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Xorg/Guide

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Xorg is the X Window server which allows users to have a graphical environment at their fingertips. This guide explains what Xorg is, how to install it, and the various configuration options.

What is the X Window server?

Graphical vs command-line

An average user may be frightened at the thought of having to type in commands. Why wouldn't they be able to point and click their way through the freedom provided by Gentoo (and Linux in general)? Well, of course you are able to do this! Linux offers a wide variety of flashy user interfaces and environments which you can install on top of your existing installation.

This is one of the biggest surprises new users come across: a graphical user interface is nothing more than an application which runs on your system. It is not part of the Linux kernel or any other internals of the system. It is a powerful tool that fully enables the graphical abilities of your workstation.

As standards are important, a standard for drawing and moving windows on a screen, interacting with the user through mouse, keyboard and other basic, yet important aspects has been created and named the X Window System, commonly abbreviated as X11 or just X. It is used on Unix, Linux and Unix-like operating systems throughout the world.

The application that provides Linux users with the ability to run graphical user interfaces and that uses the X11 standard is Xorg-X11, a fork of the XFree86 project. XFree86 has decided to use a license that might not be compatible with the GPL license; the use of Xorg is therefore recommended. The official Portage tree does not provide an XFree86 package anymore.

The X.org project

The X.org project created and maintains a freely redistributable, open-source implementation of the X11 system. It is an open source X11-based desktop infrastructure.

Xorg provides an interface between your hardware and the graphical software you want to run. Besides that, Xorg is also fully network-aware, meaning you are able to run an application on one system while viewing it on a different one.

Installation

Before you can install Xorg, you need to prepare your system for it. First, we'll set up the kernel to support input devices and video cards. Then we'll prepare /etc/portage/make.conf so that the right drivers and Xorg packages are built and installed.

Input driver support

Support for Event interface (CONFIG_INPUT_EVDEV) needs to be activated by making a change to the kernel configuration. Read the Kernel Configuration Guide if you don't know how to setup your kernel.

KERNEL Enabling evdev in the kernel
Device Drivers --->
  Input device support --->
  <*>  Event interface

Kernel modesetting

Modern open source video drivers rely on kernel mode setting (KMS). KMS provides an improved graphical boot with less flickering, faster user switching, a built-in framebuffer console, seamless switching from the console to Xorg, and other features.

Important
KMS conflicts with legacy framebuffer drivers, which must remain disabled in the kernel configuration.

First prepare the kernel for KMS. This step regardless of which Xorg video driver will be used:

KERNEL Disable legacy framebuffer support and enable basic console FB support
Device Drivers --->
   Graphics support --->
      Frame Buffer Devices --->
         <*> Support for frame buffer devices --->
         ## (Disable all drivers, including VGA, Intel, nVidia, and ATI, except EFI-based Framebuffer Support, only if you are using UEFI)
 
    ## (Further down, enable basic console support. KMS uses this.)
    Console display driver support --->
      <*>  Framebuffer Console Support

Next configure the kernel to use the proper KMS driver for the video card. Intel, nVidia, and AMD/ATI are the most common cards, so follow code listing for each card below.

For Intel cards see the kernel section of the Intel article.

For nVidia cards:

KERNEL nVidia settings
Device Drivers --->
   Graphics support --->
      <M/*>  Nouveau (nVidia) cards

For newer AMD/ATI cards (RadeonHD 2000 and up), emerge sys-kernel/linux-firmware (the package includes radeon and amdgpu; the separate package x11-drivers/radeon-ucode doesn't exist anymore). Once one of these packages has been installed, make the Radeon driver a module in the kernel or, optionally, configure the kernel as detailed in the firmware section of the Radeon article or, for newer AMD graphics cards (GCN1.1+), the firmware section of article AMDGPU:

KERNEL AMD/ATI Radeon settings
## (Setup the kernel to use the radeon-ucode firmware)
Device Drivers --->
   Generic Driver Options --->
   [*]  Include in-kernel firmware blobs in kernel binary
  ## # ATI card specific, (see Radeon page for details which firmware files to include)
   (radeon/<CARD-MODEL>.bin ...)
  ## # Specify the root directory
   (/lib/firmware/) External firmware blobs to build into the kernel binary
 
