From 6bdc29395da567421a93a6d794eecec768a67502 Mon Sep 17 00:00:00 2001
From: Michael Kaplan <m.kaplan@evva.com>
Date: Fri, 24 Nov 2017 11:05:28 +0100
Subject: [PATCH] CpuUid: buffer size assertion added

Added note in hal that a value higher than 0 is expected from the target implementation for the cpu_uid_get_length() function.

Added MBED_ASSERT for checking cpu_uid_get_length() return value in the driver.
---
 drivers/CpuUid.cpp | 1 +
 hal/cpu_uid_api.h  | 5 ++++-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/CpuUid.cpp b/drivers/CpuUid.cpp
index da5b9459f2..950afc80f9 100644
--- a/drivers/CpuUid.cpp
+++ b/drivers/CpuUid.cpp
@@ -26,6 +26,7 @@ const char CpuUid::_hexChars[16] = {'0', '1', '2', '3', '4', '5', '6', '7', '8',
 CpuUid::CpuUid() : _data(NULL)
 {
     _size = cpu_uid_get_length();
+    MBED_ASSERT(_size > 0);
     if (0 < _size)
     {
         _data = new uint8_t[_size];
diff --git a/hal/cpu_uid_api.h b/hal/cpu_uid_api.h
index 1ff24ce17c..06d90573fd 100644
--- a/hal/cpu_uid_api.h
+++ b/hal/cpu_uid_api.h
@@ -37,7 +37,10 @@ extern "C" {
  * 
  * @return Number of uid bytes
  * 
- * @note Shall be used to get the needed size of the byte buffer
+ * @note
+ *  Shall be used by the driver to get the needed size of the byte buffer.
+ *  Target implementation must return a value higher than 0 or the driver will assert.
+ * 
  */
 int cpu_uid_get_length(void);