Tribblix: manual page: xorg.conf.4

xorg.conf(4) Device and Network Interfaces xorg.conf(4)

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

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

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

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

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

Section "SectionName"
SectionEntry
...
EndSection

The section names are:

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

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

Keyboard Keyboard configuration
Pointer Pointer/mouse configuration

The old XInput section is no longer recognised.

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

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

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

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

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

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

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

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

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

1, on, true, yes

and the following boolean option values are recognised as FALSE:

0, off, false, no

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

Example: the following option entries are equivalent:

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

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

Hz, k, kHz, M, MHz

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

FILES SECTION

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

The entries that can appear in this section are:

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

Catalogue directories:

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

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

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

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

Font server identifiers:

Font server identifiers have the form:

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

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

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

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

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

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

/usr/lib/xorg/modules/amd64

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

/usr/share/X11/xkb

SERVERFLAGS SECTION

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

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

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

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

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

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

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

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

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

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

Option "AllowMouseOpenFail" "boolean"
This tells the mousedrv(7) and vmmouse(7) drivers to not
report failure if the mouse device can't be
opened/initialised. It has no effect on the evdev(7) or other
drivers. Default: false.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

MODULE SECTION

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

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

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

Example: the DRI extension module can be loaded with the
following entry:

Load "dri"

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

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

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

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

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

To see what extension modules are available, check the extensions
subdirectory under:

/usr/lib/xorg/modules/amd64

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(7) on Linux systems, and kbd(7) and mousedrv(7) on other
platforms.

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

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

Option "CorePointer"
Deprecated, see Floating

Option "CoreKeyboard"
Deprecated, see Floating

Option "AlwaysCore" "boolean"
Deprecated, see Floating

Option "SendCoreEvents" "boolean"
Deprecated, see Floating

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

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

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

POINTER ACCELERATION

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

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

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

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

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

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

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

Option "AccelerationNumerator" "integer"

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

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

INPUTCLASS SECTION

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

InputClass sections have the following format:

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

MatchIsKeyboard "bool"

MatchIsPointer "bool"

MatchIsJoystick "bool"

MatchIsTablet "bool"

MatchIsTouchpad "bool"

MatchIsTouchscreen "bool"

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

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

OUTPUTCLASS SECTION

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

OutputClass sections have the following format:

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

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

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

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

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

For example:

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

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

DEVICE SECTION

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

Device sections have the following format:

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

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

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

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

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

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

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

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

DacSpeed speed

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

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

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

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

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

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

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

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

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

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

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

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

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

VIDEOADAPTOR SECTION

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

MONITOR SECTION

The config file may have multiple Monitor sections. There should
normally be at least one, for the monitor being used, but a default
configuration will be created when one isn't specified.

Monitor sections have the following format:

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

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

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

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

Option "Monitor-outputname" "monitorsection"

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

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

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

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

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

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

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

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

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

Gamma gamma-value

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

MODES SECTION

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

Modes sections have the following format:

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

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

SCREEN SECTION

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

Screen sections have the following format:

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

The Identifier entry is mandatory. All others are optional.

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

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

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

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

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

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

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

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

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

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

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

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

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

DISPLAY SUBSECTION

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

Display subsections have the following format:

SubSection "Display"
Depth depth
entries
...
EndSubSection

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

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

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

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

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

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

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

StaticGray
GrayScale
StaticColor
PseudoColor
TrueColor
DirectColor

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

TrueColor
DirectColor

Not all drivers support DirectColor at these depths.

The visual types available for the depth 4 are (default is
StaticColor):

StaticGray
GrayScale
StaticColor
PseudoColor

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

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

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

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

SERVERLAYOUT SECTION

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

ServerLayout sections have the following format:

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

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

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

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

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

x y

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

RightOf "screen-id"

LeftOf "screen-id"

Above "screen-id"

Below "screen-id"

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

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

"CorePointer"
"CoreKeyboard"
"SendCoreEvents"

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

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

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

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

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

Here is an example of a ServerLayout section for a dual headed
configuration with two mice:

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

DRI SECTION

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

VENDOR SECTION

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

AUTHORS

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

X Version 11 xorg-server 1.16.4 xorg.conf(4)