xorg.conf

xorg.conf(5x)                                                      xorg.conf(5x)



NAME
       xorg.conf - Configuration File for Xorg

INTRODUCTION
       Xorg supports several mechanisms for supplying/obtaining configuration
       and run-time parameters: command line options, environment variables, the
       xorg.conf configuration file, 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(1x) and Xorg(1x) 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 for its initial setup.
       This 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-4
           /etc/X11/xorg.conf
           /etc/xorg.conf
           /usr/etc/X11/xorg.conf.<hostname>
           /usr/etc/X11/xorg.conf-4
           /usr/etc/X11/xorg.conf
           /usr/lib/X11/xorg.conf.<hostname>
           /usr/lib/X11/xorg.conf-4
           /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
           $HOME/xorg.conf
           /etc/X11/xorg.conf-4
           /etc/X11/xorg.conf
           /etc/xorg.conf
           /usr/etc/X11/xorg.conf.<hostname>
           /usr/etc/X11/xorg.conf-4
           /usr/etc/X11/xorg.conf
           /usr/lib/X11/xorg.conf.<hostname>
           /usr/lib/X11/xorg.conf-4
           /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).

       The xorg.conf file is composed of a number of sections which may be
       present in any order.  Each section has the form:

           Section  "SectionName"
               SectionEntry
               ...
           EndSection

       The section names are:

           Files          File pathnames
           ServerFlags    Server flags
           Module         Dynamic module loading
           InputDevice    Input device 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(1x) and Xorg(1x)).  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 may be either absolute directory paths, or a
              font server identifier.  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:

                  /usr/lib/X11/fonts/misc/
                  /usr/lib/X11/fonts/TTF/
                  /usr/lib/X11/fonts/Type1/
                  /usr/lib/X11/fonts/CID/
                  /usr/lib/X11/fonts/75dpi/
                  /usr/lib/X11/fonts/100dpi/

              The recommended font path contains the following font path
              elements:

                  /usr/lib/X11/fonts/local/
                  /usr/lib/X11/fonts/misc/
                  /usr/lib/X11/fonts/75dpi/:unscaled
                  /usr/lib/X11/fonts/100dpi/:unscaled
                  /usr/lib/X11/fonts/Type1/
                  /usr/lib/X11/fonts/CID/
                  /usr/lib/X11/fonts/Speedo/
                  /usr/lib/X11/fonts/75dpi/
                  /usr/lib/X11/fonts/100dpi/

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

       RGBPath "path"
              sets the path name for the RGB color database.  When this entry is
              not specified in the config file, the server falls back to the
              compiled-in default RGB path, which is:

                  /usr/lib/X11/rgb

       Note that an implicit .txt is added to this path if the server was
       compiled to use text rather than binary format RGB color databases.

       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.

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 "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 Ctrl+Alt+Backspace sequence.  That
              sequence is normally used to terminate the Xorg server.  When this
              option is enabled, that key sequence has no special meaning and is
              passed to clients.  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 "DisableModInDev"  "boolean"
              This disables the parts of the Xorg-Misc extension that can be
              used to modify the input device settings dynamically.  Default:
              that functionality is enabled.

       Option "AllowNonLocalModInDev"  "boolean"
              This allows a client to connect from another host and change
              keyboard and mouse settings in the running server.  Default: off.

       Option "AllowMouseOpenFail"  "boolean"
              This allows the server to start up even if the mouse device can't
              be opened/initialised.  Default: false.

       Option "VTInit"  "command"
              Runs command after the VT used by the server has been opened.  The
              command string is passed to "/bin/sh -c", and is run with the real
              user's id with stdin and stdout set to the VT.  The purpose of
              this option is to allow system dependent VT initialisation
              commands to be run.  This option should rarely be needed.
              Default: not set.

       Option "VTSysReq"  "boolean"
              enables the SYSV-style VT switch sequence for non-SYSV systems
              which support VT switching.  This sequence is Alt-SysRq followed
              by a function key (Fn).  This prevents the Xorg server trapping
              the keys used for the default VT switch sequence, which means that
              clients can access them.  Default: off.

       Option "XkbDisable" "boolean"
              disable/enable the XKEYBOARD extension.  The -kb command line
              option overrides this config file option.  Default: XKB is
              enabled.

