313 lines
12 KiB
HTML
313 lines
12 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 BFD library.
|
||
|
|
|
||
|
|
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 the
|
||
|
|
Invariant Sections being "GNU General Public License" and "Funding
|
||
|
|
Free Software", the Front-Cover texts being (a) (see below), and with
|
||
|
|
the Back-Cover Texts being (b) (see below). A copy of the license is
|
||
|
|
included in the section entitled "GNU Free Documentation License".
|
||
|
|
|
||
|
|
(a) The FSF's Front-Cover Text is:
|
||
|
|
|
||
|
|
A GNU Manual
|
||
|
|
|
||
|
|
(b) The FSF's Back-Cover Text is:
|
||
|
|
|
||
|
|
You have freedom to copy and modify this GNU Manual, like GNU
|
||
|
|
software. Copies published by the Free Software Foundation raise
|
||
|
|
funds for GNU development. -->
|
||
|
|
<!-- Created by GNU Texinfo 5.2, http://www.gnu.org/software/texinfo/ -->
|
||
|
|
<head>
|
||
|
|
<title>Untitled Document: aout</title>
|
||
|
|
|
||
|
|
<meta name="description" content="Untitled Document: aout">
|
||
|
|
<meta name="keywords" content="Untitled Document: aout">
|
||
|
|
<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="BFD-Index.html#BFD-Index" rel="index" title="BFD Index">
|
||
|
|
<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
|
||
|
|
<link href="BFD-back-ends.html#BFD-back-ends" rel="up" title="BFD back ends">
|
||
|
|
<link href="coff.html#coff" rel="next" title="coff">
|
||
|
|
<link href="What-to-Put-Where.html#What-to-Put-Where" rel="prev" title="What to Put Where">
|
||
|
|
<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="aout"></a>
|
||
|
|
<div class="header">
|
||
|
|
<p>
|
||
|
|
Next: <a href="coff.html#coff" accesskey="n" rel="next">coff</a>, Previous: <a href="What-to-Put-Where.html#What-to-Put-Where" accesskey="p" rel="prev">What to Put Where</a>, Up: <a href="BFD-back-ends.html#BFD-back-ends" accesskey="u" rel="up">BFD back ends</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="BFD-Index.html#BFD-Index" title="Index" rel="index">Index</a>]</p>
|
||
|
|
</div>
|
||
|
|
<hr>
|
||
|
|
<a name="a_002eout-backends"></a>
|
||
|
|
<h3 class="section">3.2 a.out backends</h3>
|
||
|
|
|
||
|
|
|
||
|
|
<p><strong>Description</strong><br>
|
||
|
|
BFD supports a number of different flavours of a.out format,
|
||
|
|
though the major differences are only the sizes of the
|
||
|
|
structures on disk, and the shape of the relocation
|
||
|
|
information.
|
||
|
|
</p>
|
||
|
|
<p>The support is split into a basic support file <samp>aoutx.h</samp>
|
||
|
|
and other files which derive functions from the base. One
|
||
|
|
derivation file is <samp>aoutf1.h</samp> (for a.out flavour 1), and
|
||
|
|
adds to the basic a.out functions support for sun3, sun4, 386
|
||
|
|
and 29k a.out files, to create a target jump vector for a
|
||
|
|
specific target.
|
||
|
|
</p>
|
||
|
|
<p>This information is further split out into more specific files
|
||
|
|
for each machine, including <samp>sunos.c</samp> for sun3 and sun4,
|
||
|
|
<samp>newsos3.c</samp> for the Sony NEWS, and <samp>demo64.c</samp> for a
|
||
|
|
demonstration of a 64 bit a.out format.
|
||
|
|
</p>
|
||
|
|
<p>The base file <samp>aoutx.h</samp> defines general mechanisms for
|
||
|
|
reading and writing records to and from disk and various
|
||
|
|
other methods which BFD requires. It is included by
|
||
|
|
<samp>aout32.c</samp> and <samp>aout64.c</samp> to form the names
|
||
|
|
<code>aout_32_swap_exec_header_in</code>, <code>aout_64_swap_exec_header_in</code>, etc.
