xorg.conf 双显卡情况下，指定显示卡 （不同于计算卡）

• Refer To:

https://www.x.org/releases/current/doc/man/man5/xorg.conf.5.xhtml

 

• For Device Section:

 

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 module "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 single 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 documentation 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 rating 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 documentation 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-specific 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 modesetting 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.