xorg.conf(5)xorg.conf(5)NAMExorg.conf - configuration File 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 configuration file, auto-detection, and fallback
defaults. When the same information is supplied in more than one way,
the highest precedence mechanism is used. The list of mechanisms is
ordered from highest precedence to lowest. Note that not all parame‐
ters 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 mod‐
ule specific configuration parameters are described in the relevant
driver or module manual page.
DESCRIPTION
Xorg uses a configuration file called xorg.conf for its initial setup.
This configuration file is searched for in the following places when
the server is started as a normal user:
/etc/X11/<cmdline>
/usr/X11R6/etc/X11/<cmdline>
/etc/X11/$XORGCONFIG
/usr/X11R6/etc/X11/$XORGCONFIG
/etc/X11/xorg.conf-4
/etc/X11/xorg.conf
/etc/xorg.conf
/usr/X11R6/etc/X11/xorg.conf.<hostname>
/usr/X11R6/etc/X11/xorg.conf-4
/usr/X11R6/etc/X11/xorg.conf
/usr/X11R6/lib/X11/xorg.conf.<hostname>
/usr/X11R6/lib/X11/xorg.conf-4
/usr/X11R6/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/X11R6/etc/X11/<cmdline>
$XORGCONFIG
/etc/X11/$XORGCONFIG
/usr/X11R6/etc/X11/$XORGCONFIG
/etc/X11/xorg.conf-4
/etc/X11/xorg.conf
/etc/xorg.conf
/usr/X11R6/etc/X11/xorg.conf.<hostname>
/usr/X11R6/etc/X11/xorg.conf-4
/usr/X11R6/etc/X11/xorg.conf
/usr/X11R6/lib/X11/xorg.conf.<hostname>
/usr/X11R6/lib/X11/xorg.conf-4
/usr/X11R6/lib/X11/xorg.conf
where <cmdline> is the path specified with the -config command line
option (which may be absolute or relative), $XORGCONFIG is the path
specified by that environment variable (absolute or relative), $HOME is
the path specified by that environment variable (usually the home
directory), and <hostname> is the machine's hostname as reported by
gethostname(3).
The xorg.conf file is composed of a number of sections which may be
present in any order. Each section has the form:
Section "SectionName"
SectionEntry
...
EndSection
The section names are:
Files File pathnames
ServerFlags Server flags
Module Dynamic module loading
Extensions Extension enabling
InputDevice Input device description
Device Graphics device description
VideoAdaptor Xv video adaptor description
Monitor Monitor description
Modes Video modes descriptions
Screen Screen configuration
ServerLayout Overall layout
DRI DRI-specific configuration
Vendor Vendor-specific configuration
The following obsolete section names are still recognised for compati‐
bility purposes. In new config files, the InputDevice section should
be used instead.
Keyboard Keyboard configuration
Pointer Pointer/mouse configuration
The old XInput section is no longer recognised.
The ServerLayout sections are at the highest level. They bind together
the input and output devices that will be used in a session. The input
devices are described in the InputDevice sections. Output devices usu‐
ally consist of multiple independent components (e.g., a graphics board
and a monitor). These multiple components are bound together in the
Screen sections, and it is these that are referenced by the ServerLay‐
out section. Each Screen section binds together a graphics board and a
monitor. The graphics boards are described in the Device sections, and
the monitors are described in the Monitor sections.
Config file keywords are case-insensitive, and “_” characters are
ignored. Most strings (including Option names) are also case-insensi‐
tive, and insensitive to white space and “_” characters.
Each config file entry usually takes up a single line in the file.
They consist of a keyword, which is possibly followed by one or more
arguments, with the number and types of the arguments depending on the
keyword. The argument types are:
Integer an integer number in decimal, hex or octal
Real a floating point number
String a string enclosed in double quote marks (")
Note: hex integer values must be prefixed with “0x”, and octal values
with “0”.
A special keyword called Option may be used to provide free-form data
to various components of the server. The Option keyword takes either
one or two string arguments. The first is the option name, and the
optional second argument is the option value. Some commonly used
option value types include:
Integer an integer number in decimal, hex or octal
Real a floating point number
String a sequence of characters
Boolean a boolean value (see below)
Frequency a frequency value (see below)
Note that all Option values, not just strings, must be enclosed in
quotes.
Boolean options may optionally have a value specified. When no value
is specified, the option's value is TRUE. The following boolean option
values are recognised as TRUE:
1, on, true, yes
and the following boolean option values are recognised as FALSE:
0, off, false, no
If an option name is prefixed with "No", then the option value is
negated.
Example: the following option entries are equivalent:
Option "Accel" "Off"
Option "NoAccel"
Option "NoAccel" "On"
Option "Accel" "false"
Option "Accel" "no"
Frequency option values consist of a real number that is optionally
followed by one of the following frequency units:
Hz, k, kHz, M, MHz
When the unit name is omitted, the correct units will be determined
from the value and the expectations of the appropriate range of the
value. It is recommended that the units always be specified when using
frequency option values to avoid any errors in determining the value.
FILES SECTION
The Files section is used to specify some path names required by the
server. Some of these paths can also be set from the command line (see
Xserver(1) and Xorg(1)). The command line settings override the values
specified in the config file. The Files section is optional, as are
all of the entries that may appear in it.
