source: clfs-embedded/BOOK/cross-tools/x86/uclibc.xml@ c14754c

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

  <title>uClibc-&uclibc-version;</title>

  <indexterm zone="ch-cross-tools-uclibc">
    <primary sortas="a-uClibc">uClibc</primary>
    <secondary>cross tools</secondary>
  </indexterm>

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

    <para>The uClibc package contains the main C library. This library provides
    the basic routines for allocating memory, searching directories, opening and
    closing files, reading and writing files, string handling, pattern matching,
    arithmetic, and so on.</para>

  </sect2>

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

    <para os="a">Since we are cross-compiling, we need to make sure when we
    configuration for our architecture we get the correct information. The
    following sed makes sure we are using the proper settings for our
    architecture: (This is a place holder for the other architectures</para>

<screen os="b"><userinput>cp extra/Configs/Config.in extra/Configs/Config.in.orig
sed -e "s:default TARGET_i386:default TARGET_i386:" \
   extra/Configs/Config.in.orig > extra/Configs/Config.in</userinput></screen>

    <para os="c">By default uClibc symlinks the headers to the source directory.
    This is not acceptable in our build scenario. So sed the Makefiles to copy them
    instead.</para>

<screen os="d"><userinput>cp Makefile Makefile.orig
sed -e 's/$(LN) -fs/cp/g' Makefile.orig > Makefile
for file in `find libc/sysdeps/linux -name Makefile`; do
        cp $file $file.orig
        sed -e 's/$(LN) -fs/cp/g' -e 's@../libc/@$(TOPDIR)libc/@g' $file.orig > $file
done</userinput></screen>

    <note os="e">
      <para>Below we are just telling uClibc to use the default configuration of
      uClibc. For those for more adventureous, you can use make menuconfig, and
      do a more custom build of your uClibc.</para>
    </note>

    <para os="f">Create default configuration:</para>

<screen os="g"><userinput>make defconfig</userinput></screen>

   <para os="h">We will need to edit the configuration file, to make sure everything gets
   compiled and put into it's proper locations:</para>

<screen os="i"><userinput>cp .config .config.orig
sed -e "/^CROSS_COMPILER_PREFIX/s:=.*:=\"${CLFS_TARGET}-\":" \
    -e "/^KERNEL_SOURCE/s:=.*:=\"${CLFS}/usr\":" \
    -e "/^SHARED_LIB_LOADER_PREFIX/s:=.*:=\"/lib\":" \
    -e "/^DEVEL_PREFIX/s:=.*:=\"/usr\":" \
    -e "/^RUNTIME_PREFIX/s:=.*:=\"/\":" \
    .config.orig > .config</userinput></screen>

    <para os="j">We will need to make sure that some settings in uClibc are set so we
    can utilize all the features of BusyBox:</para>

<screen os="k"><userinput>UCLIBC_OPTIONS="DO_C99_MATH UCLIBC_HAS_RPC UCLIBC_HAS_CTYPE_CHECKED UCLIBC_HAS_WCHAR UCLIBC_HAS_HEXADECIMAL_FLOATS
                UCLIBC_HAS_FOPEN_EXCLUSIVE_MODE UCLIBC_HAS_PRINTF_M_SPEC UCLIBC_HAS_FTW UCLIBC_HAS_IPV6"
for config in $UCLIBC_OPTIONS; do
        cp .config .config.orig
        sed -e "s:# ${config} is not set:${config}=y:" .config.orig > .config
done
echo "UCLIBC_HAS_FULL_RPC=y" >> .config</userinput></screen>

    <para os="l">Compile the package:</para>

<screen os="m"><userinput>make TARGET_ARCH=i386</userinput></screen>

   <para os="n">We will remove the files that were copied over from our Linux Headers during
   the building of uClibc. These files were copied into the include directory of the source
   directory of uClibc:</para>

<screen os="o"><userinput>rm include/{asm,asm-generic,linux}</userinput></screen>

    <para os="p">Install the package:</para>

<screen os="q"><userinput>make PREFIX=${CLFS} install</userinput></screen>

  </sect2>

  <sect2 id="contents-uclibc" role="content">
    <title>Contents of uClibc</title>

    <segmentedlist>
      <segtitle>Installed uClibc</segtitle>

      <seglistitem>
        <seg>To Be Written</seg>
      </seglistitem>
    </segmentedlist>
<!--
    <variablelist>
      <bridgehead renderas="sect3">Short Descriptions</bridgehead>
      <?dbfo list-presentation="list"?>
      <?dbhtml list-presentation="table"?>

     <varlistentry id="uclibc">
        <term><filename
        class="headerfile">/usr/include/{asm,linux}/*.h</filename></term>
        <listitem>
          <para>The Linux API headers</para>
          <indexterm zone="ch-system-linux-headers linux-headers">
            <primary
            sortas="e-/usr/include/{asm,linux}/*.h">/usr/include/{asm,linux}/*.h</primary>
          </indexterm>
        </listitem>
      </varlistentry>
    </variablelist>
-->

  </sect2>
</sect1>