, a module that uses the int10 call to
	      the BIOS of the graphics card to initialize it.  Default: false.

       Each Screen section may optionally contain one or more Display  subsec-
       tions.	Those  subsections  provide depth/fbbpp specific configuration
       information, and the one chosen depends on the depth and/or fbbpp  that
       is  being  used	for  the  screen.   The	 Display  subsection format is
       described in the section below.


DISPLAY SUBSECTION
       Each  Screen  section  may  have	 multiple  Display  subsections.   The
       "active"	 Display subsection is the first that matches the depth and/or
       fbbpp values being used, or failing that, the first that has neither  a
       depth  or fbbpp value specified.	 The Display subsections are optional.
       When there isn't one that matches the depth and/or fbbpp	 values	 being
       used,  all the parameters that can be specified here fall back to their
       defaults.

       Display subsections have the following format:

	       SubSection "Display"
		   Depth  depth
		   entries
		   ...
	       EndSubSection

       Depth  depth
	      This entry specifies what colour depth the Display subsection is
	      to  be used for.	This entry is usually specified, but it may be
	      omitted to create a match-all Display subsection or when wishing
	      to  match	 only against the FbBpp parameter.  The range of depth
	      values that are allowed depends on  the  driver.	 Most  drivers
	      support  8,  15,	16  and 24.  Some also support 1 and/or 4, and
	      some may support other values (like 30).	Note: depth means  the
	      number  of  bits	in a pixel that are actually used to determine
	      the pixel colour.	 32 is not a valid depth value.	 Most hardware
	      that  uses  32  bits  per pixel only uses 24 of them to hold the
	      colour information, which means that the colour depth is 24, not
	      32.

       FbBpp  bpp
	      This entry specifies the framebuffer format this Display subsec-
	      tion is to be used for.  This entry is only needed when  provid-
	      ing depth 24 configurations that allow a choice between a 24 bpp
	      packed framebuffer format and a 32bpp sparse framebuffer format.
	      In most cases this entry should not be used.

       Weight  red-weight green-weight blue-weight
	      This  optional  entry specifies the relative RGB weighting to be
	      used for a screen is being used at depth	16  for	 drivers  that
	      allow  multiple  formats.	  This	may also be specified from the
	      command line with the -weight option (see Xorg(1)).

       Virtual	xdim ydim
	      This optional entry specifies the virtual screen	resolution  to
	      be  used.	  xdim	must  be a multiple of either 8 or 16 for most
	      drivers, and a multiple of 32 when running in  monochrome	 mode.
	      The  given  value	 will be rounded down if this is not the case.
	      Video modes which are too large for the specified	 virtual  size
	      will  be	rejected.   If	this entry is not present, the virtual
	      screen resolution will be set to accommodate all the valid video
	      modes  given in the Modes entry.	Some drivers/hardware combina-
	      tions do not support virtual screens.  Refer to the  appropriate
	      driver-specific documentation for details.

       ViewPort	 x0 y0
	      This  optional  entry  sets the upper left corner of the initial
	      display.	This is only relevant when the virtual screen  resolu-
	      tion is different from the resolution of the initial video mode.
	      If this entry is not given, then the  initial  display  will  be
	      centered in the virtual display area.

       Modes  "mode-name" ...
	      This  optional  entry  specifies the list of video modes to use.
	      Each mode-name specified must be in double  quotes.   They  must
	      correspond  to  those specified or referenced in the appropriate
	      Monitor section (including implicitly referenced	built-in  VESA
	      standard	modes).	  The  server will delete modes from this list
	      which don't satisfy various requirements.	 The first valid  mode
	      in  this list will be the default display mode for startup.  The
	      list of valid modes is  converted	 internally  into  a  circular
	      list.    It  is  possible	 to  switch  to	 the  next  mode  with
	      Ctrl+Alt+Keypad-Plus and to the previous mode with Ctrl+Alt+Key-
	      pad-Minus.   When	 this entry is omitted, the valid modes refer-
	      enced by the appropriate Monitor section will be used.   If  the
	      Monitor  section	contains  no modes, then the selection will be
	      taken from the built-in VESA standard modes.

