doc/en/xorg-config.xml

<?xml version='1.0' encoding='UTF-8'?>
<!DOCTYPE guide SYSTEM "/dtd/guide.dtd">
<!-- $Header: /var/cvsroot/gentoo/xml/htdocs/doc/en/xorg-config.xml,v 1.44 2011/03/02 08:16:43 nightmorph Exp $ -->

<guide>
<title>The X Server Configuration HOWTO</title>

<author title="Author">
  <mail link="swift"/>
</author>
<author title="Author">
  <mail link="nightmorph"/>
</author>

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

<!-- The content of this document is licensed under the CC-BY-SA license -->
<!-- See http://creativecommons.org/licenses/by-sa/2.5 -->
<license/>

<version>7</version>
<date>2011-03-23</date>

<chapter>
<title>What is the X Window Server?</title>
<section>
<title>Graphical vs Command-Line</title>
<body>

<p>
The average user may be frightened at the thought of having to type in commands.
Why wouldn't he be able to point and click his 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.
</p>

<p>
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
<e>not</e> 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.
</p>

<p>
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 <e>X Window System</e>,
commonly abbreviated as <e>X11</e> or just <e>X</e>. It is used on Unix, Linux
and Unix-like operating systems throughout the world.
</p>

<p>
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.
</p>

</body>
</section>
<section>
<title>The X.org Project</title>
<body>

<p>
The <uri link="http://www.x.org">X.org</uri> project created and
maintains a freely redistributable, open-source implementation of the X11
system. It is an open source X11-based desktop infrastructure.
</p>

<p>
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.
</p>

</body>
</section>
</chapter>

<chapter>
<title>Installing Xorg</title>
<section>
<body>

<p>
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 <path>/etc/make.conf</path> so that the right drivers and Xorg packages
are built and installed.
</p>

</body>
</section>
<section>
<title>Input driver support</title>
<body>

<p>
By default, Xorg uses <c>evdev</c>, a generic input driver. You'll need to
activate support for <c>evdev</c> by making a change to your kernel
configuration. Read the <uri link="/doc/en/kernel-config.xml">Kernel
Configuration Guide</uri> if you don't know how to setup your kernel.
</p>

<pre caption="Enabling evdev in the kernel">
Device Drivers ---&gt;
  Input device support ---&gt;
  &lt;*&gt;  Event interface
</pre>

</body>
</section>
<section>
<title>Kernel modesetting</title>
<body>

<p>
Modern open-source video drivers rely on kernel modesetting (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. KMS conflicts with legacy framebuffer drivers, which must remain
<b>disabled</b> in your kernel configuration.
</p>

<p>
First, prepare your kernel for KMS. You need to do this step regardless of which
Xorg video driver you're using.
</p>

<pre caption="Configuring framebuffers">
Device Drivers ---&gt;
  Graphics support ---&gt;
    Support for frame buffer devices ---&gt;
    <comment>(Disable all drivers, including VGA, Intel, nVidia, and ATI)</comment>

    <comment>(Further down, enable basic console support. KMS uses this.)</comment>
    Console display driver support ---&gt;
      &lt;*&gt;  Framebuffer Console Support
</pre>

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

<p>
For Intel cards:
</p>

<pre caption="Intel settings">
Device Drivers ---&gt;
  Graphics support ---&gt;
    /dev/agpgart (AGP Support) ---&gt;
    &lt;*&gt;  Intel 440LX/BX/GX, I8xx and E7x05 chipset support
    Direct Rendering Manager (XFree86 4.1.0 and higher DRI support) ---&gt;
    &lt;*&gt;  Intel 830M, 845G, 852GM, 855GM, 865G (i915 driver)
         i915 driver
    [*]    Enable modesetting on intel by default
</pre>

<p>
For nVidia cards:
</p>

<pre caption="nVidia settings">
<comment>(Enable DRM)</comment>
Device Drivers ---&gt;
  Graphics support ---&gt;
  &lt;*&gt;  Direct Rendering Manager ---&gt;

<comment>(Nouveau is currently in the Staging drivers section)</comment>
Device Drivers ---&gt;
  Staging drivers ---&gt;
  [ ]  Exclude Staging drivers from being built
  &lt;*&gt;    Nouveau (nVidia) cards
</pre>

