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1346 lines
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Written by: Lionel Cons <Lionel.Cons@cern.ch> (original author)
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Karl Berry <karl@freefriends.org>
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Olaf Bachmann <obachman@mathematik.uni-kl.de>
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<HEAD>
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<TITLE>Debugging with GDB: Remote Debugging</TITLE>
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<META NAME="description" CONTENT="Debugging with GDB: Remote Debugging">
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<A NAME="SEC162"></A>
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<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0>
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<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_17.html#SEC161"> < </A>]</TD>
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</TR></TABLE>
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<H1> 17. Debugging Remote Programs </H1>
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<!--docid::SEC162::-->
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<P>
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If you are trying to debug a program running on a machine that cannot run
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GDB in the usual way, it is often useful to use remote debugging.
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For example, you might use remote debugging on an operating system kernel,
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or on a small system which does not have a general purpose operating system
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powerful enough to run a full-featured debugger.
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</P><P>
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Some configurations of GDB have special serial or TCP/IP interfaces
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to make this work with particular debugging targets. In addition,
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GDB comes with a generic serial protocol (specific to GDB,
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but not specific to any particular target system) which you can use if you
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write the remote stubs--the code that runs on the remote system to
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communicate with GDB.
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</P><P>
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Other remote targets may be available in your
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configuration of GDB; use <CODE>help target</CODE> to list them.
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</P><P>
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<BLOCKQUOTE><TABLE BORDER=0 CELLSPACING=0>
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<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="gdb_18.html#SEC163">17.1 Connecting to a Remote Target</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Connecting to a remote target</TD></TR>
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<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="gdb_18.html#SEC164">17.2 Sending files to a remote system</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP"></TD></TR>
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<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="gdb_18.html#SEC165">17.3 Using the <CODE>gdbserver</CODE> Program</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Using the gdbserver program</TD></TR>
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<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="gdb_18.html#SEC172">17.4 Remote Configuration</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Remote configuration</TD></TR>
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<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="gdb_18.html#SEC173">17.5 Implementing a Remote Stub</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Implementing a remote stub</TD></TR>
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</TABLE></BLOCKQUOTE>
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<P>
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<A NAME="Connecting"></A>
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<HR SIZE="6">
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<A NAME="SEC163"></A>
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<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0>
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<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_toc.html#SEC_Contents">Contents</A>]</TD>
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<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_38.html#SEC764">Index</A>]</TD>
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<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_abt.html#SEC_About"> ? </A>]</TD>
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</TR></TABLE>
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<H2> 17.1 Connecting to a Remote Target </H2>
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<!--docid::SEC163::-->
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<P>
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On the GDB host machine, you will need an unstripped copy of
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your program, since GDB needs symbol and debugging information.
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Start up GDB as usual, using the name of the local copy of your
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program as the first argument.
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</P><P>
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<A NAME="IDX792"></A>
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GDB can communicate with the target over a serial line, or
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over an <FONT SIZE="-1">IP</FONT> network using <FONT SIZE="-1">TCP</FONT> or <FONT SIZE="-1">UDP</FONT>. In
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each case, GDB uses the same protocol for debugging your
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program; only the medium carrying the debugging packets varies. The
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<CODE>target remote</CODE> command establishes a connection to the target.
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Its arguments indicate which medium to use:
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</P><P>
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<DL COMPACT>
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<DT><CODE>target remote <VAR>serial-device</VAR></CODE>
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<DD><A NAME="IDX793"></A>
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Use <VAR>serial-device</VAR> to communicate with the target. For example,
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to use a serial line connected to the device named <TT>`/dev/ttyb'</TT>:
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<P>
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<TABLE><tr><td> </td><td class=smallexample><FONT SIZE=-1><pre>target remote /dev/ttyb
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</FONT></pre></td></tr></table></P><P>
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If you're using a serial line, you may want to give GDB the
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<SAMP>`--baud'</SAMP> option, or use the <CODE>set remotebaud</CODE> command
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(see section <A HREF="gdb_18.html#SEC172">set remotebaud</A>) before the
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<CODE>target</CODE> command.
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</P><P>
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<DT><CODE>target remote <CODE><VAR>host</VAR>:<VAR>port</VAR></CODE></CODE>
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<DD><DT><CODE>target remote <CODE>tcp:<VAR>host</VAR>:<VAR>port</VAR></CODE></CODE>
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<DD><A NAME="IDX794"></A>
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Debug using a <FONT SIZE="-1">TCP</FONT> connection to <VAR>port</VAR> on <VAR>host</VAR>.
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The <VAR>host</VAR> may be either a host name or a numeric <FONT SIZE="-1">IP</FONT>
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address; <VAR>port</VAR> must be a decimal number. The <VAR>host</VAR> could be
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the target machine itself, if it is directly connected to the net, or
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it might be a terminal server which in turn has a serial line to the
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target.
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<P>
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For example, to connect to port 2828 on a terminal server named
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<CODE>manyfarms</CODE>:
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</P><P>
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<TABLE><tr><td> </td><td class=smallexample><FONT SIZE=-1><pre>target remote manyfarms:2828
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</FONT></pre></td></tr></table></P><P>
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If your remote target is actually running on the same machine as your
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debugger session (e.g. a simulator for your target running on the
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same host), you can omit the hostname. For example, to connect to
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port 1234 on your local machine:
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</P><P>
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<TABLE><tr><td> </td><td class=smallexample><FONT SIZE=-1><pre>target remote :1234
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</FONT></pre></td></tr></table></P><P>
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Note that the colon is still required here.
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</P><P>
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<DT><CODE>target remote <CODE>udp:<VAR>host</VAR>:<VAR>port</VAR></CODE></CODE>
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<DD><A NAME="IDX795"></A>
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Debug using <FONT SIZE="-1">UDP</FONT> packets to <VAR>port</VAR> on <VAR>host</VAR>. For example, to
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connect to <FONT SIZE="-1">UDP</FONT> port 2828 on a terminal server named <CODE>manyfarms</CODE>:
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<P>
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<TABLE><tr><td> </td><td class=smallexample><FONT SIZE=-1><pre>target remote udp:manyfarms:2828
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</FONT></pre></td></tr></table></P><P>
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When using a <FONT SIZE="-1">UDP</FONT> connection for remote debugging, you should
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keep in mind that the `U' stands for "Unreliable". <FONT SIZE="-1">UDP</FONT>
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can silently drop packets on busy or unreliable networks, which will
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cause havoc with your debugging session.
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</P><P>
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<DT><CODE>target remote | <VAR>command</VAR></CODE>
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<DD><A NAME="IDX796"></A>
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Run <VAR>command</VAR> in the background and communicate with it using a
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pipe. The <VAR>command</VAR> is a shell command, to be parsed and expanded
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by the system's command shell, <CODE>/bin/sh</CODE>; it should expect remote
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protocol packets on its standard input, and send replies on its
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standard output. You could use this to run a stand-alone simulator
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that speaks the remote debugging protocol, to make net connections
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using programs like <CODE>ssh</CODE>, or for other similar tricks.
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<P>
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If <VAR>command</VAR> closes its standard output (perhaps by exiting),
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GDB will try to send it a <CODE>SIGTERM</CODE> signal. (If the
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program has already exited, this will have no effect.)
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</P><P>
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</DL>
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<P>
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Once the connection has been established, you can use all the usual
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commands to examine and change data and to step and continue the
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remote program.