       Option "BlankTime"  "time"
              sets the inactivity timeout for the blanking 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(1x).  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(1x).  Default: 20 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(1x).  Default: 30 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(1x).  Default: 40 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 "PC98"  "boolean"
              Specify that the machine is a Japanese PC-98 machine.  This should
              not be enabled for anything other than the Japanese-specific PC-98
              architecture.  Default: auto-detected.

       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 "AllowDeactivateGrabs" "boolean"
              This option enables the use of the Ctrl+Alt+Keypad-Divide key
              sequence to deactivate any active keyboard and mouse grabs.
              Default: off.

       Option "AllowClosedownGrabs" "boolean"
              This option enables the use of the Ctrl+Alt+Keypad-Multiply key
              sequence to kill clients with an active keyboard or mouse grab as
              well as killing any application that may have locked the server,
              normally using the XGrabServer(3x) Xlib function.  Default: off.
              Note that the options AllowDeactivateGrabs and AllowClosedownGrabs
              will allow users to remove the grab used by screen saver/locker
              programs.  An API was written to such cases. If you enable this
              option, make sure your screen saver/locker is updated.

       Option "HandleSpecialKeys" "when"
              This option controls when the server uses the builtin handler to
              process special key combinations (such as Ctrl+Alt+Backspace).
              Normally the XKEYBOARD extension keymaps will provide mappings for
              each of the special key combinations, so the builtin handler is
              not needed unless the XKEYBOARD extension is disabled.  The value
              of when can be Always, Never, or WhenNeeded.  Default: Use the
              builtin handler only if needed.  The server will scan the keymap
              for a mapping to the Terminate action and, if found, use XKEYBOARD
              for processing actions, otherwise the builtin handler will be
              used.

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 types of modules normally loaded in this section are Xorg
       server extension modules, and font rasteriser 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" prefix, or the ".a", ".o", or ".so"
              suffixes.

              Example: the Type 1 font rasteriser can be loaded with the
              following entry:

                  Load "type1"

       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 Xorg-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, input, extensions, fonts, and internal
       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 font and extension modules are available, check the contents
       of the following directories:

           /usr/lib/modules/fonts
           /usr/lib/modules/extensions

       The "bitmap" font modules is loaded automatically.  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.

INPUTDEVICE SECTION
       The config file may have multiple InputDevice sections.  There will
       normally be at least two: one for the core (primary) keyboard, and one of
       the core pointer.  If either of these two is missing, a default
       configuration for the missing ones will be used.  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 "keyboard" and "mouse".

       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
       "keyboard" or "kbd") driver is used.  The final fallback is to use built-
       in default configurations.

       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 "CorePointer"
              When this is set, the input device is installed as the core
              (primary) pointer device.  There must be exactly one core pointer.
              If this option is not set here, or in the ServerLayout section, or
              from the -pointer command line option, then the first input device
              that is capable of being used as a core pointer will be selected
              as the core pointer.  This option is implicitly set when the
              obsolete Pointer section is used.

       Option "CoreKeyboard"
              When this is set, the input device is to be installed as the core
              (primary) keyboard device.  There must be exactly one core
              keyboard.  If this option is not set here, in the ServerLayout
              section, or from the -keyboard command line option, then the first
              input device that is capable of being used as a core keyboard will
              be selected as the core keyboard.  This option is implicitly set
              when the obsolete Keyboard section is used.

       Option "AlwaysCore"  "boolean"

       Option "SendCoreEvents"  "boolean"
              Both of these options are equivalent, and when enabled cause the
              input device to always report core events.  This can be used, for
              example, to allow an additional pointer device to generate core
              pointer events (like moving the cursor, etc).

       Option "HistorySize"  "number"
           Sets the motion history size.  Default: 0.

       Option "SendDragEvents"  "boolean"
              ???

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 Xorg server with the -scanpci command line option.

       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 give, 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.

       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 provides information about the specifications of the
       monitor, monitor-specific Options, and information about the video modes
       to use with the monitor.  Specifying video modes is optional because the
       server now has a built-in list of VESA standard modes.  When modes are
       specified explicitly in the Monitor section (with the Modes, 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.

