61 lines
2.2 KiB
HTML
61 lines
2.2 KiB
HTML
<html>
|
|
<title>Chapter 5: Program Loading and Dynamic Linking</title><p>
|
|
<h1>Introduction</h1><p>
|
|
This section describes the object file
|
|
information and system actions that create running programs.
|
|
Some information here applies to all systems;
|
|
information specific to one processor resides in
|
|
sections marked accordingly.
|
|
<p>
|
|
Executable and shared object files statically represent programs.
|
|
To execute such programs, the system uses the files to create
|
|
dynamic program representations, or process images.
|
|
As section ''Virtual Address Space'' in Chapter 3 of the
|
|
processor supplement describes, a process image has segments that
|
|
hold its text, data, stack, and so on. This chapter's major sections
|
|
discuss the following:
|
|
<ul>
|
|
<li>
|
|
<a href=ch5.pheader.html>Program Header.</a>
|
|
This section complements Chapter 4, describing
|
|
object file structures that relate directly to program execution.
|
|
The primary data structure, a program header table, locates
|
|
segment images within the file and contains other information
|
|
necessary to create the memory image for the program.
|
|
<li>
|
|
<a href=ch5.prog_loading.html>Program Loading.</a>
|
|
Given an object file, the system must load
|
|
it into memory for the program to run.
|
|
<li>
|
|
<a href=ch5.dynamic.html>Dynamic linking.</a>
|
|
After the system loads the program it must complete
|
|
the process image by resolving symbolic references among the object
|
|
files that compose the process.
|
|
</ul>
|
|
<hr>
|
|
<img src=warning.gif alt="NOTE:">
|
|
The processor supplement defines a naming convention for ELF constants
|
|
that have processor ranges specified. Names such as <code>DT_</code>,
|
|
<code>PT_</code>,
|
|
for processor specific extensions, incorporate the name of the
|
|
processor: <code>DT_M32_SPECIAL</code>, for example.
|
|
Pre-existing processor
|
|
extensions not using this convention will be supported.
|
|
<table>
|
|
<th>Pre-Existing Extensions</th>
|
|
<tr>
|
|
<td><code>DT_JUMP_REL</code></td>
|
|
</tr>
|
|
</table>
|
|
<hr>
|
|
<a href=ch4.reloc.html><img src=previous.gif alt="Previous"></a>
|
|
<a href=contents.html><img src=contents.gif alt="Contents"></a>
|
|
<a href=ch5.pheader.html><img src=next.gif alt="Next"></a>
|
|
<hr>
|
|
<i>
|
|
<small>
|
|
© 1997, 1998, 1999, 2000, 2001 The Santa Cruz Operation, Inc. All rights reserved.
|
|
</small>
|
|
</i>
|
|
</html>
|