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</P><P>
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<A NAME="IDX797"></A>
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<A NAME="IDX798"></A>
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Whenever GDB is waiting for the remote program, if you type the
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interrupt character (often <KBD>Ctrl-c</KBD>), GDB attempts to stop the
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program. This may or may not succeed, depending in part on the hardware
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and the serial drivers the remote system uses. If you type the
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interrupt character once again, GDB displays this prompt:
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</P><P>
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<TABLE><tr><td> </td><td class=smallexample><FONT SIZE=-1><pre>Interrupted while waiting for the program.
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Give up (and stop debugging it)? (y or n)
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</FONT></pre></td></tr></table></P><P>
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If you type <KBD>y</KBD>, GDB abandons the remote debugging session.
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(If you decide you want to try again later, you can use <SAMP>`target
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remote'</SAMP> again to connect once more.) If you type <KBD>n</KBD>, GDB
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goes back to waiting.
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</P><P>
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<DL COMPACT>
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<A NAME="IDX799"></A>
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<DT><CODE>detach</CODE>
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<DD>When you have finished debugging the remote program, you can use the
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<CODE>detach</CODE> command to release it from GDB control.
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Detaching from the target normally resumes its execution, but the results
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will depend on your particular remote stub. After the <CODE>detach</CODE>
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command, GDB is free to connect to another target.
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<P>
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<A NAME="IDX800"></A>
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<DT><CODE>disconnect</CODE>
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<DD>The <CODE>disconnect</CODE> command behaves like <CODE>detach</CODE>, except that
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the target is generally not resumed. It will wait for GDB
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(this instance or another one) to connect and continue debugging. After
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the <CODE>disconnect</CODE> command, GDB is again free to connect to
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another target.
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<P>
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<A NAME="IDX801"></A>
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<A NAME="IDX802"></A>
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<A NAME="IDX803"></A>
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<A NAME="IDX804"></A>
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<DT><CODE>monitor <VAR>cmd</VAR></CODE>
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<DD>This command allows you to send arbitrary commands directly to the
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remote monitor. Since GDB doesn't care about the commands it
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sends like this, this command is the way to extend GDB---you
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can add new commands that only the external monitor will understand
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and implement.
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</DL>
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<P>
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<A NAME="File Transfer"></A>
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<HR SIZE="6">
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<A NAME="SEC164"></A>
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<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0>
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<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC163"> < </A>]</TD>
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<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC165"> > </A>]</TD>
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<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC165"> << </A>]</TD>
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<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC162"> Up </A>]</TD>
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<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_19.html#SEC177"> >> </A>]</TD>
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<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb.html#SEC_Top">Top</A>]</TD>
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<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_toc.html#SEC_Contents">Contents</A>]</TD>
|
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<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_38.html#SEC764">Index</A>]</TD>
|
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<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_abt.html#SEC_About"> ? </A>]</TD>
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</TR></TABLE>
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<H2> 17.2 Sending files to a remote system </H2>
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<!--docid::SEC164::-->
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<P>
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Some remote targets offer the ability to transfer files over the same
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connection used to communicate with GDB. This is convenient
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for targets accessible through other means, e.g. GNU/Linux systems
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running <CODE>gdbserver</CODE> over a network interface. For other targets,
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e.g. embedded devices with only a single serial port, this may be
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the only way to upload or download files.
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</P><P>
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Not all remote targets support these commands.
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</P><P>
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<DL COMPACT>
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<A NAME="IDX805"></A>
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<DT><CODE>remote put <VAR>hostfile</VAR> <VAR>targetfile</VAR></CODE>
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<DD>Copy file <VAR>hostfile</VAR> from the host system (the machine running
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GDB) to <VAR>targetfile</VAR> on the target system.
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<P>
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<A NAME="IDX806"></A>
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<DT><CODE>remote get <VAR>targetfile</VAR> <VAR>hostfile</VAR></CODE>
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<DD>Copy file <VAR>targetfile</VAR> from the target system to <VAR>hostfile</VAR>
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on the host system.
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<P>
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<A NAME="IDX807"></A>
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<DT><CODE>remote delete <VAR>targetfile</VAR></CODE>
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<DD>Delete <VAR>targetfile</VAR> from the target system.
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<P>
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</DL>
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<P>
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<A NAME="Server"></A>
|
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<HR SIZE="6">
|
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<A NAME="SEC165"></A>
|
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<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0>
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<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC164"> < </A>]</TD>
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<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC166"> > </A>]</TD>
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<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC172"> << </A>]</TD>
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<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC162"> Up </A>]</TD>
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<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC172"> >> </A>]</TD>
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<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb.html#SEC_Top">Top</A>]</TD>
|
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<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_toc.html#SEC_Contents">Contents</A>]</TD>
|
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<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_38.html#SEC764">Index</A>]</TD>
|
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<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_abt.html#SEC_About"> ? </A>]</TD>
|
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</TR></TABLE>
|
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<H2> 17.3 Using the <CODE>gdbserver</CODE> Program </H2>
|
|
<!--docid::SEC165::-->
|
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<P>
|
|
|
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<A NAME="IDX808"></A>
|
|
<A NAME="IDX809"></A>
|
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<CODE>gdbserver</CODE> is a control program for Unix-like systems, which
|
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allows you to connect your program with a remote GDB via
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<CODE>target remote</CODE>---but without linking in the usual debugging stub.
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</P><P>
|
|
|
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<CODE>gdbserver</CODE> is not a complete replacement for the debugging stubs,
|
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because it requires essentially the same operating-system facilities
|
|
that GDB itself does. In fact, a system that can run
|
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<CODE>gdbserver</CODE> to connect to a remote GDB could also run
|
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GDB locally! <CODE>gdbserver</CODE> is sometimes useful nevertheless,
|
|
because it is a much smaller program than GDB itself. It is
|
|
also easier to port than all of GDB, so you may be able to get
|
|
started more quickly on a new system by using <CODE>gdbserver</CODE>.
|
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Finally, if you develop code for real-time systems, you may find that
|
|
the tradeoffs involved in real-time operation make it more convenient to
|
|
do as much development work as possible on another system, for example
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by cross-compiling. You can use <CODE>gdbserver</CODE> to make a similar
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choice for debugging.
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</P><P>
|
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GDB and <CODE>gdbserver</CODE> communicate via either a serial line
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or a TCP connection, using the standard GDB remote serial
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protocol.
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</P><P>
|
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<BLOCKQUOTE>
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<EM>Warning:</EM> <CODE>gdbserver</CODE> does not have any built-in security.
