lfs-book/chapter07/console.xml

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<sect1 id="ch-scripts-console">
  <?dbhtml filename="console.html"?>

  <title>Configuring the Linux Console</title>

  <indexterm zone="ch-scripts-console">
    <primary sortas="d-console">console</primary>
    <secondary>configuring</secondary>
  </indexterm>

  <para>This section discusses how to configure the <command>console</command>
  bootscript that sets up the keyboard map, console font and console kernel log
  level. If non-ASCII characters (e.g., the copyright sign, the British pound
  sign and Euro symbol) will not be used and the keyboard is a U.S. one, much
  of this section can be skipped. Without the configuration file, (or 
  equivalent settings in <filename>rc.site</filename>), the
  <command>console</command> bootscript will do nothing.</para>

  <para>The <command>console</command> script reads the
  <filename>/etc/sysconfig/console</filename> file for configuration
  information.  Decide which keymap and screen font will be used. Various
  language-specific HOWTOs can also help with this, see <ulink
  url="http://www.tldp.org/HOWTO/HOWTO-INDEX/other-lang.html"/>. If still in
  doubt, look in the <filename class="directory">/lib/kbd</filename> directory
  for valid keymaps and screen fonts. Read <filename>loadkeys(1)</filename> and
  <filename>setfont(8)</filename> manual pages to determine the correct
  arguments for these programs.</para>

  <para>The <filename>/etc/sysconfig/console</filename> file should contain lines
  of the form: VARIABLE="value". The following variables are recognized:</para>

  <variablelist>

    <varlistentry>
      <term>LOGLEVEL</term>
      <listitem>
        <para>This variable specifies the log level for kernel messages sent
        to the console as set by <command>dmesg</command>. Valid levels are
        from "1" (no messages) to "8". The default level is "7".</para>
      </listitem>
    </varlistentry>

    <varlistentry>
      <term>KEYMAP</term>
      <listitem>
        <para>This variable specifies the arguments for the
        <command>loadkeys</command> program, typically, the name of keymap
        to load, e.g., <quote>es</quote>. If this variable is not set, the
        bootscript will not run the <command>loadkeys</command> program,
        and the default kernel keymap will be used.</para>
      </listitem>
    </varlistentry>

    <varlistentry>
      <term>KEYMAP_CORRECTIONS</term>
      <listitem>
        <para>This (rarely used) variable
        specifies the arguments for the second call to the
        <command>loadkeys</command> program. This is useful if the stock keymap
        is not completely satisfactory and a small adjustment has to be made. E.g.,
        to include the Euro sign into a keymap that normally doesn't have it,
        set this variable to <quote>euro2</quote>.</para>
      </listitem>
    </varlistentry>

    <varlistentry>
      <term>FONT</term>
      <listitem>
        <para>This variable specifies the arguments for the
        <command>setfont</command> program. Typically, this includes the font
        name, <quote>-m</quote>, and the name of the application character
        map to load. E.g., in order to load the <quote>lat1-16</quote> font
        together with the <quote>8859-1</quote> application character map
        (as it is appropriate in the USA), 
        <!-- because of the copyright sign -->
        set this variable to <quote>lat1-16 -m 8859-1</quote>.
        In UTF-8 mode, the kernel uses the application character map for
        conversion of composed 8-bit key codes in the keymap to UTF-8, and thus
        the argument of the "-m" parameter should be set to the encoding of the
        composed key codes in the keymap.</para>

      </listitem>
    </varlistentry>

    <varlistentry>
      <term>UNICODE</term>
      <listitem>
        <para>Set this variable to <quote>1</quote>, <quote>yes</quote> or
        <quote>true</quote> in order to put the
        console into UTF-8 mode. This is useful in UTF-8 based locales and
        harmful otherwise.</para>
      </listitem>
    </varlistentry>

    <varlistentry>
      <term>LEGACY_CHARSET</term>
      <listitem>
        <para>For many keyboard layouts, there is no stock Unicode keymap in
        the Kbd package. The <command>console</command> bootscript will
        convert an available keymap to UTF-8 on the fly if this variable is
        set to the encoding of the available non-UTF-8 keymap.</para>
      </listitem>
    </varlistentry>

  </variablelist>

  <para>Some examples:</para>

  <itemizedlist>

    <listitem>
      <para>For a non-Unicode setup, only the KEYMAP and FONT variables are
      generally needed. E.g., for a Polish setup, one would use:</para>

