Add description of LED support
git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@1767 42af7a65-404d-4744-a932-0658087f49c3
This commit is contained in:
patacongo
parent
ee9d904536
commit
5ea2767852
@ -12,7 +12,7 @@
|
||||
<h1><big><font color="#3c34ec">
|
||||
<i>NuttX RTOS Porting Guide</i>
|
||||
</font></big></h1>
|
||||
<p>Last Updated: April 19, 2009</p>
|
||||
<p>Last Updated: May 9, 2009</p>
|
||||
</td>
|
||||
</tr>
|
||||
</table>
|
||||
@ -92,10 +92,16 @@
|
||||
<a href="#exports">4.2 APIs Exported by NuttX to Architecture-Specific Logic</a>
|
||||
<ul>
|
||||
<a href="#osstart">4.2.1 <code>os_start()</code></a><br>
|
||||
<a href="#listmgmt">4.2.2 OS List Management APIs</a><br><br>
|
||||
<a href="#listmgmt">4.2.2 OS List Management APIs</a><br>
|
||||
<a href="#schedprocesstimer">4.2.3 <code>sched_process_timer()</code></a><br>
|
||||
<a href="#irqdispatch">4.2.4 <code>irq_dispatch()</code></a>
|
||||
</ul>
|
||||
<a href="#ledsupport">4.3 LED Support</a>
|
||||
<ul>
|
||||
<a href="#ledheaders">4.3.1 Header Files</a><br>
|
||||
<a href="#leddefinitions">4.3.2 LED Definitions</a><br>
|
||||
<a href="#ledapis">4.3.3 Common LED interfaces</a>
|
||||
</ul>
|
||||
</ul>
|
||||
<a href="#NxFileSystem">5.0 NuttX File System</a><br>
|
||||
<a href="#apndxconfigs">Appendix A: NuttX Configuration Settings</a><br>
|
||||
@ -1423,6 +1429,142 @@ The system can be re-made subsequently by just typing <code>make</code>.
|
||||
the appropriate, registered handling logic.
|
||||
</p>
|
||||
|
||||
<h2><a name="ledsupport">4.3 LED Support</a></h2>
|
||||
|
||||
<p>
|
||||
A board architecture may or may not have LEDs.
|
||||
If the board does have LEDs, then most architectures provide similar LED support that is enabled when <code>CONFIG_ARCH_LEDS</code>
|
||||
is selected in the NuttX configuration file.
|
||||
This LED support is part of architecture-specific logic and is not managed by the core NuttX logic.
|
||||
However, the support provided by each architecture is sufficiently similar that it can be documented here.
|
||||
</p>
|
||||
|
||||
<h3><a name="ledheaders">4.3.1 Header Files</a></h3>
|
||||
|
||||
<p>
|
||||
LED-related definitions are provided in two header files:
|
||||
<ul>
|
||||
<li>
|
||||
LED definitions are provided for each board in the <code>board.h</code> that resides
|
||||
in the <code><i><board-name></i>/include/board.h</code> file (which is also
|
||||
linked to <code>include/arch/board/board.h</code> when the RTOS is configured).
|
||||
Those definitions are discussed <a href="#leddefinitions">below</a>.
|
||||
</li>
|
||||
<li>
|
||||
The board-specific logic provides unique instances of the LED interfaces.
|
||||
This is because the implementation of LED support may be very different
|
||||
on different boards.
|
||||
Prototypes for these board-specific implementations are, however, provided
|
||||
in architecture-common header files.
|
||||
That header file is usually at <code><i><arch-name></i>/src/common/up_internal.h</code>,
|
||||
but could be at other locations in particular architectures.
|
||||
These prototypes are discussed <a href="#ledapis">below</a>.
|
||||
</li>
|
||||
</ul>
|
||||
</p>
|
||||
|
||||
<h3><a name="leddefinitions">4.3.2 LED Definitions</a></h3>
|
||||
|
||||
<p>
|
||||
The implementation of LED support is very specific to a board architecture.
|
||||
Some boards have several LEDS, others have only one or two.
|
||||
Some have none.
|
||||
Others LED matrices and show alphnumeric data, etc.
|
||||
The NuttX logic does not refer to specific LEDS, rather, it refers to an event to be shown on the LEDS
|
||||
in whatever manner is appropriate for the board;
|
||||
the way that this event is presented depends upon the hardware available on the board.
|
||||
</p>
|
||||
<p>
|
||||
The model used by NuttX is that the board can show 8 events defined as follows in <code><i><board-name></i>/include/board.h</code>:
|
||||
</p>
|
||||
<ul><pre>
|
||||
#define LED_STARTED ??