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Do not run <CODE>gdbserver</CODE> connected to any public network; a
|
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GDB connection to <CODE>gdbserver</CODE> provides access to the
|
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target system with the same privileges as the user running
|
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<CODE>gdbserver</CODE>.
|
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</BLOCKQUOTE>
|
|
<P>
|
|
|
|
<HR SIZE="6">
|
|
<A NAME="SEC166"></A>
|
|
<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0>
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<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC165"> < </A>]</TD>
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<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC167"> > </A>]</TD>
|
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<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC172"> << </A>]</TD>
|
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<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC165"> Up </A>]</TD>
|
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<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC170"> >> </A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb.html#SEC_Top">Top</A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_toc.html#SEC_Contents">Contents</A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_38.html#SEC764">Index</A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_abt.html#SEC_About"> ? </A>]</TD>
|
|
</TR></TABLE>
|
|
<H3> 17.3.1 Running <CODE>gdbserver</CODE> </H3>
|
|
<!--docid::SEC166::-->
|
|
<P>
|
|
|
|
Run <CODE>gdbserver</CODE> on the target system. You need a copy of the
|
|
program you want to debug, including any libraries it requires.
|
|
<CODE>gdbserver</CODE> does not need your program's symbol table, so you can
|
|
strip the program if necessary to save space. GDB on the host
|
|
system does all the symbol handling.
|
|
</P><P>
|
|
|
|
To use the server, you must tell it how to communicate with GDB;
|
|
the name of your program; and the arguments for your program. The usual
|
|
syntax is:
|
|
</P><P>
|
|
|
|
<TABLE><tr><td> </td><td class=smallexample><FONT SIZE=-1><pre>target> gdbserver <VAR>comm</VAR> <VAR>program</VAR> [ <VAR>args</VAR> <small>...</small> ]
|
|
</FONT></pre></td></tr></table></P><P>
|
|
|
|
<VAR>comm</VAR> is either a device name (to use a serial line) or a TCP
|
|
hostname and portnumber. For example, to debug Emacs with the argument
|
|
<SAMP>`foo.txt'</SAMP> and communicate with GDB over the serial port
|
|
<TT>`/dev/com1'</TT>:
|
|
</P><P>
|
|
|
|
<TABLE><tr><td> </td><td class=smallexample><FONT SIZE=-1><pre>target> gdbserver /dev/com1 emacs foo.txt
|
|
</FONT></pre></td></tr></table></P><P>
|
|
|
|
<CODE>gdbserver</CODE> waits passively for the host GDB to communicate
|
|
with it.
|
|
</P><P>
|
|
|
|
To use a TCP connection instead of a serial line:
|
|
</P><P>
|
|
|
|
<TABLE><tr><td> </td><td class=smallexample><FONT SIZE=-1><pre>target> gdbserver host:2345 emacs foo.txt
|
|
</FONT></pre></td></tr></table></P><P>
|
|
|
|
The only difference from the previous example is the first argument,
|
|
specifying that you are communicating with the host GDB via
|
|
TCP. The <SAMP>`host:2345'</SAMP> argument means that <CODE>gdbserver</CODE> is to
|
|
expect a TCP connection from machine <SAMP>`host'</SAMP> to local TCP port 2345.
|
|
(Currently, the <SAMP>`host'</SAMP> part is ignored.) You can choose any number
|
|
you want for the port number as long as it does not conflict with any
|
|
TCP ports already in use on the target system (for example, <CODE>23</CODE> is
|
|
reserved for <CODE>telnet</CODE>).<A NAME="DOCF7" HREF="gdb_fot.html#FOOT7">(7)</A> You must use the same port number with the host GDB
|
|
<CODE>target remote</CODE> command.
|
|
</P><P>
|
|
|
|
<HR SIZE="6">
|
|
<A NAME="SEC167"></A>
|
|
<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0>
|
|
<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC166"> < </A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC168"> > </A>]</TD>
|
|
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|
|
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|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC170"> >> </A>]</TD>
|
|
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|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_toc.html#SEC_Contents">Contents</A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_38.html#SEC764">Index</A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_abt.html#SEC_About"> ? </A>]</TD>
|
|
</TR></TABLE>
|
|
<H4> 17.3.1.1 Attaching to a Running Program </H4>
|
|
<!--docid::SEC167::-->
|
|
<P>
|
|
|
|
On some targets, <CODE>gdbserver</CODE> can also attach to running programs.
|
|
This is accomplished via the <CODE>--attach</CODE> argument. The syntax is:
|
|
</P><P>
|
|
|
|
<TABLE><tr><td> </td><td class=smallexample><FONT SIZE=-1><pre>target> gdbserver --attach <VAR>comm</VAR> <VAR>pid</VAR>
|
|
</FONT></pre></td></tr></table></P><P>
|
|
|
|
<VAR>pid</VAR> is the process ID of a currently running process. It isn't necessary
|
|
to point <CODE>gdbserver</CODE> at a binary for the running process.
|
|
</P><P>
|
|
|
|
<A NAME="IDX810"></A>
|
|
<A NAME="IDX811"></A>
|
|
You can debug processes by name instead of process ID if your target has the
|
|
<CODE>pidof</CODE> utility:
|
|
</P><P>
|
|
|
|
<TABLE><tr><td> </td><td class=smallexample><FONT SIZE=-1><pre>target> gdbserver --attach <VAR>comm</VAR> `pidof <VAR>program</VAR>`
|
|
</FONT></pre></td></tr></table></P><P>
|
|
|
|
In case more than one copy of <VAR>program</VAR> is running, or <VAR>program</VAR>
|
|
has multiple threads, most versions of <CODE>pidof</CODE> support the
|
|
<CODE>-s</CODE> option to only return the first process ID.
|
|
</P><P>
|
|
|
|
<HR SIZE="6">
|
|
<A NAME="SEC168"></A>
|
|
<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0>
|
|
<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC167"> < </A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC169"> > </A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC169"> << </A>]</TD>
|
|
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|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC170"> >> </A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb.html#SEC_Top">Top</A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_toc.html#SEC_Contents">Contents</A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_38.html#SEC764">Index</A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_abt.html#SEC_About"> ? </A>]</TD>
|
|
</TR></TABLE>
|
|
<H4> 17.3.1.2 Multi-Process Mode for <CODE>gdbserver</CODE> </H4>
|
|
<!--docid::SEC168::-->
|
|
<P>
|
|
|
|
When you connect to <CODE>gdbserver</CODE> using <CODE>target remote</CODE>,
|
|
<CODE>gdbserver</CODE> debugs the specified program only once. When the
|
|
program exits, or you detach from it, GDB closes the connection
|
|
and <CODE>gdbserver</CODE> exits.
|
|
</P><P>
|
|
|
|
If you connect using <KBD>target extended-remote</KBD>, <CODE>gdbserver</CODE>
|
|
enters multi-process mode. When the debugged program exits, or you
|
|
detach from it, GDB stays connected to <CODE>gdbserver</CODE> even
|
|
though no program is running. The <CODE>run</CODE> and <CODE>attach</CODE>
|
|
commands instruct <CODE>gdbserver</CODE> to run or attach to a new program.
|
|
The <CODE>run</CODE> command uses <CODE>set remote exec-file</CODE> (see <A HREF="gdb_18.html#set remote exec-file">set remote exec-file</A>) to select the program to run. Command line
|
|
arguments are supported, except for wildcard expansion and I/O
|
|
redirection (see section <A HREF="gdb_5.html#SEC21">4.3 Your Program's Arguments</A>).
|
|
</P><P>
|
|
|
|
To start <CODE>gdbserver</CODE> without supplying an initial command to run
|
|
or process ID to attach, use the <SAMP>`--multi'</SAMP> command line option.
|
|
Then you can connect using <KBD>target extended-remote</KBD> and start
|
|
the program you want to debug.
|
|
</P><P>
|
|
|
|
<CODE>gdbserver</CODE> does not automatically exit in multi-process mode.
|
|
You can terminate it by using <CODE>monitor exit</CODE>
|
|
(see <A HREF="gdb_18.html#Monitor Commands for gdbserver">Monitor Commands for gdbserver</A>).
