Updates.

[tinyos-2.x.git] / doc / html / tep107.html

diff --git a/doc/html/tep107.html b/doc/html/tep107.html
index 907c5754b68c24413d87d7f7a51cfd610c932a40..ab3eaed5070c1f26ce9a808a615744fbeeee02d1 100644 (file)
--- a/doc/html/tep107.html
+++ b/doc/html/tep107.html
@@ -303,9 +303,9 @@ ul.auto-toc {
 <td>Philip Levis</td></tr>
 <tr class="field"><th class="docinfo-name">Draft-Created:</th><td class="field-body">10-Dec-2004</td>
 </tr>
-<tr class="field"><th class="docinfo-name">Draft-Version:</th><td class="field-body">1.7</td>
+<tr class="field"><th class="docinfo-name">Draft-Version:</th><td class="field-body">1.9</td>
 </tr>
-<tr class="field"><th class="docinfo-name">Draft-Modified:</th><td class="field-body">2007-02-05</td>
+<tr class="field"><th class="docinfo-name">Draft-Modified:</th><td class="field-body">2007-02-10</td>
 </tr>
 <tr class="field"><th class="docinfo-name">Draft-Discuss:</th><td class="field-body">TinyOS Developer List &lt;tinyos-devel at mail.millennium.berkeley.edu&gt;</td>
 </tr>
@@ -483,8 +483,19 @@ operations besides those which are absolutely necessary for further code,
 such as scheduler initialization, to execute.
 Examples of platform_bootstrap() operations are configuring the memory
 system and setting the processor mode. Generally, platform_bootstrap()
-is an empty function. The platform_bootstrap() function SHOULD be
-specified in a platform's <tt class="docutils literal"><span class="pre">hardware.h</span></tt> file.</p>
+is an empty function. TinyOS's top-level include file, <tt class="docutils literal"><span class="pre">tos.h</span></tt>, includes
+a default implementation of this function which does nothing. If a platform
+needs to replace the default, it SHOULD put it in a platform's
+<tt class="docutils literal"><span class="pre">platform.h</span></tt> file as a #define. The implementation of <tt class="docutils literal"><span class="pre">tos.h</span></tt>
+supports this:</p>
+<pre class="literal-block">
+/* This platform_bootstrap macro exists in accordance with TEP
+   107. A platform may override this through a platform.h file. */
+#include &lt;platform.h&gt;
+#ifndef platform_bootstrap
+#define platform_bootstrap() {}
+#endif
+</pre>
 <p>The boot sequence has three separate initializations: Scheduler,
 PlatformInit, and SoftwareInit. The boot configuration (MainC) wires
 the first two automatically, to TinySchedulerC (discussed in TEP 106)
@@ -519,9 +530,7 @@ initialization order. As these hidden dependencies must be due to
 hardware, the sequence is platform-specific. A port of TinyOS to a
 new plaform MUST include a component PlatformC which provides
 one and only one instance of the Init interface.</p>
-<p>Generally, component intialization occurs through SoftwareInit.
-PlatformInit is for a small subset of initializations whose properties
-requires that they be performed separately. Initializations invoked
+<p>Initializations invoked
 through PlatformC meet some or all of the following criteria:</p>
 <ol class="arabic simple">
 <li>The initialization requires configuring hardware resources. This implies that the code is platform-specific.</li>
@@ -538,6 +547,14 @@ all three criteria. LED configuration is a special case: while it
 nominally meets all three criteria, the most important one is the third:
 as LEDs are often needed during SoftwareInit initialization, they must
 be set up before it is invoked.</p>
+<p>Note that not all code which meets some of these criteria is wired through
+PlatformC. In particular, criterion 1 is typically necessary but not
+sufficient to require PlatformC. For example, a timer system that
+configures overflow and capture settings or  a UART stack that sets the
+baud rate and transmission options can often be wired to SoftwareInit.
+They are encapsulated abstractions which will not be invoked or
+started until the boot event, and only need to be configured if the
+system includes their functionality.</p>
 <p>Components whose initialization does not directly depend on hardware
 resources SHOULD wire to MainC.SoftwareInit. If a component requires a
 specific initialization ordering, then it is responsible for