The entries that can appear in this section are:
FontPath "path"
sets the search path for fonts. This path is a comma separated
list of font path elements which the Xorg server searches for
font databases. Multiple FontPath entries may be specified, and
they will be concatenated to build up the fontpath used by the
server. Font path elements can be absolute directory paths,
catalogue directories or a font server identifier. The formats
of the later two are explained below:
Catalogue directories:
Catalogue directories can be specified using the prefix cat‐
alogue: before the directory name. The directory can then be
populated with symlinks pointing to the real font directo‐
ries, using the following syntax in the symlink name:
<identifier>:[attribute]:pri=<priority>
where <identifier> is an alphanumeric identifier,
[attribute] is an attribute which will be passed to the
underlying FPE and <priority> is a number used to order the
fontfile FPEs. Examples:
75dpi:unscaled:pri=20 -> /usr/share/X11/fonts/75dpi
gscript:pri=60 -> /usr/share/fonts/default/ghostscript
misc:unscaled:pri=10 -> /usr/share/X11/fonts/misc
Font server identifiers:
Font server identifiers have the form:
<trans>/<hostname>:<port-number>
where <trans> is the transport type to use to connect to the
font server (e.g., unix for UNIX-domain sockets or tcp for a
TCP/IP connection), <hostname> is the hostname of the
machine running the font server, and <port-number> is the
port number that the font server is listening on (usually
7100).
When this entry is not specified in the config file, the server
falls back to the compiled-in default font path, which contains
the following font path elements (which can be set inside a cat‐
alogue directory):
/usr/X11R6/lib/X11/fonts/misc/
/usr/X11R6/lib/X11/fonts/TTF/
/usr/X11R6/lib/X11/fonts/Type1/
/usr/X11R6/lib/X11/fonts/75dpi/
/usr/X11R6/lib/X11/fonts/100dpi/
The recommended font path contains the following font path ele‐
ments:
/usr/X11R6/lib/X11/fonts/local/
/usr/X11R6/lib/X11/fonts/misc/
/usr/X11R6/lib/X11/fonts/75dpi/:unscaled
/usr/X11R6/lib/X11/fonts/100dpi/:unscaled
/usr/X11R6/lib/X11/fonts/Type1/
/usr/X11R6/lib/X11/fonts/75dpi/
/usr/X11R6/lib/X11/fonts/100dpi/
Font path elements that are found to be invalid are removed from
the font path when the server starts up.
ModulePath "path"
sets the search path for loadable Xorg server modules. This
path is a comma separated list of directories which the Xorg
server searches for loadable modules loading in the order speci‐
fied. Multiple ModulePath entries may be specified, and they
will be concatenated to build the module search path used by the
server.
SERVERFLAGS SECTION
In addition to options specific to this section (described below), the
ServerFlags section is used to specify some global Xorg server options.
All of the entries in this section are Options, although for compati‐
bility purposes some of the old style entries are still recognised.
Those old style entries are not documented here, and using them is dis‐
couraged. The ServerFlags section is optional, as are the entries that
may be specified in it.
Options specified in this section (with the exception of the "Default‐
ServerLayout" Option) may be overridden by Options specified in the
active ServerLayout section. Options with command line equivalents are
overridden when their command line equivalent is used. The options
recognised by this section are:
Option "DefaultServerLayout" "layout-id"
This specifies the default ServerLayout section to use in the
absence of the -layout command line option.
Option "NoTrapSignals" "boolean"
This prevents the Xorg server from trapping a range of unex‐
pected fatal signals and exiting cleanly. Instead, the Xorg
server will die and drop core where the fault occurred. The
default behaviour is for the Xorg server to exit cleanly, but
still drop a core file. In general you never want to use this
option unless you are debugging an Xorg server problem and know
how to deal with the consequences.
Option "DontVTSwitch" "boolean"
This disallows the use of the Ctrl+Alt+Fn sequence (where Fn
refers to one of the numbered function keys). That sequence is
normally used to switch to another "virtual terminal" on operat‐
ing systems that have this feature. When this option is
enabled, that key sequence has no special meaning and is passed
to clients. Default: off.
Option "DontZap" "boolean"
This disallows the use of the Ctrl+Alt+Backspace sequence. That
sequence is normally used to terminate the Xorg server. When
this option is enabled (as per default), that key sequence has
no special meaning. Default: on.
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 allows the server to start up even if the mouse device
can't be opened/initialised. Default: false.
Option "VTSysReq" "boolean"
enables the SYSV-style VT switch sequence for non-SYSV systems
which support VT switching. This sequence is Alt-SysRq followed
by a function key (Fn). This prevents the Xorg server trapping
the keys used for the default VT switch sequence, which means
that clients can access them. Default: off.
Option "XkbDisable" "boolean"
disable/enable the XKEYBOARD extension. The -kb command line
option overrides this config file option. Default: XKB is
enabled.
Option "BlankTime" "time"
sets the inactivity timeout for the blank phase of the screen‐
saver. time is in minutes. This is equivalent to the Xorg
server's -s flag, and the value can be changed at run-time with
xset(1). Default: 10 minutes.
Option "StandbyTime" "time"
sets the inactivity timeout for the standby phase of DPMS mode.
time is in minutes, and the value can be changed at run-time
with xset(1). Default: 20 minutes. This is only suitable for
VESA DPMS compatible monitors, and may not be supported by all
video drivers. It is only enabled for screens that have the
"DPMS" option set (see the MONITOR section below).
Option "SuspendTime" "time"
sets the inactivity timeout for the suspend phase of DPMS mode.
time is in minutes, and the value can be changed at run-time
with xset(1). Default: 30 minutes. This is only suitable for
VESA DPMS compatible monitors, and may not be supported by all
video drivers. It is only enabled for screens that have the
"DPMS" option set (see the MONITOR section below).
Option "OffTime" "time"
sets the inactivity timeout for the off phase of DPMS mode.
time is in minutes, and the value can be changed at run-time
with xset(1). Default: 40 minutes. This is only suitable for
VESA DPMS compatible monitors, and may not be supported by all
video drivers. It is only enabled for screens that have the
"DPMS" option set (see the MONITOR section below).
Option "Pixmap" "bpp"
This sets the pixmap format to use for depth 24. Allowed values
for bpp are 24 and 32. Default: 32 unless driver constraints
don't allow this (which is rare). Note: some clients don't
behave well when this value is set to 24.
Option "PC98" "boolean"
Specify that the machine is a Japanese PC-98 machine. This
should not be enabled for anything other than the Japanese-spe‐
cific PC-98 architecture. Default: auto-detected.
