You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
100 lines
4.1 KiB
HTML
100 lines
4.1 KiB
HTML
<html lang="en">
|
|
<head>
|
|
<title>How It Works - Untitled</title>
|
|
<meta http-equiv="Content-Type" content="text/html">
|
|
<meta name="description" content="Untitled">
|
|
<meta name="generator" content="makeinfo 4.7">
|
|
<link title="Top" rel="start" href="index.html#Top">
|
|
<link rel="up" href="Overview.html#Overview" title="Overview">
|
|
<link rel="prev" href="History.html#History" title="History">
|
|
<link rel="next" href="What-BFD-Version-2-Can-Do.html#What-BFD-Version-2-Can-Do" title="What BFD Version 2 Can Do">
|
|
<link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage">
|
|
<!--
|
|
This file documents the BFD library.
|
|
|
|
Copyright (C) 1991, 2000, 2001, 2003, 2006, 2007 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 1.1 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.-->
|
|
<meta http-equiv="Content-Style-Type" content="text/css">
|
|
<style type="text/css"><!--
|
|
pre.display { font-family:inherit }
|
|
pre.format { font-family:inherit }
|
|
pre.smalldisplay { font-family:inherit; font-size:smaller }
|
|
pre.smallformat { font-family:inherit; font-size:smaller }
|
|
pre.smallexample { font-size:smaller }
|
|
pre.smalllisp { font-size:smaller }
|
|
span.sc { font-variant:small-caps }
|
|
span.roman { font-family: serif; font-weight: normal; }
|
|
--></style>
|
|
</head>
|
|
<body>
|
|
<div class="node">
|
|
<p>
|
|
<a name="How-It-Works"></a>Next: <a rel="next" accesskey="n" href="What-BFD-Version-2-Can-Do.html#What-BFD-Version-2-Can-Do">What BFD Version 2 Can Do</a>,
|
|
Previous: <a rel="previous" accesskey="p" href="History.html#History">History</a>,
|
|
Up: <a rel="up" accesskey="u" href="Overview.html#Overview">Overview</a>
|
|
<hr><br>
|
|
</div>
|
|
|
|
<h3 class="section">1.2 How To Use BFD</h3>
|
|
|
|
<p>To use the library, include <span class="file">bfd.h</span> and link with <span class="file">libbfd.a</span>.
|
|
|
|
<p>BFD provides a common interface to the parts of an object file
|
|
for a calling application.
|
|
|
|
<p>When an application successfully opens a target file (object, archive, or
|
|
whatever), a pointer to an internal structure is returned. This pointer
|
|
points to a structure called <code>bfd</code>, described in
|
|
<span class="file">bfd.h</span>. Our convention is to call this pointer a BFD, and
|
|
instances of it within code <code>abfd</code>. All operations on
|
|
the target object file are applied as methods to the BFD. The mapping is
|
|
defined within <code>bfd.h</code> in a set of macros, all beginning
|
|
with <span class="samp">bfd_</span> to reduce namespace pollution.
|
|
|
|
<p>For example, this sequence does what you would probably expect:
|
|
return the number of sections in an object file attached to a BFD
|
|
<code>abfd</code>.
|
|
|
|
<pre class="example"> <!-- @cartouche -->
|
|
#include "bfd.h"
|
|
|
|
unsigned int number_of_sections (abfd)
|
|
bfd *abfd;
|
|
{
|
|
return bfd_count_sections (abfd);
|
|
}
|
|
<!-- @end cartouche -->
|
|
</pre>
|
|
<p>The abstraction used within BFD is that an object file has:
|
|
|
|
<ul>
|
|
<li>a header,
|
|
<li>a number of sections containing raw data (see <a href="Sections.html#Sections">Sections</a>),
|
|
<li>a set of relocations (see <a href="Relocations.html#Relocations">Relocations</a>), and
|
|
<li>some symbol information (see <a href="Symbols.html#Symbols">Symbols</a>).
|
|
</ul>
|
|
Also, BFDs opened for archives have the additional attribute of an index
|
|
and contain subordinate BFDs. This approach is fine for a.out and coff,
|
|
but loses efficiency when applied to formats such as S-records and
|
|
IEEE-695.
|
|
|
|
</body></html>
|
|
|