Xorg.conf driver section

Ask Ubuntu is a question and answer site for Ubuntu users and developers. It only takes a minute to sign up.

Connect and share knowledge within a single location that is structured and easy to search. So I use "Xorg :1 -configure" to get the default xorg.

Then change the "Device" part, and copy xorg. Reboot Ubuntu. I try to degrade the Xorg version in Ubuntu Then I try it in vmvare machine. Ubuntu Community Ask! Sign up to join this community. The best answers are voted up and rise to the top.

Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Learn more. Asked 1 year, 5 months ago. Active 1 year, 5 months ago. Viewed times. I need to use fbdev driver framebuffer in Xorg to get better system latency.

Sadly, in Ubuntu The acceleration factor is a rational which, together with threshold, can be used to tweak profiles to suit the users needs.

The simple and limited profiles use it directly i. Typically, 1 is unaccelerated and values up to 5 are sensible. Set the threshold, which is roughly the velocity usually device units per 10 ms required for acceleration to become effective.

The precise effect varies with the profile however. The config file may have multiple InputClass sections. These sections are optional and are used to provide configuration for a class of input devices as they are automatically added. An input device can match more than one InputClass section. Each class can override settings from a previous class, so it is best to arrange the sections with the most generic matches first.

The Identifier entry is required in all InputClass sections. The Identifier entry specifies the unique name for this input class. After all classes have been examined, the " inputdriver " module from the first Driver entry will be enabled when using the loadable server.

When an input device is automatically added, its characteristics are checked against all InputClass sections. Each section can contain optional entries to narrow the match of the class. If none of the optional entries appear, the InputClass section is generic and will match any input device.

If more than one of these entries appear, they all must match for the configuration to apply. There are two types of match entries used in InputClass sections.

The first allows various tokens to be matched against attributes of the device. An entry can be constructed to match attributes from different devices by separating arguments with a ' ' character. Multiple entries of the same type may be supplied to add multiple matching conditions on the same attribute. For example:. This entry can be used to check if the substring " matchproduct " occurs in the device's product name. This entry can be used to check if the substring " matchvendor " occurs in the device's vendor name.

This entry can be used to check if the device file matches the " matchdevice " pathname pattern. This entry can be used to check if the operating system matches the case-insensitive " matchos " string.

This entry is only supported on platforms providing the uname 2 system call. The ID is constructed as lowercase hexadecimal numbers separated by a ':'. This is the same format as the lsusb 8 program. Check the case-sensitive string " matchdriver " against the currently configured driver of the device.

Ordering of sections using this entry is important since it will not match unless the driver has been set by the config backend or a previous InputClass section. This entry can be used to check if tags assigned by the config backend matches the " matchtag " pattern.

A match is found if at least one of the tags given in " matchtag " matches at least one of the tags assigned by the backend. Check the case-sensitive string " matchlayout " against the currently active ServerLayout section.

The empty string "" matches an implicit layout which appears if no named ServerLayout sections have been found. These NoMatch directives match if the subsequent match is not met by the device. The second type of entry is used to match device types. These entries take a boolean argument similar to Option entries. When an input device has been matched to the InputClass section, any Option entries are applied to the device.

One InputClass specific Option is recognized. See the InputDevice section above for a description of the remaining Option entries. This optional entry specifies that the device should be ignored entirely, and not added to the server. This can be useful when the device is handled by another program and no X events should be generated. The config file may have multiple OutputClass sections. These sections are optional and are used to provide configuration for a class of output devices as they are automatically added.

An output device can match more than one OutputClass section. The Identifier entry is required in all OutputClass sections. The Identifier entry specifies the unique name for this output class. The Driver entry specifies the name of the driver to use for this output device. After all classes have been examined, the " outputdriver " module from the first Driver entry will be enabled when using the loadable server. When an output device is automatically added, its characteristics are checked against all OutputClass sections.

If none of the optional entries appear, the OutputClass section is generic and will match any output device. The following list of tokens can be matched against attributes of the device. When an output device has been matched to the OutputClass section, any Option entries are applied to the device.

One OutputClass specific Option is recognized. See the Device section below for a description of the remaining Option entries. This option specifies that the matched device should be treated as the primary GPU, replacing the selection of the GPU used as output by the firmware. When an output device matches an OutputClass section, any ModulePath entries in that OutputClass are pre-pended to the search path for loadable Xorg server modules. See ModulePath in the Files section for more info.

