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 <a name="Debug-Session"></a>
 <div class="header">
 <p>
 Previous: <a href="Bootstrapping.html#Bootstrapping" accesskey="p" rel="prev">Bootstrapping</a>, Up: <a href="Remote-Stub.html#Remote-Stub" accesskey="u" rel="up">Remote Stub</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="Putting-it-All-Together"></a>
 <h4 class="subsection">20.5.3 Putting it All Together</h4>

 <a name="index-remote-serial-debugging-summary"></a>
 <p>In summary, when your program is ready to debug, you must follow these
 steps.
 </p>
 <ol>
 <li> Make sure you have defined the supporting low-level routines
 (see <a href="Bootstrapping.html#Bootstrapping">What You Must Do for the Stub</a>):
 <div class="display">
 <pre class="display"><code>getDebugChar</code>, <code>putDebugChar</code>,
 <code>flush_i_cache</code>, <code>memset</code>, <code>exceptionHandler</code>.
 </pre></div>

 </li><li> Insert these lines in your program&rsquo;s startup code, before the main
 procedure is called:

 <div class="smallexample">
 <pre class="smallexample">set_debug_traps();
 breakpoint();
 </pre></div>

 <p>On some machines, when a breakpoint trap is raised, the hardware
 automatically makes the PC point to the instruction after the
 breakpoint.  If your machine doesn&rsquo;t do that, you may need to adjust
 <code>handle_exception</code> to arrange for it to return to the instruction
 after the breakpoint on this first invocation, so that your program
 doesn&rsquo;t keep hitting the initial breakpoint instead of making
 progress.
 </p>
 </li><li> For the 680x0 stub only, you need to provide a variable called
 <code>exceptionHook</code>.  Normally you just use:

 <div class="smallexample">
 <pre class="smallexample">void (*exceptionHook)() = 0;
 </pre></div>

 <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><small>GDB</small></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>
 </li><li> Compile and link together: your program, the <small>GDB</small> debugging stub for
 your target architecture, and the supporting subroutines.

 </li><li> Make sure you have a serial connection between your target machine and
 the <small>GDB</small> host, and identify the serial port on the host.

 </li><li> Download your program to your target machine (or get it there by
 whatever means the manufacturer provides), and start it.

 </li><li> Start <small>GDB</small> on the host, and connect to the target
 (see <a href="Connecting.html#Connecting">Connecting to a Remote Target</a>).

 </li></ol>

 <hr>
 <div class="header">
 <p>
 Previous: <a href="Bootstrapping.html#Bootstrapping" accesskey="p" rel="prev">Bootstrapping</a>, Up: <a href="Remote-Stub.html#Remote-Stub" accesskey="u" rel="up">Remote Stub</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>
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	<a name="Debug-Session"></a>
	<div class="header">
	<p>
	Previous: <a href="Bootstrapping.html#Bootstrapping" accesskey="p" rel="prev">Bootstrapping</a>, Up: <a href="Remote-Stub.html#Remote-Stub" accesskey="u" rel="up">Remote Stub</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="Putting-it-All-Together"></a>
	<h4 class="subsection">20.5.3 Putting it All Together</h4>

	<a name="index-remote-serial-debugging-summary"></a>
	<p>In summary, when your program is ready to debug, you must follow these
	steps.
	</p>
	<ol>
	<li> Make sure you have defined the supporting low-level routines
	(see <a href="Bootstrapping.html#Bootstrapping">What You Must Do for the Stub</a>):
	<div class="display">
	<pre class="display"><code>getDebugChar</code>, <code>putDebugChar</code>,
	<code>flush_i_cache</code>, <code>memset</code>, <code>exceptionHandler</code>.
	</pre></div>

	</li><li> Insert these lines in your program’s startup code, before the main
	procedure is called:

	<div class="smallexample">
	<pre class="smallexample">set_debug_traps();
	breakpoint();
	</pre></div>

	<p>On some machines, when a breakpoint trap is raised, the hardware
	automatically makes the PC point to the instruction after the
	breakpoint. If your machine doesn’t do that, you may need to adjust
	<code>handle_exception</code> to arrange for it to return to the instruction
	after the breakpoint on this first invocation, so that your program
	doesn’t keep hitting the initial breakpoint instead of making
	progress.
	</p>
	</li><li> For the 680x0 stub only, you need to provide a variable called
	<code>exceptionHook</code>. Normally you just use:

	<div class="smallexample">
	<pre class="smallexample">void (*exceptionHook)() = 0;
	</pre></div>

	<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><small>GDB</small></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>
	</li><li> Compile and link together: your program, the <small>GDB</small> debugging stub for
	your target architecture, and the supporting subroutines.

	</li><li> Make sure you have a serial connection between your target machine and
	the <small>GDB</small> host, and identify the serial port on the host.

	</li><li> Download your program to your target machine (or get it there by
	whatever means the manufacturer provides), and start it.

	</li><li> Start <small>GDB</small> on the host, and connect to the target
	(see <a href="Connecting.html#Connecting">Connecting to a Remote Target</a>).

	</li></ol>

	<hr>
	<div class="header">
	<p>
	Previous: <a href="Bootstrapping.html#Bootstrapping" accesskey="p" rel="prev">Bootstrapping</a>, Up: <a href="Remote-Stub.html#Remote-Stub" accesskey="u" rel="up">Remote Stub</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>
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