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Next: <a href="HIDDEN.html#HIDDEN" accesskey="n" rel="next">HIDDEN</a>, Up: <a href="Assignments.html#Assignments" accesskey="u" rel="up">Assignments</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="LD-Index.html#LD-Index" title="Index" rel="index">Index</a>]</p>
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<a name="Simple-Assignments-1"></a>
<h4 class="subsection">3.5.1 Simple Assignments</h4>

<p>You may assign to a symbol using any of the C assignment operators:
</p>
<dl compact="compact">
<dt><code><var>symbol</var> = <var>expression</var> ;</code></dt>
<dt><code><var>symbol</var> += <var>expression</var> ;</code></dt>
<dt><code><var>symbol</var> -= <var>expression</var> ;</code></dt>
<dt><code><var>symbol</var> *= <var>expression</var> ;</code></dt>
<dt><code><var>symbol</var> /= <var>expression</var> ;</code></dt>
<dt><code><var>symbol</var> &lt;&lt;= <var>expression</var> ;</code></dt>
<dt><code><var>symbol</var> &gt;&gt;= <var>expression</var> ;</code></dt>
<dt><code><var>symbol</var> &amp;= <var>expression</var> ;</code></dt>
<dt><code><var>symbol</var> |= <var>expression</var> ;</code></dt>
</dl>

<p>The first case will define <var>symbol</var> to the value of
<var>expression</var>.  In the other cases, <var>symbol</var> must already be
defined, and the value will be adjusted accordingly.
</p>
<p>The special symbol name &lsquo;<samp>.</samp>&rsquo; indicates the location counter.  You
may only use this within a <code>SECTIONS</code> command.  See <a href="Location-Counter.html#Location-Counter">Location Counter</a>.
</p>
<p>The semicolon after <var>expression</var> is required.
</p>
<p>Expressions are defined below; see <a href="Expressions.html#Expressions">Expressions</a>.
</p>
<p>You may write symbol assignments as commands in their own right, or as
statements within a <code>SECTIONS</code> command, or as part of an output
section description in a <code>SECTIONS</code> command.
</p>
<p>The section of the symbol will be set from the section of the
expression; for more information, see <a href="Expression-Section.html#Expression-Section">Expression Section</a>.
</p>
<p>Here is an example showing the three different places that symbol
assignments may be used:
</p>
<div class="smallexample">
<pre class="smallexample">floating_point = 0;
SECTIONS
{
  .text :
    {
      *(.text)
      _etext = .;
    }
  _bdata = (. + 3) &amp; ~ 3;
  .data : { *(.data) }
}
</pre></div>
<p>In this example, the symbol &lsquo;<samp>floating_point</samp>&rsquo; will be defined as
zero.  The symbol &lsquo;<samp>_etext</samp>&rsquo; will be defined as the address following
the last &lsquo;<samp>.text</samp>&rsquo; input section.  The symbol &lsquo;<samp>_bdata</samp>&rsquo; will be
defined as the address following the &lsquo;<samp>.text</samp>&rsquo; output section aligned
upward to a 4 byte boundary.
</p>


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