3 files changed, 17 insertions, 2 deletions
diff --git a/components/libc/armlibc/stubs.c b/components/libc/armlibc/stubs.c
index 1c79ce2861..4ca7cf056f 100644
--- a/components/libc/armlibc/stubs.c
+++ b/components/libc/armlibc/stubs.c
@@ -168,7 +168,8 @@ int _sys_write(FILEHANDLE fh, const unsigned char *buf, unsigned len, int mode)
 
         console_device = rt_console_get_device();
         if (console_device != 0) rt_device_write(console_device, 0, buf, len);
-        return len;
+
+		return 0;
 #endif
     }
 
diff --git a/components/libc/minilibc/stdlib.c b/components/libc/minilibc/stdlib.c
index 51cb07fee0..e29ae9bc2e 100644
--- a/components/libc/minilibc/stdlib.c
+++ b/components/libc/minilibc/stdlib.c
@@ -54,6 +54,7 @@ long int atol(const char* s)
 	return sign?-v:v;
 }
 
+#ifdef RT_USING_HEAP
 void *malloc(size_t size)
 {
 	return rt_malloc(size);
@@ -73,5 +74,6 @@ void *calloc(size_t nelem, size_t elsize)
 {
 	return rt_calloc(nelem, elsize);
 }
+#endif
 
 #endif
diff --git a/components/libc/newlib/libc.c b/components/libc/newlib/libc.c
index f7bb8e3f9b..73270969b8 100644
--- a/components/libc/newlib/libc.c
+++ b/components/libc/newlib/libc.c
@@ -9,6 +9,15 @@
 #include <pthread.h>
 #endif
 
+#ifdef RT_USING_DFS
+#include <dfs_posix.h>
+
+#ifdef RT_USING_DFS_DEVFS
+#include <devfs.h>
+#endif
+
+#endif
+
 void libc_system_init(const char* tty_name)
 {
 #ifdef RT_USING_DFS
@@ -18,13 +27,16 @@ void libc_system_init(const char* tty_name)
 #error Please enable devfs by defining RT_USING_DFS_DEVFS in rtconfig.h
 #endif
 
-	/* init console device */
+	/* initialize console device */
 	rt_console_init(tty_name);
 
 	/* open console as stdin/stdout/stderr */
 	fd = open("/dev/console", O_RDONLY, 0);	/* for stdin */
 	fd = open("/dev/console", O_WRONLY, 0);	/* for stdout */
 	fd = open("/dev/console", O_WRONLY, 0);	/* for stderr */
+	
+	/* skip warning */
+	fd = fd;
 #endif
 
 	/* set PATH and HOME */