add arduino nano stdin driver

include/arduino-nano/driver/stdin.h

+#ifndef STANDARDINPUT_H
+#define STANDARDINPUT_H
+
+class StandardInput {
+	private:
+		StandardInput(const StandardInput &copy);
+		char buffer[8];
+		unsigned char write_pos, read_pos;
+
+	public:
+		StandardInput() : write_pos(0), read_pos(0) {}
+		void setup();
+		bool hasKey();
+		char getKey();
+
+		inline void addKey(char key) {
+			buffer[write_pos++] = key;
+			write_pos %= 8;
+		}
+};
+
+extern StandardInput kin;
+
+#endif

src/arch/arduino-nano/Makefile.inc

@@ -23,6 +23,10 @@ TARGETS += src/arch/arduino-nano/driver/gpio.cc
 TARGETS += src/arch/arduino-nano/driver/stdout.cc
 TARGETS += src/arch/arduino-nano/driver/uptime.cc
 
+ifneq ($(findstring stdin,${arch_drivers}), )
+	TARGETS += src/arch/arduino-nano/driver/stdin.cc
+endif
+
 OBJECTS = ${TARGETS:.cc=.o}
 
 .cc.o:

src/arch/arduino-nano/arch.cc

@@ -24,10 +24,14 @@ void Arch::setup(void)
 	sei();
 }
 
+#ifdef WITH_WAKEUP
+void wakeup();
+#endif
+
 #if defined(WITH_LOOP) || defined(TIMER_S)
 
 #include "driver/uptime.h"
-extern void loop();
+void loop();
 
 #endif
 
@@ -41,6 +45,9 @@ void Arch::idle_loop(void)
 #ifdef WITH_LOOP
 		loop();
 #endif
+#ifdef WITH_WAKEUP
+		wakeup();
+#endif
 #ifdef TIMER_S
 		uptime.tick_s();
 #endif

src/arch/arduino-nano/driver/stdin.cc

+#include "driver/stdin.h"
+#include <avr/io.h>
+#include <avr/interrupt.h>
+
+void StandardInput::setup()
+{
+	UCSR0B |= _BV(RXCIE0);
+}
+
+bool StandardInput::hasKey()
+{
+	if (write_pos != read_pos) {
+		return true;
+	}
+	return false;
+}
+
+char StandardInput::getKey()
+{
+	char ret = buffer[read_pos++];
+	read_pos %= 8;
+	return ret;
+}
+
+StandardInput kin;
+
+ISR(USART_RX_vect)
+{
+	while (UCSR0A & _BV(RXC0)) {
+		kin.addKey(UDR0);
+	}
+}