| <html lang="en"> |
| <head> |
| <title>Target Commands - Debugging with GDB</title> |
| <meta http-equiv="Content-Type" content="text/html"> |
| <meta name="description" content="Debugging with GDB"> |
| <meta name="generator" content="makeinfo 4.13"> |
| <link title="Top" rel="start" href="index.html#Top"> |
| <link rel="up" href="Targets.html#Targets" title="Targets"> |
| <link rel="prev" href="Active-Targets.html#Active-Targets" title="Active Targets"> |
| <link rel="next" href="Byte-Order.html#Byte-Order" title="Byte Order"> |
| <link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage"> |
| <!-- |
| Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, |
| 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 |
| 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.''--> |
| <meta http-equiv="Content-Style-Type" content="text/css"> |
| <style type="text/css"><!-- |
| pre.display { font-family:inherit } |
| pre.format { font-family:inherit } |
| pre.smalldisplay { font-family:inherit; font-size:smaller } |
| pre.smallformat { font-family:inherit; font-size:smaller } |
| pre.smallexample { font-size:smaller } |
| pre.smalllisp { font-size:smaller } |
| span.sc { font-variant:small-caps } |
| span.roman { font-family:serif; font-weight:normal; } |
| span.sansserif { font-family:sans-serif; font-weight:normal; } |
| --></style> |
| <link rel="stylesheet" type="text/css" href="../cs.css"> |
| </head> |
| <body> |
| <div class="node"> |
| <a name="Target-Commands"></a> |
| <p> |
| Next: <a rel="next" accesskey="n" href="Byte-Order.html#Byte-Order">Byte Order</a>, |
| Previous: <a rel="previous" accesskey="p" href="Active-Targets.html#Active-Targets">Active Targets</a>, |
| Up: <a rel="up" accesskey="u" href="Targets.html#Targets">Targets</a> |
| <hr> |
| </div> |
| |
| <h3 class="section">19.2 Commands for Managing Targets</h3> |
| |
| <dl> |
| <dt><code>target </code><var>type</var> <var>parameters</var><dd>Connects the <span class="sc">gdb</span> host environment to a target machine or |
| process. A target is typically a protocol for talking to debugging |
| facilities. You use the argument <var>type</var> to specify the type or |
| protocol of the target machine. |
| |
| <p>Further <var>parameters</var> are interpreted by the target protocol, but |
| typically include things like device names or host names to connect |
| with, process numbers, and baud rates. |
| |
| <p>The <code>target</code> command does not repeat if you press <RET> again |
| after executing the command. |
| |
| <p><a name="index-help-target-1039"></a><br><dt><code>help target</code><dd>Displays the names of all targets available. To display targets |
| currently selected, use either <code>info target</code> or <code>info files</code> |
| (see <a href="Files.html#Files">Commands to Specify Files</a>). |
| |
| <br><dt><code>help target </code><var>name</var><dd>Describe a particular target, including any parameters necessary to |
| select it. |
| |
| <p><a name="index-set-gnutarget-1040"></a><br><dt><code>set gnutarget </code><var>args</var><dd><span class="sc">gdb</span> uses its own library BFD to read your files. <span class="sc">gdb</span> |
| knows whether it is reading an <dfn>executable</dfn>, |
| a <dfn>core</dfn>, or a <dfn>.o</dfn> file; however, you can specify the file format |
| with the <code>set gnutarget</code> command. Unlike most <code>target</code> commands, |
| with <code>gnutarget</code> the <code>target</code> refers to a program, not a machine. |
| |
| <blockquote> |
| <em>Warning:</em> To specify a file format with <code>set gnutarget</code>, |
| you must know the actual BFD name. |
| </blockquote> |
| |
| <p class="noindent">See <a href="Files.html#Files">Commands to Specify Files</a>. |
| |
| <p><a name="index-show-gnutarget-1041"></a><br><dt><code>show gnutarget</code><dd>Use the <code>show gnutarget</code> command to display what file format |
| <code>gnutarget</code> is set to read. If you have not set <code>gnutarget</code>, |
| <span class="sc">gdb</span> will determine the file format for each file automatically, |
| and <code>show gnutarget</code> displays ‘<samp><span class="samp">The current BDF target is "auto"</span></samp>’. |
| </dl> |
| |
| <p><a name="index-common-targets-1042"></a>Here are some common targets (available, or not, depending on the GDB |
| configuration): |
| |
| |
| <a name="index-target-1043"></a> |
| <dl><dt><code>target exec </code><var>program</var><dd><a name="index-executable-file-target-1044"></a>An executable file. ‘<samp><span class="samp">target exec </span><var>program</var></samp>’ is the same as |
| ‘<samp><span class="samp">exec-file </span><var>program</var></samp>’. |
| |
| <br><dt><code>target core </code><var>filename</var><dd><a name="index-core-dump-file-target-1045"></a>A core dump file. ‘<samp><span class="samp">target core </span><var>filename</var></samp>’ is the same as |
