This work was originally derived from X386 1.2 which was contributed to X11R5 by Snitily Graphics Consulting Service. The XFree86 X server architecture was redesigned for the 4.0 release, and it includes among other things a loadable module system donated by Metro Link, Inc. The current XFree86 release is compatible with X11R6.6.

XFree86 operates under a wide range of operating systems and hardware platforms. The Intel x86 (IA32) architecture is the most widely supported hardware platform. Other hardware platforms include Compaq Alpha, Intel IA64, SPARC and PowerPC. The most widely supported operating systems are the free/OpenSource UNIX-like systems such as Linux, FreeBSD, NetBSD and OpenBSD. Commercial UNIX operating systems such as Solaris (x86) and UnixWare are also supported. Other supported operating systems include LynxOS, and GNU Hurd. Darwin and Mac OS X are supported with the XDarwin(1) X server. Win32/Cygwin is supported with the XWin X server.

Local

On most platforms, the "Local" connection type is a UNIX-domain socket. On some System V platforms, the "local" connection types also include STREAMS pipes, named pipes, and some other mechanisms.

TCP/IP

XFree86 listens on port 6000+n, where n is the display number. This connection type can be disabled with the -nolisten option (see the xserver(1) man page for details).

The XLOCAL environment variable should contain a list of one more more of the following:

NAMED
PTS
SCO
ISC

which represent SVR4 Named Streams pipe, Old-style USL Streams pipe, SCO XSight Streams pipe, and ISC Streams pipe, respectively. You can select a single mechanism (e.g. XLOCAL=NAMED), or an ordered list (e.g. XLOCAL="NAMED:PTS:SCO"). This variable overrides the compiled-in defaults. For SVR4 it is recommended that NAMED be the first preference connection. The default setting is PTS:NAMED:ISC:SCO.

To globally override the compiled-in defaults, you should define (and export if using sh or ksh) XLOCAL globally. If you use startx/xinit, the definition should be at the top of your .xinitrc file. If you use xdm, the definitions should be early on in the /usr/X11R6/lib/X11/xdm/Xsession script.

vtXX

XX specifies the Virtual Terminal device number which XFree86 will use. Without this option, XFree86 will pick the first available Virtual Terminal that it can locate. This option applies only to platforms such as Linux, BSD, SVR3 and SVR4, that have virtual terminal support.

-allowMouseOpenFail

Allow the server to start up even if the mouse device can't be opened or initialised. This is equivalent to the AllowMouseOpenFail xf86config(5x) file option.

-allowNonLocalModInDev

Allow changes to keyboard and mouse settings from non-local clients. By default, connections from non-local clients are not allowed to do this. This is equivalent to the AllowNonLocalModInDev xf86config(5x) file option.

-allowNonLocalXvidtune

Make the VidMode extension available to remote clients. This allows the xvidtune client to connect from another host. This is equivalent to the AllowNonLocalXvidtune xf86config(5x) file option. By default non-local connections are not allowed.

-bgamma value

Set the blue gamma correction. value must be between 0.1 and 10. The default is 1.0. Not all drivers support this. See also the -gamma, -rgamma, and -ggamma options.

-bpp n

No longer supported. Use -depth to set the color depth, and use -fbbpp if you really need to force a non-default framebuffer (hardware) pixel format.

-configure

When this option is specified, the X server loads all video driver modules, probes for available hardware, and writes out an initial xf86config(5x) file based on what was detected. This option currently has some problems on some platforms, but in most cases it is a good way to bootstrap the configuration process. This option is only available when the server is run as root (i.e, with real-uid 0).

-crt /dev/ttyXX

SCO only. This is the same as the vt option, and is provided for compatibility with the native SCO X server.

-depth n

Sets the default color depth. Legal values are 1, 4, 8, 15, 16, and 24. Not all drivers support all values.

-disableModInDev

Disable dynamic modification of input device settings. This is equivalent to the DisableModInDev xf86config(5x) file option.

-disableVidMode

Disable the the parts of the VidMode extension (used by the xvidtune client) that can be used to change the video modes. This is equivalent to the DisableVidModeExtension xf86config(5x) file option.

-fbbpp n

Sets the number of framebuffer bits per pixel. You should only set this if you're sure it's necessary; normally the server can deduce the correct value from -depth above. Useful if you want to run a depth 24 configuration with a 24 bpp framebuffer rather than the (possibly default) 32 bpp framebuffer (or vice versa). Legal values are 1, 8, 16, 24, 32. Not all drivers support all values.

-flipPixels

Swap the default values for the black and white pixels.

-gamma value

Set the gamma correction. value must be between 0.1 and 10. The default is 1.0. This value is applied equally to the R, G and B values. Those values can be set independently with the -rgamma, -bgamma, and -ggamma options. Not all drivers support this.

-ggamma value

Set the green gamma correction. value must be between 0.1 and 10. The default is 1.0. Not all drivers support this. See also the -gamma, -rgamma, and -bgamma options.

-ignoreABI

The X server checks the ABI revision levels of each module that it loads. It will normally refuse to load modules with ABI revisions that are newer than the server's. This is because such modules might use interfaces that the server does not have. When this option is specified, mismatches like this are downgraded from fatal errors to warnings. This option should be used with care.

