Add cr after a lf is printed (configurable)

Formatting

components/esp32/Kconfig

@@ -1,4 +1,4 @@
-menu "WiFi config"
+menu "ESP32-specific config"
 
 config WIFI_ENABLED
     bool "Enable low-level WiFi stack"
@@ -36,4 +36,15 @@ config WIFI_EVENT_TASK_STACK_SIZE
     help
         Config WiFi event task stack size in different application.
 
+
+config NEWLIB_STDOUT_ADDCR
+	bool "Standard-out output adds carriage return before newline"
+	default y
+	help
+		Most people are used to end their printf strings with a newline. If this
+		is sent as is to the serial port, most terminal programs will only move the
+		cursor one line down, not also move it to the beginning of the line. This
+		is usually done by an added CR character. Enabling this will make the
+		standard output code automatically add a CR character before a LF.
+
 endmenu

components/esp32/syscalls.c

@@ -137,6 +137,11 @@ ssize_t _write_r(struct _reent *r, int fd, const void * data, size_t size) {
     const char* p = (const char*) data;
     if (fd == STDOUT_FILENO) {
         while(size--) {
+#if CONFIG_NEWLIB_STDOUT_ADDCR
+            if (*p=='\n') {
+                uart_tx_one_char('\r');
+            }
+#endif
             uart_tx_one_char(*p);
             ++p;
         }