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87 lines
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<title>Output Section Address - Untitled</title>
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This file documents the GNU linker LD
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version 2.19.
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Copyright (C) 1991, 92, 93, 94, 95, 96, 97, 98, 99, 2000,
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<p>
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<a name="Output-Section-Address"></a>Next: <a rel="next" accesskey="n" href="Input-Section.html#Input-Section">Input Section</a>,
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Previous: <a rel="previous" accesskey="p" href="Output-Section-Name.html#Output-Section-Name">Output Section Name</a>,
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Up: <a rel="up" accesskey="u" href="SECTIONS.html#SECTIONS">SECTIONS</a>
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<h4 class="subsection">3.6.3 Output Section Address</h4>
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<p><a name="index-address_002c-section-364"></a><a name="index-section-address-365"></a>The <var>address</var> is an expression for the VMA (the virtual memory
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address) of the output section. If you do not provide <var>address</var>,
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the linker will set it based on <var>region</var> if present, or otherwise
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based on the current value of the location counter.
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<p>If you provide <var>address</var>, the address of the output section will be
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set to precisely that. If you provide neither <var>address</var> nor
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<var>region</var>, then the address of the output section will be set to the
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current value of the location counter aligned to the alignment
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requirements of the output section. The alignment requirement of the
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output section is the strictest alignment of any input section contained
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within the output section.
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<p>For example,
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<pre class="smallexample"> .text . : { *(.text) }
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</pre>
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<p class="noindent">and
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<pre class="smallexample"> .text : { *(.text) }
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</pre>
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<p class="noindent">are subtly different. The first will set the address of the
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<span class="samp">.text</span> output section to the current value of the location
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counter. The second will set it to the current value of the location
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counter aligned to the strictest alignment of a <span class="samp">.text</span> input
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section.
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<p>The <var>address</var> may be an arbitrary expression; <a href="Expressions.html#Expressions">Expressions</a>.
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For example, if you want to align the section on a 0x10 byte boundary,
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so that the lowest four bits of the section address are zero, you could
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do something like this:
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<pre class="smallexample"> .text ALIGN(0x10) : { *(.text) }
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</pre>
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<p class="noindent">This works because <code>ALIGN</code> returns the current location counter
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aligned upward to the specified value.
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<p>Specifying <var>address</var> for a section will change the value of the
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location counter.
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</body></html>
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