Added config option for newline conversion

hal/common/retarget.cpp

@@ -88,9 +88,11 @@ FileHandle::~FileHandle() {
 #if DEVICE_SERIAL
 extern int stdio_uart_inited;
 extern serial_t stdio_uart;
+#ifdef MBED_CONF_CORE_STDIO_CONVERT_NEWLINES
 static char stdio_in_prev;
 static char stdio_out_prev;
 #endif
+#endif
 
 static void init_serial() {
 #if DEVICE_SERIAL
@@ -228,6 +230,7 @@ extern "C" int PREFIX(_write)(FILEHANDLE fh, const unsigned char *buffer, unsign
     if (fh < 3) {
 #if DEVICE_SERIAL
         if (!stdio_uart_inited) init_serial();
+#ifdef MBED_CONF_CORE_STDIO_CONVERT_NEWLINES
         for (unsigned int i = 0; i < length; i++) {
             if (buffer[i] == '\n' && stdio_out_prev != '\r') {
                  serial_putc(&stdio_uart, '\r');
@@ -235,6 +238,11 @@ extern "C" int PREFIX(_write)(FILEHANDLE fh, const unsigned char *buffer, unsign
             serial_putc(&stdio_uart, buffer[i]);
             stdio_out_prev = buffer[i];
         }
+#else
+        for (unsigned int i = 0; i < length; i++) {
+            serial_putc(&stdio_uart, buffer[i]);
+        }
+#endif
 #endif
         n = length;
     } else {
@@ -260,6 +268,7 @@ extern "C" int PREFIX(_read)(FILEHANDLE fh, unsigned char *buffer, unsigned int
         // only read a character at a time from stdin
 #if DEVICE_SERIAL
         if (!stdio_uart_inited) init_serial();
+#ifdef MBED_CONF_CORE_STDIO_CONVERT_NEWLINES
         while (true) {
             char c = serial_getc(&stdio_uart);
             if ((c == '\r' && stdio_in_prev != '\n') ||
@@ -278,6 +287,9 @@ extern "C" int PREFIX(_read)(FILEHANDLE fh, unsigned char *buffer, unsigned int
                 break;
             }
         }
+#else
+        *buffer = serial_getc(&stdio_uart);
+#endif
 #endif
         n = 1;
     } else {

mbed_lib.json

@@ -0,0 +1,8 @@
+{
+    "name": "core",
+    "config": {
+        "stdio-convert-newlines": {
+            "help": "Enable conversion to standard newlines on stdin/stdout"
+        }
+    }
+}