The config file may have multiple Device sections. There must be at least one, for the video card being used. The Identifier and Driver entries are required in all Device sections. 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. This specifies the bus location of the graphics card. The " domain" part can be left out for PCI domain 0.

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. This option is mandatory for cards where a single PCI entity can drive more than one display i. 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. 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. 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.

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.

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. 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.

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. 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. This optional entry specifies the IO base address. This optional entry specifies a numerical ID representing the chip type.

This can be used to override the auto-detection, but that should only be done when the driver-specific documentation recommends it. This optional entry specifies the chip revision number.

Only apply this Device section if X server was started with -seat seat-id option. If enabled, bring up monitors of a screen in clone mode instead of horizontal extended layout by default. Defaults to off; the video driver can change the default value, but this option can always override it. 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. The config file may have multiple Monitor sections. There should normally be at least one, for the monitor being used, but a default configuration will be created when one isn't specified. The only mandatory entry in a Monitor section is the Identifier entry.

The Identifier entry specifies the unique name for this monitor. The Monitor section may be used to provide information about the specifications of the monitor, monitor-specific Options , and information about the video modes to use with the monitor. With RandR 1. Using the name of the output defined by the video driver plus the identifier of a monitor section, one associates a monitor section with an output by adding an option to the Device section in the following format:.

Option "Monitor- outputname " " monitorsection ". In the absence of specific association of monitor sections to outputs, if a monitor section is present the server will associate it with an output to preserve compatibility for previous single-head configurations.

Specifying video modes is optional because the server will use the DDC or other information provided by the monitor to automatically configure the list of modes available. When modes are specified explicitly in the Monitor section with the Mode , ModeLine , or UseModes keywords , built-in modes with the same names are not included.

Built-in modes with different names are, however, still implicitly included, when they meet the requirements of the monitor. A range of values is two values separated by a dash. By default the values are in units of kHz. The data given here is used by the Xorg server to determine if video modes are within the specifications of the monitor.

This information should be available in the monitor's handbook. If this entry is omitted, a default range of kHz is used. By default the values are in units of Hz. If this entry is omitted, a default range of Hz is used. This optional entry gives the width and height, in millimetres, of the picture area of the monitor.

If given this is used to calculate the horizontal and vertical pitch DPI of the screen. This is an optional entry that can be used to specify the gamma correction for the monitor.

It may be specified as either a single value or as three separate RGB values. The values should be in the range 0. Not all drivers are capable of using this information. Include the set of modes listed in the Modes section called modesection-id. This makes all of the modes defined in that section available for use by this monitor. This is an optional multi-line entry that can be used to provide definitions for video modes for the monitor.

In most cases this isn't necessary because the built-in set of VESA standard modes will be sufficient. The Mode keyword indicates the start of a multi-line video mode description. The mode description is terminated with the EndMode keyword.

The mode description consists of the following entries:. Not all drivers use this information. This option might become necessary to override the default value supplied by the server if any. If the last few pixels on a scan line appear on the left of the screen, this value should be decreased.

Values less than 1 are treated as 1, which is the default. Generally, the "DoubleScan" Flag mentioned above doubles this value. This entry is a more compact version of the Mode entry, and it also can be used to specify video modes for the monitor. This is a single line format for specifying video modes. The mode-description is in four sections, the first three of which are mandatory. The first is the dot pixel clock. This is a single number specifying the pixel clock rate for the mode in MHz.

The second section is a list of four numbers specifying the horizontal timings. These numbers are the hdisp , hsyncstart , hsyncend , and htotal values. The third section is a list of four numbers specifying the vertical timings.

These numbers are the vdisp , vsyncstart , vsyncend , and vtotal values. The final section is a list of flags specifying other characteristics of the mode. Interlace indicates that the mode is interlaced. DoubleScan indicates a mode where each scanline is doubled.

Composite can be used to specify composite sync on hardware where this is supported. This option controls whether the server should enable the DPMS extension for power management for this screen. The default is to enable the extension. This option controls whether the video card should drive the sync signal on the green color pin. Not all cards support this option, and most monitors do not require it.

The default is off. This optional entry specifies that the monitor should be treated as the primary monitor. RandR 1. This optional entry specifies a mode to be marked as the preferred initial mode of the monitor.

