209 lines
8.6 KiB
HTML
209 lines
8.6 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: M</title>
|
|
|
|
<meta name="description" content="Using as: M">
|
|
<meta name="keywords" content="Using as: M">
|
|
<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="Invoking.html#Invoking" rel="up" title="Invoking">
|
|
<link href="MD.html#MD" rel="next" title="MD">
|
|
<link href="listing.html#listing" rel="prev" title="listing">
|
|
<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="M"></a>
|
|
<div class="header">
|
|
<p>
|
|
Next: <a href="MD.html#MD" accesskey="n" rel="next">MD</a>, Previous: <a href="listing.html#listing" accesskey="p" rel="prev">listing</a>, Up: <a href="Invoking.html#Invoking" accesskey="u" rel="up">Invoking</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="Assemble-in-MRI-Compatibility-Mode_003a-_002dM"></a>
|
|
<h3 class="section">2.9 Assemble in MRI Compatibility Mode: <samp>-M</samp></h3>
|
|
|
|
<a name="index-_002dM"></a>
|
|
<a name="index-MRI-compatibility-mode"></a>
|
|
<p>The <samp>-M</samp> or <samp>--mri</samp> option selects MRI compatibility mode. This
|
|
changes the syntax and pseudo-op handling of <code>as</code> to make it
|
|
compatible with the <code>ASM68K</code> or the <code>ASM960</code> (depending upon the
|
|
configured target) assembler from Microtec Research. The exact nature of the
|
|
MRI syntax will not be documented here; see the MRI manuals for more
|
|
information. Note in particular that the handling of macros and macro
|
|
arguments is somewhat different. The purpose of this option is to permit
|
|
assembling existing MRI assembler code using <code>as</code>.
|
|
</p>
|
|
<p>The MRI compatibility is not complete. Certain operations of the MRI assembler
|
|
depend upon its object file format, and can not be supported using other object
|
|
file formats. Supporting these would require enhancing each object file format
|
|
individually. These are:
|
|
</p>
|
|
<ul>
|
|
<li> global symbols in common section
|
|
|
|
<p>The m68k MRI assembler supports common sections which are merged by the linker.
|
|
Other object file formats do not support this. <code>as</code> handles
|
|
common sections by treating them as a single common symbol. It permits local
|
|
symbols to be defined within a common section, but it can not support global
|
|
symbols, since it has no way to describe them.
|
|
</p>
|
|
</li><li> complex relocations
|
|
|
|
<p>The MRI assemblers support relocations against a negated section address, and
|
|
relocations which combine the start addresses of two or more sections. These
|
|
are not support by other object file formats.
|
|
</p>
|
|
</li><li> <code>END</code> pseudo-op specifying start address
|
|
|
|
<p>The MRI <code>END</code> pseudo-op permits the specification of a start address.
|
|
This is not supported by other object file formats. The start address may
|
|
instead be specified using the <samp>-e</samp> option to the linker, or in a linker
|
|
script.
|
|
</p>
|
|
</li><li> <code>IDNT</code>, <code>.ident</code> and <code>NAME</code> pseudo-ops
|
|
|
|
<p>The MRI <code>IDNT</code>, <code>.ident</code> and <code>NAME</code> pseudo-ops assign a module
|
|
name to the output file. This is not supported by other object file formats.
|
|
</p>
|
|
</li><li> <code>ORG</code> pseudo-op
|
|
|
|
<p>The m68k MRI <code>ORG</code> pseudo-op begins an absolute section at a given
|
|
address. This differs from the usual <code>as</code> <code>.org</code> pseudo-op,
|
|
which changes the location within the current section. Absolute sections are
|
|
not supported by other object file formats. The address of a section may be
|
|
assigned within a linker script.
|
|
</p></li></ul>
|
|
|
|
<p>There are some other features of the MRI assembler which are not supported by
|
|
<code>as</code>, typically either because they are difficult or because they
|
|
seem of little consequence. Some of these may be supported in future releases.
