Change API for getch to make it the caller's responsibility to poll for

input, allowing it to do other stuff if it wants to.

main.c

@@ -172,7 +172,8 @@ int main(void) {
 	while (1) {
 		char c;
 		putstr("prompt> ");
-		c = getch();
+		while (!getch(&c))
+			FP0XVAL ^= 0x04000000;
 		if (c == 0x0a)
 			continue;
 		putch(c);

uart.c

@@ -4,8 +4,6 @@
 
 #define UARTBASE 0xE000C000
 
-#define FP0XVAL (*((volatile unsigned int *) 0x3FFFC014))
-
 #define RBR 0x00
 #define THR 0x00
 #define DLL 0x00
@@ -172,14 +170,11 @@ void puthex(unsigned int n) {
 	putstr(s+i);
 }
 
-char getch(void) {
-	char c;
-
-	while (uart_rxread == uart_rxwrite) {
-		FP0XVAL ^= 0x04000000;
-	}
+bool getch(char *c) {
+	if (uart_rxread == uart_rxwrite)
+		return FALSE;
 
-	c = uart_rxbuf[uart_rxread];
+	*c = uart_rxbuf[uart_rxread];
 	uart_rxread = (uart_rxread + 1) % UART_RXBUFSIZE;
-	return c;
+	return TRUE;
 }

uart.h

@@ -1,11 +1,13 @@
 #ifndef __UART_H
 #define __UART_H
 
+#include "types.h"
+
 void init_uart(void);
 void putch(char c);
 void putstr(char *s);
 void putint(unsigned int n);
 void puthex(unsigned int n);
-char getch(void);
+bool getch(char *c);
 
 #endif /* __UART_H */