|
|
</P><P>
|
|
|
|
<HR SIZE="6">
|
|
<A NAME="SEC169"></A>
|
|
<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0>
|
|
<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC168"> < </A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC170"> > </A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC172"> << </A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC166"> Up </A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC170"> >> </A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb.html#SEC_Top">Top</A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_toc.html#SEC_Contents">Contents</A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_38.html#SEC764">Index</A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_abt.html#SEC_About"> ? </A>]</TD>
|
|
</TR></TABLE>
|
|
<H4> 17.3.1.3 Other Command-Line Arguments for <CODE>gdbserver</CODE> </H4>
|
|
<!--docid::SEC169::-->
|
|
<P>
|
|
|
|
You can include <SAMP>`--debug'</SAMP> on the <CODE>gdbserver</CODE> command line.
|
|
<CODE>gdbserver</CODE> will display extra status information about the debugging
|
|
process. This option is intended for <CODE>gdbserver</CODE> development and
|
|
for bug reports to the developers.
|
|
</P><P>
|
|
|
|
<HR SIZE="6">
|
|
<A NAME="SEC170"></A>
|
|
<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0>
|
|
<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC169"> < </A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC171"> > </A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC171"> << </A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC165"> Up </A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC172"> >> </A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb.html#SEC_Top">Top</A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_toc.html#SEC_Contents">Contents</A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_38.html#SEC764">Index</A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_abt.html#SEC_About"> ? </A>]</TD>
|
|
</TR></TABLE>
|
|
<H3> 17.3.2 Connecting to <CODE>gdbserver</CODE> </H3>
|
|
<!--docid::SEC170::-->
|
|
<P>
|
|
|
|
Run GDB on the host system.
|
|
</P><P>
|
|
|
|
First make sure you have the necessary symbol files. Load symbols for
|
|
your application using the <CODE>file</CODE> command before you connect. Use
|
|
<CODE>set sysroot</CODE> to locate target libraries (unless your GDB
|
|
was compiled with the correct sysroot using <CODE>--with-sysroot</CODE>).
|
|
</P><P>
|
|
|
|
The symbol file and target libraries must exactly match the executable
|
|
and libraries on the target, with one exception: the files on the host
|
|
system should not be stripped, even if the files on the target system
|
|
are. Mismatched or missing files will lead to confusing results
|
|
during debugging. On GNU/Linux targets, mismatched or missing
|
|
files may also prevent <CODE>gdbserver</CODE> from debugging multi-threaded
|
|
programs.
|
|
</P><P>
|
|
|
|
Connect to your target (see section <A HREF="gdb_18.html#SEC163">Connecting to a Remote Target</A>).
|
|
For TCP connections, you must start up <CODE>gdbserver</CODE> prior to using
|
|
the <CODE>target remote</CODE> command. Otherwise you may get an error whose
|
|
text depends on the host system, but which usually looks something like
|
|
<SAMP>`Connection refused'</SAMP>. Don't use the <CODE>load</CODE>
|
|
command in GDB when using <CODE>gdbserver</CODE>, since the program is
|
|
already on the target.
|
|
</P><P>
|
|
|
|
<HR SIZE="6">
|
|
<A NAME="SEC171"></A>
|
|
<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0>
|
|
<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC170"> < </A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC172"> > </A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC172"> << </A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC165"> Up </A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC172"> >> </A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb.html#SEC_Top">Top</A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_toc.html#SEC_Contents">Contents</A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_38.html#SEC764">Index</A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_abt.html#SEC_About"> ? </A>]</TD>
|
|
</TR></TABLE>
|
|
<H3> 17.3.3 Monitor Commands for <CODE>gdbserver</CODE> </H3>
|
|
<!--docid::SEC171::-->
|
|
<A NAME="Monitor Commands for gdbserver"></A>
|
|
<P>
|
|
|
|
During a GDB session using <CODE>gdbserver</CODE>, you can use the
|
|
<CODE>monitor</CODE> command to send special requests to <CODE>gdbserver</CODE>.
|
|
Here are the available commands.
|
|
</P><P>
|
|
|
|
<DL COMPACT>
|
|
<DT><CODE>monitor help</CODE>
|
|
<DD>List the available monitor commands.
|
|
<P>
|
|
|
|
<DT><CODE>monitor set debug 0</CODE>
|
|
<DD><DT><CODE>monitor set debug 1</CODE>
|
|
<DD>Disable or enable general debugging messages.
|
|
<P>
|
|
|
|
<DT><CODE>monitor set remote-debug 0</CODE>
|
|
<DD><DT><CODE>monitor set remote-debug 1</CODE>
|
|
<DD>Disable or enable specific debugging messages associated with the remote
|
|
protocol (see section <A HREF="gdb_33.html#SEC694">D. GDB Remote Serial Protocol</A>).
|
|
<P>
|
|
|
|
<DT><CODE>monitor exit</CODE>
|
|
<DD>Tell gdbserver to exit immediately. This command should be followed by
|
|
<CODE>disconnect</CODE> to close the debugging session. <CODE>gdbserver</CODE> will
|
|
detach from any attached processes and kill any processes it created.
|
|
Use <CODE>monitor exit</CODE> to terminate <CODE>gdbserver</CODE> at the end
|
|
of a multi-process mode debug session.
|
|
<P>
|
|
|
|
</DL>
|
|
<P>
|
|
|
|
<A NAME="Remote Configuration"></A>
|
|
<HR SIZE="6">
|
|
<A NAME="SEC172"></A>
|
|
<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0>
|
|
<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC171"> < </A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC173"> > </A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC173"> << </A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC162"> Up </A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_19.html#SEC177"> >> </A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb.html#SEC_Top">Top</A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_toc.html#SEC_Contents">Contents</A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_38.html#SEC764">Index</A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_abt.html#SEC_About"> ? </A>]</TD>
|
|
</TR></TABLE>
|
|
<H2> 17.4 Remote Configuration </H2>
|
|
<!--docid::SEC172::-->
|
|
<P>
|
|
|
|
<A NAME="IDX812"></A>
|
|
<A NAME="IDX813"></A>
|
|
This section documents the configuration options available when
|
|
debugging remote programs. For the options related to the File I/O
|
|
extensions of the remote protocol, see <A HREF="gdb_33.html#SEC722">system-call-allowed</A>.
|
|
</P><P>
|
|
|
|
<DL COMPACT>
|
|
<DT><CODE>set remoteaddresssize <VAR>bits</VAR></CODE>
|
|
<DD><A NAME="IDX814"></A>
|
|
<A NAME="IDX815"></A>
|
|
Set the maximum size of address in a memory packet to the specified
|
|
number of bits. GDB will mask off the address bits above
|
|
that number, when it passes addresses to the remote target. The
|
|
default value is the number of bits in the target's address.
|
|
<P>
|
|
|
|
<DT><CODE>show remoteaddresssize</CODE>
|
|
<DD>Show the current value of remote address size in bits.
|
|
<P>
|
|
|
|
<DT><CODE>set remotebaud <VAR>n</VAR></CODE>
|
|
<DD><A NAME="IDX816"></A>
|
|
Set the baud rate for the remote serial I/O to <VAR>n</VAR> baud. The
|
|
value is used to set the speed of the serial port used for debugging
|
|
remote targets.
|
|
<P>
|
|
|
|
<DT><CODE>show remotebaud</CODE>
|
|
<DD>Show the current speed of the remote connection.