## (Enable Radeon KMS support)
Device Drivers --->
   Graphics support --->
   <M/*>    ATI Radeon
   [*]      Enable modesetting on radeon by default
   [ ]      Enable userspace modesetting on radeon (DEPRECATED)
KERNEL AMDGPU settings
## (Setup the kernel to use the amdgpu firmware)
Device Drivers --->
   Generic Driver Options --->
   [*]  Include in-kernel firmware blobs in kernel binary
  ## # AMD card specific, (see AMDGPU page for details which firmware files to include)
   (amdgpu/<CARD-MODEL>.bin ...)
  ## # Specify the root directory
   (/lib/firmware/) External firmware blobs to build into the kernel binary
 
## (Enable Radeon KMS support)
Device Drivers --->
   Graphics support --->
   <M/*> Direct Rendering Manager (XFree86 4.1.0 and higher DRI support) --->
   <M/*> AMD GPU
         [ /*] Enable amdgpu support for SI parts
         [ /*] Enable amdgpu support for CIK parts 
         [*]   Enable AMD powerplay component  
         ACP (Audio CoProcessor) Configuration  ---> 
             [*] Enable AMD Audio CoProcessor IP support (CONFIG_DRM_AMD_ACP)
         Display Engine Configuration  --->
             [*] AMD DC - Enable new display engine
             [ /*] DC support for Polaris and older ASICs
             [ /*] AMD FBC - Enable Frame Buffer Compression
             [ /*] DCN 1.0 Raven family
   <M/*> HSA kernel driver for AMD GPU devices
Note
Old Radeon cards (X1900 series and older) do not need extra firmware or any firmware configuration. For them simply enable the Direct Rendering Manager (DRM) and ATI Radeon modesetting.
Note
Linux kernel >= 3.9 does not have the Enable modesetting on radeon by default since it is already implied by default. Do not be alarmed if you find this option missing in new kernels.
Note
Linux kernel >= 4.15 does include Display Core (DC) which is required for AMDGPU to work. This newer driver was written for GCN5.0 Vega and DCN1.0 Raven Ridge (APU), but also adds additional functionality for older Radeon graphics cards starting with GCN1.1 Southern Islands and newer. It is planned to make this additional support for older Radeon cards the standard, so do not be alarmed if you find this option missing in newer kernels.

Exit the kernel configuration, rebuild the kernel, and reboot.

Now that KMS has been set up, continue preparing /etc/portage/make.conf in the next section.

make.conf

Now that the kernel is prepared, two important variables in the /etc/portage/make.conf file must be configured before installing Xorg.

The first variable is VIDEO_CARDS. This is used to set the video drivers that you intend to use and is usually based on the kind of video card you have. The most common settings are nouveau for nVidia cards or radeon for ATI cards. Both have actively developed, well-supported open-source drivers. If you have a newer AMD video card (Southern Islands and up), you may also try the new open-source amdgpu driver. See the AMDGPU article for more details.

Note
You may also try the proprietary drivers from nVidia and AMD/ATI, nvidia and fglrx respectively. However, setting up the proprietary drivers is beyond the scope of this guide. Please read the Gentoo Linux nVidia Guide and Gentoo Linux ATI FAQ. If you don't know which drivers you should choose, refer to these guides for more information.

The intel driver may be used for desktops or laptops with common Intel integrated graphics chipsets.

Note
The VIDEO_CARDS variable may contain more than one value as long as each value is separated by a space.

The second variable is INPUT_DEVICES and is used to determine which drivers are to be built for input devices.

make.defaults has Libinput as the default input device driver.

To check what is presently activated, run:

user $portageq envvar INPUT_DEVICES

In case alternative input devices, such as a Synaptics touchpad for a laptop are needed, be sure to add them to INPUT_DEVICES the /etc/portage/make.conf file:

CODE Sample make.conf entries
## (For mouse, keyboard, and Synaptics touchpad support)
INPUT_DEVICES="libinput synaptics"
## (For nVidia cards)
VIDEO_CARDS="nouveau"
## (For AMD/ATI cards)
VIDEO_CARDS="radeon"

If the suggested settings does not work emerge the x11-base/xorg-drivers package (see the step below). Check all the options available and choose those which apply to the system. This example is for a system with a keyboard, mouse, Synaptics touchpad, and a Radeon video card.

root #emerge --pretend --verbose x11-base/xorg-drivers
 
These are the packages that would be merged, in order:
 
