Initial commit of source code.

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

src/avr/irq.h

@@ -0,0 +1,29 @@
+#ifndef __AVR_IRQ_H
+#define __AVR_IRQ_H
+// Definitions for irq enable/disable on AVR
+
+#include <avr/interrupt.h> // cli
+#include "compiler.h" // barrier
+
+static inline void irq_disable(void) {
+    cli();
+    barrier();
+}
+
+static inline void irq_enable(void) {
+    barrier();
+    sei();
+}
+
+static inline uint8_t irq_save(void) {
+    uint8_t flag = SREG;
+    irq_disable();
+    return flag;
+}
+
+static inline void irq_restore(uint8_t flag) {
+    barrier();
+    SREG = flag;
+}
+
+#endif // irq.h