mirror of
https://github.com/Telecominfraproject/OpenCellular.git
synced 2025-12-31 02:51:26 +00:00
097c2bb04c
* Include trng.h from trng.c before any other header to verify that the header is self-contained. * Add inclusion of stdint.h to trng.h to provide definition for uint32_t. BUG=none BRANCH=none TEST=make -j buildall Change-Id: I78fb6d915c357236ca0fed2a57f093f0eec07fe9 Reviewed-on: https://chromium-review.googlesource.com/417424 Commit-Ready: Carl Hamilton <carlh@chromium.org> Tested-by: Carl Hamilton <carlh@chromium.org> Reviewed-by: Vadim Bendebury <vbendeb@chromium.org>
67 lines
1.7 KiB
C
67 lines
1.7 KiB
C
/* 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 "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_TIMEOUT)) {
|
|
/* TRNG timed out, restart */
|
|
GWRITE(TRNG, STOP_WORK, 1);
|
|
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);
|
|
}
|
|
}
|