1<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> 2<html> 3<!-- Copyright (C) 1988-2021 Free Software Foundation, Inc. 4 5Permission is granted to copy, distribute and/or modify this document 6under the terms of the GNU Free Documentation License, Version 1.3 or 7any later version published by the Free Software Foundation; with the 8Invariant Sections being "Free Software" and "Free Software Needs 9Free Documentation", with the Front-Cover Texts being "A GNU Manual," 10and with the Back-Cover Texts as in (a) below. 11 12(a) The FSF's Back-Cover Text is: "You are free to copy and modify 13this GNU Manual. 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This is useful, for example, when <var>port</var> 87specifies a ‘<samp>bytevector</samp>’ and you want the bytevector to be disassembled 88as if it came from that address. The <var>start-pc</var> passed to the reader 89for <var>port</var> is offset by the same amount. 90</p> 91<p>Example: 92</p><div class="smallexample"> 93<pre class="smallexample">(gdb) guile (use-modules (rnrs io ports)) 94(gdb) guile (define pc (value->integer (parse-and-eval "$pc"))) 95(gdb) guile (define mem (open-memory #:start pc)) 96(gdb) guile (define bv (get-bytevector-n mem 10)) 97(gdb) guile (define bv-port (open-bytevector-input-port bv)) 98(gdb) guile (define arch (current-arch)) 99(gdb) guile (arch-disassemble arch pc #:port bv-port #:offset pc) 100(((address . 4195516) (asm . "mov $0x4005c8,%edi") (length . 5))) 101</pre></div> 102 103<p>The optional arguments <var>size</var> and 104<var>count</var> determine the number of instructions in the returned list. 105If either <var>size</var> or <var>count</var> is specified as zero, then 106no instructions are disassembled and an empty list is returned. 107If both the optional arguments <var>size</var> and <var>count</var> are 108specified, then a list of at most <var>count</var> disassembled instructions 109whose start address falls in the closed memory address interval from 110<var>start-pc</var> to (<var>start-pc</var> + <var>size</var> - 1) are returned. 111If <var>size</var> is not specified, but <var>count</var> is specified, 112then <var>count</var> number of instructions starting from the address 113<var>start-pc</var> are returned. If <var>count</var> is not specified but 114<var>size</var> is specified, then all instructions whose start address 115falls in the closed memory address interval from <var>start-pc</var> to 116(<var>start-pc</var> + <var>size</var> - 1) are returned. 117If neither <var>size</var> nor <var>count</var> are specified, then a single 118instruction at <var>start-pc</var> is returned. 119</p> 120<p>Each element of the returned list is an alist (associative list) 121with the following keys: 122</p> 123<dl compact="compact"> 124<dt><code>address</code></dt> 125<dd><p>The value corresponding to this key is a Guile integer of 126the memory address of the instruction. 127</p> 128</dd> 129<dt><code>asm</code></dt> 130<dd><p>The value corresponding to this key is a string value which represents 131the instruction with assembly language mnemonics. The assembly 132language flavor used is the same as that specified by the current CLI 133variable <code>disassembly-flavor</code>. See <a href="Machine-Code.html#Machine-Code">Machine Code</a>. 134</p> 135</dd> 136<dt><code>length</code></dt> 137<dd><p>The value corresponding to this key is the length of the instruction in bytes. 138</p> 139</dd> 140</dl> 141</dd></dl> 142 143<hr> 144<div class="header"> 145<p> 146Next: <a href="I_002fO-Ports-in-Guile.html#I_002fO-Ports-in-Guile" accesskey="n" rel="next">I/O Ports in Guile</a>, Previous: <a href="Architectures-In-Guile.html#Architectures-In-Guile" accesskey="p" rel="previous">Architectures In Guile</a>, Up: <a href="Guile-API.html#Guile-API" accesskey="u" rel="up">Guile API</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> 147</div> 148 149 150 151</body> 152</html> 153