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.
127 lines
6.6 KiB
HTML
127 lines
6.6 KiB
HTML
4 years ago
|
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
|
||
|
|
<html>
|
||
|
|
<!-- Copyright (C) 1988-2019 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 6.4, http://www.gnu.org/software/texinfo/ -->
|
||
|
|
<head>
|
||
|
|
<title>Interrupts (Debugging with GDB)</title>
|
||
|
|
|
||
|
|
<meta name="description" content="Interrupts (Debugging with GDB)">
|
||
|
|
<meta name="keywords" content="Interrupts (Debugging with GDB)">
|
||
|
|
<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-Protocol.html#Remote-Protocol" rel="up" title="Remote Protocol">
|
||
|
|
<link href="Notification-Packets.html#Notification-Packets" rel="next" title="Notification Packets">
|
||
|
|
<link href="Host-I_002fO-Packets.html#Host-I_002fO-Packets" rel="prev" title="Host I/O Packets">
|
||
|
|
<style type="text/css">
|
||
|
|
<!--
|
||
|
|
a.summary-letter {text-decoration: none}
|
||
|
|
blockquote.indentedblock {margin-right: 0em}
|
||
|
|
blockquote.smallindentedblock {margin-right: 0em; font-size: smaller}
|
||
|
|
blockquote.smallquotation {font-size: smaller}
|
||
|
|
div.display {margin-left: 3.2em}
|
||
|
|
div.example {margin-left: 3.2em}
|
||
|
|
div.lisp {margin-left: 3.2em}
|
||
|
|
div.smalldisplay {margin-left: 3.2em}
|
||
|
|
div.smallexample {margin-left: 3.2em}
|
||
|
|
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.nolinebreak {white-space: nowrap}
|
||
|
|
span.roman {font-family: initial; font-weight: normal}
|
||
|
|
span.sansserif {font-family: sans-serif; font-weight: normal}
|
||
|
|
ul.no-bullet {list-style: none}
|
||
|
|
-->
|
||
|
|
</style>
|
||
|
|
|
||
|
|
|
||
|
|
</head>
|
||
|
|
|
||
|
|
<body lang="en">
|
||
|
|
<a name="Interrupts"></a>
|
||
|
|
<div class="header">
|
||
|
|
<p>
|
||
|
|
Next: <a href="Notification-Packets.html#Notification-Packets" accesskey="n" rel="next">Notification Packets</a>, Previous: <a href="Host-I_002fO-Packets.html#Host-I_002fO-Packets" accesskey="p" rel="prev">Host I/O Packets</a>, Up: <a href="Remote-Protocol.html#Remote-Protocol" accesskey="u" rel="up">Remote Protocol</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="Interrupts-1"></a>
|
||
|
|
<h3 class="section">E.8 Interrupts</h3>
|
||
|
|
<a name="index-interrupts-_0028remote-protocol_0029"></a>
|
||
|
|
<a name="interrupting-remote-targets"></a>
|
||
|
|
<p>In all-stop mode, when a program on the remote target is running,
|
||
|
|
<small>GDB</small> may attempt to interrupt it by sending a ‘<samp>Ctrl-C</samp>’,
|
||
|
|
<code>BREAK</code> or a <code>BREAK</code> followed by <code>g</code>, control of which
|
||
|
|
is specified via <small>GDB</small>’s ‘<samp>interrupt-sequence</samp>’.
|
||
|
|
</p>
|
||
|
|
<p>The precise meaning of <code>BREAK</code> is defined by the transport
|
||
|
|
mechanism and may, in fact, be undefined. <small>GDB</small> does not
|
||
|
|
currently define a <code>BREAK</code> mechanism for any of the network
|
||
|
|
interfaces except for TCP, in which case <small>GDB</small> sends the
|
||
|
|
<code>telnet</code> BREAK sequence.
|
||
|
|
</p>
|
||
|
|
<p>‘<samp>Ctrl-C</samp>’, on the other hand, is defined and implemented for all
|
||
|
|
transport mechanisms. It is represented by sending the single byte
|
||
|
|
<code>0x03</code> without any of the usual packet overhead described in
|
||
|
|
the Overview section (see <a href="Overview.html#Overview">Overview</a>). When a <code>0x03</code> byte is
|
||
|
|
transmitted as part of a packet, it is considered to be packet data
|
||
|
|
and does <em>not</em> represent an interrupt. E.g., an ‘<samp>X</samp>’ packet
|
||
|
|
(see <a href="Packets.html#X-packet">X packet</a>), used for binary downloads, may include an unescaped
|
||
|
|
<code>0x03</code> as part of its packet.
|
||
|
|
</p>
|
||
|
|
<p><code>BREAK</code> followed by <code>g</code> is also known as Magic SysRq g.
|
||
|
|
When Linux kernel receives this sequence from serial port,
|
||
|
|
it stops execution and connects to gdb.
|
||
|
|
</p>
|
||
|
|
<p>In non-stop mode, because packet resumptions are asynchronous
|
||
|
|
(see <a href="Packets.html#vCont-packet">vCont packet</a>), <small>GDB</small> is always free to send a remote
|
||
|
|
command to the remote stub, even when the target is running. For that
|
||
|
|
reason, <small>GDB</small> instead sends a regular packet (see <a href="Packets.html#vCtrlC-packet">vCtrlC packet</a>) with the usual packet framing instead of the single byte
|
||
|
|
<code>0x03</code>.
|
||
|
|
</p>
|
||
|
|
<p>Stubs are not required to recognize these interrupt mechanisms and the
|
||
|
|
precise meaning associated with receipt of the interrupt is
|
||
|
|
implementation defined. If the target supports debugging of multiple
|
||
|
|
threads and/or processes, it should attempt to interrupt all
|
||
|
|
currently-executing threads and processes.
|
||
|
|
If the stub is successful at interrupting the
|
||
|
|
running program, it should send one of the stop
|
||
|
|
reply packets (see <a href="Stop-Reply-Packets.html#Stop-Reply-Packets">Stop Reply Packets</a>) to <small>GDB</small> as a result
|
||
|
|
of successfully stopping the program in all-stop mode, and a stop reply
|
||
|
|
for each stopped thread in non-stop mode.
|
||
|
|
Interrupts received while the
|
||
|
|
program is stopped are queued and the program will be interrupted when
|
||
|
|
it is resumed next time.
|
||
|
|
</p>
|
||
|
|
<hr>
|
||
|
|
<div class="header">
|
||
|
|
<p>
|
||
|
|
Next: <a href="Notification-Packets.html#Notification-Packets" accesskey="n" rel="next">Notification Packets</a>, Previous: <a href="Host-I_002fO-Packets.html#Host-I_002fO-Packets" accesskey="p" rel="prev">Host I/O Packets</a>, Up: <a href="Remote-Protocol.html#Remote-Protocol" accesskey="u" rel="up">Remote Protocol</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>
|