|
||
|
|
</p>
|
||
|
|
<p>As an example, this is what goes on to make the back end for a
|
||
|
|
sun4, from <samp>aout32.c</samp>:
|
||
|
|
</p>
|
||
|
|
<div class="example">
|
||
|
|
<pre class="example"> #define ARCH_SIZE 32
|
||
|
|
#include "aoutx.h"
|
||
|
|
</pre></div>
|
||
|
|
|
||
|
|
<p>Which exports names:
|
||
|
|
</p>
|
||
|
|
<div class="example">
|
||
|
|
<pre class="example"> ...
|
||
|
|
aout_32_canonicalize_reloc
|
||
|
|
aout_32_find_nearest_line
|
||
|
|
aout_32_get_lineno
|
||
|
|
aout_32_get_reloc_upper_bound
|
||
|
|
...
|
||
|
|
</pre></div>
|
||
|
|
|
||
|
|
<p>from <samp>sunos.c</samp>:
|
||
|
|
</p>
|
||
|
|
<div class="example">
|
||
|
|
<pre class="example"> #define TARGET_NAME "a.out-sunos-big"
|
||
|
|
#define VECNAME sparc_aout_sunos_be_vec
|
||
|
|
#include "aoutf1.h"
|
||
|
|
</pre></div>
|
||
|
|
|
||
|
|
<p>requires all the names from <samp>aout32.c</samp>, and produces the jump vector
|
||
|
|
</p>
|
||
|
|
<div class="example">
|
||
|
|
<pre class="example"> sparc_aout_sunos_be_vec
|
||
|
|
</pre></div>
|
||
|
|
|
||
|
|
<p>The file <samp>host-aout.c</samp> is a special case. It is for a large set
|
||
|
|
of hosts that use “more or less standard” a.out files, and
|
||
|
|
for which cross-debugging is not interesting. It uses the
|
||
|
|
standard 32-bit a.out support routines, but determines the
|
||
|
|
file offsets and addresses of the text, data, and BSS
|
||
|
|
sections, the machine architecture and machine type, and the
|
||
|
|
entry point address, in a host-dependent manner. Once these
|
||
|
|
values have been determined, generic code is used to handle
|
||
|
|
the object file.
|
||
|
|
</p>
|
||
|
|
<p>When porting it to run on a new system, you must supply:
|
||
|
|
</p>
|
||
|
|
<div class="example">
|
||
|
|
<pre class="example"> HOST_PAGE_SIZE
|
||
|
|
HOST_SEGMENT_SIZE
|
||
|
|
HOST_MACHINE_ARCH (optional)
|
||
|
|
HOST_MACHINE_MACHINE (optional)
|
||
|
|
HOST_TEXT_START_ADDR
|
||
|
|
HOST_STACK_END_ADDR
|
||
|
|
</pre></div>
|
||
|
|
|
||
|
|
<p>in the file <samp>../include/sys/h-<var>XXX</var>.h</samp> (for your host). These
|
||
|
|
values, plus the structures and macros defined in <samp>a.out.h</samp> on
|
||
|
|
your host system, will produce a BFD target that will access
|
||
|
|
ordinary a.out files on your host. To configure a new machine
|
||
|
|
to use <samp>host-aout.c</samp>, specify:
|
||
|
|
</p>
|
||
|
|
<div class="example">
|
||
|
|
<pre class="example"> TDEFAULTS = -DDEFAULT_VECTOR=host_aout_big_vec
|
||
|
|
TDEPFILES= host-aout.o trad-core.o
|
||
|
|
</pre></div>
|
||
|
|
|
||
|
|
<p>in the <samp>config/<var>XXX</var>.mt</samp> file, and modify <samp>configure.ac</samp>
|
||
|
|
to use the
|
||
|
|
<samp><var>XXX</var>.mt</samp> file (by setting "<code>bfd_target=XXX</code>") when your
|
||
|
|
configuration is selected.
|
||
|
|
</p>
|
||
|
|
<a name="Relocations-2"></a>
|
||
|
|
<h4 class="subsection">3.2.1 Relocations</h4>
|
||
|
|
|
||
|
|
|
||
|
|
<p><strong>Description</strong><br>
|
||
|
|
The file <samp>aoutx.h</samp> provides for both the <em>standard</em>
|
||
|
|
and <em>extended</em> forms of a.out relocation records.
