diff --git a/software/bios/isr.c b/software/bios/isr.c
index 25badec3b..21c480aae 100644
--- a/software/bios/isr.c
+++ b/software/bios/isr.c
@@ -16,10 +16,16 @@
  */
 
 #include <hw/interrupts.h>
+#include <hw/uart.h>
 #include <irq.h>
+#include <uart.h>
 
 void isr(void)
 {
 	unsigned int irqs;
+	
 	irqs = irq_pending() & irq_getmask();
+	
+	if(irqs & IRQ_UART)
+		uart_isr();
 }
diff --git a/software/bios/main.c b/software/bios/main.c
index b2f90e3b3..36e21c628 100644
--- a/software/bios/main.c
+++ b/software/bios/main.c
@@ -1,16 +1,14 @@
-#include <hw/uart.h>
-
-static void print(const char *s)
-{
-	while(*s) {
-		while(CSR_UART_EV_STAT & UART_EV_TX);
-		CSR_UART_RXTX = *s;
-		s++;
-	}
-}
+#include <stdio.h>
+#include <irq.h>
+#include <uart.h>
 
 int main(void)
 {
-	print("Hello World\n");
+	irq_setmask(0);
+	irq_setie(1);
+	uart_init();
+	
+	printf("Hello World with IRQs\n");
+	
 	while(1);
 }
diff --git a/software/include/base/irq.h b/software/include/base/irq.h
index 43e447344..37cf73fd0 100644
--- a/software/include/base/irq.h
+++ b/software/include/base/irq.h
@@ -18,9 +18,16 @@
 #ifndef __IRQ_H
 #define __IRQ_H
 
-static inline void irq_enable(unsigned int en)
+static inline unsigned int irq_getie(void)
 {
-       __asm__ __volatile__("wcsr IE, %0" : : "r" (en));
+       unsigned int ie;
+       __asm__ __volatile__("rcsr %0, IE" : "=r" (ie));
+       return ie;
+}
+
+static inline void irq_setie(unsigned int ie)
+{
+       __asm__ __volatile__("wcsr IE, %0" : : "r" (ie));
 }
 
 static inline unsigned int irq_getmask(void)
@@ -47,16 +54,4 @@ static inline void irq_ack(unsigned int mask)
        __asm__ __volatile__("wcsr IP, %0" : : "r" (mask));
 }
 
-static inline unsigned int irq_getie(void)
-{
-       unsigned int ie;
-       __asm__ __volatile__("rcsr %0, IE" : "=r" (ie));
-       return ie;
-}
-
-static inline void irq_setie(unsigned int ie)
-{
-       __asm__ __volatile__("wcsr IE, %0" : : "r" (ie));
-}
-
 #endif /* __IRQ_H */
diff --git a/software/libbase/uart.c b/software/libbase/uart.c
index 6ca28629f..8490bcdf8 100644
--- a/software/libbase/uart.c
+++ b/software/libbase/uart.c
@@ -44,7 +44,9 @@ static volatile int tx_cts;
 
 void uart_isr(void)
 {
-	unsigned int stat = CSR_UART_EV_PENDING;
+	unsigned int stat;
+	
+	stat = CSR_UART_EV_PENDING;
 
 	if(stat & UART_EV_RX) {
 		rx_buf[rx_produce] = CSR_UART_RXTX;