Add links to KB articles

include/mbedtls/config.h

@@ -1903,6 +1903,10 @@
  * Windows. For other platforms, you'll want to disable it, and write your
  * own networking callbacks to be passed to \c mbedtls_ssl_set_bio().
  *
+ * \note See also our Knowledge Base article about porting to a new
+ * environment:
+ * https://tls.mbed.org/kb/how-to/how-do-i-port-mbed-tls-to-a-new-environment-OS
+ *
  * Module:  library/net.c
  *
  * This module provides networking routines.
@@ -2251,7 +2255,8 @@
  * By default mbed TLS assumes it is used in a non-threaded environment or that
  * contexts are not shared between threads. If you do intend to use contexts
  * between threads, you will need to enable this layer to prevent race
- * conditions.
+ * conditions. See also our Knowledge Base article about threading:
+ * https://tls.mbed.org/kb/development/thread-safety-and-multi-threading
  *
  * Module:  library/threading.c
  *
@@ -2277,6 +2282,10 @@
  * your own implementation of the whole module by setting
  * \c MBEDTLS_TIMING_ALT in the current file.
  *
+ * \note See also our Knowledge Base article about porting to a new
+ * environment:
+ * https://tls.mbed.org/kb/how-to/how-do-i-port-mbed-tls-to-a-new-environment-OS
+ *
  * Module:  library/timing.c
  * Caller:  library/havege.c
  *

include/mbedtls/ssl.h

@@ -1149,6 +1149,7 @@ typedef int mbedtls_ssl_get_timer_t( void * ctx );
  *                 here, except if using an event-driven style.
  *
  * \note           See also the "DTLS tutorial" article in our knowledge base.
+ *                 https://tls.mbed.org/kb/how-to/dtls-tutorial
  */
 void mbedtls_ssl_set_timer_cb( mbedtls_ssl_context *ssl,
                                void *p_timer,