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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
       mechanisms 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  parameters,  with  their  defaults,  are  described
       below.   Driver   and  module  specific  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
       directories 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
       directory 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  directories
       reserved for system use. These are to separate configuration files from
       the vendor or 3rd party packages from those  of  local  administration.
       These files are found in the following directories:

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

       The  xorg.conf  and  xorg.conf.d  files  are  composed  of  a number of
       sections which may be present in any order, or omitted to  use  default
       configuration 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
       compatibility 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
       usually 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
       ServerLayout  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-
       insensitive, 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
                  catalogue: before the directory name. The directory can then
                  be  populated  with  symlinks  pointing  to  the  real  font
                  directories, 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
              catalogue 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
              specified.   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/lib/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
       compatibility  purposes  some  of  the  old  style  entries  are  still
       recognised.  Those old style entries are not documented here, and using
       them is discouraged.  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
       "DefaultServerLayout" 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
              unexpected 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
              operating  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
              (usually 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
              screensaver.  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 "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 "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
              visuals.  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
              disabled 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
       commonly 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
              following entry:

                  Load "dri"

       Disable  "modulename"
              This  instructs  the  server  to  not  load  the  module  called
              modulename.  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
       disabled 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
       multimedia 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
       subdirectory under:

           /usr/lib/xorg/modules

       The “extmod”, “dbe”,  “dri”,  “dri2”,  “glx”,  and  “record”  extension
       modules  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
       second.  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
              following 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
       sections.  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
       references.  The most commonly used input drivers are evdev(4) on Linux
       systems, 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
              CorePointer, CoreKeyboard, AlwaysCore, and  SendCoreEvents,  are
              the  inverse  of  option  Floating (i.e.  SendCoreEvents "on" is
              equivalent 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
              represent 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
              current  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
              threshold,  can  be  used  to  tweak  profiles to suit the users
              needs. The simple and limited profiles  use  it  directly  (i.e.
              they  accelerate  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
              supported 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
              currently 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
              InputClass 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
              currently  active  ServerLayout  section.  The  empty  string ""
              matches  an  implicit  layout  which   appears   if   no   named
              ServerLayout sections 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
       description 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
       output devices as they are automatically added.  An output  device  can
       match  more  than  one  OutputClass  section.   Each class can override
       settings 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
       output  device.   After   all   classes   have   been   examined,   the
       "outputdriver"  module from the first Driver entry will be enabled when
       using the loadable 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
       module  "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
              single  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
              documentation 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
              rating  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
              documentation 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-
              specific 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.

       TextClockFreq  freq
              This optional entry specifies the pixel clock frequency that  is
              used  for  the regular text mode.  The frequency is specified in
              MHz.  This is rarely used.

       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
              modesetting 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
       normally  be  at  least  one, for the monitor being used, but a default
       configuration 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
       specifications  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
       specific outputs of the video card.   Using  the  name  of  the  output
       defined  by  the video driver plus the identifier of a monitor section,
       one associates 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
       configurations.

       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
              specifications  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
              specifications 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
              modesection-id.   This  makes  all  of the modes defined in that
              section 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
              terminated  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
                  composite   sync   on  hardware  where  this  is  supported.
                  Additionally, 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
                  supplied  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.
                  Generally,  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,
              hsyncstart, 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
              characteristics  of the mode.  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 composite sync on hardware where this  is  supported.
              Additionally, on some hardware, +CSync and -CSync may be used to
              select the composite sync polarity.  The HSkew and VScan options
              mentioned  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
              preferred  initial  mode  of the monitor.  (RandR 1.2-supporting
              drivers 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
              keypad  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
              positioned 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
              positioned 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
              positioned 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
              positioned 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
              supported  default  modes  to  the list of modes offered on this
              monitor. By default, the server  will  add  default  modes;  you
              should  only disable this if you can guarantee that EDID will be
              available 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
       sections 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
       section.

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
              configuration  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
              documentation.   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.

       Option "NoMTRR"
              Disables MTRR (Memory Type Range Register) support, a feature of
              modern  processors  which  can  improve  video  performance by a
              factor of up to 2.5.  Some hardware has buggy MTRR support,  and
              some  video  drivers  have  been  known to exhibit problems when
              MTRR's are used.

       Each  Screen  section  may  optionally  contain  one  or  more  Display
       subsections.     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
              subsection is to be used for.  This entry is  only  needed  when
              providing  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
              combinations 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
              resolution 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+Keypad-Minus.   When  this  entry is omitted, the valid
              modes referenced 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
              StaticColor):

                  StaticGray
                  GrayScale
                  StaticColor
                  PseudoColor

              The  visual  type  available  for  the  depth  1 (monochrome) is
              StaticGray.

       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
              documentation.   Some  of  the latter are described above in the
              section 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
       considered 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
              position-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
                  coordinates 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
                  positioning 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
              InputDevice  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
       configuration 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
       section can be found on-line at <http://dri.freedesktop.org/>.

VENDOR SECTION

       The optional Vendor section may  be  used  to  provide  vendor-specific
       configuration  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),
       rendition(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),
       synaptics(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>.



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