72 lines
3.0 KiB
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72 lines
3.0 KiB
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<title>ARM Mapping Symbols - Using as</title>
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This file documents the GNU Assembler "as".
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<a name="ARM-Mapping-Symbols"></a>
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<p>
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Next: <a rel="next" accesskey="n" href="ARM-Unwinding-Tutorial.html#ARM-Unwinding-Tutorial">ARM Unwinding Tutorial</a>,
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Previous: <a rel="previous" accesskey="p" href="ARM-Opcodes.html#ARM-Opcodes">ARM Opcodes</a>,
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Up: <a rel="up" accesskey="u" href="ARM_002dDependent.html#ARM_002dDependent">ARM-Dependent</a>
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<h4 class="subsection">9.4.6 Mapping Symbols</h4>
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<p>The ARM ELF specification requires that special symbols be inserted
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into object files to mark certain features:
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<a name="index-g_t_0040code_007b_0024a_007d-815"></a>
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<dl><dt><code>$a</code><dd>At the start of a region of code containing ARM instructions.
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<p><a name="index-g_t_0040code_007b_0024t_007d-816"></a><br><dt><code>$t</code><dd>At the start of a region of code containing THUMB instructions.
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<p><a name="index-g_t_0040code_007b_0024d_007d-817"></a><br><dt><code>$d</code><dd>At the start of a region of data.
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</dl>
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<p>The assembler will automatically insert these symbols for you - there
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is no need to code them yourself. Support for tagging symbols ($b,
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$f, $p and $m) which is also mentioned in the current ARM ELF
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specification is not implemented. This is because they have been
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dropped from the new EABI and so tools cannot rely upon their
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presence.
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</body></html>
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