       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 make 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.  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
              Modes entry description can also be used here.

       Options
              Some Option flags that may be useful to include in Monitor
              sections (when needed) include "DPMS", and "SyncOnGreen".


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 and Device entries are 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 mandatory entry specifies the Device section to be used for
              this screen.  This is what ties a specific graphics 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.

       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 XAA (X Acceleration Architecture), a mechanism that makes
              video cards' 2D hardware acceleration available to the Xorg
              server.  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 "BiosLocation" "address"
              Set the location of the BIOS for the Int10 module. One may select
              a BIOS of another card for posting or the legacy V_BIOS range
              located at 0xc0000 or an alternative address (BUS_ISA).  This is
              only useful under very special circumstances and should be used
              with extreme care.

       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.

       Option "XaaNoCPUToScreenColorExpandFill"
              Disables accelerated rectangular expansion blits from source
              patterns stored in system memory (using a memory-mapped aperture).

       Option "XaaNoColor8x8PatternFillRect"
              Disables accelerated fills of a rectangular region with a full-
              color pattern.

       Option "XaaNoColor8x8PatternFillTrap"
              Disables accelerated fills of a trapezoidal region with a full-
              color pattern.

       Option "XaaNoDashedBresenhamLine"
              Disables accelerated dashed Bresenham line draws.

       Option "XaaNoDashedTwoPointLine"
              Disables accelerated dashed line draws between two arbitrary
              points.

       Option "XaaNoImageWriteRect"
              Disables accelerated transfers of full-color rectangular patterns
              from system memory to video memory (using a memory-mapped
              aperture).

       Option "XaaNoMono8x8PatternFillRect"
              Disables accelerated fills of a rectangular region with a
              monochrome pattern.

       Option "XaaNoMono8x8PatternFillTrap"
              Disables accelerated fills of a trapezoidal region with a
              monochrome pattern.

       Option "XaaNoOffscreenPixmaps"
              Disables accelerated draws into pixmaps stored in offscreen video
              memory.

       Option "XaaNoPixmapCache"
              Disables caching of patterns in offscreen video memory.

       Option "XaaNoScanlineCPUToScreenColorExpandFill"
              Disables accelerated rectangular expansion blits from source
              patterns stored in system memory (one scan line at a time).

       Option "XaaNoScanlineImageWriteRect"
              Disables accelerated transfers of full-color rectangular patterns
              from system memory to video memory (one scan line at a time).

       Option "XaaNoScreenToScreenColorExpandFill"
              Disables accelerated rectangular expansion blits from source
              patterns stored in offscreen video memory.

       Option "XaaNoScreenToScreenCopy"
              Disables accelerated copies of rectangular regions from one part
              of video memory to another part of video memory.

       Option "XaaNoSolidBresenhamLine"
              Disables accelerated solid Bresenham line draws.

       Option "XaaNoSolidFillRect"
              Disables accelerated solid-color fills of rectangles.

       Option "XaaNoSolidFillTrap"
              Disables accelerated solid-color fills of Bresenham trapezoids.

       Option "XaaNoSolidHorVertLine"
              Disables accelerated solid horizontal and vertical line draws.

       Option "XaaNoSolidTwoPointLine"
              Disables accelerated solid line draws between two arbitrary
              points.

       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 driver
              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(1x)).

       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(1x) 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 Xorg (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.

       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.

FILES
       For an example of an xorg.conf file, see the file installed as
       /usr/lib/X11/xorg.conf.eg.

SEE ALSO
       X(7), Xserver(1x), Xorg(1x), apm(4), chips(4), cirrus(4), cyrix(4),
       fbdev(4), glide(4), glint(4), i128(4), i740(4), i810(4), imstt(4),
       mga(4), neomagic(4), nv(4), r128(4), rendition(4), savage(4), s3virge(4),
       siliconmotion(4), sis(4), sunbw2(4), suncg14(4), suncg3(4), suncg6(4),
       sunffb(4), sunleo(4), suntcx(4), tdfx(4), tga(4), trident(4), tseng(4),
       v4l(4), vesa(4), vga(4), vmware(4),

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



X Version 11                    xorg-server 1.1.1                  xorg.conf(5x)