| ‘<samp><span class="samp">core-file </span><var>filename</var></samp>’. |
| |
| <br><dt><code>target remote </code><var>medium</var><dd><a name="index-remote-target-1046"></a>A remote system connected to <span class="sc">gdb</span> via a serial line or network |
| connection. This command tells <span class="sc">gdb</span> to use its own remote |
| protocol over <var>medium</var> for debugging. See <a href="Remote-Debugging.html#Remote-Debugging">Remote Debugging</a>. |
| |
| <p>For example, if you have a board connected to <samp><span class="file">/dev/ttya</span></samp> on the |
| machine running <span class="sc">gdb</span>, you could say: |
| |
| <pre class="smallexample"> target remote /dev/ttya |
| </pre> |
| <p><code>target remote</code> supports the <code>load</code> command. This is only |
| useful if you have some other way of getting the stub to the target |
| system, and you can put it somewhere in memory where it won't get |
| clobbered by the download. |
| |
| <br><dt><code>target sim </code><span class="roman">[</span><var>simargs</var><span class="roman">]</span><code> ...</code><dd><a name="index-built_002din-simulator-target-1047"></a>Builtin CPU simulator. <span class="sc">gdb</span> includes simulators for most architectures. |
| In general, |
| <pre class="smallexample"> target sim |
| load |
| run |
| </pre> |
| <p class="noindent">works; however, you cannot assume that a specific memory map, device |
| drivers, or even basic I/O is available, although some simulators do |
| provide these. For info about any processor-specific simulator details, |
| see the appropriate section in <a href="Embedded-Processors.html#Embedded-Processors">Embedded Processors</a>. |
| |
| </dl> |
| |
| <p>Some configurations may include these targets as well: |
| |
| <dl> |
| <dt><code>target nrom </code><var>dev</var><dd><a name="index-NetROM-ROM-emulator-target-1048"></a>NetROM ROM emulator. This target only supports downloading. |
| |
| </dl> |
| |
| <p>Different targets are available on different configurations of <span class="sc">gdb</span>; |
| your configuration may have more or fewer targets. |
| |
| <p>Many remote targets require you to download the executable's code once |
| you've successfully established a connection. You may wish to control |
| various aspects of this process. |
| |
| <dl> |
| <dt><code>set hash</code><dd><a name="index-set-hash_0040r_007b_002c-for-remote-monitors_007d-1049"></a><a name="index-hash-mark-while-downloading-1050"></a>This command controls whether a hash mark ‘<samp><span class="samp">#</span></samp>’ is displayed while |
| downloading a file to the remote monitor. If on, a hash mark is |
| displayed after each S-record is successfully downloaded to the |
| monitor. |
| |
| <br><dt><code>show hash</code><dd><a name="index-show-hash_0040r_007b_002c-for-remote-monitors_007d-1051"></a>Show the current status of displaying the hash mark. |
| |
| <br><dt><code>set debug monitor</code><dd><a name="index-set-debug-monitor-1052"></a><a name="index-display-remote-monitor-communications-1053"></a>Enable or disable display of communications messages between |
| <span class="sc">gdb</span> and the remote monitor. |
| |
| <br><dt><code>show debug monitor</code><dd><a name="index-show-debug-monitor-1054"></a>Show the current status of displaying communications between |
| <span class="sc">gdb</span> and the remote monitor. |
| </dl> |
| |
| |
| <a name="index-load-_0040var_007bfilename_007d-1055"></a> |
| <dl><dt><code>load </code><var>filename</var><dd><a name="load"></a>Depending on what remote debugging facilities are configured into |
| <span class="sc">gdb</span>, the <code>load</code> command may be available. Where it exists, it |
| is meant to make <var>filename</var> (an executable) available for debugging |
| on the remote system—by downloading, or dynamic linking, for example. |
| <code>load</code> also records the <var>filename</var> symbol table in <span class="sc">gdb</span>, like |
| the <code>add-symbol-file</code> command. |
| |
| <p>If your <span class="sc">gdb</span> does not have a <code>load</code> command, attempting to |
| execute it gets the error message “<code>You can't do that when your |
| target is ...</code>” |
| |
| <p>The file is loaded at whatever address is specified in the executable. |
| For some object file formats, you can specify the load address when you |
| link the program; for other formats, like a.out, the object file format |
| specifies a fixed address. |
| <!-- FIXME! This would be a good place for an xref to the GNU linker doc. --> |
| |
| <p>Depending on the remote side capabilities, <span class="sc">gdb</span> may be able to |
| load programs into flash memory. |
| |
| <p><code>load</code> does not repeat if you press <RET> again after using it. |
| </dl> |
| |
| </body></html> |
| |