Option "NoPM" "boolean"
Disables something to do with power management events. Default:
PM enabled on platforms that support it.
Option "Xinerama" "boolean"
enable or disable XINERAMA extension. Default is disabled.
Option "AIGLX" "boolean"
enable or disable AIGLX. AIGLX is enabled by default.
Option "GlxVisuals" "string"
This option controls how many GLX visuals the GLX modules sets
up. The default value is typical, which will setup up a typical
subset of the GLXFBConfigs provided by the driver as GLX visu‐
als. Other options are minimal, which will set up the minimal
set allowed by the GLX specification and all which will setup
GLX visuals for all GLXFBConfigs.
Option "UseDefaultFontPath" "boolean"
Include the default font path even if other paths are specified
in xorg.conf. If enabled, other font paths are included as well.
Enabled by default.
Option "IgnoreABI" "boolean"
Allow modules built for a different, potentially incompatible
version of the X server to load. Disabled by default.
Option "AllowEmptyInput" "boolean"
If enabled, don't add the standard keyboard and mouse drivers,
if there are no input devices in the config file. Enabled by
default if AutoAddDevices and AutoEnableDevices is enabled, oth‐
erwise disabled. If AllowEmptyInput is on, devices using the
kbd, mouse or vmmouse driver are ignored.
Option "AutoAddDevices" "boolean"
If this option is disabled, then no devices will be added from
HAL events. 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 "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 types of modules normally loaded in this section are
Xorg server extension modules, and font rasteriser modules. Most other
module types are loaded automatically when they are needed via other
mechanisms. The Module section is optional, as are all of the entries
that may be specified in it.
Entries in this section may be in two forms. The first and most com‐
monly used form is an entry that uses the Load keyword, as described
here:
Load "modulename"
This instructs the server to load the module called modulename.
The module name given should be the module's standard name, not
the module file name. The standard name is case-sensitive, and
does not include the “lib” prefix, or the “.a”, “.o”, or “.so”
suffixes.
Example: the FreeType font rasteriser can be loaded with the
following entry:
Load "freetype"
Disable "modulename"
This instructs the server to not load the module called module‐
name. Some modules are loaded by default in the server, and
this overrides that default. If a Load instruction is given for
the same module, it overrides the Disable instruction and the
module is loaded. The module name given should be the module's
standard name, not the module file name. As with the Load
instruction, the standard name is case-sensitive, and does not
include the "lib" prefix, or the ".a", ".o", or ".so" suffixes.
The second form of entry is a SubSection, with the subsection name
being the module name, and the contents of the SubSection being Options
that are passed to the module when it is loaded.
Example: the extmod module (which contains a miscellaneous group of
server extensions) can be loaded, with the XFree86-DGA extension dis‐
abled by using the following entry:
SubSection "extmod"
Option "omit XFree86-DGA"
EndSubSection
Modules are searched for in each directory specified in the ModulePath
search path, and in the drivers, input, extensions, fonts, and internal
subdirectories of each of those directories. In addition to this,
operating system specific subdirectories of all the above are searched
first if they exist.
To see what font and extension modules are available, check the con‐
tents of the following directories:
/usr/X11R6/lib/modules/fonts
/usr/X11R6/lib/modules/extensions
The “extmod”, “dbe”, “glx”, and “dri” extension modules are loaded
automatically, unless disabled with "Disable" entries. It is recom‐
mended that at very least the “extmod” extension module be loaded. If
it isn't, some commonly used server extensions (like the SHAPE exten‐
sion) will not be available.
EXTENSIONS SECTION
The Extensions section is used to specify which X11 protocol extensions
should be enabled or disabled. The Extensions section is optional, as
are all of the entries that may be specified in it.
Entries in this section are listed as Option statements with the name
of the extension as the first argument, and a boolean value as the sec‐
ond. The extension name is case-sensitive, and matches the form shown
in the output of "Xorg -extension ?".
Example: the MIT-SHM extension can be disabled with the follow‐
ing entry:
Section "Extensions"
Option "MIT-SHM" "Disable"
EndSection
INPUTDEVICE SECTION
The config file may have multiple InputDevice sections. There will
normally be at least two: one for the core (primary) keyboard, and one
of the core pointer. If either of these two is missing, a default con‐
figuration for the missing ones will be used. Currently the default
configuration may not work as expected on all platforms.
InputDevice sections have the following format:
Section "InputDevice"
Identifier "name"
Driver "inputdriver"
options
...
EndSection
The Identifier and Driver entries are required in all InputDevice sec‐
tions. All other entries are optional.
The Identifier entry specifies the unique name for this input device.
The Driver entry specifies the name of the driver to use for this input
device. When using the loadable server, the input driver module
"inputdriver" will be loaded for each active InputDevice section. An
InputDevice section is considered active if it is referenced by an
active ServerLayout section, if it is referenced by the -keyboard or
-pointer command line options, or if it is selected implicitly as the
core pointer or keyboard device in the absence of such explicit refer‐
ences. The most commonly used input drivers are evdev(4) on Linux sys‐
tems, and kbd(4) and mousedrv(4) on other platforms.
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.
InputDevice sections recognise some driver-independent Options, which
are described here. See the individual input driver manual pages for a
description of the device-specific options.
Option "CorePointer"
When this is set, the input device is installed as the core
(primary) pointer device. There must be exactly one core
pointer. If this option is not set here, or in the ServerLayout
section, or from the -pointer command line option, then the
first input device that is capable of being used as a core
pointer will be selected as the core pointer. This option is
implicitly set when the obsolete Pointer section is used.
Option "CoreKeyboard"
When this is set, the input device is to be installed as the
core (primary) keyboard device. There must be exactly one core
keyboard. If this option is not set here, in the ServerLayout
section, or from the -keyboard command line option, then the
first input device that is capable of being used as a core key‐
board will be selected as the core keyboard. This option is
implicitly set when the obsolete Keyboard section is used.
