git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@40 35acf78f-673a-0410-8e92-d51de3d6d3f4

demos/ARM7-LPC214x-GCC/chcore.c

@@ -145,6 +145,8 @@ void hwinit(void) {
 
 void chSysPause(void) {
 
+  chThdSetPriority(IDLEPRIO);
+
   while (TRUE) {
 // Note, it is disabled because it causes trouble with the JTAG probe.
 // Enable it in the final code only.

demos/Win32-MSVS/chcore.c

@@ -35,7 +35,7 @@ void InitCore(void) {
     printf("QueryPerformanceFrequency() error");
     exit(1);
   }
-  printf("Core Frequency   %d Hz\n", slice.LowPart);
+  printf("Core Frequency   %u Hz\n", slice.LowPart);
   slice.QuadPart /= CH_FREQUENCY;
   QueryPerformanceCounter(&nextcnt);
   nextcnt.QuadPart += slice.QuadPart;
@@ -69,6 +69,8 @@ static void ChkIntSources(void) {
 
 void __fastcall chSysPause(void) {
 
+  chThdSetPriority(IDLEPRIO);
+
   while (TRUE) {
 
     ChkIntSources();

demos/Win32-MinGW/chcore.c

@@ -58,7 +58,7 @@ void InitCore(void) {
     printf("QueryPerformanceFrequency() error");
     exit(1);
   }
-  printf("Core Frequency   %d Hz\n", (int)slice.LowPart);
+  printf("Core Frequency   %u Hz\n", (int)slice.LowPart);
   slice.QuadPart /= CH_FREQUENCY;
   QueryPerformanceCounter(&nextcnt);
   nextcnt.QuadPart += slice.QuadPart;
@@ -92,6 +92,8 @@ static void ChkIntSources(void) {
 
 __attribute__((fastcall)) void chSysPause(void) {
 
+  chThdSetPriority(IDLEPRIO);
+
   while (TRUE) {
 
     ChkIntSources();

readme.txt

@@ -39,6 +39,11 @@ AVR-AT90CANx-GCC    - Port on AVER AT90CAN128, not complete yet.
 *****************************************************************************
 
 *** 0.3.2 ***
+- Modified the chSysInit() to give the idle thread absolute priority, the
+  priority is then lowered to the minimum value into the chSysPause(). This
+  is done in order to ensure that the initializations performed into the
+  main() procedure are performed before any thread starts.
+- Added chThdSetPriority() new API.
 - Added a generic events generator timer to the library code.
 - Added the "#ifdef __cplusplus" stuff to the header files.
 - Removed an obsolete definition in ./src/templates/chtypes.h.

src/chinit.c

@@ -37,8 +37,12 @@ static Thread idlethread;
  *   chThdCreate(...); // Starts one or more user threads.
  *   chSysPause();
  * @endcode
- * @note Interrupts should be still disabled when \p chSysInit() is invoked and
- *       are internally enabled.
+ * @note Interrupts should be still disabled when \p chSysInit() is invoked
+ *       and are internally enabled.
+ * @note The idle thread has absolute priority when exiting from the
+ *       \p chSysInit(), this is done to make sure that all the initializations
+ *       performed in the \p main() procedure are completed before any thread
+ *       starts. The priority is set to \p IDLEPRIO into the \p chSysPause().
  */
 void chSysInit(void) {
 
@@ -49,7 +53,7 @@ void chSysInit(void) {
   /*
    * Now this instructions flow becomes the idle thread.
    */
-  _InitThread(IDLEPRIO, 0, &idlethread);
+  _InitThread(ABSPRIO, 0, &idlethread);
   idlethread.p_state = PRCURR;
   currp = &idlethread;
 

src/chthreads.c

@@ -100,6 +100,27 @@ Thread *chThdCreate(t_prio prio, t_tmode mode, void *workspace,
   return tp;
 }
 
+/**
+ * Changes the thread priority, reschedules if necessary.
+ * @param newprio the new priority of the invoking thread
+ */
+void chThdSetPriority(t_prio newprio) {
+
+  chSysLock();
+
+#ifdef CH_USE_RT_SEMAPHORES
+  if (currp->p_rtcnt)
+    currp->p_prio = newprio + MEPRIO;
+  else
+    currp->p_prio = newprio;
+#else
+  currp->p_prio = newprio;
+#endif
+  chSchRescheduleI();
+
+  chSysUnlock();
+}
+
 #ifdef CH_USE_RESUME
 /**
  * Resumes a thread created with the \p P_SUSPENDED option.

src/include/threads.h

@@ -191,6 +191,7 @@ extern "C" {
 #endif
   Thread *chThdCreate(t_prio prio, t_tmode mode, void *workspace,
                       t_size wsize, t_tfunc pf, void *arg);
+  void chThdSetPriority(t_prio newprio);
   void chThdResume(Thread *tp);
   void chThdExit(t_msg msg);
 #ifdef CH_USE_TERMINATE

src/templates/chcore.c

@@ -33,14 +33,28 @@
 /**
  * This function implements the idle thread infinite loop. The function should
  * put the processor in the lowest power mode capable to serve interrupts.
+ * The priority is internally set to the minimum system value so that this
+ * thread is executed only if there are no other ready threads in the system.
  */
-void chSysPause(void) {}
+void chSysPause(void) {
+
+  chThdSetPriority(IDLEPRIO);
+
+  while (TRUE)
+    ;
+}
 
 /**
  * Abonormal system termination handler. Invoked by the ChibiOS/RT when an
  * abnormal unrecoverable condition is met.
  */
-void chSysHalt(void) {}
+void chSysHalt(void) {
+
+  chSysLock();
+
+  while (TRUE)
+    ;
+}
 
 /**
  * Context switch.