|
|
<P>
|
|
|
|
<DT><CODE>set remotebreak</CODE>
|
|
<DD><A NAME="IDX817"></A>
|
|
<A NAME="IDX818"></A>
|
|
<A NAME="set remotebreak"></A>
|
|
If set to on, GDB sends a <CODE>BREAK</CODE> signal to the remote
|
|
when you type <KBD>Ctrl-c</KBD> to interrupt the program running
|
|
on the remote. If set to off, GDB sends the <SAMP>`Ctrl-C'</SAMP>
|
|
character instead. The default is off, since most remote systems
|
|
expect to see <SAMP>`Ctrl-C'</SAMP> as the interrupt signal.
|
|
<P>
|
|
|
|
<DT><CODE>show remotebreak</CODE>
|
|
<DD>Show whether GDB sends <CODE>BREAK</CODE> or <SAMP>`Ctrl-C'</SAMP> to
|
|
interrupt the remote program.
|
|
<P>
|
|
|
|
<DT><CODE>set remoteflow on</CODE>
|
|
<DD><DT><CODE>set remoteflow off</CODE>
|
|
<DD><A NAME="IDX819"></A>
|
|
Enable or disable hardware flow control (<CODE>RTS</CODE>/<CODE>CTS</CODE>)
|
|
on the serial port used to communicate to the remote target.
|
|
<P>
|
|
|
|
<DT><CODE>show remoteflow</CODE>
|
|
<DD><A NAME="IDX820"></A>
|
|
Show the current setting of hardware flow control.
|
|
<P>
|
|
|
|
<DT><CODE>set remotelogbase <VAR>base</VAR></CODE>
|
|
<DD>Set the base (a.k.a. radix) of logging serial protocol
|
|
communications to <VAR>base</VAR>. Supported values of <VAR>base</VAR> are:
|
|
<CODE>ascii</CODE>, <CODE>octal</CODE>, and <CODE>hex</CODE>. The default is
|
|
<CODE>ascii</CODE>.
|
|
<P>
|
|
|
|
<DT><CODE>show remotelogbase</CODE>
|
|
<DD>Show the current setting of the radix for logging remote serial
|
|
protocol.
|
|
<P>
|
|
|
|
<DT><CODE>set remotelogfile <VAR>file</VAR></CODE>
|
|
<DD><A NAME="IDX821"></A>
|
|
Record remote serial communications on the named <VAR>file</VAR>. The
|
|
default is not to record at all.
|
|
<P>
|
|
|
|
<DT><CODE>show remotelogfile.</CODE>
|
|
<DD>Show the current setting of the file name on which to record the
|
|
serial communications.
|
|
<P>
|
|
|
|
<DT><CODE>set remotetimeout <VAR>num</VAR></CODE>
|
|
<DD><A NAME="IDX822"></A>
|
|
<A NAME="IDX823"></A>
|
|
Set the timeout limit to wait for the remote target to respond to
|
|
<VAR>num</VAR> seconds. The default is 2 seconds.
|
|
<P>
|
|
|
|
<DT><CODE>show remotetimeout</CODE>
|
|
<DD>Show the current number of seconds to wait for the remote target
|
|
responses.
|
|
<P>
|
|
|
|
<A NAME="IDX824"></A>
|
|
<A NAME="IDX825"></A>
|
|
<A NAME="set remote hardware-watchpoint-limit"></A>
|
|
<A NAME="set remote hardware-breakpoint-limit"></A>
|
|
<DT><CODE>set remote hardware-watchpoint-limit <VAR>limit</VAR></CODE>
|
|
<DD><DT><CODE>set remote hardware-breakpoint-limit <VAR>limit</VAR></CODE>
|
|
<DD>Restrict GDB to using <VAR>limit</VAR> remote hardware breakpoint or
|
|
watchpoints. A limit of -1, the default, is treated as unlimited.
|
|
<P>
|
|
|
|
<DT><CODE>set remote exec-file <VAR>filename</VAR></CODE>
|
|
<DD><DT><CODE>show remote exec-file</CODE>
|
|
<DD><A NAME="set remote exec-file"></A>
|
|
<A NAME="IDX826"></A>
|
|
Select the file used for <CODE>run</CODE> with <CODE>target
|
|
extended-remote</CODE>. This should be set to a filename valid on the
|
|
target system. If it is not set, the target will use a default
|
|
filename (e.g. the last program run).
|
|
</DL>
|
|
<P>
|
|
|
|
<A NAME="IDX827"></A>
|
|
The GDB remote protocol autodetects the packets supported by
|
|
your debugging stub. If you need to override the autodetection, you
|
|
can use these commands to enable or disable individual packets. Each
|
|
packet can be set to <SAMP>`on'</SAMP> (the remote target supports this
|
|
packet), <SAMP>`off'</SAMP> (the remote target does not support this packet),
|
|
or <SAMP>`auto'</SAMP> (detect remote target support for this packet). They
|
|
all default to <SAMP>`auto'</SAMP>. For more information about each packet,
|
|
see <A HREF="gdb_33.html#SEC694">D. GDB Remote Serial Protocol</A>.
|
|
</P><P>
|
|
|
|
During normal use, you should not have to use any of these commands.
|
|
If you do, that may be a bug in your remote debugging stub, or a bug
|
|
in GDB. You may want to report the problem to the
|
|
GDB developers.
