refactor(trng): cleanup the existing TRNG support
This patch adds the following changes to complete the existing
TRNG implementation:
1. Adds a feature specific scope for buildlog generation.
2. Updates the docs on the build flag "TRNG_SUPPORT" and its values.
3. Makefile update and improves the existing comments at few sections
for better understanding of the underlying logic.
Change-Id: I3f72f0ccd5c94005a2df87158cf23199d2160d37
Signed-off-by: Jayanth Dodderi Chidanand <jayanthdodderi.chidanand@arm.com>
diff --git a/include/plat/common/platform.h b/include/plat/common/platform.h
index c90441c..c7b7908 100644
--- a/include/plat/common/platform.h
+++ b/include/plat/common/platform.h
@@ -16,10 +16,10 @@
#if ENABLE_RME
#include <services/rmm_core_manifest.h>
#endif
+#include <drivers/fwu/fwu_metadata.h>
#if TRNG_SUPPORT
#include "plat_trng.h"
-#endif
-#include <drivers/fwu/fwu_metadata.h>
+#endif /* TRNG_SUPPORT */
#if DRTM_SUPPORT
#include "plat_drtm.h"
#endif /* DRTM_SUPPORT */
diff --git a/include/services/trng_svc.h b/include/services/trng_svc.h
index ed4d557..92417c2 100644
--- a/include/services/trng_svc.h
+++ b/include/services/trng_svc.h
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2021, ARM Limited. All rights reserved.
+ * Copyright (c) 2021-2022, ARM Limited. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
@@ -17,7 +17,7 @@
#define ARM_TRNG_FEATURES U(0x84000051)
#define ARM_TRNG_GET_UUID U(0x84000052)
#define ARM_TRNG_RND32 U(0x84000053)
-#define ARM_TRNG_RND64 U(0xc4000053)
+#define ARM_TRNG_RND64 U(0xC4000053)
/* TRNG version numbers */
#define TRNG_VERSION_MAJOR (0x1)
@@ -30,19 +30,17 @@
#define TRNG_E_NO_ENTROPY (-3)
#define TRNG_E_NOT_IMPLEMENTED (-4)
-#if TRNG_SUPPORT
-void trng_setup(void);
-bool is_trng_fid(uint32_t smc_fid);
-#else
-static inline void trng_setup(void)
-{
-}
+/* TRNG Entropy Bit Numbers */
+#define TRNG_RND32_ENTROPY_MAXBITS (96U)
+#define TRNG_RND64_ENTROPY_MAXBITS (192U)
-static inline bool is_trng_fid(uint32_t smc_fid)
-{
- return false;
-}
-#endif
+/* Public API to perform the initial TRNG entropy setup */
+void trng_setup(void);
+
+/* Public API to verify function id is part of TRNG */
+bool is_trng_fid(uint32_t smc_fid);
+
+/* Handler to be called to handle TRNG smc calls */
uintptr_t trng_smc_handler(
uint32_t smc_fid,
u_register_t x1,