blob: 236eb5ba37d2582345d72cb88faa4f9dd904d2b5 [file] [log] [blame]
/*
* Copyright (c) 2017, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <arch_helpers.h>
#include <common/debug.h>
#include <lib/utils.h>
#include <platform_def.h>
#include "juno_decl.h"
u_register_t plat_get_stack_protector_canary(void)
{
u_register_t c[TRNG_NBYTES / sizeof(u_register_t)];
u_register_t ret = 0;
size_t i;
if (juno_getentropy(c, sizeof(c)) != 0) {
ERROR("Not enough entropy to initialize canary value\n");
panic();
}
/*
* On Juno we get 128-bits of entropy in one round.
* Fuse the values together to form the canary.
*/
for (i = 0; i < ARRAY_SIZE(c); i++)
ret ^= c[i];
return ret;
}