source: BOOK/cross-tools/x86/glibc-headers.xml @ f0ed7ed

<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE sect1 PUBLIC "-//OASIS//DTD DocBook XML V4.4//EN"
  "http://www.oasis-open.org/docbook/xml/4.4/docbookx.dtd" [
  <!ENTITY % general-entities SYSTEM "../../general.ent">
  %general-entities;
]>

<sect1 id="ch-cross-tools-glibc-headers" role="wrap">
  <?dbhtml filename="glibc-headers.html"?>

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

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

  <xi:include xmlns:xi="http://www.w3.org/2003/XInclude"
  href="../../final-system/common/glibc.xml"
  xpointer="xpointer(//*[@role='package'])"/>

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

    <para os="s1">The following sed removes a dependency of gcc 3.4.x from
    the glibc we are using in cross-lfs. The reason we are changing it is
    because this only installs the headers, no compiling takes place. In the
    next glibc chapter, we use the gcc that's built right after this chapter.</para>

<screen os="s2"><userinput>cp configure{,.orig}
sed -e 's/3.4/3.[0-9]/g' configure.orig > configure</userinput></screen>

    <xi:include xmlns:xi="http://www.w3.org/2003/XInclude"
    href="../../final-system/common/glibc.xml"
    xpointer="xpointer(//*[@os='e'])"/>

    <xi:include xmlns:xi="http://www.w3.org/2003/XInclude"
    href="../../final-system/common/glibc.xml"
    xpointer="xpointer(//*[@os='f'])"/>

    <xi:include xmlns:xi="http://www.w3.org/2003/XInclude"
    href="../common/glibc.xml"
    xpointer="xpointer(//*[@os='dd'])"/>

    <xi:include xmlns:xi="http://www.w3.org/2003/XInclude"
    href="../common/glibc.xml"
    xpointer="xpointer(//*[@os='de'])"/>

    <para os="df">Glibc has an issue cross-compiling the headers, where it can
    misdetect the capabilities of Binutils and decide they are inadequate.  The
    following line fixes this:</para>

<screen os="dg"><userinput>echo "libc_cv_initfini_array=yes" &gt;&gt; config.cache
</userinput></screen>

    <xi:include xmlns:xi="http://www.w3.org/2003/XInclude"
    href="../../final-system/common/glibc.xml"
    xpointer="xpointer(//*[@os='g'])"/>

<screen os="s3"><userinput>CC=gcc ../glibc-&glibc-version;/configure --prefix=/tools \
    --host=${LFS_TARGET} --build=${LFS_HOST} \
    --disable-sanity-checks --enable-kernel=2.6.0 \
    --with-headers=/tools/include --cache-file=config.cache \
    --with-binutils=/cross-tools/${LFS_TARGET}/bin</userinput></screen>

   <warning os="e1">
      <para><emphasis>Any</emphasis> error message you see about nptl at this point
       can safely be ignored.</para>
   </warning>

    <variablelist os="ca">
      <title>The meaning of the configure options:</title>

      <varlistentry os="ca1">
        <term><parameter>CC=gcc</parameter></term>
        <listitem>
          <para>Tells GLIBC to use the hosts GCC compiler.</para>
        </listitem>
      </varlistentry>

      <varlistentry os="ca2">
        <term><parameter>--build=${LFS_HOST}</parameter></term>
        <listitem>
          <para>When used with --host, this creates a cross-architecture
          executable that creates files for ${LFS_TARGET} but runs on ${LFS_HOST).</para>
        </listitem>
      </varlistentry>

      <varlistentry os="ca3">
        <term><parameter>--host=${LFS_TARGET}</parameter></term>
        <listitem>
          <para>When used with --build, this creates a cross-architecture
          executable that creates files for ${LFS_TARGET} but runs on ${LFS_HOST).</para>
        </listitem>
      </varlistentry>

      <varlistentry os="ca4">
        <term><parameter>--disable-sanity-checks</parameter></term>
        <listitem>
          <para>This switch disables any checks that are in place.</para>
        </listitem>
      </varlistentry>

      <varlistentry os="ca5">
        <term><parameter>--enable-kernel=2.6.0</parameter></term>
        <listitem>
          <para>This tells Glibc to compile the library with support
          for 2.6.x Linux kernels.</para>
        </listitem>
      </varlistentry>

      <varlistentry os="ca6">
        <term><parameter>--with-headers=/tools/include</parameter></term>
        <listitem>
          <para>This tells Glibc to compile itself against the headers
          recently installed to the <filename class="directory">/tools</filename>
          directory, so that it knows exactly what features the kernel has
          and can optimize itself accordingly.</para>
        </listitem>
      </varlistentry>

      <varlistentry os="ca7">
        <term><parameter>--with-binutils=/cross-tools/${LFS_TARGET}/bin</parameter></term>
        <listitem>
          <para>This tells GLIBC to use the binutils for our specific target architecture.</para>
        </listitem>
      </varlistentry>

    </variablelist>

    <para os="cb">Now, install the headers:</para>

<screen os="cd"><userinput>make install-headers</userinput></screen>

    <para os="ce">Some files aren't installed by the above command, so we will copy the additional header files we need:</para>

    <para os="cf">First we will copy a common file over to <filename
    class="directory">/tools/include</filename>:</para>

<screen os="cg"><userinput>install -d /tools/include/bits
cp bits/stdio_lim.h /tools/include/bits</userinput></screen>

    <para os="ch">Now we will create a blank stub file:</para>

<screen os="ci"><userinput>touch /tools/include/gnu/stubs.h</userinput></screen>

    <para os="cj">For NPTL we use the following command:</para>

<screen os="ck"><userinput>cp ../glibc-&glibc-version;/nptl/sysdeps/pthread/pthread.h /tools/include/</userinput></screen>

    <para os="cl">Now we copy the architecture specific header over:</para>

<screen os="cm"><userinput>cp ../glibc-&glibc-version;/nptl/sysdeps/unix/sysv/linux/i386/bits/pthreadtypes.h /tools/include/bits/</userinput></screen>

  </sect2>

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

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

  </sect2>

</sect1>