From 4447782ab450fb58efd91b0360c27bcd3ef3befa Mon Sep 17 00:00:00 2001
From: adamdunkels <adamdunkels>
Date: Tue, 30 Mar 2010 23:02:23 +0000
Subject: [PATCH] Print out a stack trace when a node reboots because of the
 watchdog

---
 cpu/msp430/watchdog.c | 62 ++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 59 insertions(+), 3 deletions(-)

diff --git a/cpu/msp430/watchdog.c b/cpu/msp430/watchdog.c
index 75a1c8d67..acff7a03c 100644
--- a/cpu/msp430/watchdog.c
+++ b/cpu/msp430/watchdog.c
@@ -28,13 +28,66 @@
  *
  * This file is part of the Contiki operating system.
  *
- * @(#)$Id: watchdog.c,v 1.5 2008/02/11 10:45:19 adamdunkels Exp $
+ * @(#)$Id: watchdog.c,v 1.6 2010/03/30 23:02:23 adamdunkels Exp $
  */
 #include <io.h>
+#include <signal.h>
 #include "dev/watchdog.h"
 
 static int stopped = 0;
 /*---------------------------------------------------------------------------*/
+static void
+printchar(char c)
+{
+  /* Loop until the transmission buffer is available. */
+  while((IFG2 & UTXIFG1) == 0);
+
+  /* Transmit the data. */
+  TXBUF1 = c;
+}
+/*---------------------------------------------------------------------------*/
+static void
+hexprint(uint8_t v)
+{
+  const char hexconv[] = "0123456789abcdef";
+  printchar(hexconv[v >> 4]);
+  printchar(hexconv[v & 0x0f]);
+}
+/*---------------------------------------------------------------------------*/
+static void
+printstring(char *s)
+{
+  while(*s) {
+    printchar(*s++);
+  }
+}
+/*---------------------------------------------------------------------------*/
+interrupt(WDT_VECTOR)
+watchdog_interrupt(void)
+{
+  uint8_t dummy;
+  static uint8_t *ptr;
+  static int i;
+
+  ptr = &dummy;
+
+  printstring("Watchdog reset");
+  /*  printstring("Watchdog reset at PC $");
+  hexprint(ptr[3]);
+  hexprint(ptr[2]);*/
+  printstring("\nStack:\n");
+
+  for(i = 0; i < 64; ++i) {
+    hexprint(ptr[i]);
+    printchar(' ');
+    if((i & 0x0f) == 0x0f) {
+      printchar('\n');
+    }
+  }
+  printchar('\n');
+  watchdog_reboot();
+}
+/*---------------------------------------------------------------------------*/
 void
 watchdog_init(void)
 {
@@ -42,6 +95,9 @@ watchdog_init(void)
      initialization. */
   stopped = 0;
   watchdog_stop();
+
+  IFG1 &= ~WDTIFG;
+  IE1 |= WDTIE;
 }
 /*---------------------------------------------------------------------------*/
 void
@@ -51,7 +107,7 @@ watchdog_start(void)
      unless watchdog_periodic() is called. */
   stopped--;
   if(!stopped) {
-    WDTCTL = WDTPW | WDTCNTCL | WDT_ARST_1000;
+    WDTCTL = WDTPW | WDTCNTCL | WDT_ARST_1000 | WDTTMSEL;
   }
 }
 /*---------------------------------------------------------------------------*/
@@ -61,7 +117,7 @@ watchdog_periodic(void)
   /* This function is called periodically to restart the watchdog
      timer. */
   if(!stopped) {
-    WDTCTL = (WDTCTL & 0xff) | WDTPW | WDTCNTCL;
+    WDTCTL = (WDTCTL & 0xff) | WDTPW | WDTCNTCL | WDTTMSEL;;
   }
 }
 /*---------------------------------------------------------------------------*/