1 /*
2  * Copyright (c) 2017, ARM Limited and Contributors. All rights reserved.
3  *
4  * SPDX-License-Identifier: BSD-3-Clause
5  */
6 
7 #include <arch_helpers.h>
8 #include <common/debug.h>
9 #include <lib/utils.h>
10 #include <plat/common/plat_trng.h>
11 #include <platform_def.h>
12 
plat_get_stack_protector_canary(void)13 u_register_t plat_get_stack_protector_canary(void)
14 {
15 	uint64_t entropy;
16 
17 	if (!plat_get_entropy(&entropy)) {
18 		ERROR("Not enough entropy to initialize canary value\n");
19 		panic();
20 	}
21 
22 	if (sizeof(entropy) == sizeof(u_register_t)) {
23 		return entropy;
24 	}
25 
26 	return (entropy & 0xffffffffULL) ^ (entropy >> 32);
27 }
28