6.4 X11 Configuration

6.4.1 Before Starting

In most cases, X11 is self-configuring. Those with older or unusual equipment may find it helpful to gather some hardware information before beginning configuration.

• Monitor sync frequencies

• Video card chipset

• Video card memory

Screen resolution and refresh rate are determined by the monitor's horizontal and vertical sync frequencies. Almost all monitors support electronic autodetection of these values. A few monitors do not provide these values, and the specifications must be determined from the printed manual or manufacturer web site.

The video card chipset is also autodetected, and used to select the proper video driver. It is beneficial for the user to be aware of which chipset is installed for when autodetection does not provide the desired result.

Video card memory determines the maximum resolution and color depth which can be displayed.

6.4.2 Configuring X11

Xorg uses HAL to autodetect keyboards and mice. The sysutils/hal and devel/dbus ports are installed as dependencies of x11/xorg, but must be enabled by the following entries in the /etc/rc.conf file:

hald_enable="YES"
dbus_enable="YES"

These services should be started (either manually or by rebooting) before further Xorg configuration or use is attempted.

Xorg can often work without any further configuration steps by simply typing at prompt:

% startx

The automatic configuration may fail to work with some hardware, or may not set things up quite as desired. In these cases, manual configuration will be necessary.

Configuration of X11 is a multi-step process. The first step is to build an initial configuration file. As the super user, simply run:

# Xorg -configure

This will generate an X11 configuration skeleton file in the /root directory called xorg.conf.new (whether you su(1) or do a direct login affects the inherited supervisor $HOME directory variable). The X11 program will attempt to probe the graphics hardware on the system and write a configuration file to load the proper drivers for the detected hardware on the target system.

The next step is to test the existing configuration to verify that Xorg can work with the graphics hardware on the target system. Type:

# Xorg -config xorg.conf.new -retro

If a black and grey grid and an X mouse cursor appear, the configuration was successful. To exit the test, switch to the virtual console used to start it by pressing Ctrl+Alt+Fn (F1 for the first virtual console) and press Ctrl+C.

If the mouse does not work, you will need to first configure it before proceeding. See Section 3.10.10 in the FreeBSD install chapter. In recent Xorg versions, the InputDevice sections in xorg.conf are ignored in favor of the autodetected devices. To restore the old behavior, add the following line to the ServerLayout or ServerFlags section of this file:

Option "AutoAddDevices" "false"

Input devices may then be configured as in previous versions, along with any other options needed (e.g., keyboard layout switching).

The xorg.conf.new configuration file may now be tuned to taste. Open the file in a text editor such as emacs(1) or ee(1). If the monitor is an older or unusual model that does not support autodetection of sync frequencies, those settings can be added to xorg.conf.new under the "Monitor" section:

Section "Monitor"
	Identifier   "Monitor0"
	VendorName   "Monitor Vendor"
	ModelName    "Monitor Model"
	HorizSync    30-107
	VertRefresh  48-120
EndSection

Most monitors support sync frequency autodetection, making manual entry of these values unnecessary. For the few monitors that do not support autodetection, avoid potential damage by only entering values provided by the manufacturer.

X allows DPMS (Energy Star) features to be used with capable monitors. The xset(1) program controls the time-outs and can force standby, suspend, or off modes. If you wish to enable DPMS features for your monitor, you must add the following line to the monitor section:

Option       "DPMS"

While the xorg.conf.new configuration file is still open in an editor, select the default resolution and color depth desired. This is defined in the "Screen" section:

Section "Screen"
	Identifier "Screen0"
	Device     "Card0"
	Monitor    "Monitor0"
	DefaultDepth 24
	SubSection "Display"
		Viewport  0 0
		Depth     24
		Modes     "1024x768"
	EndSubSection
EndSection

The DefaultDepth keyword describes the color depth to run at by default. This can be overridden with the -depth command line switch to Xorg(1). The Modes keyword describes the resolution to run at for the given color depth. Note that only VESA standard modes are supported as defined by the target system's graphics hardware. In the example above, the default color depth is twenty-four bits per pixel. At this color depth, the accepted resolution is 1024 by 768 pixels.

Finally, write the configuration file and test it using the test mode given above.

If all is well, the configuration file needs to be installed in a common location where Xorg(1) can find it. This is typically /etc/X11/xorg.conf or /usr/local/etc/X11/xorg.conf.

# cp xorg.conf.new /etc/X11/xorg.conf

The X11 configuration process is now complete. Xorg may be now started with the startx(1) utility. The X11 server may also be started with the use of xdm(1).

6.4.3 Advanced Configuration Topics

Section "Screen"
Identifier "Screen0"
Device     "Card0"
Monitor    "Monitor0"
DefaultDepth 24
SubSection "Display"
	Viewport  0 0
	Depth     24
	Modes     "1680x1050"
EndSubSection
EndSection

(II) MGA(0): Supported additional Video Mode:
(II) MGA(0): clock: 146.2 MHz   Image Size:  433 x 271 mm
(II) MGA(0): h_active: 1680  h_sync: 1784  h_sync_end 1960 h_blank_end 2240 h_border: 0
(II) MGA(0): v_active: 1050  v_sync: 1053  v_sync_end 1059 v_blanking: 1089 v_border: 0
(II) MGA(0): Ranges: V min: 48  V max: 85 Hz, H min: 30  H max: 94 kHz, PixClock max 170 MHz

ModeLine <name> <clock> <4 horiz. timings> <4 vert. timings>

Section "Monitor"
Identifier      "Monitor1"
VendorName      "Bigname"
ModelName       "BestModel"
ModeLine        "1680x1050" 146.2 1680 1784 1960 2240 1050 1053 1059 1089
Option          "DPMS"
EndSection