/* * Copyright (c) 2013-2019, ARM Limited and Contributors. All rights reserved. * * SPDX-License-Identifier: BSD-3-Clause */ #include #include #include #include #include #include #include .globl bl31_entrypoint .globl bl31_warm_entrypoint /* ----------------------------------------------------- * bl31_entrypoint() is the cold boot entrypoint, * executed only by the primary cpu. * ----------------------------------------------------- */ func bl31_entrypoint #if !RESET_TO_BL31 /* --------------------------------------------------------------- * Stash the previous bootloader arguments x0 - x3 for later use. * --------------------------------------------------------------- */ mov x20, x0 mov x21, x1 mov x22, x2 mov x23, x3 /* --------------------------------------------------------------------- * For !RESET_TO_BL31 systems, only the primary CPU ever reaches * bl31_entrypoint() during the cold boot flow, so the cold/warm boot * and primary/secondary CPU logic should not be executed in this case. * * Also, assume that the previous bootloader has already initialised the * SCTLR_EL3, including the endianness, and has initialised the memory. * --------------------------------------------------------------------- */ el3_entrypoint_common \ _init_sctlr=0 \ _warm_boot_mailbox=0 \ _secondary_cold_boot=0 \ _init_memory=0 \ _init_c_runtime=1 \ _exception_vectors=runtime_exceptions #else /* --------------------------------------------------------------------- * For RESET_TO_BL31 systems which have a programmable reset address, * bl31_entrypoint() is executed only on the cold boot path so we can * skip the warm boot mailbox mechanism. * --------------------------------------------------------------------- */ el3_entrypoint_common \ _init_sctlr=1 \ _warm_boot_mailbox=!PROGRAMMABLE_RESET_ADDRESS \ _secondary_cold_boot=!COLD_BOOT_SINGLE_CPU \ _init_memory=1 \ _init_c_runtime=1 \ _exception_vectors=runtime_exceptions /* --------------------------------------------------------------------- * For RESET_TO_BL31 systems, BL31 is the first bootloader to run so * there's no argument to relay from a previous bootloader. Zero the * arguments passed to the platform layer to reflect that. * --------------------------------------------------------------------- */ mov x20, 0 mov x21, 0 mov x22, 0 mov x23, 0 #endif /* RESET_TO_BL31 */ /* -------------------------------------------------------------------- * If PIE is enabled, fixup the Global descriptor Table and dynamic * relocations * -------------------------------------------------------------------- */ #if ENABLE_PIE mov_imm x0, BL31_BASE mov_imm x1, BL31_LIMIT bl fixup_gdt_reloc #endif /* ENABLE_PIE */ /* -------------------------------------------------------------------- * Perform BL31 setup * -------------------------------------------------------------------- */ mov x0, x20 mov x1, x21 mov x2, x22 mov x3, x23 bl bl31_setup /* -------------------------------------------------------------------- * Enable pointer authentication * -------------------------------------------------------------------- */ #if ENABLE_PAUTH mrs x0, sctlr_el3 orr x0, x0, #SCTLR_EnIA_BIT msr sctlr_el3, x0 isb #endif /* ENABLE_PAUTH */ /* -------------------------------------------------------------------- * Jump to main function. * -------------------------------------------------------------------- */ bl bl31_main /* -------------------------------------------------------------------- * Clean the .data & .bss sections to main memory. This ensures * that any global data which was initialised by the primary CPU * is visible to secondary CPUs before they enable their data * caches and participate in coherency. * -------------------------------------------------------------------- */ adr x0, __DATA_START__ adr x1, __DATA_END__ sub x1, x1, x0 bl clean_dcache_range adr x0, __BSS_START__ adr x1, __BSS_END__ sub x1, x1, x0 bl clean_dcache_range b el3_exit endfunc bl31_entrypoint /* -------------------------------------------------------------------- * This CPU has been physically powered up. It is either resuming from * suspend or has simply been turned on. In both cases, call the BL31 * warmboot entrypoint * -------------------------------------------------------------------- */ func bl31_warm_entrypoint #if ENABLE_RUNTIME_INSTRUMENTATION /* * This timestamp update happens with cache off. The next * timestamp collection will need to do cache maintenance prior * to timestamp update. */ pmf_calc_timestamp_addr rt_instr_svc, RT_INSTR_EXIT_HW_LOW_PWR mrs x1, cntpct_el0 str x1, [x0] #endif /* * On the warm boot path, most of the EL3 initialisations performed by * 'el3_entrypoint_common' must be skipped: * * - Only when the platform bypasses the BL1/BL31 entrypoint by * programming the reset address do we need to initialise SCTLR_EL3. * In other cases, we assume this has been taken care by the * entrypoint code. * * - No need to determine the type of boot, we know it is a warm boot. * * - Do not try to distinguish between primary and secondary CPUs, this * notion only exists for a cold boot. * * - No need to initialise the memory or the C runtime environment, * it has been done once and for all on the cold boot path. */ el3_entrypoint_common \ _init_sctlr=PROGRAMMABLE_RESET_ADDRESS \ _warm_boot_mailbox=0 \ _secondary_cold_boot=0 \ _init_memory=0 \ _init_c_runtime=0 \ _exception_vectors=runtime_exceptions /* * We're about to enable MMU and participate in PSCI state coordination. * * The PSCI implementation invokes platform routines that enable CPUs to * participate in coherency. On a system where CPUs are not * cache-coherent without appropriate platform specific programming, * having caches enabled until such time might lead to coherency issues * (resulting from stale data getting speculatively fetched, among * others). Therefore we keep data caches disabled even after enabling * the MMU for such platforms. * * On systems with hardware-assisted coherency, or on single cluster * platforms, such platform specific programming is not required to * enter coherency (as CPUs already are); and there's no reason to have * caches disabled either. */ #if HW_ASSISTED_COHERENCY || WARMBOOT_ENABLE_DCACHE_EARLY mov x0, xzr #else mov x0, #DISABLE_DCACHE #endif bl bl31_plat_enable_mmu bl psci_warmboot_entrypoint #if ENABLE_RUNTIME_INSTRUMENTATION pmf_calc_timestamp_addr rt_instr_svc, RT_INSTR_EXIT_PSCI mov x19, x0 /* * Invalidate before updating timestamp to ensure previous timestamp * updates on the same cache line with caches disabled are properly * seen by the same core. Without the cache invalidate, the core might * write into a stale cache line. */ mov x1, #PMF_TS_SIZE mov x20, x30 bl inv_dcache_range mov x30, x20 mrs x0, cntpct_el0 str x0, [x19] #endif b el3_exit endfunc bl31_warm_entrypoint