Add MBEDTLS_ENTROPY_HARDWARE_ALT

Makes it easier for an external module to plug its hardware entropy collector.

include/mbedtls/config.h

@@ -277,6 +277,19 @@
 //#define MBEDTLS_AES_ENCRYPT_ALT
 //#define MBEDTLS_AES_DECRYPT_ALT
 
+/**
+ * \def MBEDTLS_EMTROPY_HARDWARE_ALT
+ *
+ * Uncomment this macro to let mbed TLS use your own implementation of a
+ * hardware entropy collector.
+ *
+ * Your function must be called \c mbedtls_hardware_poll(), have the same
+ * prototype as declared in entropy_poll.h, and accept NULL as first argument.
+ *
+ * Uncomment to use your own hardware entropy collector.
+ */
+//#define MBEDTLS_ENTROPY_HARDWARE_ALT
+
 /**
  * \def MBEDTLS_AES_ROM_TABLES
  *