-keeptty

Prevent the server from detaching its initial controlling terminal. This option is only useful when debugging the server. Not all platforms support (or can use) this option.

-keyboard keyboard-name

Use the xf86config(5x) file InputDevice section called keyboard-name as the core keyboard. This option is ignored when the Layout section specifies a core keyboard. In the absence of both a Layout section and this option, the first relevant InputDevice section is used for the core keyboard.

-layout layout-name

Use the xf86config(5x) file Layout section called layout-name. By default the first Layout section is used.

-logfile filename

Use the file called filename as the X server log file. The default log file is /var/log/XFree86.n.log on most platforms, where n is the display number of the X server. The default may be in a different directory on some platforms. This option is only available when the server is run as root (i.e, with real-uid 0).

-logverbose [n]

Sets the verbosity level for information printed to the X server log file. If the n value isn't supplied, each occurrance of this option increments the log file verbosity level. When the n value is supplied, the log file verbosity level is set to that value. The default log file verbosity level is 3.

-modulepath searchpath

Set the module search path to searchpath. searchpath is a comma separated list of directories to search for X server modules. This option is only available when the server is run as root (i.e, with real-uid 0).

-nosilk

Disable Silken Mouse support.

-pixmap24

Set the internal pixmap format for depth 24 pixmaps to 24 bits per pixel. The default is usually 32 bits per pixel. There is normally little reason to use this option. Some client applications don't like this pixmap format, even though it is a perfectly legal format. This is equvalent to the Pixmap xf86config(5x) file option.

-pixmap32

Set the internal pixmap format for depth 24 pixmaps to 32 bits per pixel. This is usually the default. This is equvalent to the Pixmap xf86config(5x) file option.

-pointer pointer-name

Use the xf86config(5x) file InputDevice section called pointer-name as the core pointer. This option is ignored when the Layout section specifies a core pointer. In the absence of both a Layout section and this option, the first relevant InputDevice section is used for the core pointer.

-probeonly

Causes the server to exit after the device probing stage. The XF86Config file is still used when this option is given, so information that can be auto-detected should be commented out.

-quiet

Suppress most informational messages at startup. The verbosity level is set to zero.

-rgamma value

Set the red gamma correction. value must be between 0.1 and 10. The default is 1.0. Not all drivers support this. See also the -gamma, -bgamma, and -ggamma options.

-scanpci

When this option is specified, the X server scans the PCI bus, and prints out some information about each device that was detected. See also scanpci(1) and pcitweak(1).

-screen screen-name

Use the xf86config(5x) file Screen section called screen-name. By default the screens referenced by the default Layout section are used, or the first Screen section when there are no Layout sections.

-showconfig

This is the same as the -version option, and is included for compatibility reasons. It may be removed in a future release, so the -version option should be used instead.

-weight nnn

Set RGB weighting at 16 bpp. The default is 565. This applies only to those drivers which support 16 bpp.

-verbose [n]

Sets the verbosity level for information printed on stderr. If the n value isn't supplied, each occurrance of this option increments the verbosity level. When the n value is supplied, the verbosity level is set to that value. The default verbosity level is 0.

-version

Print out the server version, patchlevel, release date, the operating system/platform it was built on, and whether it includes module loader support.

-xf86config file

Read the server configuration from file. This option will work for any file when the server is run as root (i.e, with real-uid 0), or for files relative to a directory in the config search path for all other users.

The XFree86 server is normally configured to recognize various special combinations of key presses that instruct the server to perform some action, rather than just sending the keypress event to a client application. The default XKEYBOARD keymap defines the key combinations listed below. The server also has these key combinations builtin to its event handler for cases where the XKEYBOARD extension is not being used. When using the XKEYBOARD extension, which key combinations perform which actions is completely configurable.

For more information about when the builtin event handler is used to recognize the special key combinations, see the documentation on the HandleSpecialKeys option in the xf86config(5x) man page.

The special combinations of key presses recognized directly by XFree86 are:

Ctrl+Alt+Backspace

Immediately kills the server -- no questions asked. This can be disabled with the DontZap xf86config(5x) file option.

Ctrl+Alt+Keypad-Plus

Change video mode to next one specified in the configuration file. This can be disabled with the DontZoom xf86config(5x) file option.

Ctrl+Alt+Keypad-Minus

Change video mode to previous one specified in the configuration file. This can be disabled with the DontZoom xf86config(5x) file option.

Ctrl+Alt+Keypad-Multiply

Not treated specially by default. If the AllowClosedownGrabs xf86config(5x) file option is specified, this key sequence kills clients with an active keyboard or mouse grab as well as killing any application that may have locked the server, normally using the xgrabserver(3x) Xlib function.

Ctrl+Alt+Keypad-Divide

Not treated specially by default. If the AllowDeactivateGrabs xf86config(5x) file option is specified, this key sequence deactivates any active keyboard and mouse grabs.

Ctrl+Alt+F1...F12

For BSD and Linux systems with virtual terminal support, these keystroke combinations are used to switch to virtual terminals 1 through 12, respectively. This can be disabled with the DontVTSwitch xf86config(5x) file option.