|
||
|
|
</p>
|
||
|
|
<p>The standard records contain only an
|
||
|
|
address, a symbol index, and a type field. The extended records
|
||
|
|
(used on 29ks and sparcs) also have a full integer for an
|
||
|
|
addend.
|
||
|
|
</p>
|
||
|
|
<a name="Internal-entry-points"></a>
|
||
|
|
<h4 class="subsection">3.2.2 Internal entry points</h4>
|
||
|
|
|
||
|
|
|
||
|
|
<p><strong>Description</strong><br>
|
||
|
|
<samp>aoutx.h</samp> exports several routines for accessing the
|
||
|
|
contents of an a.out file, which are gathered and exported in
|
||
|
|
turn by various format specific files (eg sunos.c).
|
||
|
|
</p>
|
||
|
|
<a name="index-aout_005fsize_005fswap_005fexec_005fheader_005fin"></a>
|
||
|
|
<a name="aout_005fsize_005fswap_005fexec_005fheader_005fin"></a>
|
||
|
|
<h4 class="subsubsection">3.2.2.1 <code>aout_<var>size</var>_swap_exec_header_in</code></h4>
|
||
|
|
<p><strong>Synopsis</strong>
|
||
|
|
</p><div class="example">
|
||
|
|
<pre class="example">void aout_<var>size</var>_swap_exec_header_in,
|
||
|
|
(bfd *abfd,
|
||
|
|
struct external_exec *bytes,
|
||
|
|
struct internal_exec *execp);
|
||
|
|
</pre></div>
|
||
|
|
<p><strong>Description</strong><br>
|
||
|
|
Swap the information in an executable header <var>raw_bytes</var> taken
|
||
|
|
from a raw byte stream memory image into the internal exec header
|
||
|
|
structure <var>execp</var>.
|
||
|
|
</p>
|
||
|
|
<a name="index-aout_005fsize_005fswap_005fexec_005fheader_005fout"></a>
|
||
|
|
<a name="aout_005fsize_005fswap_005fexec_005fheader_005fout"></a>
|
||
|
|
<h4 class="subsubsection">3.2.2.2 <code>aout_<var>size</var>_swap_exec_header_out</code></h4>
|
||
|
|
<p><strong>Synopsis</strong>
|
||
|
|
</p><div class="example">
|
||
|
|
<pre class="example">void aout_<var>size</var>_swap_exec_header_out
|
||
|
|
(bfd *abfd,
|
||
|
|
struct internal_exec *execp,
|
||
|
|
struct external_exec *raw_bytes);
|
||
|
|
</pre></div>
|
||
|
|
<p><strong>Description</strong><br>
|
||
|
|
Swap the information in an internal exec header structure
|
||
|
|
<var>execp</var> into the buffer <var>raw_bytes</var> ready for writing to disk.
|
||
|
|
</p>
|
||
|
|
<a name="index-aout_005fsize_005fsome_005faout_005fobject_005fp"></a>
|
||
|
|
<a name="aout_005fsize_005fsome_005faout_005fobject_005fp"></a>
|
||
|
|
<h4 class="subsubsection">3.2.2.3 <code>aout_<var>size</var>_some_aout_object_p</code></h4>
|
||
|
|
<p><strong>Synopsis</strong>
|
||
|
|
</p><div class="example">
|
||
|
|
<pre class="example">const bfd_target *aout_<var>size</var>_some_aout_object_p
|
||
|
|
(bfd *abfd,
|
||
|
|
struct internal_exec *execp,
|
||
|
|
const bfd_target *(*callback_to_real_object_p) (bfd *));
|
||
|
|
</pre></div>
|
||
|
|
<p><strong>Description</strong><br>
|
||
|
|
Some a.out variant thinks that the file open in <var>abfd</var>
|
||
|
|
checking is an a.out file. Do some more checking, and set up
|
||
|
|
for access if it really is. Call back to the calling
|
||
|
|
environment’s "finish up" function just before returning, to
|
||
|
|
handle any last-minute setup.
