Initial commit of source code.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

src/avr/watchdog.c

@@ -0,0 +1,38 @@
+// Initialization of AVR watchdog timer.
+//
+// Copyright (C) 2016  Kevin O'Connor <kevin@koconnor.net>
+//
+// This file may be distributed under the terms of the GNU GPLv3 license.
+
+#include <avr/interrupt.h> // WDT_vect
+#include <avr/wdt.h> // wdt_enable
+#include "command.h" // shutdown
+#include "sched.h" // DECL_TASK
+
+static uint8_t watchdog_shutdown;
+
+ISR(WDT_vect)
+{
+    watchdog_shutdown = 1;
+    shutdown("Watchdog timer!");
+}
+
+static void
+watchdog_reset(void)
+{
+    wdt_reset();
+    if (watchdog_shutdown) {
+        WDTCSR |= 1<<WDIE;
+        watchdog_shutdown = 0;
+    }
+}
+DECL_TASK(watchdog_reset);
+
+static void
+watchdog_init(void)
+{
+    // 0.5s timeout, interrupt and system reset
+    wdt_enable(WDTO_500MS);
+    WDTCSR |= 1<<WDIE;
+}
+DECL_INIT(watchdog_init);