|
|
</P><P>
|
|
|
|
For each packet <VAR>name</VAR>, the command to enable or disable the
|
|
packet is <CODE>set remote <VAR>name</VAR>-packet</CODE>. The available settings
|
|
are:
|
|
</P><P>
|
|
|
|
<TABLE>
|
|
<TR><TD>Command Name</TD>
|
|
</TD><TD> Remote Packet
|
|
</TD><TD> Related Features
|
|
|
|
</TR>
|
|
<TR><TD><CODE>fetch-register</CODE></TD>
|
|
</TD><TD> <CODE>p</CODE>
|
|
</TD><TD> <CODE>info registers</CODE>
|
|
|
|
</TR>
|
|
<TR><TD><CODE>set-register</CODE></TD>
|
|
</TD><TD> <CODE>P</CODE>
|
|
</TD><TD> <CODE>set</CODE>
|
|
|
|
</TR>
|
|
<TR><TD><CODE>binary-download</CODE></TD>
|
|
</TD><TD> <CODE>X</CODE>
|
|
</TD><TD> <CODE>load</CODE>, <CODE>set</CODE>
|
|
|
|
</TR>
|
|
<TR><TD><CODE>read-aux-vector</CODE></TD>
|
|
</TD><TD> <CODE>qXfer:auxv:read</CODE>
|
|
</TD><TD> <CODE>info auxv</CODE>
|
|
|
|
</TR>
|
|
<TR><TD><CODE>symbol-lookup</CODE></TD>
|
|
</TD><TD> <CODE>qSymbol</CODE>
|
|
</TD><TD> Detecting multiple threads
|
|
|
|
</TR>
|
|
<TR><TD><CODE>attach</CODE></TD>
|
|
</TD><TD> <CODE>vAttach</CODE>
|
|
</TD><TD> <CODE>attach</CODE>
|
|
|
|
</TR>
|
|
<TR><TD><CODE>verbose-resume</CODE></TD>
|
|
</TD><TD> <CODE>vCont</CODE>
|
|
</TD><TD> Stepping or resuming multiple threads
|
|
|
|
</TR>
|
|
<TR><TD><CODE>run</CODE></TD>
|
|
</TD><TD> <CODE>vRun</CODE>
|
|
</TD><TD> <CODE>run</CODE>
|
|
|
|
</TR>
|
|
<TR><TD><CODE>software-breakpoint</CODE></TD>
|
|
</TD><TD> <CODE>Z0</CODE>
|
|
</TD><TD> <CODE>break</CODE>
|
|
|
|
</TR>
|
|
<TR><TD><CODE>hardware-breakpoint</CODE></TD>
|
|
</TD><TD> <CODE>Z1</CODE>
|
|
</TD><TD> <CODE>hbreak</CODE>
|
|
|
|
</TR>
|
|
<TR><TD><CODE>write-watchpoint</CODE></TD>
|
|
</TD><TD> <CODE>Z2</CODE>
|
|
</TD><TD> <CODE>watch</CODE>
|
|
|
|
</TR>
|
|
<TR><TD><CODE>read-watchpoint</CODE></TD>
|
|
</TD><TD> <CODE>Z3</CODE>
|
|
</TD><TD> <CODE>rwatch</CODE>
|
|
|
|
</TR>
|
|
<TR><TD><CODE>access-watchpoint</CODE></TD>
|
|
</TD><TD> <CODE>Z4</CODE>
|
|
</TD><TD> <CODE>awatch</CODE>
|
|
|
|
</TR>
|
|
<TR><TD><CODE>target-features</CODE></TD>
|
|
</TD><TD> <CODE>qXfer:features:read</CODE>
|
|
</TD><TD> <CODE>set architecture</CODE>
|
|
|
|
</TR>
|
|
<TR><TD><CODE>library-info</CODE></TD>
|
|
</TD><TD> <CODE>qXfer:libraries:read</CODE>
|
|
</TD><TD> <CODE>info sharedlibrary</CODE>
|
|
|
|
</TR>
|
|
<TR><TD><CODE>memory-map</CODE></TD>
|
|
</TD><TD> <CODE>qXfer:memory-map:read</CODE>
|
|
</TD><TD> <CODE>info mem</CODE>
|
|
|
|
</TR>
|
|
<TR><TD><CODE>read-spu-object</CODE></TD>
|
|
</TD><TD> <CODE>qXfer:spu:read</CODE>
|
|
</TD><TD> <CODE>info spu</CODE>
|
|
|
|
</TR>
|
|
<TR><TD><CODE>write-spu-object</CODE></TD>
|
|
</TD><TD> <CODE>qXfer:spu:write</CODE>
|
|
</TD><TD> <CODE>info spu</CODE>
|
|
|
|
</TR>
|
|
<TR><TD><CODE>get-thread-local-<BR>storage-address</CODE></TD>
|
|
</TD><TD> <CODE>qGetTLSAddr</CODE>
|
|
</TD><TD> Displaying <CODE>__thread</CODE> variables
|
|
|
|
</TR>
|
|
<TR><TD><CODE>supported-packets</CODE></TD>
|
|
</TD><TD> <CODE>qSupported</CODE>
|
|
</TD><TD> Remote communications parameters
|
|
|
|
</TR>
|
|
<TR><TD><CODE>pass-signals</CODE></TD>
|
|
</TD><TD> <CODE>QPassSignals</CODE>
|
|
</TD><TD> <CODE>handle <VAR>signal</VAR></CODE>
|
|
|
|
</TR>
|
|
<TR><TD><CODE>hostio-close-packet</CODE></TD>
|
|
</TD><TD> <CODE>vFile:close</CODE>
|
|
</TD><TD> <CODE>remote get</CODE>, <CODE>remote put</CODE>
|
|
|
|
</TR>
|
|
<TR><TD><CODE>hostio-open-packet</CODE></TD>
|
|
</TD><TD> <CODE>vFile:open</CODE>
|
|
</TD><TD> <CODE>remote get</CODE>, <CODE>remote put</CODE>
|
|
|
|
</TR>
|
|
<TR><TD><CODE>hostio-pread-packet</CODE></TD>
|
|
</TD><TD> <CODE>vFile:pread</CODE>
|
|
</TD><TD> <CODE>remote get</CODE>, <CODE>remote put</CODE>
|
|
|
|
</TR>
|
|
<TR><TD><CODE>hostio-pwrite-packet</CODE></TD>
|
|
</TD><TD> <CODE>vFile:pwrite</CODE>
|
|
</TD><TD> <CODE>remote get</CODE>, <CODE>remote put</CODE>
|
|
|
|
</TR>
|
|
<TR><TD><CODE>hostio-unlink-packet</CODE></TD>
|
|
</TD><TD> <CODE>vFile:unlink</CODE>
|
|
</TD><TD> <CODE>remote delete</CODE>
|
|
</TR></TABLE>
|
|
<P>
|
|
|
|
<A NAME="Remote Stub"></A>
|
|
<HR SIZE="6">
|
|
<A NAME="SEC173"></A>
|
|
<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0>
|
|
<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC172"> < </A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC174"> > </A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC162"> << </A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC162"> Up </A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_19.html#SEC177"> >> </A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb.html#SEC_Top">Top</A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_toc.html#SEC_Contents">Contents</A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_38.html#SEC764">Index</A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_abt.html#SEC_About"> ? </A>]</TD>
|
|
</TR></TABLE>
|
|
<H2> 17.5 Implementing a Remote Stub </H2>
|
|
<!--docid::SEC173::-->
|
|
<P>
|
|
|
|
<A NAME="IDX828"></A>
|
|
<A NAME="IDX829"></A>
|
|
<A NAME="IDX830"></A>
|
|
The stub files provided with GDB implement the target side of the
|
|
communication protocol, and the GDB side is implemented in the
|
|
GDB source file <TT>`remote.c'</TT>. Normally, you can simply allow
|
|
these subroutines to communicate, and ignore the details. (If you're
|
|
implementing your own stub file, you can still ignore the details: start
|
|
with one of the existing stub files. <TT>`sparc-stub.c'</TT> is the best
|
|
organized, and therefore the easiest to read.)
|
|
</P><P>
|
|
|
|
<A NAME="IDX831"></A>
|
|
To debug a program running on another machine (the debugging
|
|
<EM>target</EM> machine), you must first arrange for all the usual
|
|
prerequisites for the program to run by itself. For example, for a C
|
|
program, you need:
|
|
</P><P>
|
|
|
|
<OL>
|
|
<LI>
|
|
A startup routine to set up the C runtime environment; these usually
|
|
have a name like <TT>`crt0'</TT>. The startup routine may be supplied by
|
|
your hardware supplier, or you may have to write your own.
|
|
<P>
|
|
|
|
<LI>
|
|
A C subroutine library to support your program's
|
|
subroutine calls, notably managing input and output.
|
|
<P>
|
|
|
|
<LI>
|
|
A way of getting your program to the other machine--for example, a
|
|
download program. These are often supplied by the hardware
|
|
manufacturer, but you may have to write your own from hardware
|
|
documentation.
|
|
</OL>
|
|
<P>
|
|
|
|
The next step is to arrange for your program to use a serial port to
|
|
communicate with the machine where GDB is running (the <EM>host</EM>
|
|
machine). In general terms, the scheme looks like this:
|
|
</P><P>
|
|
|
|
<DL COMPACT>
|
|
<DT><EM>On the host,</EM>
|
|
<DD>GDB already understands how to use this protocol; when everything
|
|
else is set up, you can simply use the <SAMP>`target remote'</SAMP> command
|
|
(see section <A HREF="gdb_17.html#SEC158">Specifying a Debugging Target</A>).
