title: Cross compiling toolchain using crosstool-ng
body: <p>I am trying to build a Linux environment with glibc version 2.5 to compile C code using crosstool-ng. But I cannot find glibc version 2.5 in configuration for some reason. Does anyone know how to fix that?</p>
  
  <p>And I tried to use older version glibc 2.2 and got the errors when building the library.</p>
  
  <pre><code> Installing C library headers &amp; start files
  [EXTRA]    Configuring C library
  [ERROR]    configure: error: GNU libc requires kernel header files from
  [ERROR]   
  [ERROR]  &gt;&gt;
  [ERROR]  &gt;&gt;  Build failed in step 'Installing C library headers &amp; start files'
  [ERROR]  &gt;&gt;        called in step '(top-level)'
  [ERROR]  &gt;&gt;
  [ERROR]  &gt;&gt;  Error happened in: CT_DoExecLog[scripts/functions@257]
  [ERROR]  &gt;&gt;        called from: do_libc_backend_once[scripts/build/libc/glibc-eglibc.sh-common@354]
  [ERROR]  &gt;&gt;        called from: do_libc_backend[scripts/build/libc/glibc-eglibc.sh-common@149]
  [ERROR]  &gt;&gt;        called from: do_libc_start_files[scripts/build/libc/glibc-eglibc.sh-common@66]
  [ERROR]  &gt;&gt;        called from: main[scripts/crosstool-NG.sh@638]
  [ERROR]  &gt;&gt;
  [ERROR]  &gt;&gt;  For more info on this error, look at the file: 'build.log'
  [ERROR]  &gt;&gt;  There is a list of known issues, some with workarounds, in:
  [ERROR]  &gt;&gt;      '/usr/crosstool-ng/share/doc/crosstool-ng/ct-ng.1.20.0/B - Known issues.txt'
  [ERROR]   
  [ERROR]  (elapsed: 24:43.44)
  [24:45] / make: *** [build] Error 1
  </code></pre>
  
  <p>Here are all configurations I modified:</p>
  
  <pre><code>Target Option
      Target Architecture    x86
  OS
      Target OS      Linux
      Linux kernel version  -  2.6.27.62(actually need 2.6.18 but cannot find it)
  
  Binary utilities
      binutils version 2.25
  
  C-library
      C library    -- glibc 2.2    need glibc 2.5
  
  C compiler   -- gcc version 4.4.5
  </code></pre>
  
  <p>Can anyone tell me what's wrong with my configurations and how to fix it? Thanks.</p>