common: move chip agnostic trng code from stm32 to common

Making this change causes common trng functions to move memory
locations. This change only affects fingerprint (FPMCU) boards

BUG=b:280889889
TEST=make BOARD=bloonchipper, CONFIG_CMD_RAND enabled in board.h
     ALLOW_CONFIG=1 ./util/compare_build.sh -b all
 => All boards match, except the following Fingerprint boards:
        bloonchipper
	dartmonkey
	hatch_fp
	nami_fp
	nocturne_fp
	nucleo-dartmonkey

Change-Id: I4dbb5e255be0f61eb7b446af4565bea487c08e52
Signed-off-by: David Cross <davidmcross@google.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/4507892
Reviewed-by: Bobby Casey <bobbycasey@google.com>

2 files changed, 6 insertions, 70 deletions

diff --git a/chip/host/trng.c b/chip/host/trng.c
index d0def66277..f67dd6c4db 100644
--- a/chip/host/trng.c
+++ b/chip/host/trng.c
@@ -31,6 +31,11 @@ test_mockable void trng_exit(void)
 {
 }
 
+test_mockable uint32_t trng_rand(void)
+{
+	return (uint32_t)rand_r(&seed);
+}
+
 test_mockable void trng_rand_bytes(void *buffer, size_t len)
 {
 	uint8_t *b, *end;
diff --git a/chip/stm32/trng.c b/chip/stm32/trng.c
index 67d3700cf1..63641741d3 100644
--- a/chip/stm32/trng.c
+++ b/chip/stm32/trng.c
@@ -16,7 +16,7 @@
 #include "trng.h"
 #include "util.h"
 
-static uint32_t trng_rand(void)
+uint32_t trng_rand(void)
 {
 	int tries = 300;
 	/* Wait for a valid random number */
@@ -29,25 +29,6 @@ static uint32_t trng_rand(void)
 	return STM32_RNG_DR;
 }
 
-test_mockable void trng_rand_bytes(void *buffer, size_t len)
-{
-	while (len) {
-		uint32_t number = trng_rand();
-		size_t cnt = 4;
-		/* deal with the lack of alignment guarantee in the API */
-		uintptr_t align = (uintptr_t)buffer & 3;
-
-		if (len < 4 || align) {
-			cnt = MIN(4 - align, len);
-			memcpy(buffer, &number, cnt);
-		} else {
-			*(uint32_t *)buffer = number;
-		}
-		len -= cnt;
-		buffer += cnt;
-	}
-}
-
 test_mockable void trng_init(void)
 {
 #ifdef CHIP_FAMILY_STM32L4
@@ -97,53 +78,3 @@ test_mockable void trng_exit(void)
 	/* Nothing to do */
 #endif
 }
-
-#if defined(CONFIG_CMD_RAND)
-/*
- * We want to avoid accidentally exposing debug commands in RO since we can't
- * update RO once in production.
- */
-#if defined(SECTION_IS_RW)
-static int command_rand(int argc, const char **argv)
-{
-	uint8_t data[32];
-	char str_buf[hex_str_buf_size(sizeof(data))];
-
-	trng_init();
-	trng_rand_bytes(data, sizeof(data));
-	trng_exit();
-
-	snprintf_hex_buffer(str_buf, sizeof(str_buf),
-			    HEX_BUF(data, sizeof(data)));
-	ccprintf("rand %s\n", str_buf);
-
-	return EC_SUCCESS;
-}
-DECLARE_CONSOLE_COMMAND(rand, command_rand, NULL,
-			"Output random bytes to console.");
-
-static enum ec_status host_command_rand(struct host_cmd_handler_args *args)
-{
-	const struct ec_params_rand_num *p = args->params;
-	struct ec_response_rand_num *r = args->response;
-	uint16_t num_rand_bytes = p->num_rand_bytes;
-
-	if (system_is_locked())
-		return EC_RES_ACCESS_DENIED;
-
-	if (num_rand_bytes > args->response_max)
-		return EC_RES_OVERFLOW;
-
-	trng_init();
-	trng_rand_bytes(r->rand, num_rand_bytes);
-	trng_exit();
-
-	args->response_size = num_rand_bytes;
-
-	return EC_SUCCESS;
-}
-
-DECLARE_HOST_COMMAND(EC_CMD_RAND_NUM, host_command_rand,
-		     EC_VER_MASK(EC_VER_RAND_NUM));
-#endif /* SECTION_IS_RW */
-#endif /* CONFIG_CMD_RAND */