|
|
<P>
|
|
|
|
<DT><EM>On the target,</EM>
|
|
<DD>you must link with your program a few special-purpose subroutines that
|
|
implement the GDB remote serial protocol. The file containing these
|
|
subroutines is called a <EM>debugging stub</EM>.
|
|
<P>
|
|
|
|
On certain remote targets, you can use an auxiliary program
|
|
<CODE>gdbserver</CODE> instead of linking a stub into your program.
|
|
See section <A HREF="gdb_18.html#SEC165">Using the <CODE>gdbserver</CODE> Program</A>, for details.
|
|
</DL>
|
|
<P>
|
|
|
|
The debugging stub is specific to the architecture of the remote
|
|
machine; for example, use <TT>`sparc-stub.c'</TT> to debug programs on
|
|
SPARC boards.
|
|
</P><P>
|
|
|
|
<A NAME="IDX832"></A>
|
|
These working remote stubs are distributed with GDB:
|
|
</P><P>
|
|
|
|
<DL COMPACT>
|
|
|
|
<DT><CODE>i386-stub.c</CODE>
|
|
<DD><A NAME="IDX833"></A>
|
|
<A NAME="IDX834"></A>
|
|
<A NAME="IDX835"></A>
|
|
For Intel 386 and compatible architectures.
|
|
<P>
|
|
|
|
<DT><CODE>m68k-stub.c</CODE>
|
|
<DD><A NAME="IDX836"></A>
|
|
<A NAME="IDX837"></A>
|
|
<A NAME="IDX838"></A>
|
|
For Motorola 680x0 architectures.
|
|
<P>
|
|
|
|
<DT><CODE>sh-stub.c</CODE>
|
|
<DD><A NAME="IDX839"></A>
|
|
<A NAME="IDX840"></A>
|
|
<A NAME="IDX841"></A>
|
|
For Renesas SH architectures.
|
|
<P>
|
|
|
|
<DT><CODE>sparc-stub.c</CODE>
|
|
<DD><A NAME="IDX842"></A>
|
|
<A NAME="IDX843"></A>
|
|
For SPARC architectures.
|
|
<P>
|
|
|
|
<DT><CODE>sparcl-stub.c</CODE>
|
|
<DD><A NAME="IDX844"></A>
|
|
<A NAME="IDX845"></A>
|
|
<A NAME="IDX846"></A>
|
|
For Fujitsu SPARCLITE architectures.
|
|
<P>
|
|
|
|
</DL>
|
|
<P>
|
|
|
|
The <TT>`README'</TT> file in the GDB distribution may list other
|
|
recently added stubs.
|
|
</P><P>
|
|
|
|
<BLOCKQUOTE><TABLE BORDER=0 CELLSPACING=0>
|
|
<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="gdb_18.html#SEC174">17.5.1 What the Stub Can Do for You</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">What the stub can do for you</TD></TR>
|
|
<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="gdb_18.html#SEC175">17.5.2 What You Must Do for the Stub</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">What you must do for the stub</TD></TR>
|
|
<TR><TD ALIGN="left" VALIGN="TOP"><A HREF="gdb_18.html#SEC176">17.5.3 Putting it All Together</A></TD><TD> </TD><TD ALIGN="left" VALIGN="TOP">Putting it all together</TD></TR>
|
|
</TABLE></BLOCKQUOTE>
|
|
<P>
|
|
|
|
<A NAME="Stub Contents"></A>
|
|
<HR SIZE="6">
|
|
<A NAME="SEC174"></A>
|
|
<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0>
|
|
<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC173"> < </A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC175"> > </A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC162"> << </A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC173"> Up </A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_19.html#SEC177"> >> </A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb.html#SEC_Top">Top</A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_toc.html#SEC_Contents">Contents</A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_38.html#SEC764">Index</A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_abt.html#SEC_About"> ? </A>]</TD>
|
|
</TR></TABLE>
|
|
<H3> 17.5.1 What the Stub Can Do for You </H3>
|
|
<!--docid::SEC174::-->
|
|
<P>
|
|
|
|
<A NAME="IDX847"></A>
|
|
The debugging stub for your architecture supplies these three
|
|
subroutines:
|
|
</P><P>
|
|
|
|
<DL COMPACT>
|
|
<DT><CODE>set_debug_traps</CODE>
|
|
<DD><A NAME="IDX848"></A>
|
|
<A NAME="IDX849"></A>
|
|
This routine arranges for <CODE>handle_exception</CODE> to run when your
|
|
program stops. You must call this subroutine explicitly near the
|
|
beginning of your program.
|
|
<P>
|
|
|
|
<DT><CODE>handle_exception</CODE>
|
|
<DD><A NAME="IDX850"></A>
|
|
<A NAME="IDX851"></A>
|
|
This is the central workhorse, but your program never calls it
|
|
explicitly--the setup code arranges for <CODE>handle_exception</CODE> to
|
|
run when a trap is triggered.
|
|
<P>
|
|
|
|
<CODE>handle_exception</CODE> takes control when your program stops during
|
|
execution (for example, on a breakpoint), and mediates communications
|
|
with GDB on the host machine. This is where the communications
|
|
protocol is implemented; <CODE>handle_exception</CODE> acts as the GDB
|
|
representative on the target machine. It begins by sending summary
|
|
information on the state of your program, then continues to execute,
|
|
retrieving and transmitting any information GDB needs, until you
|
|
execute a GDB command that makes your program resume; at that point,
|
|
<CODE>handle_exception</CODE> returns control to your own code on the target
|
|
machine.
|
|
</P><P>
|
|
|
|
<DT><CODE>breakpoint</CODE>
|
|
<DD><A NAME="IDX852"></A>
|
|
Use this auxiliary subroutine to make your program contain a
|
|
breakpoint. Depending on the particular situation, this may be the only
|
|
way for GDB to get control. For instance, if your target
|
|
machine has some sort of interrupt button, you won't need to call this;
|
|
pressing the interrupt button transfers control to
|
|
<CODE>handle_exception</CODE>---in effect, to GDB. On some machines,
|
|
simply receiving characters on the serial port may also trigger a trap;
|
|
again, in that situation, you don't need to call <CODE>breakpoint</CODE> from
|
|
your own program--simply running <SAMP>`target remote'</SAMP> from the host
|
|
GDB session gets control.
|
|
<P>
|
|
|
|
Call <CODE>breakpoint</CODE> if none of these is true, or if you simply want
|
|
to make certain your program stops at a predetermined point for the
|
|
start of your debugging session.
|
|
</DL>
|
|
<P>
|
|
|
|
<A NAME="Bootstrapping"></A>
|
|
<HR SIZE="6">
|
|
<A NAME="SEC175"></A>
|
|
<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0>
|
|
<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC174"> < </A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC176"> > </A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC176"> << </A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC173"> Up </A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_19.html#SEC177"> >> </A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb.html#SEC_Top">Top</A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_toc.html#SEC_Contents">Contents</A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_38.html#SEC764">Index</A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_abt.html#SEC_About"> ? </A>]</TD>
|
|
</TR></TABLE>
|
|
<H3> 17.5.2 What You Must Do for the Stub </H3>
|
|
<!--docid::SEC175::-->
|
|
<P>
|
|
|
|
<A NAME="IDX853"></A>
|
|
The debugging stubs that come with GDB 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><P>
|
|
|
|
<DL COMPACT>
|
|
<DT><CODE>int getDebugChar()</CODE>
|
|
<DD><A NAME="IDX854"></A>
|
|
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>
|
|
|
|
<DT><CODE>void putDebugChar(int)</CODE>
|
|
<DD><A NAME="IDX855"></A>
|
|
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.