Calculating dependencies... done!
[ebuild   R   ]  x11-base/xorg-drivers-1.9  INPUT_DEVICES="evdev synaptics
-acecad -aiptek -elographics% -fpit% -joystick -keyboard -mouse -penmount -tslib
-virtualbox -vmmouse -void -wacom"
VIDEO_CARDS="radeon -apm -ark -ast -chips -cirrus -dummy -epson -fbdev -fglrx
(-geode) -glint -i128 (-i740) (-impact) -intel -mach64 -mga -neomagic (-newport)
-nouveau -nv -nvidia -r128 -rendition -s3 -s3virge -savage -siliconmotion -sis
-sisusb (-sunbw2) (-suncg14) (-suncg3) (-suncg6) (-sunffb) (-sunleo) (-suntcx)
-tdfx -tga -trident -tseng -v4l -vesa -via -virtualbox -vmware (-voodoo) (-xgi)"
0 kB

After setting all the necessary variables Xorg can be installed:

root #emerge --ask x11-base/xorg-server
Note
The x11-base/xorg-x11 meta-package could be installed instead of the more lightweight x11-base/xorg-server. Functionally x11-base/xorg-x11 and x11-base/xorg-server are the same, however x11-base/xorg-x11 brings in many more packages that most systems will probably not require. Additional packages include a large assortment of fonts in many languages. They are not necessary for a working X11 framework.

When the installation is finished, some environment variables will need to re-initialized before continuing. Source the profile with this command:

root #env-update
root #source /etc/profile

NVidia users

For NVidia users it might be beneficial to run nvidia-xconfig in order to generate a working xorg.conf file for the selected graphics card. Without this step the xorg.conf file will need to be created manually as described below. Missing the xorg.conf will sometimes generate a "No screens found" error to the terminal when attempting to startx.

Also the NVidia driver will only work after a reboot, so be sure to restart the system after running nvidia-xconfig.

root #nvidia-xconfig

It is both possible and recommended to set the OpenGL renderer to the hardware renderer instead of a software renderer:

root #eselect opengl set nvidia

Configuration

The X server is designed to work out-of-the-box, with no need to manually edit Xorg's configuration files. It should detect and configure devices such as displays, keyboards, and mice.

Try using startx without editing any configuration files. If Xorg will not start, or there is some other problem, then manual configuration of Xorg will be needed. This is explained in the following section.

Note
If changes have been made to the kernel, do not forget to restart the system before using startx in order to be using the newly built kernel. If the kernel was updated to a newer version in the process this will most likely require the bootloader's configuration files to be updated as well.

The xorg.conf.d directory

Important
Configuring files in xorg.conf.d should be seen as a last resort option. If possible it is desirable to run Xorg without any special configuration.

Most of the configuration files for Xorg are stored in /etc/X11/xorg.conf.d/. Each file is given a unique name and ends in .conf. The file names in Xorg's configuration directory will be read in alpha numeric order. For example, 10-evdev.conf will be read before 20-synaptics.conf; a-evdev.conf will be read before b-synaptics.conf, and so on. The files in this directory are not required to be numbered, but doing so will help to keep them organized. Organization is helpful when debugging faulty configuration files.

Note
Xorg provides example configurations in /usr/share/doc/xorg-server-${version}/xorg.conf.example.bz2. These can be used to create custom configuration files in /etc/X11/xorg.conf.d/. The examples are heavily commented, but if more documentation regarding the syntax is needed, man xorg.conf is always available. Other examples can be found in the section Other resources at the end of this guide.

Using startx

Try startx to start up the X server. startx is a script (it's installed by x11-apps/xinit) that executes an X session; that is, it starts the X server and some graphical applications on top of it. It decides which applications to run using the following logic:

  • If a file named .xinitrc exists in the home directory, it will execute the commands listed there.
  • Otherwise, it will read the value of the XSESSION variable from the /etc/env.d/90xsession file and execute the relevant session accordingly. Values for XSESSION are available in /etc/X11/Sessions/. To set a system wide default session run:
root #echo XSESSION="Xfce4" > /etc/env.d/90xsession
This will create the 90xsession file and set the default X session to Xfce. Remember to run env-update after making changes to 90xsession.
user $startx

If no window manager has been installed a solid black screen will appear. Since this can also be a sign that something is wrong, the x11-wm/twm and x11-terms/xterm packages can be installed only to test X.

Once the programs are installed, run startx again. A few xterm windows should appear, making it easy to verify the X server is working correctly. Once satisfied with the results, unmerge x11-wm/twm and x11-terms/xterm if installed in the step above to remove the testing packages. They will not be needed to setup a proper desktop environment.

