diff options
Diffstat (limited to 'chip/g/trng.c')
| -rw-r--r-- | chip/g/trng.c | 170 |
1 files changed, 0 insertions, 170 deletions
diff --git a/chip/g/trng.c b/chip/g/trng.c deleted file mode 100644 index afd9fa86e3..0000000000 --- a/chip/g/trng.c +++ /dev/null @@ -1,170 +0,0 @@ -/* Copyright 2015 The Chromium OS Authors. All rights reserved. - * Use of this source code is governed by a BSD-style license that can be - * found in the LICENSE file. - */ - -#include "common.h" -#include "flash_log.h" -#include "init_chip.h" -#include "registers.h" -#include "trng.h" - -void init_trng(void) -{ -#if (!(defined(CONFIG_CUSTOMIZED_RO) && defined(SECTION_IS_RO))) - /* - * Most of the trng initialization requires high permissions. If RO has - * dropped the permission level, dont try to read or write these high - * permission registers because it will cause rolling reboots. RO - * should do the TRNG initialization before dropping the level. - */ - if (!runlevel_is_high()) - return; -#endif - - GWRITE(TRNG, POST_PROCESSING_CTRL, - GC_TRNG_POST_PROCESSING_CTRL_SHUFFLE_BITS_MASK | - GC_TRNG_POST_PROCESSING_CTRL_CHURN_MODE_MASK); - GWRITE(TRNG, SLICE_MAX_UPPER_LIMIT, 1); - GWRITE(TRNG, SLICE_MIN_LOWER_LIMIT, 0); - GWRITE(TRNG, TIMEOUT_COUNTER, 0x7ff); - GWRITE(TRNG, TIMEOUT_MAX_TRY_NUM, 4); - GWRITE(TRNG, POWER_DOWN_B, 1); - GWRITE(TRNG, GO_EVENT, 1); -} - -uint32_t rand(void) -{ - while (GREAD(TRNG, EMPTY)) { - if (GREAD_FIELD(TRNG, FSM_STATE, FSM_IDLE)) { - /* TRNG timed out, restart */ - GWRITE(TRNG, STOP_WORK, 1); -#if !defined(SECTION_IS_RO) && defined(CONFIG_FLASH_LOG) - flash_log_add_event(FE_LOG_TRNG_STALL, 0, NULL); -#endif - GWRITE(TRNG, GO_EVENT, 1); - } - } - return GREAD(TRNG, READ_DATA); -} - -void rand_bytes(void *buffer, size_t len) -{ - int random_togo = 0; - int buffer_index = 0; - uint32_t random_value; - uint8_t *buf = (uint8_t *) buffer; - - /* - * Retrieve random numbers in 4 byte quantities and pack as many bytes - * as needed into 'buffer'. If len is not divisible by 4, the - * remaining random bytes get dropped. - */ - while (buffer_index < len) { - if (!random_togo) { - random_value = rand(); - random_togo = sizeof(random_value); - } - buf[buffer_index++] = random_value >> - ((random_togo-- - 1) * 8); - } -} - -#if !defined(SECTION_IS_RO) && defined(TEST_TRNG) -#include "console.h" -#include "watchdog.h" - -static uint32_t histogram[256]; -static int command_rand(int argc, char **argv) -{ - int count = 1000; /* Default number of cycles. */ - struct pair { - uint32_t value; - uint32_t count; - }; - struct pair min; - struct pair max; - - if (argc == 2) - count = strtoi(argv[1], NULL, 10); - - memset(histogram, 0, sizeof(histogram)); - ccprintf("Retrieving %d random words.\n", count); - while (count-- > 0) { - uint32_t rvalue; - int size; - - rvalue = rand(); - for (size = 0; size < sizeof(rvalue); size++) - histogram[((uint8_t *)&rvalue)[size]]++; - - if (!(count % 10000)) - watchdog_reload(); - } - - min.count = ~0; - max.count = 0; - for (count = 0; count < ARRAY_SIZE(histogram); count++) { - if (histogram[count] > max.count) { - max.count = histogram[count]; - max.value = count; - continue; - } - if (histogram[count] >= min.count) - continue; - - min.count = histogram[count]; - min.value = count; - } - - ccprintf("min %d(%d), max %d(%d)", min.count, min.value, - max.count, max.value); - - for (count = 0; count < ARRAY_SIZE(histogram); count++) { - if (!(count % 8)) { - ccprintf("\n"); - cflush(); - } - ccprintf(" %6d", histogram[count]); - } - ccprintf("\n"); - return EC_SUCCESS; -} -DECLARE_CONSOLE_COMMAND(rand, command_rand, NULL, NULL); -#endif /* !defined(SECTION_IS_RO) && defined(TEST_TRNG) */ - -#ifdef CRYPTO_TEST_SETUP -#include "extension.h" -/* - * This extension command is similar to TPM2_GetRandom, but made - * available for CRYPTO_TEST = 1 which disables TPM - * Command structure, shared out of band with the test driver running - * on the host: - * - * field | size | note - * =================================================================== - * text_len | 2 | size of the text to process, big endian - */ -static enum vendor_cmd_rc trng_test(enum vendor_cmd_cc code, void *buf, - size_t input_size, size_t *response_size) -{ - uint16_t text_len; - uint8_t *cmd; - size_t response_room = *response_size; - - if (input_size != sizeof(text_len)) { - *response_size = 0; - return VENDOR_RC_BOGUS_ARGS; - } - cmd = buf; - text_len = *cmd++; - text_len = text_len * 256 + *cmd++; - text_len = MIN(text_len, response_room); - rand_bytes(buf, text_len); - *response_size = text_len; - return VENDOR_RC_SUCCESS; -} - -DECLARE_VENDOR_COMMAND(VENDOR_CC_TRNG_TEST, trng_test); - -#endif /* CRYPTO_TEST_SETUP */ |