Provided by: xserver-xorg-core_21.1.16-1ubuntu1_amd64 
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 a directory reserved for system use. This is
to separate configuration files from the vendor or 3rd party packages from those of local administration.
These files are found in the following directory:
/usr/share/X11/xorg.conf.d
The xorg.conf and xorg.conf.d files are composed of a number of 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 "Debug" "string"
This comma-separated list provides a way to control various debugging switches from the config
file. At the moment the only defined value is dmabuf_capable which instructs glamor to enable
some unstable buffer management code.
Option "DefaultServerLayout" "layout-id"
This specifies the default ServerLayout section to use in the absence of the -layout command line
option.
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 "MaxClients" "integer"
Set the maximum number of clients allowed to connect to the X server. Acceptable values are 64,
128, 256 or 512.
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 "IndirectGLX" "boolean"
enable or disable indirect GLX contexts. Indirect GLX contexts are disabled 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 "AutoBindGPU" "boolean"
If enabled then secondary GPUs will be automatically set up as output-sinks and offload-sources.
Making e.g. laptop outputs connected only to the secondary GPU directly available for use without
needing to run "xrandr --setprovideroutputsource". Enabled by default.
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.
Option "AllowByteSwappedClients" "boolean"
Allow clients with a different byte-order than the server. Enabled 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"
NoMatchDriver "drivername"
...
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 above directives have equivalents for negative matching with the NoMatchProduct, NoMatchVendor,
NoMatchDevicePath, NoMatchOS, NoMatchPnPID, NoMatchUSBID, NoMatchDriver, NoMatchTag, and NoMatchLayout
directives. These NoMatch directives match if the subsequent match is not met by the device.
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"
MatchIsTabletPad "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.
When an output device has been matched to the OutputClass section, any Option entries are applied to the
device. One OutputClass specific Option is recognized. See the Device section below for a description of
the remaining Option entries.
Option "PrimaryGPU" "boolean"
This option specifies that the matched device should be treated as the primary GPU, replacing the
selection of the GPU used as output by the firmware. If multiple output devices match an
OutputClass section with the PrimaryGPU option set, the first one enumerated becomes the primary
GPU.
A OutputClass Section may contain ModulePath entries. When an output device matches an OutputClass
section, any ModulePath entries in that OutputClass are pre-pended to the search path for loadable Xorg
server modules. See ModulePath in the Files section for more info.
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@domain:device:function (e.g., “PCI:1@0:0:0” might be appropriate for an AGP
card). The "@domain" part can be left out for PCI domain 0. 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.
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.
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.
Option "NoOutputInitialSize" "width height"
Normally, the X server infers the initial screen size based on any connected outputs. However, if
no outputs are connected, the X server picks a default screen size of 1024 x 768. This option
overrides the default screen size to use when no outputs are connected. In contrast to the
"Virtual" Display SubSection entry, which applies unconditionally, "NoOutputInitialSize" is only
used if no outputs are detected when the X server starts.
Option "PreferCloneMode" "boolean"
If enabled, bring up monitors of a screen in clone mode instead of horizontal extended layout by
default. (Defaults to off; the video driver can change the default value, but this option can
always override it)
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"
GPUDevice "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.
GPUDevice "device-id"
This entry specifies the Device section to be used as a secondary GPU device for this screen.
When multiple graphics cards are present, this is what ties a specific secondary card to a screen.
The device-id must match the Identifier of a Device section in the config file. This can be
specified up to 4 times for a single screen.
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 "GlxVendorLibrary" "string"
This option specifies a space-separated list of OpenGL vendor libraries to use for the screen.
This may be used to select an alternate implementation for development, debugging, or alternate
feature sets. Default: mesa.
Option "InitPrimary" "boolean"
Use the Int10 module to initialize the primary graphics card. Normally, only secondary cards are
soft-booted using the Int10 module, as the primary card has already been initialized by the BIOS
at boot time. Default: false.
Option "NoInt10" "boolean"
Disables the Int10 module, a module that uses the int10 call to the BIOS of the graphics card to
initialize it. Default: false.
Each Screen section may optionally contain one or more Display 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 <https://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), libinput(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>.
X Version 11 xorg-server 21.1.16 xorg.conf(5)