The session (program to start) could also be given as an argument to startx:

user $startx /usr/bin/startfluxbox

You can also pass X11 server options, by preceding them with a double dash:

user $startx -- vt7

Tweaking X settings

Setting the screen resolution

If the screen resolution looks to be wrong, you will need to check two sections in your xorg.conf.d configuration. First of all, you have the Screen section which lists the resolutions that your X server will run at. This section might not list any resolutions at all. If this is the case, Xorg will estimate the resolutions based on the information in the second section, Monitor.

Now let us change the resolution. In the next example from /etc/X11/xorg.conf.d/40-monitor.conf we add the PreferredMode line so that our X server starts at 1440x900 by default. The Option in the Device section must match the name of your monitor (DVI-0), which can be obtained by running xrandr. Install xrandr (emerge xrandr) just long enough to get this information. The argument after the monitor name (in the Device section) must match the Identifier in the Monitor section.

FILE /etc/X11/xorg.conf.d/40-monitor.conf
Section "Device"
  Identifier  "RadeonHD 4550"
  Option      "Monitor-DVI-0" "DVI screen"
EndSection
Section "Monitor"
  Identifier  "DVI screen"
  Option      "PreferredMode" "1440x900"
EndSection

Run X (startx) to discover it uses the desired resolution.

Multiple monitors

More than one monitor in can be established in /etc/X11/xorg.conf.d/. Give each monitor a unique identifier, then list its physical position, such as "RightOf" or "Above" another monitor. The following example shows how to configure a DVI and a VGA monitor, with the VGA monitor as the right-hand screen:

FILE /etc/X11/xorg.conf.d/40-monitor.conf
Section "Device"
  Identifier "RadeonHD 4550"
  Option     "Monitor-DVI-0" "DVI screen"
  Option     "Monitor-VGA-0" "VGA screen"
EndSection
Section "Monitor"
  Identifier "DVI screen"
EndSection
Section "Monitor"
  Identifier "VGA screen"
  Option     "RightOf" "DVI screen"
EndSection

Configuring the keyboard

To setup X to use an international keyboard create the appropriate config file in /etc/X11/xorg.conf.d/. This example features a Czech keyboard layout:

FILE /etc/X11/xorg.conf.d/30-keyboard.conf
Section "InputClass"
  Identifier "keyboard-all"
  Driver "evdev"
  Option "XkbLayout" "us,cz"
  Option "XkbModel" "logitech_g15"
  Option "XkbRules" "xorg"
  Option "XkbOptions" "grp:alt_shift_toggle,grp:switch,grp_led:scroll,compose:rwin,terminate:ctrl_alt_bksp"
  Option "XkbVariant" ",qwerty"
  MatchIsKeyboard "on"
EndSection

For methods of switching the keyboard layout see the Keyboard layout switching article.

The "terminate" command (terminate:ctrl_alt_bksp) lets users kill the X session by using the Ctrl+Alt+Backspace key combination. This will, however, make X exit disgracefully -- something that users might want to avoid. It can be useful when programs have frozen the display entirely, or when configuring and tweaking the Xorg environment. Be careful when killing the desktop with this key combination - most programs really do not like it when they are ended this way. Some, if not all, of the information that has not been written to the disk (information stored in "open documents") will be lost.

Finishing up

Run startx and be happy about the result. Congratulations, you now (hopefully) have a working Xorg! The next step is to install a useful window manager or desktop environment such as KDE, GNOME, or Xfce. Information on installing these desktop environments can be found here on the wiki.

See also

External resources

Creating and editing config files

man xorg.conf and man evdev provide quick yet complete references about the syntax used by these configuration files. Be sure to have them open on a terminal when editing Xorg configuration files!

There are also many online resources on editing config files in /etc/X11/. Only a few are listed here; use a favorite search engine to find more.

Other resources

More information about installing and configuring various graphical desktop environments and applications can be found in the section of our documentation.

When upgrading to xorg-server 1.9 or higher, be sure to read the migration guide.

X.org provides many FAQs on their website, in addition to their other documentation.


This page is based on a document formerly found on our main website gentoo.org.
The following people contributed to the original document: Sven Vermeulen (SwifT), Joshua Saddler (nightmorph)
They are listed here because wiki history does not allow for any external attribution. If you edit the wiki article, please do not add yourself here; your contributions are recorded on each article's associated history page.