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diff --git a/share/doc/gdb/Bootstrapping.html b/share/doc/gdb/Bootstrapping.html new file mode 100644 index 0000000..7c18c87 --- /dev/null +++ b/share/doc/gdb/Bootstrapping.html @@ -0,0 +1,174 @@ +<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> +<html> +<!-- Copyright (C) 1988-2023 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 "Free Software" and "Free Software Needs +Free Documentation", with the Front-Cover Texts being "A GNU Manual," +and with the Back-Cover Texts as in (a) below. + +(a) The FSF's Back-Cover Text is: "You are free to copy and modify +this GNU Manual. Buying copies from GNU Press supports the FSF in +developing GNU and promoting software freedom." --> +<!-- Created by GNU Texinfo 5.1, http://www.gnu.org/software/texinfo/ --> +<head> +<title>Debugging with GDB: Bootstrapping</title> + +<meta name="description" content="Debugging with GDB: Bootstrapping"> +<meta name="keywords" content="Debugging with GDB: Bootstrapping"> +<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="Concept-Index.html#Concept-Index" rel="index" title="Concept Index"> +<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents"> +<link href="Remote-Stub.html#Remote-Stub" rel="up" title="Remote Stub"> +<link href="Debug-Session.html#Debug-Session" rel="next" title="Debug Session"> +<link href="Stub-Contents.html#Stub-Contents" rel="previous" title="Stub Contents"> +<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="Bootstrapping"></a> +<div class="header"> +<p> +Next: <a href="Debug-Session.html#Debug-Session" accesskey="n" rel="next">Debug Session</a>, Previous: <a href="Stub-Contents.html#Stub-Contents" accesskey="p" rel="previous">Stub Contents</a>, Up: <a href="Remote-Stub.html#Remote-Stub" accesskey="u" rel="up">Remote Stub</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p> +</div> +<hr> +<a name="What-You-Must-Do-for-the-Stub"></a> +<h4 class="subsection">20.5.2 What You Must Do for the Stub</h4> + +<a name="index-remote-stub_002c-support-routines"></a> +<p>The debugging stubs that come with <small>GDB</small> are set up for a particular +chip architecture, but they have no information about the rest of your +debugging target machine. +</p> +<p>First of all you need to tell the stub how to communicate with the +serial port. +</p> +<dl compact="compact"> +<dt><code>int getDebugChar()</code></dt> +<dd><a name="index-getDebugChar"></a> +<p>Write this subroutine to read a single character from the serial port. +It may be identical to <code>getchar</code> for your target system; a +different name is used to allow you to distinguish the two if you wish. +</p> +</dd> +<dt><code>void putDebugChar(int)</code></dt> +<dd><a name="index-putDebugChar"></a> +<p>Write this subroutine to write a single character to the serial port. +It may be identical to <code>putchar</code> for your target system; a +different name is used to allow you to distinguish the two if you wish. +</p></dd> +</dl> + +<a name="index-control-C_002c-and-remote-debugging"></a> +<a name="index-interrupting-remote-targets"></a> +<p>If you want <small>GDB</small> to be able to stop your program while it is +running, you need to use an interrupt-driven serial driver, and arrange +for it to stop when it receives a <code>^C</code> (‘<samp>\003</samp>’, the control-C +character). That is the character which <small>GDB</small> uses to tell the +remote system to stop. +</p> +<p>Getting the debugging target to return the proper status to <small>GDB</small> +probably requires changes to the standard stub; one quick and dirty way +is to just execute a breakpoint instruction (the “dirty” part is that +<small>GDB</small> reports a <code>SIGTRAP</code> instead of a <code>SIGINT</code>). +</p> +<p>Other routines you need to supply are: +</p> +<dl compact="compact"> +<dt><code>void exceptionHandler (int <var>exception_number</var>, void *<var>exception_address</var>)</code></dt> +<dd><a name="index-exceptionHandler"></a> +<p>Write this function to install <var>exception_address</var> in the exception +handling tables. You need to do this because the stub does not have any +way of knowing what the exception handling tables on your target system +are like (for example, the processor’s table might be in <small>ROM</small>, +containing entries which point to a table in <small>RAM</small>). +The <var>exception_number</var> specifies the exception which should be changed; +its meaning is architecture-dependent (for example, different numbers +might represent divide by zero, misaligned access, etc). When this +exception occurs, control should be transferred directly to +<var>exception_address</var>, and the processor state (stack, registers, +and so on) should be just as it is when a processor exception occurs. So if +you want to use a jump instruction to reach <var>exception_address</var>, it +should be a simple jump, not a jump to subroutine. +</p> +<p>For the 386, <var>exception_address</var> should be installed as an interrupt +gate so that interrupts are masked while the handler runs. The gate +should be at privilege level 0 (the most privileged level). The +<small>SPARC</small> and 68k stubs are able to mask interrupts themselves without +help from <code>exceptionHandler</code>. +</p> +</dd> +<dt><code>void flush_i_cache()</code></dt> +<dd><a name="index-flush_005fi_005fcache"></a> +<p>On <small>SPARC</small> and <small>SPARCLITE</small> only, write this subroutine to flush the +instruction cache, if any, on your target machine. If there is no +instruction cache, this subroutine may be a no-op. +</p> +<p>On target machines that have instruction caches, <small>GDB</small> requires this +function to make certain that the state of your program is stable. +</p></dd> +</dl> + +<p>You must also make sure this library routine is available: +</p> +<dl compact="compact"> +<dt><code>void *memset(void *, int, int)</code></dt> +<dd><a name="index-memset"></a> +<p>This is the standard library function <code>memset</code> that sets an area of +memory to a known value. If you have one of the free versions of +<code>libc.a</code>, <code>memset</code> can be found there; otherwise, you must +either obtain it from your hardware manufacturer, or write your own. +</p></dd> +</dl> + +<p>If you do not use the GNU C compiler, you may need other standard +library subroutines as well; this varies from one stub to another, +but in general the stubs are likely to use any of the common library +subroutines which <code><small>GCC</small></code> generates as inline code. +</p> + +<hr> +<div class="header"> +<p> +Next: <a href="Debug-Session.html#Debug-Session" accesskey="n" rel="next">Debug Session</a>, Previous: <a href="Stub-Contents.html#Stub-Contents" accesskey="p" rel="previous">Stub Contents</a>, Up: <a href="Remote-Stub.html#Remote-Stub" accesskey="u" rel="up">Remote Stub</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p> +</div> + + + +</body> +</html> |