136 lines
5.6 KiB
HTML
136 lines
5.6 KiB
HTML
|
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
|
||
|
|
<html>
|
||
|
|
<!-- This file documents the GNU Assembler "as".
|
||
|
|
|
||
|
|
Copyright (C) 1991-2016 Free Software Foundation, Inc.
|
||
|
|
|
||
|
|
Permission is granted to copy, distribute and/or modify this document
|
||
|
|
under the terms of the GNU Free Documentation License, Version 1.3
|
||
|
|
or any later version published by the Free Software Foundation;
|
||
|
|
with no Invariant Sections, with no Front-Cover Texts, and with no
|
||
|
|
Back-Cover Texts. A copy of the license is included in the
|
||
|
|
section entitled "GNU Free Documentation License".
|
||
|
|
-->
|
||
|
|
<!-- Created by GNU Texinfo 5.2, http://www.gnu.org/software/texinfo/ -->
|
||
|
|
<head>
|
||
|
|
<title>Using as: ARM-Relocations</title>
|
||
|
|
|
||
|
|
<meta name="description" content="Using as: ARM-Relocations">
|
||
|
|
<meta name="keywords" content="Using as: ARM-Relocations">
|
||
|
|
<meta name="resource-type" content="document">
|
||
|
|
<meta name="distribution" content="global">
|
||
|
|
<meta name="Generator" content="makeinfo">
|
||
|
|
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
|
||
|
|
<link href="index.html#Top" rel="start" title="Top">
|
||
|
|
<link href="AS-Index.html#AS-Index" rel="index" title="AS Index">
|
||
|
|
<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
|
||
|
|
<link href="ARM-Syntax.html#ARM-Syntax" rel="up" title="ARM Syntax">
|
||
|
|
<link href="ARM_002dNeon_002dAlignment.html#ARM_002dNeon_002dAlignment" rel="next" title="ARM-Neon-Alignment">
|
||
|
|
<link href="ARM_002dRegs.html#ARM_002dRegs" rel="prev" title="ARM-Regs">
|
||
|
|
<style type="text/css">
|
||
|
|
<!--
|
||
|
|
a.summary-letter {text-decoration: none}
|
||
|
|
blockquote.smallquotation {font-size: smaller}
|
||
|
|
div.display {margin-left: 3.2em}
|
||
|
|
div.example {margin-left: 3.2em}
|
||
|
|
div.indentedblock {margin-left: 3.2em}
|
||
|
|
div.lisp {margin-left: 3.2em}
|
||
|
|
div.smalldisplay {margin-left: 3.2em}
|
||
|
|
div.smallexample {margin-left: 3.2em}
|
||
|
|
div.smallindentedblock {margin-left: 3.2em; font-size: smaller}
|
||
|
|
div.smalllisp {margin-left: 3.2em}
|
||
|
|
kbd {font-style:oblique}
|
||
|
|
pre.display {font-family: inherit}
|
||
|
|
pre.format {font-family: inherit}
|
||
|
|
pre.menu-comment {font-family: serif}
|
||
|
|
pre.menu-preformatted {font-family: serif}
|
||
|
|
pre.smalldisplay {font-family: inherit; font-size: smaller}
|
||
|
|
pre.smallexample {font-size: smaller}
|
||
|
|
pre.smallformat {font-family: inherit; font-size: smaller}
|
||
|
|
pre.smalllisp {font-size: smaller}
|
||
|
|
span.nocodebreak {white-space:nowrap}
|
||
|
|
span.nolinebreak {white-space:nowrap}
|
||
|
|
span.roman {font-family:serif; font-weight:normal}
|
||
|
|
span.sansserif {font-family:sans-serif; font-weight:normal}
|
||
|
|
ul.no-bullet {list-style: none}
|
||
|
|
-->
|
||
|
|
</style>
|
||
|
|
|
||
|
|
|
||
|
|
</head>
|
||
|
|
|
||
|
|
<body lang="en" bgcolor="#FFFFFF" text="#000000" link="#0000FF" vlink="#800080" alink="#FF0000">
|
||
|
|
<a name="ARM_002dRelocations"></a>
|
||
|
|
<div class="header">
|
||
|
|
<p>
|
||
|
|
Next: <a href="ARM_002dNeon_002dAlignment.html#ARM_002dNeon_002dAlignment" accesskey="n" rel="next">ARM-Neon-Alignment</a>, Previous: <a href="ARM_002dRegs.html#ARM_002dRegs" accesskey="p" rel="prev">ARM-Regs</a>, Up: <a href="ARM-Syntax.html#ARM-Syntax" accesskey="u" rel="up">ARM Syntax</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="AS-Index.html#AS-Index" title="Index" rel="index">Index</a>]</p>
|
||
|
|
</div>
|
||
|
|
<hr>
|
||
|
|
<a name="ARM-relocation-generation"></a>
|
||
|
|
<h4 class="subsubsection">9.4.2.4 ARM relocation generation</h4>
|
||
|
|
|
||
|
|
<a name="index-data-relocations_002c-ARM"></a>
|
||
|
|
<a name="index-ARM-data-relocations"></a>
|
||
|
|
<p>Specific data relocations can be generated by putting the relocation name
|
||
|
|
in parentheses after the symbol name. For example:
|
||
|
|
</p>
|
||
|
|
<div class="smallexample">
|
||
|
|
<pre class="smallexample"> .word foo(TARGET1)
|
||
|
|
</pre></div>
|
||
|
|
|
||
|
|
<p>This will generate an ‘<samp>R_ARM_TARGET1</samp>’ relocation against the symbol
|
||
|
|
<var>foo</var>.
