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/services/std_svc/trng/trng_main.c b/services/std_svc/trng/trng_main.c
index 38aa649..90098a8 100644
--- a/services/std_svc/trng/trng_main.c
+++ b/services/std_svc/trng/trng_main.c
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2021, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2021-2022, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
@@ -23,9 +23,9 @@
static uintptr_t trng_rnd32(uint32_t nbits, void *handle)
{
uint32_t mask = ~0U;
- uint64_t ent[2];
+ uint64_t ent[2] = {0};
- if (nbits == 0U || nbits > 96U) {
+ if (nbits == 0U || nbits > TRNG_RND32_ENTROPY_MAXBITS) {
SMC_RET1(handle, TRNG_E_INVALID_PARAMS);
}
@@ -59,9 +59,9 @@
static uintptr_t trng_rnd64(uint32_t nbits, void *handle)
{
uint64_t mask = ~0ULL;
- uint64_t ent[3];
+ uint64_t ent[3] = {0};
- if (nbits == 0U || nbits > 192U) {
+ if (nbits == 0U || nbits > TRNG_RND64_ENTROPY_MAXBITS) {
SMC_RET1(handle, TRNG_E_INVALID_PARAMS);
}
@@ -117,9 +117,9 @@
switch (smc_fid) {
case ARM_TRNG_VERSION:
SMC_RET1(handle, MAKE_SMCCC_VERSION(
- TRNG_VERSION_MAJOR, TRNG_VERSION_MINOR
- ));
+ TRNG_VERSION_MAJOR, TRNG_VERSION_MINOR));
break; /* unreachable */
+
case ARM_TRNG_FEATURES:
if (is_trng_fid((uint32_t)x1)) {
SMC_RET1(handle, TRNG_E_SUCCESS);
@@ -127,16 +127,19 @@
SMC_RET1(handle, TRNG_E_NOT_SUPPORTED);
}
break; /* unreachable */
+
case ARM_TRNG_GET_UUID:
SMC_UUID_RET(handle, plat_trng_uuid);
break; /* unreachable */
+
case ARM_TRNG_RND32:
return trng_rnd32((uint32_t)x1, handle);
+
case ARM_TRNG_RND64:
return trng_rnd64((uint32_t)x1, handle);
+
default:
- WARN("Unimplemented TRNG Service Call: 0x%x\n",
- smc_fid);
+ WARN("Unimplemented TRNG Service Call: 0x%x\n", smc_fid);
SMC_RET1(handle, TRNG_E_NOT_IMPLEMENTED);
break; /* unreachable */
}