       Visual  "visual-name"
	      This optional entry sets the default root visual type.  This may
	      also  be specified from the command line (see the Xserver(1) man
	      page).  The visual types available for depth 8 are  (default  is
	      PseudoColor):

		  StaticGray
		  GrayScale
		  StaticColor
		  PseudoColor
		  TrueColor
		  DirectColor

	      The  visual  type	 available  for	 the  depths 15, 16 and 24 are
	      (default is TrueColor):

		  TrueColor
		  DirectColor

	      Not all drivers support DirectColor at these depths.

	      The visual types available for the depth 4 are (default is Stat-
	      icColor):

		  StaticGray
		  GrayScale
		  StaticColor
		  PseudoColor

	      The  visual type available for the depth 1 (monochrome) is Stat-
	      icGray.

       Black  red green blue
	      This optional entry allows the "black" colour to	be  specified.
	      This is only supported at depth 1.  The default is black.

       White  red green blue
	      This  optional  entry allows the "white" colour to be specified.
	      This is only supported at depth 1.  The default is white.

       Options
	      Option flags may be specified in the Display subsections.	 These
	      may   include  driver-specific  options  and  driver-independent
	      options.	The former are described in the driver-specific	 docu-
	      mentation.   Some	 of the latter are described above in the sec-
	      tion about the Screen section, and they  may  also  be  included
	      here.

SERVERLAYOUT SECTION
       The  config  file  may  have multiple ServerLayout sections.  A "server
       layout" represents the binding of one or more screens (Screen sections)
       and one or more input devices (InputDevice sections) to form a complete
       configuration.  In multi-head configurations,  it  also	specifies  the
       relative	 layout	 of  the  heads.  A ServerLayout section is considered
       "active" if it is referenced by the -layout command line option	or  by
       an  Option  "DefaultServerLayout" entry in the ServerFlags section (the
       former takes precedence over the latter).  If  those  options  are  not
       used,  the  first ServerLayout section found in the config file is con-
       sidered the active one.	If no ServerLayout sections are	 present,  the
       single  active  screen and two active (core) input devices are selected
       as described in the relevant sections above.

       ServerLayout sections have the following format:

	   Section "ServerLayout"
	       Identifier   "name"
	       Screen	    "screen-id"
	       ...
	       InputDevice  "idev-id"
	       ...
	       options
	       ...
	   EndSection

       Each ServerLayout section must have an Identifier entry	and  at	 least
       one Screen entry.

       The  Identifier entry specifies the unique name for this server layout.
       The ServerLayout section provides information  specific	to  the	 whole
       session,	 including  session-specific Options.  The ServerFlags options
       (described above) may be specified here, and ones given	here  override
       those given in the ServerFlags section.

       The entries that may be used in this section are described here.

       Screen  screen-num "screen-id" position-information
	      One of these entries must be given for each screen being used in
	      a session.  The screen-id field is mandatory, and specifies  the
	      Screen  section  being  referenced.   The	 screen-num  field  is
	      optional, and may be  used  to  specify  the  screen  number  in
	      multi-head  configurations.   When  this	field  is omitted, the
	      screens will be numbered in the order that they are  listed  in.
	      The numbering starts from 0, and must be consecutive.  The posi-
	      tion-information field describes the way	multiple  screens  are
	      positioned.   There  are	a  number  of different ways that this
	      information can be provided:

	      x y

	      Absolute	x y
		  These both specify that the upper left corner's  coordinates
		  are  (x,y).	The  Absolute keyword is optional.  Some older
		  versions of XFree86 (4.2 and earlier)	 don't	recognise  the
		  Absolute keyword, so it's safest to just specify the coordi-
		  nates without it.

	      RightOf	"screen-id"

	      LeftOf	"screen-id"

	      Above	"screen-id"

	      Below	"screen-id"

	      Relative	"screen-id" x y
		  These give the screen's location relative to another screen.
		  The first four position the screen immediately to the right,
		  left, above or below the other screen.  When positioning  to
		  the  right  or  left, the top edges are aligned.  When posi-
		  tioning above or below, the left  edges  are	aligned.   The
		  Relative  form  specifies  the offset of the screen's origin
		  (upper left  corner)	relative  to  the  origin  of  another
		  screen.

