From 38c49099c9f8fdca5d3e057e3458894f8b7994d2 Mon Sep 17 00:00:00 2001
From: Bernard Xiong <bernard.xiong@gmail.com>
Date: Fri, 28 Dec 2018 21:41:01 +0800
Subject: [PATCH] [libc] Fix the printf issue when disable DFS

---
 components/libc/compilers/newlib/syscalls.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/components/libc/compilers/newlib/syscalls.c b/components/libc/compilers/newlib/syscalls.c
index e4cda478cb..759feafe67 100644
--- a/components/libc/compilers/newlib/syscalls.c
+++ b/components/libc/compilers/newlib/syscalls.c
@@ -9,6 +9,8 @@
 #include <reent.h>
 #include <sys/errno.h>
 #include <sys/time.h>
+#include <stdio.h>
+
 #include <rtthread.h>
 
 #ifdef RT_USING_DFS
@@ -218,7 +220,7 @@ _ssize_t
 _write_r(struct _reent *ptr, int fd, const void *buf, size_t nbytes)
 {
 #ifndef RT_USING_DFS
-    if (fd == 0)
+    if (fileno(stdout) == fd)
     {
         rt_device_t console;