This optional entry specifies modes to be marked as zoom modes. All these keypad available modes are selected from the screen mode list. This list is a copy of the compatibility output monitor mode list. Since this output is the output connected to the lowest dot-area monitor, as determined from its largest size mode, that monitor defines the available zoom modes. This optional entry specifies the position of the monitor within the X screen. This optional entry specifies that the monitor should be positioned to the left of the output not monitor of the given name.

This optional entry specifies that the monitor should be positioned to the right of the output not monitor of the given name.

This optional entry specifies that the monitor should be positioned above the output not monitor of the given name. This optional entry specifies that the monitor should be positioned below the output not monitor of the given name.

This optional entry specifies whether the monitor should be turned on at startup. By default, the server will attempt to enable all connected monitors. This optional entry specifies whether the server should add supported default modes to the list of modes offered on this monitor.

By default, the server will add default modes; you should only disable this if you can guarantee that EDID will be available at all times, or if you have added custom modelines which the server can use. This optional entry specifies that the monitor should be ignored entirely, and not reported through RandR. This is useful if the hardware reports the presence of outputs that don't exist.

This optional entry specifies the initial rotation of the given monitor. Valid values for rotation are "normal", "left", "right", and "inverted". The config file may have multiple Modes sections, or none. These sections provide a way of defining sets of video modes independently of the Monitor sections. Monitor sections may include the definitions provided in these sections by using the UseModes keyword.

In most cases the Modes sections are not necessary because the built-in set of VESA standard modes will be sufficient. The Identifier entry specifies the unique name for this set of mode descriptions. The other entries permitted in Modes sections are the Mode and ModeLine entries that are described above in the Monitor section.

The config file may have multiple Screen sections. If neither of those is present, the first Screen section found in the config file is considered the active one. The Identifier entry specifies the unique name for this screen. The Screen section provides information specific to the whole screen, including screen-specific Options. In multi-head configurations, there will be multiple active Screen sections, one for each head.

The entries available for this section are:. This entry specifies the Device section to be used for this screen. When multiple graphics cards are present, this is what ties a specific card to a screen. The device-id must match the Identifier of a Device section in the config file. This entry specifies the Device section to be used as a secondary GPU device for this screen. When multiple graphics cards are present, this is what ties a specific secondary card to a screen. This can be specified up to 4 times for a single screen.

If a Monitor name is not specified, a default configuration is used. Currently the default configuration may not function as expected on all platforms. The -depth command line option can be used to override this. If neither is specified, the default depth is driver-specific, but in most cases is 8. The -fbbpp command line option can be used to override this.

In most cases the driver will chose the best default value for this. The only case where there is even a choice in this value is for depth 24, where some hardware supports both a packed 24 bit framebuffer layout and a sparse 32 bit framebuffer layout.

Only apply this Screen section if X server was started with -seat seat-id option. Various Option flags may be specified in the Screen section. Some are driver-specific and are described in the driver documentation. Others are driver-independent, and will eventually be described here. Enables 2D hardware acceleration.

This option is on by default, but it may be necessary to turn it off if there are bugs in the driver. There are many options to disable specific accelerated operations, listed below. Note that disabling an operation will have no effect if the operation is not accelerated whether due to lack of support in the hardware or in the driver.

This option specifies a space-separated list of OpenGL vendor libraries to use for the screen. This may be used to select an alternate implementation for development, debugging, or alternate feature sets.

Default: mesa. Use the Int10 module to initialize the primary graphics card. Normally, only secondary cards are soft-booted using the Int10 module, as the primary card has already been initialized by the BIOS at boot time. Disables the Int10 module, a module that uses the int10 call to the BIOS of the graphics card to initialize it. Each Screen section may optionally contain one or more Display subsections. The Display subsection format is described in the section below.

Each Screen section may have multiple Display subsections. The Display subsections are optional. This entry specifies what colour depth the Display subsection is to be used for. This entry is usually specified, but it may be omitted to create a match-all Display subsection or when wishing to match only against the FbBpp parameter. The range of depth values that are allowed depends on the driver. Most drivers support 8, 15, 16 and Note: depth means the number of bits in a pixel that are actually used to determine the pixel colour.

Most hardware that uses 32 bits per pixel only uses 24 of them to hold the colour information, which means that the colour depth is 24, not This entry specifies the framebuffer format this Display subsection is to be used for.