|
|
</DL>
|
|
<P>
|
|
|
|
<A NAME="IDX856"></A>
|
|
<A NAME="IDX857"></A>
|
|
If you want GDB 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 GDB uses to tell the
|
|
remote system to stop.
|
|
</P><P>
|
|
|
|
Getting the debugging target to return the proper status to GDB
|
|
probably requires changes to the standard stub; one quick and dirty way
|
|
is to just execute a breakpoint instruction (the "dirty" part is that
|
|
GDB reports a <CODE>SIGTRAP</CODE> instead of a <CODE>SIGINT</CODE>).
|
|
</P><P>
|
|
|
|
Other routines you need to supply are:
|
|
</P><P>
|
|
|
|
<DL COMPACT>
|
|
<DT><CODE>void exceptionHandler (int <VAR>exception_number</VAR>, void *<VAR>exception_address</VAR>)</CODE>
|
|
<DD><A NAME="IDX858"></A>
|
|
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 ROM,
|
|
containing entries which point to a table in RAM).
|
|
<VAR>exception_number</VAR> is the exception number 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>
|
|
|
|
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
|
|
SPARC and 68k stubs are able to mask interrupts themselves without
|
|
help from <CODE>exceptionHandler</CODE>.
|
|
</P><P>
|
|
|
|
<DT><CODE>void flush_i_cache()</CODE>
|
|
<DD><A NAME="IDX859"></A>
|
|
On SPARC and SPARCLITE 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>
|
|
|
|
On target machines that have instruction caches, GDB requires this
|
|
function to make certain that the state of your program is stable.
|
|
</DL>
|
|
<P>
|
|
|
|
You must also make sure this library routine is available:
|
|
</P><P>
|
|
|
|
<DL COMPACT>
|
|
<DT><CODE>void *memset(void *, int, int)</CODE>
|
|
<DD><A NAME="IDX860"></A>
|
|
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.
|
|
</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>GCC</CODE> generates as inline code.
|
|
</P><P>
|
|
|
|
<A NAME="Debug Session"></A>
|
|
<HR SIZE="6">
|
|
<A NAME="SEC176"></A>
|
|
<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0>
|
|
<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC175"> < </A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_19.html#SEC177"> > </A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC162"> << </A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC173"> Up </A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_19.html#SEC177"> >> </A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb.html#SEC_Top">Top</A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_toc.html#SEC_Contents">Contents</A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_38.html#SEC764">Index</A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_abt.html#SEC_About"> ? </A>]</TD>
|
|
</TR></TABLE>
|
|
<H3> 17.5.3 Putting it All Together </H3>
|
|
<!--docid::SEC176::-->
|
|
<P>
|
|
|
|
<A NAME="IDX861"></A>
|
|
In summary, when your program is ready to debug, you must follow these
|
|
steps.
|
|
</P><P>
|
|
|
|
<OL>
|
|
<LI>
|
|
Make sure you have defined the supporting low-level routines
|
|
(see section <A HREF="gdb_18.html#SEC175">What You Must Do for the Stub</A>):
|
|
<TABLE><tr><td> </td><td class=display><pre style="font-family: serif"><CODE>getDebugChar</CODE>, <CODE>putDebugChar</CODE>,
|
|
<CODE>flush_i_cache</CODE>, <CODE>memset</CODE>, <CODE>exceptionHandler</CODE>.
|
|
</pre></td></tr></table><P>
|
|
|
|
<LI>
|
|
Insert these lines near the top of your program:
|
|
<P>
|
|
|
|
<TABLE><tr><td> </td><td class=smallexample><FONT SIZE=-1><pre>set_debug_traps();
|
|
breakpoint();
|
|
</FONT></pre></td></tr></table></P><P>
|
|
|
|
<LI>
|
|
For the 680x0 stub only, you need to provide a variable called
|
|
<CODE>exceptionHook</CODE>. Normally you just use:
|
|
<P>
|
|
|
|
<TABLE><tr><td> </td><td class=smallexample><FONT SIZE=-1><pre>void (*exceptionHook)() = 0;
|
|
</FONT></pre></td></tr></table></P><P>
|
|
|
|
but if before calling <CODE>set_debug_traps</CODE>, you set it to point to a
|
|
function in your program, that function is called when
|
|
<CODE>GDB</CODE> continues after stopping on a trap (for example, bus
|
|
error). The function indicated by <CODE>exceptionHook</CODE> is called with
|
|
one parameter: an <CODE>int</CODE> which is the exception number.
|
|
</P><P>
|
|
|
|
<LI>
|
|
Compile and link together: your program, the GDB debugging stub for
|
|
your target architecture, and the supporting subroutines.
|
|
<P>
|
|
|
|
<LI>
|
|
Make sure you have a serial connection between your target machine and
|
|
the GDB host, and identify the serial port on the host.
|
|
<P>
|
|
|
|
<LI>
|
|
Download your program to your target machine (or get it there by
|
|
whatever means the manufacturer provides), and start it.
|
|
<P>
|
|
|
|
<LI>
|
|
Start GDB on the host, and connect to the target
|
|
(see section <A HREF="gdb_18.html#SEC163">Connecting to a Remote Target</A>).
|
|
<P>
|
|
|
|
</OL>
|
|
<P>
|
|
|
|
<A NAME="Configurations"></A>
|
|
<HR SIZE="6">
|
|
<TABLE CELLPADDING=1 CELLSPACING=1 BORDER=0>
|
|
<TR><TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_18.html#SEC162"> << </A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_19.html#SEC177"> >> </A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT"> <TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb.html#SEC_Top">Top</A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_toc.html#SEC_Contents">Contents</A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_38.html#SEC764">Index</A>]</TD>
|
|
<TD VALIGN="MIDDLE" ALIGN="LEFT">[<A HREF="gdb_abt.html#SEC_About"> ? </A>]</TD>
|
|
</TR></TABLE>
|
|
<BR>
|
|
<FONT SIZE="-1">
|
|
|
|
<address>
|
|
|
|
<p>Please send FSF & GNU inquiries & questions to <a
|
|
href="mailto:gnu@gnu.org">gnu@gnu.org</a>. There are also <a
|
|
href="http://www.gnu.org/home.html#ContactInfo">other ways to
|
|
contact</a> the FSF.</p>
|
|
|
|
<p>These pages are maintained by <a
|
|
href="http://www.gnu.org/software/gdb/">the GDB developers</a>.</p>
|
|
|
|
<p>Copyright Free Software Foundation, Inc., 59 Temple Place - Suite
|
|
330, Boston, MA 02111, USA.</p>
|
|
|
|
<p>Verbatim copying and distribution of this entire article is
|
|
permitted in any medium, provided this notice is preserved.</p>
|
|
|
|
</address>
|
|
|
|
This document was generated
|
|
by <I>GDB Administrator</I> on <I>March, 27 2008</I>
|
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using <A HREF="http://www.mathematik.uni-kl.de/~obachman/Texi2html
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"><I>texi2html</I></A>
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