Option "AlwaysCore" "boolean"
Option "SendCoreEvents" "boolean"
Both of these options are equivalent, and when enabled cause the
input device to always report core events. This can be used,
for example, to allow an additional pointer device to generate
core pointer events (like moving the cursor, etc).
Option "HistorySize" "number"
Sets the motion history size. Default: 0.
Option "SendDragEvents" "boolean"
???
DEVICE SECTION
The config file may have multiple Device sections. There must be at
least one, for the video card being used.
Device sections have the following format:
Section "Device"
Identifier "name"
Driver "driver"
entries
...
EndSection
The Identifier and Driver entries are required in all Device sections.
All other entries are optional.
The Identifier entry specifies the unique name for this graphics
device. The Driver entry specifies the name of the driver to use for
this graphics device. When using the loadable server, the driver mod‐
ule "driver" will be loaded for each active Device section. A Device
section is considered active if it is referenced by an active Screen
section.
Device sections recognise some driver-independent entries and Options,
which are described here. Not all drivers make use of these
driver-independent entries, and many of those that do don't require
them to be specified because the information is auto-detected. See the
individual graphics driver manual pages for further information about
this, and for a description of the device-specific options. Note that
most of the Options listed here (but not the other entries) may be
specified in the Screen section instead of here in the Device section.
BusID "bus-id"
This specifies the bus location of the graphics card. For
PCI/AGP cards, the bus-id string has the form
PCI:bus:device:function (e.g., “PCI:1:0:0” might be appropriate
for an AGP card). This field is usually optional in single-head
configurations when using the primary graphics card. In multi-
head configurations, or when using a secondary graphics card in
a single-head configuration, this entry is mandatory. Its main
purpose is to make an unambiguous connection between the device
section and the hardware it is representing. This information
can usually be found by running the pciaccess tool scanpci.
Screen number
This option is mandatory for cards where a single PCI entity can
drive more than one display (i.e., multiple CRTCs sharing a sin‐
gle graphics accelerator and video memory). One Device section
is required for each head, and this parameter determines which
head each of the Device sections applies to. The legal values
of number range from 0 to one less than the total number of
heads per entity. Most drivers require that the primary screen
(0) be present.
Chipset "chipset"
This usually optional entry specifies the chipset used on the
graphics board. In most cases this entry is not required
because the drivers will probe the hardware to determine the
chipset type. Don't specify it unless the driver-specific docu‐
mentation recommends that you do.
Ramdac "ramdac-type"
This optional entry specifies the type of RAMDAC used on the
graphics board. This is only used by a few of the drivers, and
in most cases it is not required because the drivers will probe
the hardware to determine the RAMDAC type where possible. Don't
specify it unless the driver-specific documentation recommends
that you do.
DacSpeed speed
DacSpeed speed-8 speed-16 speed-24 speed-32
This optional entry specifies the RAMDAC speed rating (which is
usually printed on the RAMDAC chip). The speed is in MHz. When
one value is given, it applies to all framebuffer pixel sizes.
When multiple values are given, they apply to the framebuffer
pixel sizes 8, 16, 24 and 32 respectively. This is not used by
many drivers, and only needs to be specified when the speed rat‐
ing of the RAMDAC is different from the defaults built in to
driver, or when the driver can't auto-detect the correct
defaults. Don't specify it unless the driver-specific documen‐
tation recommends that you do.
Clocks clock ...
specifies the pixel that are on your graphics board. The clocks
are in MHz, and may be specified as a floating point number.
The value is stored internally to the nearest kHz. The ordering
of the clocks is important. It must match the order in which
they are selected on the graphics board. Multiple Clocks lines
may be specified, and each is concatenated to form the list.
Most drivers do not use this entry, and it is only required for
some older boards with non-programmable clocks. Don't specify
this entry unless the driver-specific documentation explicitly
recommends that you do.
ClockChip "clockchip-type"
This optional entry is used to specify the clock chip type on
graphics boards which have a programmable clock generator. Only
a few Xorg drivers support programmable clock chips. For
details, see the appropriate driver manual page.
VideoRam mem
This optional entry specifies the amount of video ram that is
installed on the graphics board. This is measured in kBytes.
In most cases this is not required because the Xorg server
probes the graphics board to determine this quantity. The
driver-specific documentation should indicate when it might be
needed.
BiosBase baseaddress
This optional entry specifies the base address of the video BIOS
for the VGA board. This address is normally auto-detected, and
should only be specified if the driver-specific documentation
recommends it.
MemBase baseaddress
This optional entry specifies the memory base address of a
graphics board's linear frame buffer. This entry is not used by
many drivers, and it should only be specified if the driver-spe‐
cific documentation recommends it.
IOBase baseaddress
This optional entry specifies the IO base address. This entry
is not used by many drivers, and it should only be specified if
the driver-specific documentation recommends it.
ChipID id
This optional entry specifies a numerical ID representing the
chip type. For PCI cards, it is usually the device ID. This
can be used to override the auto-detection, but that should only
be done when the driver-specific documentation recommends it.
ChipRev rev
This optional entry specifies the chip revision number. This
can be used to override the auto-detection, but that should only
be done when the driver-specific documentation recommends it.
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.
Option "ModeDebug" "boolean"
Enable printing of additional debugging information about mode‐
setting to the server log.
Options
Option flags may be specified in the Device sections. These
include driver-specific options and driver-independent options.
The former are described in the driver-specific documentation.
Some of the latter are described below in the section about the
Screen section, and they may also be included here.
VIDEOADAPTOR SECTION
Nobody wants to say how this works. Maybe nobody knows ...
MONITOR SECTION
The config file may have multiple Monitor sections. There should nor‐
mally be at least one, for the monitor being used, but a default con‐
figuration will be created when one isn't specified.
Monitor sections have the following format:
Section "Monitor"
Identifier "name"
entries
...