       InputDevice  "idev-id" "option" ...
	      One of these entries should be given for each input device being
	      used in a session.  Normally at least two are required, one each
	      for  the	core pointer and keyboard devices.  If either of those
	      is missing, suitable InputDevice entries are searched for	 using
	      the  method  described  above  in	 the INPUTDEVICE section.  The
	      idev-id field is mandatory, and specifies the name of the Input-
	      Device  section being referenced.	 Multiple option fields may be
	      specified, each in double quotes.	 The  options  permitted  here
	      are  any	that  may  also	 be given in the InputDevice sections.
	      Normally only session-specific input  device  options  would  be
	      used here.  The most commonly used options are:

		  "CorePointer"
		  "CoreKeyboard"
		  "SendCoreEvents"

	      and  the	first two should normally be used to indicate the core
	      pointer and core keyboard devices respectively.

       MatchSeat  seat-id
	      Only apply this ServerLayout section if  X  server  was  started
	      with -seat seat-id option.

       Options
	      In  addition  to	the  following,	 any  option  permitted in the
	      ServerFlags section may also be specified here.  When  the  same
	      option  appears  in  both places, the value given here overrides
	      the one given in the ServerFlags section.

       Option "IsolateDevice"  "bus-id"
	      Restrict device resets to the specified bus-id.  See  the	 BusID
	      option  (described  in  DEVICE SECTION, above) for the format of
	      the bus-id parameter.   This  option  overrides  SingleCard,  if
	      specified.  At present, only PCI devices can be isolated in this
	      manner.

       Option "SingleCard"  "boolean"
	      As IsolateDevice, except that the bus ID of the first device  in
	      the layout is used.

       Here is an example of a ServerLayout section for a dual headed configu-
       ration with two mice:

	   Section "ServerLayout"
	       Identifier  "Layout 1"
	       Screen	   "MGA 1"
	       Screen	   "MGA 2" RightOf "MGA 1"
	       InputDevice "Keyboard 1" "CoreKeyboard"
	       InputDevice "Mouse 1"	"CorePointer"
	       InputDevice "Mouse 2"	"SendCoreEvents"
	       Option	   "BlankTime"	"5"
	   EndSection

DRI SECTION
       This optional section is used  to  provide  some	 information  for  the
       Direct Rendering Infrastructure.	 Details about the format of this sec-
       tion can be found on-line at <http://dri.freedesktop.org/>.

VENDOR SECTION
       The optional Vendor section may be used to provide vendor-specific con-
       figuration  information.	  Multiple Vendor sections may be present, and
       they may contain an Identifier entry and multiple  Option  flags.   The
       data therein is not used in this release.

SEE ALSO
       General: X(7), Xserver(1), Xorg(1), cvt(1), gtf(1).

       Not all modules or interfaces are available on all platforms.

       Display	 drivers:   apm(4),  ati(4),  chips(4),	 cirrus(4),  cyrix(4),
       fbdev(4), glide(4), glint(4),  i128(4),	i740(4),  imstt(4),  intel(4),
       mga(4),	neomagic(4),  nv(4), openchrome(4), r128(4), radeon(4), rendi-
       tion(4), savage(4), s3virge(4),	siliconmotion(4),  sis(4),  sisusb(4),
       sunbw2(4),  suncg14(4),	suncg3(4),  suncg6(4),	sunffb(4),  sunleo(4),
       suntcx(4),   tdfx(4),   trident(4),   tseng(4),	 vesa(4),   vmware(4),
       voodoo(4), wsfb(4), xgi(4), xgixp(4).

       Input drivers: acecad(4), citron(4), elographics(4), evdev(4), fpit(4),
       joystick(4),  kbd(4),  mousedrv(4),  mutouch(4),	 penmount(4),	synap-
       tics(4), vmmouse(4), void(4), wacom(4).

       Other modules and interfaces: exa(4), fbdevhw(4), v4l(4).

AUTHORS
       This    manual	 page	was   largely	rewritten   by	 David	 Dawes
       <dawes@xfree86.org>.



X Version 11		      xorg-server 1.17.4		  xorg.conf(5)