<p>
For newer AMD/ATI cards (<uri link="/doc/en/ati-faq.xml">RadeonHD 2000 and
up</uri>), you will need to emerge <c>radeon-ucode</c>. Once you have installed
<c>radeon-ucode</c>, configure your kernel as shown:
</p>

<pre caption="AMD/ATI settings">
<comment>(Setup the kernel to use the radeon-ucode firmware)</comment>
Device Drivers ---&gt;
  Generic Driver Options ---&gt;
  [*]  Include in-kernel firmware blobs in kernel binary
  <comment># RadeonHD 2000, 3000, and 4000 series cards:</comment>
  (radeon/R600_rlc.bin radeon/R700_rlc.bin) External firmware blobs
  <comment># RadeonHD 5000, a.k.a Evergreen, and newer cards:</comment>
  (radeon/CEDAR_me.bin radeon/CEDAR_pfp.bin radeon/CEDAR_rlc.bin
   radeon/CYPRESS_me.bin radeon/CYPRESS_pfp.bin radeon/CYPRESS_rlc.bin
   radeon/JUNIPER_me.bin radeon/JUNIPER_pfp.bin radeon/JUNIPER_rlc.bin
   radeon/REDWOOD_me.bin radeon/REDWOOD_pfp.bin 
   radeon/REDWOOD_rlc.bin) External firmware blobs
  <comment># Radeon HD 6200/6300 aka. Ontario/Zacate:</comment>
  (radeon/PALM_me.bin radeon/PALM_pfp.bin radeon/SUMO_rlc.bin) External
   firmware blobs
  <comment># Radeon HD 6400-6900 aka. Northern Islands:</comment>
  (radeon/BARTS_mc.bin radeon/BARTS_me.bin radeon/BARTS_pfp.bin
   radeon/BTC_rlc.bin radeon/CAICOS_mc.bin radeon/CAICOS_me.bin
   radeon/CAICOS_pfp.bin radeon/TURKS_mc.bin radeon/TURKS_me.bin
   radeon/TURKS_pfp.bin) External firmware blobs
   (/lib/firmware/) Firmware blobs root directory

<comment>(Enable Radeon KMS support)</comment>
Device Drivers ---&gt;
  Graphics support ---&gt;
  &lt;*&gt;  Direct Rendering Manager ---&gt;
  &lt;*&gt;    ATI Radeon
  [*]      Enable modesetting on radeon by default
</pre>

<note>
Old Radeon cards (X1900 series and older) don't need the <c>radeon-ucode</c>
package or any firmware configuration. Just enable the Direct Rendering Manager
and ATI Radeon modesetting.
</note>

<p>
Now that you're done setting up KMS, continue with preparing
<path>/etc/make.conf</path> in the next section.
</p>

</body>
</section>
<section>
<title>make.conf configuration</title>
<body>

<p>
Now that your kernel is prepared, you have to configure two important variables
in the <path>/etc/make.conf</path> file before you can install Xorg.
</p>

<p>
The first variable is <c>VIDEO_CARDS</c>. 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 <c>nouveau</c> for nVidia cards or <c>radeon</c>
for ATI cards. Both have actively developed, well-supported open-source
drivers.
</p>

<note>
You may also try the proprietary drivers from nVidia and AMD/ATI, <c>nvidia</c>
and <c>fglrx</c> respectively. However, setting up the proprietary drivers is
beyond the scope of this guide. Please read the <uri
link="/doc/en/nvidia-guide.xml">Gentoo Linux nVidia Guide</uri> and <uri
link="/doc/en/ati-faq.xml">Gentoo Linux ATI FAQ</uri>. If you don't know which
drivers you should choose, refer to these guides for more information.
</note>

<p>
The <c>intel</c> driver may be used for desktops or laptops with common Intel
integrated graphics chipsets.
</p>

<note>
<c>VIDEO_CARDS</c> may contain more than one driver, each separated with a
space.
</note>

<p>
The second variable is <c>INPUT_DEVICES</c> and is used to determine which
drivers are to be built for input devices. In most cases setting it to
<c>evdev</c> should work just fine. If you use alternative input
devices, such as a Synaptics touchpad for a laptop, be sure to add it to
<c>INPUT_DEVICES</c>.
</p>

<p>
Now you should decide which drivers you will use and add necessary settings to
the <path>/etc/make.conf</path> file:
</p>