EndSection
The only mandatory entry in a Monitor section is the Identifier entry.
The Identifier entry specifies the unique name for this monitor. The
Monitor section may be used to provide information about the specifica‐
tions of the monitor, monitor-specific Options, and information about
the video modes to use with the monitor.
With RandR 1.2-enabled drivers, monitor sections may be tied to spe‐
cific outputs of the video card. Using the name of the output defined
by the video driver plus the identifier of a monitor section, one asso‐
ciates a monitor section with an output by adding an option to the
Device section in the following format:
Option "Monitor-outputname" "monitorsection"
(for example, Option "Monitor-VGA" "VGA monitor" for a VGA output)
In the absence of specific association of monitor sections to outputs,
if a monitor section is present the server will associate it with an
output to preserve compatibility for previous single-head configura‐
tions.
Specifying video modes is optional because the server will use the DDC
or other information provided by the monitor to automatically configure
the list of modes available. When modes are specified explicitly in
the Monitor section (with the Modes, ModeLine, or UseModes keywords),
built-in modes with the same names are not included. Built-in modes
with different names are, however, still implicitly included, when they
meet the requirements of the monitor.
The entries that may be used in Monitor sections are described below.
VendorName "vendor"
This optional entry specifies the monitor's manufacturer.
ModelName "model"
This optional entry specifies the monitor's model.
HorizSync horizsync-range
gives the range(s) of horizontal sync frequencies supported by
the monitor. horizsync-range may be a comma separated list of
either discrete values or ranges of values. A range of values
is two values separated by a dash. By default the values are in
units of kHz. They may be specified in MHz or Hz if MHz or Hz
is added to the end of the line. The data given here is used by
the Xorg server to determine if video modes are within the spec‐
ifications of the monitor. This information should be available
in the monitor's handbook. If this entry is omitted, a default
range of 28-33kHz is used.
VertRefresh vertrefresh-range
gives the range(s) of vertical refresh frequencies supported by
the monitor. vertrefresh-range may be a comma separated list of
either discrete values or ranges of values. A range of values
is two values separated by a dash. By default the values are in
units of Hz. They may be specified in MHz or kHz if MHz or kHz
is added to the end of the line. The data given here is used by
the Xorg server to determine if video modes are within the spec‐
ifications of the monitor. This information should be available
in the monitor's handbook. If this entry is omitted, a default
range of 43-72Hz is used.
DisplaySize width height
This optional entry gives the width and height, in millimetres,
of the picture area of the monitor. If given this is used to
calculate the horizontal and vertical pitch (DPI) of the screen.
Gamma gamma-value
Gamma red-gamma green-gamma blue-gamma
This is an optional entry that can be used to specify the gamma
correction for the monitor. It may be specified as either a
single value or as three separate RGB values. The values should
be in the range 0.1 to 10.0, and the default is 1.0. Not all
drivers are capable of using this information.
UseModes "modesection-id"
Include the set of modes listed in the Modes section called mod‐
esection-id. This makes all of the modes defined in that sec‐
tion available for use by this monitor.
Mode "name"
This is an optional multi-line entry that can be used to provide
definitions for video modes for the monitor. In most cases this
isn't necessary because the built-in set of VESA standard modes
will be sufficient. The Mode keyword indicates the start of a
multi-line video mode description. The mode description is ter‐
minated with the EndMode keyword. The mode description consists
of the following entries:
DotClock clock
is the dot (pixel) clock rate to be used for the mode.
HTimings hdisp hsyncstart hsyncend htotal
specifies the horizontal timings for the mode.
VTimings vdisp vsyncstart vsyncend vtotal
specifies the vertical timings for the mode.
Flags "flag" ...
specifies an optional set of mode flags, each of which is a
separate string in double quotes. "Interlace" indicates
that the mode is interlaced. "DoubleScan" indicates a mode
where each scanline is doubled. "+HSync" and "-HSync" can
be used to select the polarity of the HSync signal.
"+VSync" and "-VSync" can be used to select the polarity of
the VSync signal. "Composite" can be used to specify com‐
posite sync on hardware where this is supported. Addition‐
ally, on some hardware, "+CSync" and "-CSync" may be used to
select the composite sync polarity.
HSkew hskew
specifies the number of pixels (towards the right edge of
the screen) by which the display enable signal is to be
skewed. Not all drivers use this information. This option
might become necessary to override the default value sup‐
plied by the server (if any). “Roving” horizontal lines
indicate this value needs to be increased. If the last few
pixels on a scan line appear on the left of the screen, this
value should be decreased.
VScan vscan
specifies the number of times each scanline is painted on
the screen. Not all drivers use this information. Values
less than 1 are treated as 1, which is the default. Gener‐
ally, the "DoubleScan" Flag mentioned above doubles this
value.
ModeLine "name" mode-description
This entry is a more compact version of the Mode entry, and it
also can be used to specify video modes for the monitor. is a
single line format for specifying video modes. In most cases
this isn't necessary because the built-in set of VESA standard
modes will be sufficient.
The mode-description is in four sections, the first three of
which are mandatory. The first is the dot (pixel) clock. This
is a single number specifying the pixel clock rate for the mode
in MHz. The second section is a list of four numbers specifying
the horizontal timings. These numbers are the hdisp, hsync‐
start, hsyncend, and htotal values. The third section is a list
of four numbers specifying the vertical timings. These numbers
are the vdisp, vsyncstart, vsyncend, and vtotal values. The
final section is a list of flags specifying other characteris‐
tics of the mode. Interlace indicates that the mode is inter‐
laced. DoubleScan indicates a mode where each scanline is dou‐
bled. +HSync and -HSync can be used to select the polarity of
the HSync signal. +VSync and -VSync can be used to select the
polarity of the VSync signal. Composite can be used to specify
composite sync on hardware where this is supported. Addition‐
ally, on some hardware, +CSync and -CSync may be used to select
the composite sync polarity. The HSkew and VScan options men‐
tioned above in the Modes 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 "TargetRefresh" "rate"
This optional entry specifies the vertical refresh rate that the
server should aim for when selecting video modes. Without this
option, the default is to prefer modes with higher refresh
rates.
