* 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

main.c

@@ -4,6 +4,7 @@
 #include "timer.h"
 #include "uart.h"
 #include "interrupt.h"
+#include "event.h"
 
 #define PINSEL0 (*((volatile unsigned char *) 0xE002C000))
 #define FP0XDIR (*((volatile unsigned int *) 0x3FFFC000))
@@ -255,6 +256,10 @@ int main(void) {
 			timer_set_period(10000*TIMER_MS);
 			reply("done");
 			break;
+		case 'E':
+			event_dispatch();
+			reply("done");
+			break;
 		default:
 			reply("Unrecognised command.");
 			break;