lfs-book/chapter05/glibc.xml

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  "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
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<sect1 id="ch-tools-glibc" role="wrap">
  <?dbhtml filename="glibc.html"?>

  <sect1info condition="script">
    <productname>glibc</productname>
    <productnumber>&glibc-version;</productnumber>
    <address>&glibc-url;</address>
  </sect1info>

  <title>Glibc-&glibc-version;</title>

  <indexterm zone="ch-tools-glibc">
    <primary sortas="a-Glibc">Glibc</primary>
    <secondary>tools</secondary>
  </indexterm>

  <sect2 role="package">
    <title/>

    <xi:include xmlns:xi="http://www.w3.org/2001/XInclude"
    href="../chapter06/glibc.xml"
    xpointer="xpointer(/sect1/sect2[1]/para[1])"/>

    <segmentedlist>
      <segtitle>&buildtime;</segtitle>
      <segtitle>&diskspace;</segtitle>

      <seglistitem>
        <seg>&glibc-ch5-sbu;</seg>
        <seg>&glibc-ch5-du;</seg>
      </seglistitem>
    </segmentedlist>

  </sect2>

  <sect2 role="installation">
    <title>Installation of Glibc</title>

    <para>The Glibc documentation recommends building Glibc 
    in a dedicated build directory:</para>

<screen><userinput remap="pre">mkdir -v build
cd       build</userinput></screen>

    <para>Next, prepare Glibc for compilation:</para>

<screen><userinput remap="configure">../configure                             \
      --prefix=/tools                    \
      --host=$LFS_TGT                    \
      --build=$(../scripts/config.guess) \
      --enable-kernel=&min-kernel;             \
      --with-headers=/tools/include      \
      libc_cv_forced_unwind=yes          \
      libc_cv_c_cleanup=yes</userinput></screen>

    <variablelist>
      <title>The meaning of the configure options:</title>

      <varlistentry>
        <term><parameter>--host=$LFS_TGT, --build=$(../scripts/config.guess)</parameter></term>
        <listitem>
          <para>The combined effect of these switches is that Glibc's build system
          configures itself to cross-compile, using the cross-linker and
          cross-compiler in <filename class="directory">/tools</filename>.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><parameter>--enable-kernel=&min-kernel;</parameter></term>
        <listitem>
          <para>This tells Glibc to compile the library with support
          for &min-kernel; and later Linux kernels.  Workarounds for older
          kernels are not enabled.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><parameter>--with-headers=/tools/include</parameter></term>
        <listitem>
          <para>This tells Glibc to compile itself against the headers recently
          installed to the tools directory, so that it knows exactly what
          features the kernel has and can optimize itself accordingly.</para>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><parameter>libc_cv_forced_unwind=yes</parameter></term>
        <listitem>
          <para>The linker installed during
          <xref linkend="ch-tools-binutils-pass1"/> was cross-compiled and as
          such cannot be used until Glibc has been installed.  This means that
          the configure test for force-unwind support will fail, as it relies on
          a working linker.  The libc_cv_forced_unwind=yes variable is passed in
          order to inform <command>configure</command> that force-unwind
          support is available without it having to run the test.</para>
        </listitem>
      </varlistentry>
      <varlistentry>
        <term><parameter>libc_cv_c_cleanup=yes</parameter></term>
        <listitem>
          <para>Similarly, we pass libc_cv_c_cleanup=yes through to the
          <command>configure</command> script so that the test is skipped and C
          cleanup handling support is configured.</para>
        </listitem>
      </varlistentry>
<!--  <varlistentry>
        <term><parameter>libc_cv_ctors_header=yes</parameter></term>
        <listitem>
          <para>Similarly, we pass libc_cv_ctors_header=yes through to the
          <command>configure</command> script so that the test is skipped and
          gcc constructor support is configured.</para>
        </listitem>
      </varlistentry>-->

    </variablelist>

    <para>During this stage the following warning might appear:</para>

    <blockquote>
<screen><computeroutput>configure: WARNING:
*** These auxiliary programs are missing or
*** incompatible versions: msgfmt
*** some features will be disabled.
*** Check the INSTALL file for required versions.</computeroutput></screen>
    </blockquote>

    <para>The missing or incompatible <command>msgfmt</command> program is
    generally harmless. This <command>msgfmt</command> program is part of the
    Gettext package which the host distribution should provide.</para>

    <note><para>There have been reports that this package may fail when 
    building as a "parallel make".  If this occurs, rerun the make command
    with a "-j1" option.</para></note>

    <para>Compile the package:</para>

<screen><userinput remap="make">make</userinput></screen>

    <para>Install the package:</para>

<screen><userinput remap="install">make install</userinput></screen>

  <caution>
    <para>At this point, it is imperative to stop and ensure that the basic
    functions (compiling and linking) of the new toolchain are working as
    expected. To perform a sanity check, run the following commands:</para>

<screen><userinput>echo 'int main(){}' &gt; dummy.c
$LFS_TGT-gcc dummy.c
readelf -l a.out | grep ': /tools'</userinput></screen>

    <para>If everything is working correctly, there should be no errors,
    and the output of the last command will be of the form:</para>

<screen><computeroutput>[Requesting program interpreter: /tools/lib/ld-linux.so.2]</computeroutput></screen>

    <para>Note that for 64-bit machines, the interpreter name will be
    <filename>/tools/lib64/ld-linux-x86-64.so.2</filename>.</para>

    <para>If the output is not shown as above or there was no output at all,
    then something is wrong. Investigate and retrace the steps to find out
    where the problem is and correct it. This issue must be resolved before
    continuing on.</para>

    <para>Once all is well, clean up the test files:</para>

<screen><userinput>rm -v dummy.c a.out</userinput></screen>

  </caution>

  <note><para>Building Binutils in the section after next will serve as an
  additional check that the toolchain has been built properly. If Binutils
  fails to build, it is an indication that something has gone wrong with the
  previous Binutils, GCC, or Glibc installations.</para></note>

  </sect2>

  <sect2 role="content">
    <title/>

    <para>Details on this package are located in
    <xref linkend="contents-glibc" role="."/></para>

  </sect2>

</sect1>