Option "PreferredMode" "string"
This optional entry specifies a mode to be marked as the pre‐
ferred initial mode of the monitor. (RandR 1.2-supporting driv‐
ers only)
Option "Position" "x y"
This optional entry specifies the position of the monitor within
the X screen. (RandR 1.2-supporting drivers only)
Option "LeftOf" "output"
This optional entry specifies that the monitor should be posi‐
tioned to the left of the output (not monitor) of the given
name. (RandR 1.2-supporting drivers only)
Option "RightOf" "output"
This optional entry specifies that the monitor should be posi‐
tioned to the right of the output (not monitor) of the given
name. (RandR 1.2-supporting drivers only)
Option "Above" "output"
This optional entry specifies that the monitor should be posi‐
tioned above the output (not monitor) of the given name. (RandR
1.2-supporting drivers only)
Option "Below" "output"
This optional entry specifies that the monitor should be posi‐
tioned below the output (not monitor) of the given name. (RandR
1.2-supporting drivers only)
Option "Enable" "bool"
This optional entry specifies whether the monitor should be
turned on at startup. By default, the server will attempt to
enable all connected monitors. (RandR 1.2-supporting drivers
only)
Option "MinClock" "frequency"
This optional entry specifies the minimum dot clock, in kHz,
that is supported by the monitor.
Option "MaxClock" "frequency"
This optional entry specifies the maximum dot clock, in kHz,
that is supported by the monitor.
Option "Ignore" "bool"
This optional entry specifies that the monitor should be ignored
entirely, and not reported through RandR. This is useful if the
hardware reports the presence of outputs that don't exist.
(RandR 1.2-supporting drivers only)
Option "Rotate" "rotation"
This optional entry specifies the initial rotation of the given
monitor. Valid values for rotation are "normal", "left",
"right", and "inverted". (RandR 1.2-supporting drivers only)
MODES SECTION
The config file may have multiple Modes sections, or none. These sec‐
tions provide a way of defining sets of video modes independently of
the Monitor sections. Monitor sections may include the definitions
provided in these sections by using the UseModes keyword. In most
cases the Modes sections are not necessary because the built-in set of
VESA standard modes will be sufficient.
Modes sections have the following format:
Section "Modes"
Identifier "name"
entries
...
EndSection
The Identifier entry specifies the unique name for this set of mode
descriptions. The other entries permitted in Modes sections are the
Mode and ModeLine entries that are described above in the Monitor sec‐
tion.
SCREEN SECTION
The config file may have multiple Screen sections. There must be at
least one, for the “screen” being used. A “screen” represents the
binding of a graphics device (Device section) and a monitor (Monitor
section). A Screen section is considered “active” if it is referenced
by an active ServerLayout section or by the -screen command line
option. If neither of those is present, the first Screen section found
in the config file is considered the active one.
Screen sections have the following format:
Section "Screen"
Identifier "name"
Device "devid"
Monitor "monid"
entries
...
SubSection "Display"
entries
...
EndSubSection
...
EndSection
The Identifier and Device entries are mandatory. All others are
optional.
The Identifier entry specifies the unique name for this screen. The
Screen section provides information specific to the whole screen,
including screen-specific Options. In multi-head configurations, there
will be multiple active Screen sections, one for each head. The
entries available for this section are:
Device "device-id"
This mandatory entry specifies the Device section to be used for
this screen. This is what ties a specific graphics card to a
screen. The device-id must match the Identifier of a Device
section in the config file.
Monitor "monitor-id"
specifies which monitor description is to be used for this
screen. If a Monitor name is not specified, a default configu‐
ration is used. Currently the default configuration may not
function as expected on all platforms.
VideoAdaptor "xv-id"
specifies an optional Xv video adaptor description to be used
with this screen.
DefaultDepth depth
specifies which color depth the server should use by default.
The -depth command line option can be used to override this. If
neither is specified, the default depth is driver-specific, but
in most cases is 8.
DefaultFbBpp bpp
specifies which framebuffer layout to use by default. The
-fbbpp command line option can be used to override this. In
most cases the driver will chose the best default value for
this. The only case where there is even a choice in this value
is for depth 24, where some hardware supports both a packed 24
bit framebuffer layout and a sparse 32 bit framebuffer layout.
Options
Various Option flags may be specified in the Screen section.
Some are driver-specific and are described in the driver docu‐
mentation. Others are driver-independent, and will eventually
be described here.
Option "Accel"
Enables XAA (X Acceleration Architecture), a mechanism that
makes video cards' 2D hardware acceleration available to the
Xorg server. This option is on by default, but it may be neces‐
sary 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 fac‐
tor of up to 2.5. Some hardware has buggy MTRR support, and
some video drivers have been known to exhibit problems when
MTRR's are used.
Option "XaaNoCPUToScreenColorExpandFill"
Disables accelerated rectangular expansion blits from source
patterns stored in system memory (using a memory-mapped aper‐
ture).
Option "XaaNoColor8x8PatternFillRect"
Disables accelerated fills of a rectangular region with a
full-color pattern.
Option "XaaNoColor8x8PatternFillTrap"
Disables accelerated fills of a trapezoidal region with a
full-color pattern.
Option "XaaNoDashedBresenhamLine"
Disables accelerated dashed Bresenham line draws.
Option "XaaNoDashedTwoPointLine"
Disables accelerated dashed line draws between two arbitrary
points.
Option "XaaNoImageWriteRect"
Disables accelerated transfers of full-color rectangular pat‐
terns from system memory to video memory (using a memory-mapped
aperture).
Option "XaaNoMono8x8PatternFillRect"
Disables accelerated fills of a rectangular region with a mono‐
chrome pattern.