|
||||
#define LED_HEAPALLOCATE ??
|
||||
#define LED_IRQSENABLED ??
|
||||
#define LED_STACKCREATED ??
|
||||
#define LED_INIRQ ??
|
||||
#define LED_SIGNAL ??
|
||||
#define LED_ASSERTION ??
|
||||
#define LED_PANIC ??
|
||||
</pre></ul>
|
||||
<p>
|
||||
The specific value assigned to each pre-processor variable can be whatever makes the implementation easiest for the board logic.
|
||||
The <i>meaning</i> associated with each definition is as follows:
|
||||
</p>
|
||||
<ul>
|
||||
<li>
|
||||
<code>LED_STARTED</code> is the value that describes the setting of the LEDs when the LED logic is first initialized.
|
||||
This LED value is set but never cleared.
|
||||
</li>
|
||||
<li>
|
||||
<code>LED_HEAPALLOCATE</code> indicates that the NuttX heap has been configured.
|
||||
This is an important place in the boot sequence because if the memory is configured wrong, it will probably crash leaving this LED setting.
|
||||
This LED value is set but never cleared.
|
||||
</li>
|
||||
<li>
|
||||
<code>LED_IRQSENABLED</code> indicates that interrupts have been enabled.
|
||||
Again, during bring-up (or if there are hardware problems), it is very likely that the system may crash just when interrupts are enabled, leaving this setting on the LEDs.
|
||||
This LED value is set but never cleared.
|
||||
</li>
|
||||
<li>
|
||||
<code>LED_STACKCREATED</code> is set each time a new stack is created.
|
||||
If set, it means that the system attempted to start at least one new thread.
|
||||
This LED value is set but never cleared.
|
||||
</li>
|
||||
<li>
|
||||
<code>LED_INIRQ</code> is set and cleared on entry and exit from each interrupt.
|
||||
If interrupts are working okay, this LED will have a dull glow.
|
||||
</li>
|
||||
<li>
|
||||
<code>LED_SIGNAL</code> is set and cleared on entry and exit from a signal handler.
|
||||
Signal handlers are tricky so this is especially useful during bring-up or a new architecture.
|
||||
</li>
|
||||
<li>
|
||||
<code>LED_ASSERTION</code> is set if an assertion occurs.
|
||||
</li>
|
||||
<li>
|
||||
<code>LED_PANIC</code> will blink at around 1Hz if the system panics and hangs.
|
||||
</li>
|
||||
</ul>
|
||||
|
||||
<h3><a name="ledapis">4.3.3 Common LED interfaces</a></h3>
|
||||
|
||||
<p>
|
||||
The <code><i><arch-name></i>/src/common/up_internal.h</code> probably has definitions
|
||||
like:
|
||||
</p>
|
||||
<ul><pre>
|
||||
/* Defined in board/up_leds.c */
|
||||
|
||||
#ifdef CONFIG_ARCH_LEDS
|
||||
extern void up_ledinit(void);
|
||||
extern void up_ledon(int led);
|
||||
extern void up_ledoff(int led);
|
||||
#else
|
||||
# define up_ledinit()
|
||||
# define up_ledon(led)
|
||||
# define up_ledoff(led)
|
||||
#endif
|
||||
</pre></ul>
|
||||
<p>
|
||||
Where:
|
||||
<p>
|
||||
<ul>
|
||||
<li>
|
||||
<code>void up_ledinit(void)</code> is called early in power-up initialization to initialize the LED hardware.
|
||||
</li>
|
||||
<li>
|
||||
<code>up_ledon(int led)</code> is called to instantiate the LED presentation of the event.
|
||||
The <code>led</code> argument is one of the definitions provided in <code><i><board-name></i>/include/board.h</code>.
|
||||
</li>
|
||||
<li>
|
||||
<code>up_ledoff(int led</code>is called to terminate the LED presentation of the event.
|
||||
The <code>led</code> argument is one of the definitions provided in <code><i><board-name></i>/include/board.h</code>.
|
||||
Note that only <code>LED_INIRQ</code>, <code>LED_SIGNAL</code>, <code>LED_ASSERTION</code>, and <code>LED_PANIC</code>
|
||||
indications are terminated.
|
||||
</li>
|
||||
</ul>
|
||||
|
||||
<table width ="100%">
|
||||
<tr bgcolor="#e4e4e4">
|
||||
<td>
|
||||
|
||||
Loading…
Reference in New Issue
Block a user