|
|
</p>
|
|
<ul>
|
|
<li> EBCDIC strings
|
|
|
|
<p>EBCDIC strings are not supported.
|
|
</p>
|
|
</li><li> packed binary coded decimal
|
|
|
|
<p>Packed binary coded decimal is not supported. This means that the <code>DC.P</code>
|
|
and <code>DCB.P</code> pseudo-ops are not supported.
|
|
</p>
|
|
</li><li> <code>FEQU</code> pseudo-op
|
|
|
|
<p>The m68k <code>FEQU</code> pseudo-op is not supported.
|
|
</p>
|
|
</li><li> <code>NOOBJ</code> pseudo-op
|
|
|
|
<p>The m68k <code>NOOBJ</code> pseudo-op is not supported.
|
|
</p>
|
|
</li><li> <code>OPT</code> branch control options
|
|
|
|
<p>The m68k <code>OPT</code> branch control options—<code>B</code>, <code>BRS</code>, <code>BRB</code>,
|
|
<code>BRL</code>, and <code>BRW</code>—are ignored. <code>as</code> automatically
|
|
relaxes all branches, whether forward or backward, to an appropriate size, so
|
|
these options serve no purpose.
|
|
</p>
|
|
</li><li> <code>OPT</code> list control options
|
|
|
|
<p>The following m68k <code>OPT</code> list control options are ignored: <code>C</code>,
|
|
<code>CEX</code>, <code>CL</code>, <code>CRE</code>, <code>E</code>, <code>G</code>, <code>I</code>, <code>M</code>,
|
|
<code>MEX</code>, <code>MC</code>, <code>MD</code>, <code>X</code>.
|
|
</p>
|
|
</li><li> other <code>OPT</code> options
|
|
|
|
<p>The following m68k <code>OPT</code> options are ignored: <code>NEST</code>, <code>O</code>,
|
|
<code>OLD</code>, <code>OP</code>, <code>P</code>, <code>PCO</code>, <code>PCR</code>, <code>PCS</code>, <code>R</code>.
|
|
</p>
|
|
</li><li> <code>OPT</code> <code>D</code> option is default
|
|
|
|
<p>The m68k <code>OPT</code> <code>D</code> option is the default, unlike the MRI assembler.
|
|
<code>OPT NOD</code> may be used to turn it off.
|
|
</p>
|
|
</li><li> <code>XREF</code> pseudo-op.
|
|
|
|
<p>The m68k <code>XREF</code> pseudo-op is ignored.
|
|
</p>
|
|
</li><li> <code>.debug</code> pseudo-op
|
|
|
|
<p>The i960 <code>.debug</code> pseudo-op is not supported.
|
|
</p>
|
|
</li><li> <code>.extended</code> pseudo-op
|
|
|
|
<p>The i960 <code>.extended</code> pseudo-op is not supported.
|
|
</p>
|
|
</li><li> <code>.list</code> pseudo-op.
|
|
|
|
<p>The various options of the i960 <code>.list</code> pseudo-op are not supported.
|
|
</p>
|
|
</li><li> <code>.optimize</code> pseudo-op
|
|
|
|
<p>The i960 <code>.optimize</code> pseudo-op is not supported.
|
|
</p>
|
|
</li><li> <code>.output</code> pseudo-op
|
|
|
|
<p>The i960 <code>.output</code> pseudo-op is not supported.
|
|
</p>
|
|
</li><li> <code>.setreal</code> pseudo-op
|
|
|
|
<p>The i960 <code>.setreal</code> pseudo-op is not supported.
|
|
</p>
|
|
</li></ul>
|
|
|
|
<hr>
|
|
<div class="header">
|
|
<p>
|
|
Next: <a href="MD.html#MD" accesskey="n" rel="next">MD</a>, Previous: <a href="listing.html#listing" accesskey="p" rel="prev">listing</a>, Up: <a href="Invoking.html#Invoking" accesskey="u" rel="up">Invoking</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>
|
|
|
|
|
|
|
|
</body>
|
|
</html>
|