|
||
|
|
</p>
|
||
|
|
<a name="index-aout_005fsize_005fmkobject"></a>
|
||
|
|
<a name="aout_005fsize_005fmkobject"></a>
|
||
|
|
<h4 class="subsubsection">3.2.2.4 <code>aout_<var>size</var>_mkobject</code></h4>
|
||
|
|
<p><strong>Synopsis</strong>
|
||
|
|
</p><div class="example">
|
||
|
|
<pre class="example">bfd_boolean aout_<var>size</var>_mkobject, (bfd *abfd);
|
||
|
|
</pre></div>
|
||
|
|
<p><strong>Description</strong><br>
|
||
|
|
Initialize BFD <var>abfd</var> for use with a.out files.
|
||
|
|
</p>
|
||
|
|
<a name="index-aout_005fsize_005fmachine_005ftype"></a>
|
||
|
|
<a name="aout_005fsize_005fmachine_005ftype"></a>
|
||
|
|
<h4 class="subsubsection">3.2.2.5 <code>aout_<var>size</var>_machine_type</code></h4>
|
||
|
|
<p><strong>Synopsis</strong>
|
||
|
|
</p><div class="example">
|
||
|
|
<pre class="example">enum machine_type aout_<var>size</var>_machine_type
|
||
|
|
(enum bfd_architecture arch,
|
||
|
|
unsigned long machine,
|
||
|
|
bfd_boolean *unknown);
|
||
|
|
</pre></div>
|
||
|
|
<p><strong>Description</strong><br>
|
||
|
|
Keep track of machine architecture and machine type for
|
||
|
|
a.out’s. Return the <code>machine_type</code> for a particular
|
||
|
|
architecture and machine, or <code>M_UNKNOWN</code> if that exact architecture
|
||
|
|
and machine can’t be represented in a.out format.
|
||
|
|
</p>
|
||
|
|
<p>If the architecture is understood, machine type 0 (default)
|
||
|
|
is always understood.
|
||
|
|
</p>
|
||
|
|
<a name="index-aout_005fsize_005fset_005farch_005fmach"></a>
|
||
|
|
<a name="aout_005fsize_005fset_005farch_005fmach"></a>
|
||
|
|
<h4 class="subsubsection">3.2.2.6 <code>aout_<var>size</var>_set_arch_mach</code></h4>
|
||
|
|
<p><strong>Synopsis</strong>
|
||
|
|
</p><div class="example">
|
||
|
|
<pre class="example">bfd_boolean aout_<var>size</var>_set_arch_mach,
|
||
|
|
(bfd *,
|
||
|
|
enum bfd_architecture arch,
|
||
|
|
unsigned long machine);
|
||
|
|
</pre></div>
|
||
|
|
<p><strong>Description</strong><br>
|
||
|
|
Set the architecture and the machine of the BFD <var>abfd</var> to the
|
||
|
|
values <var>arch</var> and <var>machine</var>. Verify that <var>abfd</var>’s format
|
||
|
|
can support the architecture required.
|
||
|
|
</p>
|
||
|
|
<a name="index-aout_005fsize_005fnew_005fsection_005fhook"></a>
|
||
|
|
<a name="aout_005fsize_005fnew_005fsection_005fhook"></a>
|
||
|
|
<h4 class="subsubsection">3.2.2.7 <code>aout_<var>size</var>_new_section_hook</code></h4>
|
||
|
|
<p><strong>Synopsis</strong>
|
||
|
|
</p><div class="example">
|
||
|
|
<pre class="example">bfd_boolean aout_<var>size</var>_new_section_hook,
|
||
|
|
(bfd *abfd,
|
||
|
|
asection *newsect);
|
||
|
|
</pre></div>
|
||
|
|
<p><strong>Description</strong><br>
|
||
|
|
Called by the BFD in response to a <code>bfd_make_section</code>
|
||
|
|
request.
|
||
|
|
</p>
|
||
|
|
|
||
|
|
<hr>
|
||
|
|
<div class="header">
|
||
|
|
<p>
|
||
|
|
Next: <a href="coff.html#coff" accesskey="n" rel="next">coff</a>, Previous: <a href="What-to-Put-Where.html#What-to-Put-Where" accesskey="p" rel="prev">What to Put Where</a>, Up: <a href="BFD-back-ends.html#BFD-back-ends" accesskey="u" rel="up">BFD back ends</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="BFD-Index.html#BFD-Index" title="Index" rel="index">Index</a>]</p>
|
||
|
|
</div>
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
</body>
|
||
|
|
</html>
|