diff --git a/drivers/UARTSerial.h b/drivers/UARTSerial.h
index 026215b..08c35e1 100644
--- a/drivers/UARTSerial.h
+++ b/drivers/UARTSerial.h
@@ -142,6 +142,15 @@
         return 0;
     }
 
+    /** Check current blocking or non-blocking mode for file operations.
+     *
+     *  @return             true for blocking mode, false for non-blocking mode.
+     */
+    virtual bool is_blocking() const
+    {
+        return _blocking;
+    }
+
     /** Register a callback on state change of the file.
      *
      *  The specified callback will be called on state changes such as when
diff --git a/platform/FileHandle.h b/platform/FileHandle.h
index b0cb10a..7c2c8f3 100644
--- a/platform/FileHandle.h
+++ b/platform/FileHandle.h
@@ -192,7 +192,16 @@
      */
     virtual int set_blocking(bool blocking)
     {
-        return -1;
+        return blocking ? 0 : -ENOTTY;
+    }
+
+    /** Check current blocking or non-blocking mode for file operations.
+     *
+     *  @return             true for blocking mode, false for non-blocking mode.
+     */
+    virtual bool is_blocking() const
+    {
+        return true;
     }
 
     /** Check for poll event flags
diff --git a/platform/mbed_retarget.cpp b/platform/mbed_retarget.cpp
index 433b901..bd110cf 100644
--- a/platform/mbed_retarget.cpp
+++ b/platform/mbed_retarget.cpp
@@ -344,16 +344,16 @@
 }
 
 int mbed::bind_to_fd(FileHandle *fh) {
-    int fh_i = reserve_filehandle();
-    if (fh_i < 0) {
-        return fh_i;
+    int fildes = reserve_filehandle();
+    if (fildes < 0) {
+        return fildes;
     }
 
-    filehandles[fh_i] = fh;
-    stdio_in_prev[fh_i] = 0;
-    stdio_out_prev[fh_i] = 0;
+    filehandles[fildes] = fh;
+    stdio_in_prev[fildes] = 0;
+    stdio_out_prev[fildes] = 0;
 
-    return fh_i;
+    return fildes;
 }
 
 static int unbind_from_fd(int fd, FileHandle *fh) {
@@ -464,9 +464,9 @@
 }
 
 extern "C" int open(const char *name, int oflag, ...) {
-    int fh_i = reserve_filehandle();
-    if (fh_i < 0) {
-        return fh_i;
+    int fildes = reserve_filehandle();
+    if (fildes < 0) {
+        return fildes;
     }
 
     FileHandle *res = NULL;
@@ -476,7 +476,7 @@
         /* The first part of the filename (between first 2 '/') is not a
          * registered mount point in the namespace.
          */
-        return handle_open_errors(-ENODEV, fh_i);
+        return handle_open_errors(-ENODEV, fildes);
     }
 
     if (path.isFile()) {
@@ -484,28 +484,28 @@
     } else {
         FileSystemHandle *fs = path.fileSystem();
         if (fs == NULL) {
-            return handle_open_errors(-ENODEV, fh_i);
+            return handle_open_errors(-ENODEV, fildes);
         }
         int err = fs->open(&res, path.fileName(), oflag);
         if (err) {
-            return handle_open_errors(err, fh_i);
+            return handle_open_errors(err, fildes);
         }
     }
 
-    filehandles[fh_i] = res;
-    stdio_in_prev[fh_i] = 0;
-    stdio_out_prev[fh_i] = 0;
+    filehandles[fildes] = res;
+    stdio_in_prev[fildes] = 0;
+    stdio_out_prev[fildes] = 0;
 
-    return fh_i;
+    return fildes;
 }
 
 extern "C" int PREFIX(_close)(FILEHANDLE fh) {
     return close(fh);
 }
 
-extern "C" int close(int fh) {
-    FileHandle* fhc = get_fhc(fh);
-    filehandles[fh] = NULL;
+extern "C" int close(int fildes) {
+    FileHandle* fhc = get_fhc(fildes);
+    filehandles[fildes] = NULL;
     if (fhc == NULL) {
         errno = EBADF;
         return -1;
@@ -610,9 +610,9 @@
 #endif
 }
 
-extern "C" ssize_t write(int fh, const void *buf, size_t length) {
+extern "C" ssize_t write(int fildes, const void *buf, size_t length) {
 
-    FileHandle* fhc = get_fhc(fh);
+    FileHandle* fhc = get_fhc(fildes);
     if (fhc == NULL) {
         errno = EBADF;
         return -1;
@@ -700,9 +700,9 @@
 #endif
 }
 
-extern "C" ssize_t read(int fh, void *buf, size_t length) {
+extern "C" ssize_t read(int fildes, void *buf, size_t length) {
 
-    FileHandle* fhc = get_fhc(fh);
+    FileHandle* fhc = get_fhc(fildes);
     if (fhc == NULL) {
         errno = EBADF;
         return -1;
@@ -727,8 +727,8 @@
     return isatty(fh);
 }
 