Option "XaaNoMono8x8PatternFillTrap"
Disables accelerated fills of a trapezoidal region with a mono‐
chrome pattern.
Option "XaaNoOffscreenPixmaps"
Disables accelerated draws into pixmaps stored in offscreen
video memory.
Option "XaaNoPixmapCache"
Disables caching of patterns in offscreen video memory.
Option "XaaNoScanlineCPUToScreenColorExpandFill"
Disables accelerated rectangular expansion blits from source
patterns stored in system memory (one scan line at a time).
Option "XaaNoScanlineImageWriteRect"
Disables accelerated transfers of full-color rectangular pat‐
terns from system memory to video memory (one scan line at a
time).
Option "XaaNoScreenToScreenColorExpandFill"
Disables accelerated rectangular expansion blits from source
patterns stored in offscreen video memory.
Option "XaaNoScreenToScreenCopy"
Disables accelerated copies of rectangular regions from one part
of video memory to another part of video memory.
Option "XaaNoSolidBresenhamLine"
Disables accelerated solid Bresenham line draws.
Option "XaaNoSolidFillRect"
Disables accelerated solid-color fills of rectangles.
Option "XaaNoSolidFillTrap"
Disables accelerated solid-color fills of Bresenham trapezoids.
Option "XaaNoSolidHorVertLine"
Disables accelerated solid horizontal and vertical line draws.
Option "XaaNoSolidTwoPointLine"
Disables accelerated solid line draws between two arbitrary
points.
Each Screen section may optionally contain one or more Display subsec‐
tions. Those subsections provide depth/fbbpp specific configuration
information, and the one chosen depends on the depth and/or fbbpp that
is being used for the screen. The Display subsection format is
described in the section below.
DISPLAY SUBSECTION
Each Screen section may have multiple Display subsections. The
“active” Display subsection is the first that matches the depth and/or
fbbpp values being used, or failing that, the first that has neither a
depth or fbbpp value specified. The Display subsections are optional.
When there isn't one that matches the depth and/or fbbpp values being
used, all the parameters that can be specified here fall back to their
defaults.
Display subsections have the following format:
SubSection "Display"
Depth depth
entries
...
EndSubSection
Depth depth
This entry specifies what colour depth the Display subsection is
to be used for. This entry is usually specified, but it may be
omitted to create a match-all Display subsection or when wishing
to match only against the FbBpp parameter. The range of depth
values that are allowed depends on the driver. Most drivers
support 8, 15, 16 and 24. Some also support 1 and/or 4, and
some may support other values (like 30). Note: depth means the
number of bits in a pixel that are actually used to determine
the pixel colour. 32 is not a valid depth value. Most hardware
that uses 32 bits per pixel only uses 24 of them to hold the
colour information, which means that the colour depth is 24, not
32.
FbBpp bpp
This entry specifies the framebuffer format this Display subsec‐
tion is to be used for. This entry is only needed when provid‐
ing depth 24 configurations that allow a choice between a 24 bpp
packed framebuffer format and a 32bpp sparse framebuffer format.
In most cases this entry should not be used.
Weight red-weight green-weight blue-weight
This optional entry specifies the relative RGB weighting to be
used for a screen is being used at depth 16 for drivers that
allow multiple formats. This may also be specified from the
command line with the -weight option (see Xorg(1)).
Virtual xdim ydim
This optional entry specifies the virtual screen resolution to
be used. xdim must be a multiple of either 8 or 16 for most
drivers, and a multiple of 32 when running in monochrome mode.
The given value will be rounded down if this is not the case.
Video modes which are too large for the specified virtual size
will be rejected. If this entry is not present, the virtual
screen resolution will be set to accommodate all the valid video
modes given in the Modes entry. Some drivers/hardware combina‐
tions do not support virtual screens. Refer to the appropriate
driver-specific documentation for details.
ViewPort x0 y0
This optional entry sets the upper left corner of the initial
display. This is only relevant when the virtual screen resolu‐
tion is different from the resolution of the initial video mode.
If this entry is not given, then the initial display will be
centered in the virtual display area.
Modes "mode-name" ...
This optional entry specifies the list of video modes to use.
Each mode-name specified must be in double quotes. They must
correspond to those specified or referenced in the appropriate
Monitor section (including implicitly referenced built-in VESA
standard modes). The server will delete modes from this list
which don't satisfy various requirements. The first valid mode
in this list will be the default display mode for startup. The
list of valid modes is converted internally into a circular
list. It is possible to switch to the next mode with
Ctrl+Alt+Keypad-Plus and to the previous mode with Ctrl+Alt+Key‐
pad-Minus. When this entry is omitted, the valid modes refer‐
enced by the appropriate Monitor section will be used. If the
Monitor section contains no modes, then the selection will be
taken from the built-in VESA standard modes.
Visual "visual-name"
This optional entry sets the default root visual type. This may
also be specified from the command line (see the Xserver(1) man
page). The visual types available for depth 8 are (default is
PseudoColor):
StaticGray
GrayScale
StaticColor
PseudoColor
TrueColor
DirectColor
The visual type available for the depths 15, 16 and 24 are
(default is TrueColor):
TrueColor
DirectColor
Not all drivers support DirectColor at these depths.
The visual types available for the depth 4 are (default is Stat‐
icColor):
StaticGray
GrayScale
StaticColor
PseudoColor
The visual type available for the depth 1 (monochrome) is Stat‐
icGray.
Black red green blue
This optional entry allows the “black” colour to be specified.
This is only supported at depth 1. The default is black.
White red green blue
This optional entry allows the “white” colour to be specified.
This is only supported at depth 1. The default is white.
Options
Option flags may be specified in the Display subsections. These
may include driver-specific options and driver-independent
options. The former are described in the driver-specific docu‐
mentation. Some of the latter are described above in the sec‐
tion about the Screen section, and they may also be included
here.