|
||
|
|
The following relocations are supported:
|
||
|
|
<code>GOT</code>,
|
||
|
|
<code>GOTOFF</code>,
|
||
|
|
<code>TARGET1</code>,
|
||
|
|
<code>TARGET2</code>,
|
||
|
|
<code>SBREL</code>,
|
||
|
|
<code>TLSGD</code>,
|
||
|
|
<code>TLSLDM</code>,
|
||
|
|
<code>TLSLDO</code>,
|
||
|
|
<code>TLSDESC</code>,
|
||
|
|
<code>TLSCALL</code>,
|
||
|
|
<code>GOTTPOFF</code>,
|
||
|
|
<code>GOT_PREL</code>
|
||
|
|
and
|
||
|
|
<code>TPOFF</code>.
|
||
|
|
</p>
|
||
|
|
<p>For compatibility with older toolchains the assembler also accepts
|
||
|
|
<code>(PLT)</code> after branch targets. On legacy targets this will
|
||
|
|
generate the deprecated ‘<samp>R_ARM_PLT32</samp>’ relocation. On EABI
|
||
|
|
targets it will encode either the ‘<samp>R_ARM_CALL</samp>’ or
|
||
|
|
‘<samp>R_ARM_JUMP24</samp>’ relocation, as appropriate.
|
||
|
|
</p>
|
||
|
|
<a name="index-MOVW-and-MOVT-relocations_002c-ARM"></a>
|
||
|
|
<p>Relocations for ‘<samp>MOVW</samp>’ and ‘<samp>MOVT</samp>’ instructions can be generated
|
||
|
|
by prefixing the value with ‘<samp>#:lower16:</samp>’ and ‘<samp>#:upper16</samp>’
|
||
|
|
respectively. For example to load the 32-bit address of foo into r0:
|
||
|
|
</p>
|
||
|
|
<div class="smallexample">
|
||
|
|
<pre class="smallexample"> MOVW r0, #:lower16:foo
|
||
|
|
MOVT r0, #:upper16:foo
|
||
|
|
</pre></div>
|
||
|
|
|
||
|
|
<p>Relocations ‘<samp>R_ARM_THM_ALU_ABS_G0_NC</samp>’, ‘<samp>R_ARM_THM_ALU_ABS_G1_NC</samp>’,
|
||
|
|
‘<samp>R_ARM_THM_ALU_ABS_G2_NC</samp>’ and ‘<samp>R_ARM_THM_ALU_ABS_G3_NC</samp>’ can be
|
||
|
|
generated by prefixing the value with ‘<samp>#:lower0_7:#</samp>’,
|
||
|
|
‘<samp>#:lower8_15:#</samp>’, ‘<samp>#:upper0_7:#</samp>’ and ‘<samp>#:upper8_15:#</samp>’
|
||
|
|
respectively. For example to load the 32-bit address of foo into r0:
|
||
|
|
</p>
|
||
|
|
<div class="smallexample">
|
||
|
|
<pre class="smallexample"> MOVS r0, #:upper8_15:#foo
|
||
|
|
LSLS r0, r0, #8
|
||
|
|
ADDS r0, #:upper0_7:#foo
|
||
|
|
LSLS r0, r0, #8
|
||
|
|
ADDS r0, #:lower8_15:#foo
|
||
|
|
LSLS r0, r0, #8
|
||
|
|
ADDS r0, #:lower0_7:#foo
|
||
|
|
</pre></div>
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
</body>
|
||
|
|
</html>
|