aarch64-linux-gnu-5.1/share/doc/gdb/Trace-File-Format.html - toolchains/linux-x86/gcc - Git at Google

 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
 <html>
 <!-- Copyright (C) 1988-2015 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 5.2, http://www.gnu.org/software/texinfo/ -->
 <head>
 <title>Debugging with GDB: Trace File Format</title>

 <meta name="description" content="Debugging with GDB: Trace File Format">
 <meta name="keywords" content="Debugging with GDB: Trace File Format">
 <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="index.html#Top" rel="up" title="Top">
 <link href="Index-Section-Format.html#Index-Section-Format" rel="next" title="Index Section Format">
 <link href="Process-list.html#Process-list" rel="prev" title="Process list">
 <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="Trace-File-Format"></a>
 <div class="header">
 <p>
 Next: <a href="Index-Section-Format.html#Index-Section-Format" accesskey="n" rel="next">Index Section Format</a>, Previous: <a href="Operating-System-Information.html#Operating-System-Information" accesskey="p" rel="prev">Operating System Information</a>, Up: <a href="index.html#Top" accesskey="u" rel="up">Top</a> &nbsp; [<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="Trace-File-Format-1"></a>
 <h2 class="appendix">Appendix I Trace File Format</h2>
 <a name="index-trace-file-format"></a>

 <p>The trace file comes in three parts: a header, a textual description
 section, and a trace frame section with binary data.
 </p>
 <p>The header has the form <code>\x7fTRACE0\n</code>.  The first byte is
 <code>0x7f</code> so as to indicate that the file contains binary data,
 while the <code>0</code> is a version number that may have different values
 in the future.
 </p>
 <p>The description section consists of multiple lines of <small>ASCII</small> text
 separated by newline characters (<code>0xa</code>).  The lines may include a
 variety of optional descriptive or context-setting information, such
 as tracepoint definitions or register set size.  <small>GDB</small> will
 ignore any line that it does not recognize.  An empty line marks the end
 of this section.
 </p>

 <p>The trace frame section consists of a number of consecutive frames.
 Each frame begins with a two-byte tracepoint number, followed by a
 four-byte size giving the amount of data in the frame.  The data in
 the frame consists of a number of blocks, each introduced by a
 character indicating its type (at least register, memory, and trace
 state variable).  The data in this section is raw binary, not a
 hexadecimal or other encoding; its endianness matches the target&rsquo;s
 endianness.
 </p>

 <dl compact="compact">
 <dt><code>R <var>bytes</var></code></dt>
 <dd><p>Register block.  The number and ordering of bytes matches that of a
 <code>g</code> packet in the remote protocol.  Note that these are the
 actual bytes, in target order and <small>GDB</small> register order, not a
 hexadecimal encoding.
 </p>
 </dd>
 <dt><code>M <var>address</var> <var>length</var> <var>bytes</var>...</code></dt>
 <dd><p>Memory block.  This is a contiguous block of memory, at the 8-byte
 address <var>address</var>, with a 2-byte length <var>length</var>, followed by
 <var>length</var> bytes.
 </p>
 </dd>
 <dt><code>V <var>number</var> <var>value</var></code></dt>
 <dd><p>Trace state variable block.  This records the 8-byte signed value
 <var>value</var> of trace state variable numbered <var>number</var>.
 </p>
 </dd>
 </dl>

 <p>Future enhancements of the trace file format may include additional types
 of blocks.
 </p>
 <hr>
 <div class="header">
 <p>
 Next: <a href="Index-Section-Format.html#Index-Section-Format" accesskey="n" rel="next">Index Section Format</a>, Previous: <a href="Operating-System-Information.html#Operating-System-Information" accesskey="p" rel="prev">Operating System Information</a>, Up: <a href="index.html#Top" accesskey="u" rel="up">Top</a> &nbsp; [<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>
	<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
	<html>
	<!-- Copyright (C) 1988-2015 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 5.2, http://www.gnu.org/software/texinfo/ -->
	<head>
	<title>Debugging with GDB: Trace File Format</title>

	<meta name="description" content="Debugging with GDB: Trace File Format">
	<meta name="keywords" content="Debugging with GDB: Trace File Format">
	<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="index.html#Top" rel="up" title="Top">
	<link href="Index-Section-Format.html#Index-Section-Format" rel="next" title="Index Section Format">
	<link href="Process-list.html#Process-list" rel="prev" title="Process list">
	<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="Trace-File-Format"></a>
	<div class="header">
	<p>
	Next: <a href="Index-Section-Format.html#Index-Section-Format" accesskey="n" rel="next">Index Section Format</a>, Previous: <a href="Operating-System-Information.html#Operating-System-Information" accesskey="p" rel="prev">Operating System Information</a>, Up: <a href="index.html#Top" accesskey="u" rel="up">Top</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="Trace-File-Format-1"></a>
	<h2 class="appendix">Appendix I Trace File Format</h2>
	<a name="index-trace-file-format"></a>

	<p>The trace file comes in three parts: a header, a textual description
	section, and a trace frame section with binary data.
	</p>
	<p>The header has the form <code>\x7fTRACE0\n</code>. The first byte is
	<code>0x7f</code> so as to indicate that the file contains binary data,
	while the <code>0</code> is a version number that may have different values
	in the future.
	</p>
	<p>The description section consists of multiple lines of <small>ASCII</small> text
	separated by newline characters (<code>0xa</code>). The lines may include a
	variety of optional descriptive or context-setting information, such
	as tracepoint definitions or register set size. <small>GDB</small> will
	ignore any line that it does not recognize. An empty line marks the end
	of this section.
	</p>

	<p>The trace frame section consists of a number of consecutive frames.
	Each frame begins with a two-byte tracepoint number, followed by a
	four-byte size giving the amount of data in the frame. The data in
	the frame consists of a number of blocks, each introduced by a
	character indicating its type (at least register, memory, and trace
	state variable). The data in this section is raw binary, not a
	hexadecimal or other encoding; its endianness matches the target’s
	endianness.
	</p>

	<dl compact="compact">
	<dt><code>R <var>bytes</var></code></dt>
	<dd><p>Register block. The number and ordering of bytes matches that of a
	<code>g</code> packet in the remote protocol. Note that these are the
	actual bytes, in target order and <small>GDB</small> register order, not a
	hexadecimal encoding.
	</p>
	</dd>
	<dt><code>M <var>address</var> <var>length</var> <var>bytes</var>...</code></dt>
	<dd><p>Memory block. This is a contiguous block of memory, at the 8-byte
	address <var>address</var>, with a 2-byte length <var>length</var>, followed by
	<var>length</var> bytes.
	</p>
	</dd>
	<dt><code>V <var>number</var> <var>value</var></code></dt>
	<dd><p>Trace state variable block. This records the 8-byte signed value
	<var>value</var> of trace state variable numbered <var>number</var>.
	</p>
	</dd>
	</dl>

	<p>Future enhancements of the trace file format may include additional types
	of blocks.
	</p>
	<hr>
	<div class="header">
	<p>
	Next: <a href="Index-Section-Format.html#Index-Section-Format" accesskey="n" rel="next">Index Section Format</a>, Previous: <a href="Operating-System-Information.html#Operating-System-Information" accesskey="p" rel="prev">Operating System Information</a>, Up: <a href="index.html#Top" accesskey="u" rel="up">Top</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>