Add additional comments to platform setup/teardown functions
diff --git a/include/mbedtls/platform.h b/include/mbedtls/platform.h
index 712bbe9..25b5d21 100644
--- a/include/mbedtls/platform.h
+++ b/include/mbedtls/platform.h
@@ -312,7 +312,13 @@
*
* \return 0 if successful
*
- * \note This function should be called before any other library function
+ * \note This function is intended to allow platform specific initialisation,
+ * and should be called before any other library functions. Its
+ * implementation is platform specific, and by default, unless platform
+ * specific code is provided, it does nothing.
+ *
+ * Its use and whether its necessary to be called is dependent on the
+ * platform.
*/
int mbedtls_platform_setup( mbedtls_platform_context *ctx );
/**
@@ -322,8 +328,13 @@
*
* \return 0 if successful
*
- * \note This function should be after every other mbed TLS module has been
- * correctly freed using the appropriate free function.
+ * \note This function should be called after every other mbed TLS module has
+ * been correctly freed using the appropriate free function.
+ * Its implementation is platform specific, and by default, unless
+ * platform specific code is provided, it does nothing.
+ *
+ * Its use and whether its necessary to be called is dependent on the
+ * platform.
*/
void mbedtls_platform_teardown( mbedtls_platform_context *ctx );