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<h3 class="section">G.1 Retrieving Descriptions</h3>

<p>Target descriptions can be read from the target automatically, or
specified by the user manually.  The default behavior is to read the
description from the target.  <span class="sc">gdb</span> retrieves it via the remote
protocol using &lsquo;<samp><span class="samp">qXfer</span></samp>&rsquo; requests (see <a href="General-Query-Packets.html#General-Query-Packets">qXfer</a>).  The <var>annex</var> in the &lsquo;<samp><span class="samp">qXfer</span></samp>&rsquo; packet will be
&lsquo;<samp><span class="samp">target.xml</span></samp>&rsquo;.  The contents of the &lsquo;<samp><span class="samp">target.xml</span></samp>&rsquo; annex are an
XML document, of the form described in <a href="Target-Description-Format.html#Target-Description-Format">Target Description Format</a>.

   <p>Alternatively, you can specify a file to read for the target description. 
If a file is set, the target will not be queried.  The commands to
specify a file are:

     
<a name="index-set-tdesc-filename-3639"></a>
<dl><dt><code>set tdesc filename </code><var>path</var><dd>Read the target description from <var>path</var>.

     <p><a name="index-unset-tdesc-filename-3640"></a><br><dt><code>unset tdesc filename</code><dd>Do not read the XML target description from a file.  <span class="sc">gdb</span>
will use the description supplied by the current target.

     <p><a name="index-show-tdesc-filename-3641"></a><br><dt><code>show tdesc filename</code><dd>Show the filename to read for a target description, if any. 
</dl>

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