1 /* 2 * Copyright (c) 2020, NVIDIA Corporation. All rights reserved. 3 * 4 * SPDX-License-Identifier: BSD-3-Clause 5 */ 6 7 #include <stdint.h> 8 9 #include <arch_helpers.h> 10 #include <lib/mmio.h> 11 #include <plat/common/platform.h> 12 #include <platform_def.h> 13 plat_get_stack_protector_canary(void)14u_register_t plat_get_stack_protector_canary(void) 15 { 16 u_register_t seed; 17 18 /* 19 * Ideally, a random number should be returned instead. As the 20 * platform does not have any random number generator, this is 21 * better than nothing, but not really secure. 22 */ 23 seed = mmio_read_32(TEGRA_MISC_BASE + HARDWARE_REVISION_OFFSET); 24 seed <<= 32; 25 seed |= mmio_read_32(TEGRA_TMRUS_BASE); 26 27 return seed ^ read_cntpct_el0(); 28 } 29