<screen role="nodump"><userinput>cat &gt; /etc/sysconfig/console &lt;&lt; "EOF"
<literal># Begin /etc/sysconfig/console

KEYMAP="pl2"
FONT="lat2a-16 -m 8859-2"

# End /etc/sysconfig/console</literal>
EOF</userinput></screen>
    </listitem>

    <listitem>
      <para>As mentioned above, it is sometimes necessary to adjust a
      stock keymap slightly. The following example adds the Euro symbol to the
      German keymap:</para>

<screen role="nodump"><userinput>cat &gt; /etc/sysconfig/console &lt;&lt; "EOF"
<literal># Begin /etc/sysconfig/console

KEYMAP="de-latin1"
KEYMAP_CORRECTIONS="euro2"
FONT="lat0-16 -m 8859-15"

# End /etc/sysconfig/console</literal>
EOF</userinput></screen>
    </listitem>

    <listitem>
      <para>The following is a Unicode-enabled example for Bulgarian, where a
      stock UTF-8 keymap exists:</para>

<screen role="nodump"><userinput>cat &gt; /etc/sysconfig/console &lt;&lt; "EOF"
<literal># Begin /etc/sysconfig/console

UNICODE="1"
KEYMAP="bg_bds-utf8"
FONT="LatArCyrHeb-16"

# End /etc/sysconfig/console</literal>
EOF</userinput></screen>
    </listitem>

    <listitem>
      <para>Due to the use of a 512-glyph LatArCyrHeb-16 font in the previous
      example, bright colors are no longer available on the Linux console unless
      a framebuffer is used. If one wants to have bright colors without
      framebuffer and can live without characters not belonging to his language,
      it is still possible to use a language-specific 256-glyph font, as
      illustrated below:</para>

<screen role="nodump"><userinput>cat &gt; /etc/sysconfig/console &lt;&lt; "EOF"
<literal># Begin /etc/sysconfig/console

UNICODE="1"
KEYMAP="bg_bds-utf8"
FONT="cyr-sun16"

# End /etc/sysconfig/console</literal>
EOF</userinput></screen>
    </listitem>

    <listitem>
      <para>The following example illustrates keymap autoconversion from
      ISO-8859-15 to UTF-8 and enabling dead keys in Unicode mode:</para>

<screen role="nodump"><userinput>cat &gt; /etc/sysconfig/console &lt;&lt; "EOF"
<literal># Begin /etc/sysconfig/console

UNICODE="1"
KEYMAP="de-latin1"
KEYMAP_CORRECTIONS="euro2"
LEGACY_CHARSET="iso-8859-15"
FONT="LatArCyrHeb-16 -m 8859-15"

# End /etc/sysconfig/console</literal>
EOF</userinput></screen>
    </listitem>

    <listitem>
      <para>Some keymaps have dead keys (i.e., keys that don't produce a
      character by themselves, but put an accent on the character produced
      by the next key) or define composition rules (such as: <quote>press
      Ctrl+. A E to get &AElig;</quote> in the default keymap).
      Linux-&linux-version; interprets dead keys and composition rules in the
      keymap correctly only when the source characters to be composed together
      are not multibyte. This deficiency doesn't affect keymaps for European
      languages, because there accents are added to unaccented ASCII
      characters, or two ASCII characters are composed together. However, in
      UTF-8 mode it is a problem, e.g., for the Greek language, where one
      sometimes needs to put an accent on the letter <quote>alpha</quote>.
      The solution is either to avoid the use of UTF-8, or to install the
      X window system that doesn't have this limitation in its input
      handling.</para>
    </listitem>

    <listitem>
      <para>For Chinese, Japanese, Korean and some other languages, the Linux
      console cannot be configured to display the needed characters. Users
      who need such languages should install the X Window System, fonts that
      cover the necessary character ranges, and the proper input method (e.g.,
      SCIM, it supports a wide variety of languages).</para>
    </listitem>

  </itemizedlist>

  <!-- Added because folks keep posting their console file with X questions
  to blfs-support list -->
  <note>
    <para>The <filename>/etc/sysconfig/console</filename> file only controls the    Linux text console localization. It has nothing to do with setting the
    proper keyboard layout and terminal fonts in the X Window System, with ssh
    sessions or with a serial console. In such situations, limitations mentioned
    in the last two list items above do not apply.</para>
  </note>

</sect1>