[ Pobierz całość w formacie PDF ]
.3 Don t use monitor timing values or ModeLine values for monitors other than yourmodel.If you try to drive a monitor at a frequency for which it was not designed, you candamage or even destroy it.The next section of theXF86Configfile isDevice, which specifies parameters foryour video card.Here is an example.Section "Device"Identifier "#9 GXE 64"# Nothing yet; we fill in these values later.EndSectionThis section defines properties for a particular video card.Identifieris an arbi-trary, descriptive string.You will use this string to refer to the card later.Initially, you don t need to include anything in the Device section except theIdentifier.We will use the X server itself to probe for the properties of the videocard and enter them into theDevicesection later.The XFree86 server is capable of prob-ing for the video chip set, clocks, RAMDAC, and amount of video RAM on the board.Thisis described in Section 5.6.Before we do this, however, we need to finish writing the XF86Config file.Thenext section isScreen, which specifies the monitor/video card combination to use for aparticular server.Section "Screen"Driver "Accel"Device "#9 GXE 64"Monitor "CTX 5468 NI"242 Advanced FeaturesSubsection "Display"Depth 16Modes "1024x768" "800x600" "640x480"ViewPort 0 0Virtual 1024 768EndSubsectionEndSectionTheDriverline specifies the X server that you will be using.ValidDrivervaluesare:Accel: For the XF86 S3, XF86 Mach32, XF86 Mach8, XF86 8514,XF86 P9000,XF86 AGX, andXF86 W32servers;SVGA: For theXF86 SVGAserver;VGA16: For theXF86 VGA16server;VGA2: For theXF86 Monoserver;Mono: For the non-VGA monochrome drivers in theXF86 MonoandXF86 VGA16servers.Be sure that/usr/X11R6/bin/Xis a symbolic link to this server.TheDeviceline specifies theIdentifierof theDevicesection that correspondsto the video card to use for this server.Above, we created aDevicesection with the lineIdentifier "#9 GXE 64"Therefore, we use"#9 GXE 64"on theDeviceline here.Similarly, the Monitor line specifies the name of the Monitor section to be usedwith this server.Here, "CTX 5468 NI" is the Identifier used in the Monitorsection described above.Subsection "Display" defines several properties of the XFree86 server corre-sponding to your monitor/video card combination.TheXF86Configfile describes all ofthese options in detail.Most of them are not necessary to get the system working.The options that you should know about are:Depth.Defines the number of color planes; that is, the number of bits per pixel.Usually,Depthis set to 16.For theVGA16server, you would use a depth of 4, andfor the monochrome server a depth of 1.If you use an accelerated video card with5.5.Configuring XFree86.243enough memory to support more bits per pixel, you can set Depthto 24, or 32.Ifyou have problems with depths higher than 16, set it back to 16 and attempt to debugthe problem later.Modes.This is the list of mode names which have been defined using theModeLine directive(s) in the Monitor section.In the above section, we usedModeLines named "1024x768", "800x600", and "640x48"0.Therefore,we use aModesline ofModes "1024x768" "800x600" "640x480"The first mode listed on this line is the default when XFree86 starts.After XFree86 isrunning, you can switch between the modes listed here using the keys Ctrl - Alt -Numeric + and Ctrl - Alt - Numeric -.It might be best, when you initially configure XFree86, to use lower resolution videomodes like 640x480, which tend to work with most systems.Once you have the basicconfiguration working, you can modifyXF86Configto support higher resolutions.Virtual.Set the virtual desktop size.XFree86 can use additional memory on yourvideo card to extend the size of the desktop.When you move the mouse pointer to theedge of the display, the desktop scrolls, bringing the additional space into view.Evenif you run the server at a lower video resolution like 800x600, you can setVirtualto the total resolution that your video card can support.A 1-megabyte video cardcan support 1024x768 at a depth of 8 bits per pixel; a 2-megabyte card 1280x1024at depth 8, or 1024x768 at depth 16.Of course, the entire area will not be visible atonce, but it can still be used.The Virtual feature is rather limited.If you want to use a true virtual desktop,fvwm and similar window managers allow you to have large, virtual desktops byhiding windows and using other techniques, instead of storing the entire desktop invideo memory.See the manual pages for fvwm for more details about this.ManyLinux systems usefvwmby default.ViewPort.If you are using the Virtual option which is described above,ViewPortsets the coordinates of the upper-left-hand corner of the virtual desktopwhen XFree86 starts up.Virtual 0 0is often used.If this is unspecified, thenthe desktop is centered on the virtual desktop display, which may be undesirable toyou.244 Advanced FeaturesMany other options for this section exist; see the XF86Config manual page for acomplete description.In practice, these options are not necessary to get XFree86 workinginitially.5.6 Filling in video card information.Your XF86Config file is now ready, with the exception of complete informationon the video card.We ll use the X server to probe for this information, and add it toXF86Config.Instead of probing for this information with the X server, XF86Config values formany cards are listed in the files modeDB.txt, AccelCards, and Devices.Thesefiles are all found in /usr/X11R6/lib/X11/doc.In addition, there are variousREADMEfiles for certain chip sets.You should look at these files for information on yourvideo card and use that information (the clock values, chip set type, and any options) in theXF86Configfile.If any information is missing, you can probe for it.In most of these examples we demonstrate configuration of a #9 GXE 64 video card,which uses theXF86 S3chipset.First, determine the video chip set on the card.RunningSuperProbe(found in/usr/X11R6/bin) tells you this information, but you need toknow the chip set name as it is known to the X server.To do this, run the commandX -showconfigThis gives the chip set names known to the X server.(The manual pages for each X serverlist these, too.) For example, with the acceleratedXF86 S3server, we get:XFree86 Version 3.1 / X Window System(protocol Version 11, revision 0, vendor release 6000)Operating System: LinuxConfigured drivers:S3: accelerated server for S3 graphics adaptors (Patchlevel 0)mmio_928, s3_genericThe valid chip set names for this server are mmio 928 and s3 generic.TheXF86 S3man page describes these chip sets and video cards that use them.In the case ofthe #9 GXE 64 video card,mmio 928is appropriate.If you don t know which chip set is in use, the X server can probe it for you.To do this,run the command5.6.Filling in video card information.245X -probeonly > /tmp/x.out 2>&1if you usebashas your shell.If you usecsh, try:X -probeonly &> /tmp/x.outYou should run this command while the system is unloaded; that is, while no otheractivity occurs on the system.This command also probes for your video card dot clocks(as seen below), and system load can throw off this calculation.The output from the above, in/tmp/x.out, should contain lines like:XFree86 Version 3 [ Pobierz całość w formacie PDF ]