Use events to invoke menu handling on UART receive. We now have a basic

main dispatch loop.

uart.c

@@ -1,6 +1,7 @@
 #include "uart.h"
 #include "types.h"
 #include "interrupt.h"
+#include "event.h"
 
 #define UARTBASE 0xE000C000
 
@@ -112,6 +113,7 @@ void __attribute__((interrupt("IRQ"))) uart_interrupt_handler(void)
 			}
 		}
 		uart_rxwrite = local_rxwrite;
+		event_set(EVENT_UART_INPUT);
 		break;
 
 	case 0x2: /* THRE interrupt */