diff options
| -rw-r--r-- | board/cr50/dcrypto/trng.c | 29 |
1 files changed, 12 insertions, 17 deletions
diff --git a/board/cr50/dcrypto/trng.c b/board/cr50/dcrypto/trng.c index a67d5ef766..e93d0bb051 100644 --- a/board/cr50/dcrypto/trng.c +++ b/board/cr50/dcrypto/trng.c @@ -34,16 +34,15 @@ static volatile struct trng_reg *reg_trng = (void *)(GC_TRNG_BASE_ADDR); /** * Attempts to read TRNG_EMPTY before reporting a stall. Practically data should - * be available in less than 0x7ff cycles under normal conditions. 0x7ff was - * chosen to match the hardware TRNG TIMEOUT_COUNTER. Test on boards with slow - * TRNG before reducing this number. + * be available in less than 0xfff cycles under normal conditions. + * Test on boards with slow TRNG before reducing this number. */ -#define TRNG_EMPTY_COUNT 0x7ff +#define TRNG_EMPTY_COUNT 0xfff /** * Number of attempts to reset TRNG after stall is detected. */ -#define TRNG_RESET_COUNT 16 +#define TRNG_RESET_COUNT 32 void fips_init_trng(void) { @@ -101,7 +100,7 @@ void fips_init_trng(void) */ reg_trng->allowed_values = 0x26; - reg_trng->timeout_counter = 0x7ff; + reg_trng->timeout_counter = TRNG_EMPTY_COUNT; reg_trng->timeout_max_try = 4; reg_trng->power_down_b = 1; reg_trng->go_event = 1; @@ -110,7 +109,7 @@ void fips_init_trng(void) uint64_t read_rand(void) { uint32_t empty_count = 0; - uint32_t reset_count = 0; + uint8_t reset_count = 0; #ifdef CRYPTO_TEST_SETUP /* Do we need to simulate error? */ @@ -130,19 +129,15 @@ uint64_t read_rand(void) empty_count = 0; reset_count++; reg_trng->go_event = 1; -#ifdef CONFIG_FLASH_LOG - /** - * Log stall only first time. Placing it after TRNG - * go_event increase a chance to get random in case - * of slow TRNG. - */ - if (reset_count == 1) - fips_vtable->flash_log_add_event( - FE_LOG_TRNG_STALL, 0, NULL); -#endif } empty_count++; } +#ifdef CONFIG_FLASH_LOG + /* Log stall count if happened .*/ + if (reset_count > 0) + fips_vtable->flash_log_add_event( + FE_LOG_TRNG_STALL, sizeof(reset_count), &reset_count); +#endif /** * High 32-bits set to zero in case of error; * otherwise value >> 32 == 1 |