SERVERLAYOUT SECTION
The config file may have multiple ServerLayout sections. A “server
layout” represents the binding of one or more screens (Screen sections)
and one or more input devices (InputDevice sections) to form a complete
configuration. In multi-head configurations, it also specifies the
relative layout of the heads. A ServerLayout section is considered
“active” if it is referenced by the -layout command line option or by
an Option "DefaultServerLayout" entry in the ServerFlags section (the
former takes precedence over the latter). If those options are not
used, the first ServerLayout section found in the config file is con‐
sidered the active one. If no ServerLayout sections are present, the
single active screen and two active (core) input devices are selected
as described in the relevant sections above.
ServerLayout sections have the following format:
Section "ServerLayout"
Identifier "name"
Screen "screen-id"
...
InputDevice "idev-id"
...
options
...
EndSection
Each ServerLayout section must have an Identifier entry and at least
one Screen entry.
The Identifier entry specifies the unique name for this server layout.
The ServerLayout section provides information specific to the whole
session, including session-specific Options. The ServerFlags options
(described above) may be specified here, and ones given here override
those given in the ServerFlags section.
The entries that may be used in this section are described here.
Screen screen-num "screen-id" position-information
One of these entries must be given for each screen being used in
a session. The screen-id field is mandatory, and specifies the
Screen section being referenced. The screen-num field is
optional, and may be used to specify the screen number in
multi-head configurations. When this field is omitted, the
screens will be numbered in the order that they are listed in.
The numbering starts from 0, and must be consecutive. The posi‐
tion-information field describes the way multiple screens are
positioned. There are a number of different ways that this
information can be provided:
x y
Absolute x y
These both specify that the upper left corner's coordinates
are (x,y). The Absolute keyword is optional. Some older
versions of XFree86 (4.2 and earlier) don't recognise the
Absolute keyword, so it's safest to just specify the coordi‐
nates without it.
RightOf "screen-id"
LeftOf "screen-id"
Above "screen-id"
Below "screen-id"
Relative "screen-id" x y
These give the screen's location relative to another screen.
The first four position the screen immediately to the right,
left, above or below the other screen. When positioning to
the right or left, the top edges are aligned. When posi‐
tioning above or below, the left edges are aligned. The
Relative form specifies the offset of the screen's origin
(upper left corner) relative to the origin of another
screen.
InputDevice "idev-id" "option" ...
One of these entries should be given for each input device being
used in a session. Normally at least two are required, one each
for the core pointer and keyboard devices. If either of those
is missing, suitable InputDevice entries are searched for using
the method described above in the INPUTDEVICE section. The
idev-id field is mandatory, and specifies the name of the Input‐
Device section being referenced. Multiple option fields may be
specified, each in double quotes. The options permitted here
are any that may also be given in the InputDevice sections.
Normally only session-specific input device options would be
used here. The most commonly used options are:
"CorePointer"
"CoreKeyboard"
"SendCoreEvents"
and the first two should normally be used to indicate the core
pointer and core keyboard devices respectively.
Options
In addition to the following, any option permitted in the
ServerFlags section may also be specified here. When the same
option appears in both places, the value given here overrides
the one given in the ServerFlags section.
Option "IsolateDevice" "bus-id"
Restrict device resets to the specified bus-id. See the BusID
option (described in DEVICE SECTION, above) for the format of
the bus-id parameter. This option overrides SingleCard, if
specified. At present, only PCI devices can be isolated in this
manner.
Option "SingleCard" "boolean"
As IsolateDevice, except that the bus ID of the first device in
the layout is used.
Here is an example of a ServerLayout section for a dual headed configu‐
ration with two mice:
Section "ServerLayout"
Identifier "Layout 1"
Screen "MGA 1"
Screen "MGA 2" RightOf "MGA 1"
InputDevice "Keyboard 1" "CoreKeyboard"
InputDevice "Mouse 1" "CorePointer"
InputDevice "Mouse 2" "SendCoreEvents"
Option "BlankTime" "5"
EndSection
DRI SECTION
This optional section is used to provide some information for the
Direct Rendering Infrastructure. Details about the format of this sec‐
tion can be found in the README.DRI document, which is also available
on-line at <http://dri.freedesktop.org/>.
VENDOR SECTION
The optional Vendor section may be used to provide vendor-specific con‐
figuration information. Multiple Vendor sections may be present, and
they may contain an Identifier entry and multiple Option flags. The
data therein is not used in this release.
SEE ALSO
General: X(7), Xserver(1), Xorg(1), cvt(1), gtf(1).
Not all modules or interfaces are available on all platforms.
Display drivers: apm(4), ati(4), chips(4), cirrus(4), cyrix(4),
fbdev(4), glide(4), glint(4), i128(4), i740(4), imstt(4), intel(4),
mga(4), neomagic(4), nv(4), openchrome(4), r128(4), radeon(4), rendi‐
tion(4), savage(4), s3virge(4), siliconmotion(4), sis(4), sisusb(4),
sunbw2(4), suncg14(4), suncg3(4), suncg6(4), sunffb(4), sunleo(4),
suntcx(4), tdfx(4), trident(4), tseng(4), vesa(4), vmware(4),
voodoo(4), wsfb(4), xgi(4), xgixp(4).
Input drivers: acecad(4), calcomp(4), citron(4), dmc(4), dynapro(4),
elographics(4), evdev(4), fpit(4), js_x(4), joystick(4), kbd(4), magic‐
touch(4), microtouch(4), mousedrv(4), mutouch(4), palmax(4), pen‐
mount(4), synaptics(4), tek4957(4), ur98(4), vmmouse(4), void(4),
wacom(4).
Other modules and interfaces: exa(4), fbdevhw(4), v4l(4).
AUTHORS
This manual page was largely rewritten by David Dawes
<dawes@xfree86.org>.
X Version 11 xorg-server 1.6.99.1 xorg.conf(5)
