* Make total stack size available as a symbol

* Implement SWI handler to enable/disable interrupts
* Implement event system to deal with kicking non-interrupt code

event.h

@@ -0,0 +1,19 @@
+#ifndef __EVENT_H
+#define __EVENT_H
+
+#include "types.h"
+
+#define EVENT_TIMER		0
+#define EVENT_I2C_COMPLETE	1
+
+#define EVENT_MAX		1
+
+typedef void event_handler(void);
+
+void event_set(unsigned int event);
+bool event_get(unsigned int *event);
+void event_clear(unsigned int event);
+void event_dispatch(void);
+void event_register(unsigned int event, event_handler *handler);
+
+#endif /* __EVENT_H */