XFree86

Specifies information about the video card used by the system. You must have at least one Device section in your configuration file. You may have multiple Device sections in the case of multiple video cards or multiple settings that can run a single card. The following options are required or widely used:

• BusID — Specifies the bus location of the video card. This option is only necessary for systems with multiple cards and must be set so that the Device section will use the proper settings for the correct card.

• Driver — Tells XFree86 which driver to load in order to use the video card.

• Identifier — Provides a unique name for this video card. Usually, this name is set to the exact name of the video card used in the Device section.

• Screen — An optional setting used when a video card has more than one head, or connector, to go out to a separate monitor. If you have multiple monitors connected to one video card, separate Device sections must exist for each of them with a different Screen value for each Device section. The value accepted by this option is a number starting at 0 and increasing by one for each head on the video card.

• VideoRam — The amount of RAM available on the video card in kilobytes. This setting is not normally necessary since the XFree86 server can usually probe the video card to autodetect the amount of video RAM. But since there are some video cards XFree86 cannot correctly autodetect, this option allows you to specify the amount of video RAM.

Direct Rendering Infrastructure (DRI) is an interface which primarily allows 3D software applications to take advantage of the 3D hardware acceleration capabilities on modern supported video hardware. In addition, DRI can improve 2D hardware acceleration performance when using drivers that have been enhanced to use the DRI for 2D operations. This section is ignored unless DRI is enabled in the Module section.

Since different video cards use DRI in different ways. Before changing any DRI values, read the /usr/X11R6/lib/X11/doc/README.DRI file for specific information about your particular video card.

This section sets paths for services vital to the XFree86 server, such as the font path. Common options include:

• FontPath — Sets the locations where the XFree86 server can find fonts. Different fixed paths to directories holding font files can be placed here, separated by commas. By default, Red Hat Linux uses xfs as the font server and points FontPath to unix/:7100. This tells the XFree86 server to obtain font information by using UNIX-domain sockets for inter-process communication (IPC).

  See the Section called Fonts for more information concerning XFree86 and fonts.

• ModulePath — Allows you to set up multiple directories to use for storing modules loaded by the XFree86 server.

• RgbPath — Tells the XFree86 server where the RGB color database is located on the system. This database file defines all valid color names in XFree86 and ties them to specific RGB values.

Configures an input device such as a mouse or keyboard used to submit information into the system using the XFree86 server. Most systems have at least two InputDevice sections, keyboard and mouse. Each section includes these two lines:

• Driver — Tells XFree86 the name of the driver to load to use the device.

• Identifier — Sets the name of the device, usually the name of the device followed by a number, starting with 0 for the first device. For example, the first keyboard InputDevice would have an Identifier of Keyboard0.

Most InputDevice sections contain lines assigning specific options to that device. Each of these lines start with Option and contain the name of the option in quotes, followed by the value to assign to that option. Mice usually receive options such as Protocol, such as PS/2, and Device, which designates the mouse to use for this section. The InputDevice section is well commented, allowing you to configure additional options for your particular devices by uncommenting certain lines.

Tells the XFree86 server which modules from the /usr/X11R6/lib/modules/ directory to load. Modules provide the XFree86 server with additional functionality.

	Caution
	You should not edit these values.

Refers to the type of monitor used by the system. While one Monitor section is the minimum, there may be several Monitor sections, one for each monitor in use with the machine.

	Warning
	Be careful when manually editing values in the options of the Monitor section. Inappropriate values in this section could damage or destroy your monitor. Consult the documentation that came with your monitor for the safe operating parameters available.

The following options are usually configured during installation or when using X Configuration Tool:

• HorizSync — Tells XFree86 the range of horizontal sync frequencies compatible with the monitor in kHz. These values are used as a guide by the XFree86 server so that it will know whether to use a particular Modeline entry's values with this monitor.

• Identifier — Provides a unique name for this monitor, usually numbering each monitor starting at 0. The first monitor would be named Monitor0, the second Monitor1, and so on.

• Modeline — Used to specify the video modes used by the monitor at particular resolutions, with certain horizontal sync and vertical refresh resolutions. Modeline entries are usually preceded by a comment that explains what the mode line specifies.

  If your configuration file does not include comments for the various mode lines, you can scan over the values (also called mode descriptions) to uncover what the mode line is attempting to do. See the XF86Config man page for detailed explanations of each mode description section.

• ModelName — An optional parameter that displays the model name of the monitor.

• VendorName — An optional parameter that displays the vendor that manufactured the monitor.

• VertRefresh — Lists the vertical refresh range frequencies supported by the monitor, in kHz. These values are used as a guide by the XFree86 server so that it will know whether to use a particular Modeline entry's values with this monitor.

Binds together a particular Device and Monitor that can be utilized as a pair and contain certain settings. You must have at least one Screen section in your configuration file. The following options are common:

• DefaultDepth — Tells the Screen section the default color depth to try in bits. 8 is the default, 16 provides thousands of colors, and 32 displays millions of colors.

• Device — Signifies the name of the Device section to use with this Screen section.

• Identifier — Identifies the Screen section so that it can be referred to by a ServerLayout section and be utilized.

• Monitor — Tells the name of the Monitor section to be used with this Screen section.

You may also have a Display subsection within the Screen section which tells the XFree86 server the color depth (Depth) and resolution (Mode) to try first when using this particular monitor and video card.

Contains miscellaneous global XFree86 server settings. These settings may be overridden by options placed in the ServerLayout section. Among the most useful settings:

• DontZap — Prevents the use of the [Ctrl]-[Alt]-[Backspace] key combination to immediately terminate the XFree86 server.

• DontZoom — Prevents cycling through configured video resolutions using the [Ctrl]-[Alt]-[Keypad-Plus] and [Ctrl]-[Alt]-[Keypad-Minus] key combinations.

Binds together a Screen section with the necessary InputDevice sections and various options to create a unified collection of preferences used by the XFree86 server as it starts. If you have more than one ServerLayout section, and the one to use is not specified on the command line when bringing up the XFree86 server, the first ServerLayout section in the configuration file is used.

The following options are used in a ServerLayout section:

• Identifier — A unique name used to describe this ServerLayout section.

• InputDevice — The names of any InputDevice sections to be used with the XFree86 server. Most users will only have two lines here, Keyboard0 and Mouse0, the first keyboard and mouse configured for the system. The options CoreKeyboard and CorePointer refer to the fact that these are the preferred keyboard and mouse, respectively, to use with the XFree86 server.

• Screen — The name of the Screen section to use. The number to the left of the name of the Screen section refers to the particular screen number to use in a multi-head configuration. For standard single-head video cards, this value is 0. The numbers to the right give the X and Y absolute coordinates for the upper-left corner of the screen, by default 0 0.

  Below is an example of a typical screen entry:

  Screen 0 "Screen0" 0 0