From: Stefano Rivera <stefanor@debian.org>
Date: Tue, 21 Aug 2018 10:05:03 -0700
Subject: Change putchar() & getchar() prototype to match sdcc

They changed prototype to be standards-compliant (upstream bug #2505)
---
 include/serial.h | 4 ++--
 lib/serial.c     | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/include/serial.h b/include/serial.h
index 7cdd4d7..5b7a60d 100644
--- a/include/serial.h
+++ b/include/serial.h
@@ -51,5 +51,5 @@ void sio0_init( DWORD baud_rate ) __critical ; // baud_rate max should be 57600
  putchar('\\n') or putchar('\\r') both transmit \\r\\n
  Just use one or the other. (This makes terminal echo easy)
 **/
-void putchar(char c);
-char getchar();
+int putchar(int c);
+int getchar();
diff --git a/lib/serial.c b/lib/serial.c
index ce98b2c..328cbe3 100644
--- a/lib/serial.c
+++ b/lib/serial.c
@@ -69,7 +69,7 @@ void sio0_init( DWORD baud_rate ) __critical { // baud_rate max should be 57600
 
 }
 
-char getchar() {
+int getchar() {
   char c;
   while (!RI)
     ;  
@@ -84,7 +84,7 @@ void _transchar(char c) {
  SBUF0=c;
 }
 
-void putchar (char c) {
+int putchar (int c) {
   if (c=='\n') _transchar('\r'); // transmit \r\n
   _transchar(c);  
   if (c == '\r' ) _transchar('\n'); // transmit \r\n