-extern "C" int isatty(int fh) {
-    FileHandle* fhc = get_fhc(fh);
+extern "C" int isatty(int fildes) {
+    FileHandle* fhc = get_fhc(fildes);
     if (fhc == NULL) {
         errno = EBADF;
         return 0;
@@ -765,8 +765,8 @@
     return off;
 }
 
-extern "C" off_t lseek(int fh, off_t offset, int whence) {
-    FileHandle* fhc = get_fhc(fh);
+extern "C" off_t lseek(int fildes, off_t offset, int whence) {
+    FileHandle* fhc = get_fhc(fildes);
     if (fhc == NULL) {
         errno = EBADF;
         return -1;
@@ -786,8 +786,8 @@
 }
 #endif
 
-extern "C" int fsync(int fh) {
-    FileHandle* fhc = get_fhc(fh);
+extern "C" int fsync(int fildes) {
+    FileHandle* fhc = get_fhc(fildes);
     if (fhc == NULL) {
         errno = EBADF;
         return -1;
@@ -850,8 +850,8 @@
 }
 #endif
 
-extern "C" int fstat(int fh, struct stat *st) {
-    FileHandle* fhc = get_fhc(fh);
+extern "C" int fstat(int fildes, struct stat *st) {
+    FileHandle* fhc = get_fhc(fildes);
     if (fhc == NULL) {
         errno = EBADF;
         return -1;
@@ -862,6 +862,41 @@
     return 0;
 }
 
+extern "C" int fcntl(int fildes, int cmd, ...) {
+    FileHandle *fhc = get_fhc(fildes);
+    if (fhc == NULL) {
+        errno = EBADF;
+        return -1;
+    }
+
+    switch (cmd) {
+        case F_GETFL: {
+            int flags = 0;
+            if (fhc->is_blocking()) {
+                flags |= O_NONBLOCK;
+            }
+            return flags;
+        }
+        case F_SETFL: {
+            va_list ap;
+            va_start(ap, cmd);
+            int flags = va_arg(ap, int);
+            va_end(ap);
+            int ret = fhc->set_blocking(flags & O_NONBLOCK);
+            if (ret < 0) {
+                errno = -ret;
+                return -1;
+            }
+            return 0;
+        }
+
+        default: {
+            errno = EINVAL;
+            return -1;
+        }
+    }
+}
+
 extern "C" int poll(struct pollfd fds[], nfds_t nfds, int timeout)
 {
     if (nfds > OPEN_MAX) {
diff --git a/platform/mbed_retarget.h b/platform/mbed_retarget.h
index b3c6e6d..ef7f793 100644
--- a/platform/mbed_retarget.h
+++ b/platform/mbed_retarget.h
@@ -43,14 +43,20 @@
 typedef unsigned int  gid_t;    ///< Group ID
 #endif
 
-#define O_RDONLY 0      ///< Open for reading
-#define O_WRONLY 1      ///< Open for writing
-#define O_RDWR   2      ///< Open for reading and writing
-#define O_CREAT  0x0200 ///< Create file if it does not exist
-#define O_TRUNC  0x0400 ///< Truncate file to zero length
-#define O_EXCL   0x0800 ///< Fail if file exists
-#define O_APPEND 0x0008 ///< Set file offset to end of file prior to each write
-#define O_BINARY 0x8000 ///< Open file in binary mode
+/* Flags for open() and fcntl(GETFL/SETFL)
+ * At present, fcntl only supports reading and writing O_NONBLOCK
+ */
+#define O_RDONLY 0        ///< Open for reading
+#define O_WRONLY 1        ///< Open for writing
+#define O_RDWR   2        ///< Open for reading and writing
+#define O_NONBLOCK 0x0004 ///< Non-blocking mode
+#define O_APPEND   0x0008 ///< Set file offset to end of file prior to each write
+#define O_CREAT    0x0200 ///< Create file if it does not exist
+#define O_TRUNC    0x0400 ///< Truncate file to zero length
+#define O_EXCL     0x0800 ///< Fail if file exists
+#define O_BINARY   0x8000 ///< Open file in binary mode
+
+#define O_ACCMODE   (O_RDONLY|O_WRONLY|O_RDWR)
 
 #define NAME_MAX 255    ///< Maximum size of a name in a file path
 
@@ -480,6 +486,10 @@
     DT_SOCK,    ///< This is a UNIX domain socket.
 };
 
+/* fcntl.h defines */
+#define F_GETFL 3
+#define F_SETFL 4
+
 struct pollfd {
     int fd;
     short events;
@@ -503,7 +513,8 @@
     off_t lseek(int fildes, off_t offset, int whence);
     int isatty(int fildes);
     int fsync(int fildes);
-    int fstat(int fh, struct stat *st);
+    int fstat(int fildes, struct stat *st);
+    int fcntl(int fildes, int cmd, ...);
     int poll(struct pollfd fds[], nfds_t nfds, int timeout);
     int close(int fildes);
     int stat(const char *path, struct stat *st);