diff --git a/components/esp32/freertos_hooks.c b/components/esp32/freertos_hooks.c
index 50ebd3d05..d59a20363 100644
--- a/components/esp32/freertos_hooks.c
+++ b/components/esp32/freertos_hooks.c
@@ -1,3 +1,18 @@
+// Copyright 2015-2016 Espressif Systems (Shanghai) PTE LTD
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+
 #include <stdint.h>
 #include <stdlib.h>
 #include <stdbool.h>
diff --git a/components/esp32/include/esp_freertos_hooks.h b/components/esp32/include/esp_freertos_hooks.h
index 1bb5ab194..45a164972 100644
--- a/components/esp32/include/esp_freertos_hooks.h
+++ b/components/esp32/include/esp_freertos_hooks.h
@@ -1,9 +1,27 @@
-#ifndef ESP_FREERTOS_HOOKS_H
-#define ESP_FREERTOS_HOOKS_H
+// Copyright 2015-2016 Espressif Systems (Shanghai) PTE LTD
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef __ESP_FREERTOS_HOOKS_H__
+#define __ESP_FREERTOS_HOOKS_H__
 
 #include <stdbool.h>
 #include "esp_err.h"
 
+#ifdef __cplusplus
+extern "C"
+{
+#endif
 
 /*
  Definitions for the tickhook and idlehook callbacks
@@ -17,6 +35,9 @@ typedef void (*esp_freertos_tick_cb_t)();
   *         sleep until an interrupt (or FreeRTOS tick) happens and false
   *         if it should be called again as fast as possible.
   *
+  * @warning Idle callbacks MUST NOT, UNDER ANY CIRCUMSTANCES, CALL 
+  *          A FUNCTION THAT MIGHT BLOCK.
+  *
   * @param  esp_freertos_idle_cb_t new_idle_cb : Callback to be called
   *
   * @return ESP_OK : Callback registered
@@ -54,5 +75,9 @@ void esp_deregister_freertos_idle_hook(esp_freertos_idle_cb_t old_idle_cb);
   */
 void esp_deregister_freertos_tick_hook(esp_freertos_tick_cb_t old_tick_cb);
 
+#ifdef __cplusplus
+}
+#endif
+
 
 #endif
\ No newline at end of file