build_info.h: rewrite comment for inclusion of config_psa.h
Signed-off-by: Yanray Wang <yanray.wang@arm.com>
diff --git a/include/mbedtls/build_info.h b/include/mbedtls/build_info.h
index d271049..1acf477 100644
--- a/include/mbedtls/build_info.h
+++ b/include/mbedtls/build_info.h
@@ -87,7 +87,13 @@
#define MBEDTLS_MD_C
#endif
-/* PSA crypto specific configuration options */
+/* PSA crypto specific configuration options
+ * - If config_psa.h reads a configuration option in preprocessor directive,
+ * this symbol should be consulted before its inclusion. (e.g. MBEDTLS_MD_C)
+ * - If config_psa.h writes a configuration option in conditional directive,
+ * this symbol should be consulted after its inclusion.
+ * (e.g. MBEDTLS_MD_LIGHT)
+ */
#if defined(MBEDTLS_PSA_CRYPTO_CONFIG) /* PSA_WANT_xxx influences MBEDTLS_xxx */ || \
defined(MBEDTLS_PSA_CRYPTO_C) /* MBEDTLS_xxx influences PSA_WANT_xxx */
#include "mbedtls/config_psa.h"