<pre caption="Sample make.conf entries">
<comment>(For mouse, keyboard, and Synaptics touchpad support)</comment>
INPUT_DEVICES="evdev synaptics"
<comment>(For nVidia cards)</comment>
VIDEO_CARDS="nouveau"
<comment>(For AMD/ATI cards)</comment>
VIDEO_CARDS="radeon"
</pre>

<p>
If the suggested settings don't work for you, you should run <c>emerge -pv
xorg-drivers</c>, check all the options available and choose those which apply to
your system. This example is for a system with a keyboard, mouse, Synaptics
touchpad, and a Radeon video card.
</p>

<pre caption="Displaying all the driver options available">
# <i>emerge -pv xorg-drivers</i>

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
</pre>

<p>
After setting all the necessary variables you can install the Xorg package.
</p>

<pre caption="Installing Xorg">
<comment>(Make sure udev is in your USE flags)</comment>
# <i>echo "x11-base/xorg-server udev" >> /etc/portage/package.use</i>
<comment>(Install Xorg)</comment>
# <i>emerge xorg-server</i>
</pre>

<note>
You could install the <c>xorg-x11</c> metapackage instead of the more
lightweight <c>xorg-server</c>. Functionally, <c>xorg-x11</c> and
<c>xorg-server</c> are the same. However, <c>xorg-x11</c> brings in many more
packages that you probably don't need, such as a huge assortment of fonts in
many different languages. They're not necessary for a working desktop.
</note>

<p>
When the installation is finished, you will need to re-initialise some
environment variables before you continue:
</p>

<pre caption="Re-initialising the environment variables">
# <i>env-update</i>
# <i>source /etc/profile</i>
</pre>

</body>
</section>
</chapter>

<chapter>
<title>Configuring Xorg</title>
<section>
<body>

<p>
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.
</p>

<p>
You should first try <uri link="#using_startx">starting X</uri> without editing
any configuration files. If Xorg won't start, or there's some other problem,
then you'll need to manually configure Xorg as shown in the next section.
</p>

</body>
</section>
<section>
<title>The xorg.conf.d directory</title>
<body>

<note>
Configuring files in <path>xorg.conf.d</path> should be seen as a "last resort"
option. It really desirable to run without any special configuration if
possible. If you still can't get a working configuration, then read on.
</note>

<p>
The configuration files of Xorg are stored in
<path>/etc/X11/xorg.conf.d/</path>. Each file is given a unique name and ends in
<path>.conf</path>. If the filenames start with a number, then Xorg will read
the files in numeric order. <path>10-evdev.conf</path> will be read before
<path>20-synaptics.conf</path>, and so on. You don't <e>have</e> to give them
numbers, but it may help you organize them.
</p>

<note>
Xorg provides example configurations in
<path>/usr/share/doc/xorg-server-${version}/xorg.conf.example.bz2</path>.  You
can use these to create your own configuration files in
<path>/etc/X11/xorg.conf.d/</path>. The examples are heavily commented, but if
you are in need of more documentation regarding the syntax, read <c>man
xorg.conf</c>. Other examples can be found in the <uri
link="#resources">Resources</uri> chapter at the end of this guide.
</note>

</body>
</section>
<section id="using_startx">
<title>Using startx</title>
<body>

<p>
Now try <c>startx</c> to start up your X server. <c>startx</c> is a script
that executes an <e>X session</e>; 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:
</p>

<ul>
  <li>
    If a file named <path>.xinitrc</path> exists in the home directory, it will
    execute the commands listed there.
  </li>
  <li>
    Otherwise, it will read the value of the XSESSION variable and will execute
    one of the sessions available in <path>/etc/X11/Sessions/</path>
    accordingly. You can set the value of XSESSION in
    <path>/etc/env.d/90xsession</path> to make it a default for all the users
    on the system. For example, as root, run <c>echo XSESSION="Xfce4" >
    /etc/env.d/90xsession</c>. This will create the <path>90xsession</path> file
    and set the default X session to <uri
    link="/doc/en/xfce-config.xml">Xfce</uri>. Remember to run <c>env-update</c>
    after changing <path>90xsession</path>.
  </li>
</ul>

<pre caption="Starting X">
$ <i>startx</i>
</pre>

<p>
If you haven't yet installed a window manager, all you'll see is a black screen.
Since this can also be a sign that something's wrong, you may want to emerge
<c>twm</c> and <c>xterm</c> <e>only to test X</e>.
</p>

<p>
Once those two programs are installed, run <c>startx</c> again. A few
<c>xterm</c> windows should appear, making it easier to verify that X is working
correctly. Once you're satisfied with the results, run <c>emerge --unmerge twm
xterm</c> as root to get rid of the testing packages. You won't need them once
you've setup a proper desktop environment.
</p>

</body>
</section>
</chapter>

<chapter>
<title>Tweaking X settings</title>
<section>
<title>Setting your Resolution</title>
<body>

<p>
If you feel that the screen resolution is wrong, you will need to check two
sections in your <path>xorg.conf.d</path> configuration. First of all, you have
the <e>Screen</e> 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, <e>Monitor</e>.
</p>

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

<pre caption="Changing the Monitor section">
# <i>nano -w /etc/X11/xorg.conf.d/40-monitor.conf</i>

Section "Device"
  Identifier  "RadeonHD 4550"
  Option      "Monitor-DVI-0" "DVI screen"
EndSection
Section "Monitor"
  Identifier  "DVI screen"
  Option      "PreferredMode" "1440x900"
EndSection
</pre>

<p>
Run X (<c>startx</c>) to discover it uses the resolution you want.
</p>

</body>
</section>
<section>
<title>Multiple monitors</title>
<body>

<p>
You can configure more than one monitor in <path>/etc/X11/xorg.conf.d/</path>.
All you have to do is give each monitor an identifer, 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:
</p>

<pre caption="Configuring multiple monitors">
# <i>nano -w /etc/X11/xorg.conf.d/40-monitor.conf</i>

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
</pre>

</body>
</section>
<section>
<title>Configuring your keyboard</title>
<body>

<p>
To setup X to use an international keyboard, you just have to create the
appropriate config file in <path>/etc/X11/xorg.conf.d/</path>. This example
features a Czech keyboard layout:
</p>

<pre caption="Using an international keyboard">
# <i>nano -w /etc/X11/xorg.conf.d/30-keyboard.conf</i>

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
</pre>

<p>
The "terminate" command (<c>terminate:ctrl_alt_bksp</c>) lets you kill the X
session by using the Ctrl-Alt-Backspace key combination. This will, however,
make X exit disgracefully -- something that you might not always want. It can be
useful when programs have frozen your display entirely, or when you're
configuring and tweaking your Xorg environment. Be careful when killing your
desktop with this key combination -- most programs really don't like it when you
end them this way, and you may lose some (or all) of what you were working on.
</p>

</body>
</section>
<section>
<title>Finishing up</title>
<body>

<p>
Run <c>startx</c> and be happy about the result. Congratulations, you now
(hopefully) have a working Xorg on your system. The next step is to install a
useful window manager or desktop environment such as KDE, GNOME, or Xfce, but
that's not part of this guide. Information on installing these desktop
environments can be found in our <uri link="/doc/en/?catid=desktop">Gentoo
Desktop Documentation Resources</uri>.
</p>

</body>
</section>
</chapter>

<chapter id="resources">
<title>Resources</title>
<section>
<title>Creating and editing config files</title>
<body>

<p>
First of all, <c>man xorg.conf</c> and <c>man evdev</c> provide quick yet
complete references about the syntax used by these configuration files. Be sure
to have them open on a terminal when you edit your configuration files!
</p>

<p>
There are also many online resources on editing config files in
<path>/etc/X11/</path>. We only list few of them here; be sure to <uri
link="http://www.google.com">Google</uri> for more.
</p>

</body>
</section>
<section>
<title>Other resources</title>
<body>

<p>
More information about installing and configuring various graphical desktop
environments and applications can be found in the <uri
link="/doc/en/?catid=desktop">Gentoo Desktop Documentation Resources</uri>
section of our documentation.
</p>

<p>
If you're upgrading to <c>xorg-server</c> 1.9 from an earlier version, then be
sure to read the <uri
link="/proj/en/desktop/x/x11/xorg-server-1.9-upgrade-guide.xml">migration
guide</uri>.
</p>

<p>
X.org provides many <uri link="http://www.x.org/wiki/FAQ">FAQs</uri> on their
website, in addition to their other documentation.
</p>

</body>
</section>
</chapter>
</guide>