/* * Copyright (c) 2013-2014, ARM Limited and Contributors. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * Redistributions of source code must retain the above copyright notice, this * list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above copyright notice, * this list of conditions and the following disclaimer in the documentation * and/or other materials provided with the distribution. * * Neither the name of ARM nor the names of its contributors may be used * to endorse or promote products derived from this software without specific * prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ #include #include #include .globl bl31_entrypoint /* ----------------------------------------------------- * bl31_entrypoint() is the cold boot entrypoint, * executed only by the primary cpu. * ----------------------------------------------------- */ func bl31_entrypoint /* --------------------------------------------------------------- * Preceding bootloader has populated x0 with a pointer to a * 'bl31_params' structure & x1 with a pointer to platform * specific structure * --------------------------------------------------------------- */ #if !RESET_TO_BL31 mov x20, x0 mov x21, x1 #else /* --------------------------------------------- * Set the CPU endianness before doing anything * that might involve memory reads or writes. * --------------------------------------------- */ mrs x0, sctlr_el3 bic x0, x0, #SCTLR_EE_BIT msr sctlr_el3, x0 isb /* ----------------------------------------------------- * Perform any processor specific actions upon reset * e.g. cache, tlb invalidations etc. Override the * Boot ROM(BL0) programming sequence * ----------------------------------------------------- */ bl cpu_reset_handler #endif /* --------------------------------------------- * Enable the instruction cache, stack pointer * and data access alignment checks * --------------------------------------------- */ mov x1, #(SCTLR_I_BIT | SCTLR_A_BIT | SCTLR_SA_BIT) mrs x0, sctlr_el3 orr x0, x0, x1 msr sctlr_el3, x0 isb /* --------------------------------------------- * Initialise cpu_data early to enable crash * reporting to have access to crash stack. * Since crash reporting depends on cpu_data to * report the unhandled exception, not * doing so can lead to recursive exceptions due * to a NULL TPIDR_EL3 * --------------------------------------------- */ bl init_cpu_data_ptr /* --------------------------------------------- * Set the exception vector. * --------------------------------------------- */ adr x1, runtime_exceptions msr vbar_el3, x1 /* --------------------------------------------------------------------- * The initial state of the Architectural feature trap register * (CPTR_EL3) is unknown and it must be set to a known state. All * feature traps are disabled. Some bits in this register are marked as * Reserved and should not be modified. * * CPTR_EL3.TCPAC: This causes a direct access to the CPACR_EL1 from EL1 * or the CPTR_EL2 from EL2 to trap to EL3 unless it is trapped at EL2. * CPTR_EL3.TTA: This causes access to the Trace functionality to trap * to EL3 when executed from EL0, EL1, EL2, or EL3. If system register * access to trace functionality is not supported, this bit is RES0. * CPTR_EL3.TFP: This causes instructions that access the registers * associated with Floating Point and Advanced SIMD execution to trap * to EL3 when executed from any exception level, unless trapped to EL1 * or EL2. * --------------------------------------------------------------------- */ mrs x1, cptr_el3 bic w1, w1, #TCPAC_BIT bic w1, w1, #TTA_BIT bic w1, w1, #TFP_BIT msr cptr_el3, x1 #if RESET_TO_BL31 /* ------------------------------------------------------- * Will not return from this macro if it is a warm boot. * ------------------------------------------------------- */ wait_for_entrypoint bl platform_mem_init #else /* --------------------------------------------- * This is BL31 which is expected to be executed * only by the primary cpu (at least for now). * So, make sure no secondary has lost its way. * --------------------------------------------- */ mrs x0, mpidr_el1 bl platform_is_primary_cpu cbz x0, _panic #endif /* --------------------------------------------- * Zero out NOBITS sections. There are 2 of them: * - the .bss section; * - the coherent memory section. * --------------------------------------------- */ ldr x0, =__BSS_START__ ldr x1, =__BSS_SIZE__ bl zeromem16 ldr x0, =__COHERENT_RAM_START__ ldr x1, =__COHERENT_RAM_UNALIGNED_SIZE__ bl zeromem16 /* --------------------------------------------- * Use SP_EL0 for the C runtime stack. * --------------------------------------------- */ msr spsel, #0 /* -------------------------------------------- * Allocate a stack whose memory will be marked * as Normal-IS-WBWA when the MMU is enabled. * There is no risk of reading stale stack * memory after enabling the MMU as only the * primary cpu is running at the moment. * -------------------------------------------- */ mrs x0, mpidr_el1 bl platform_set_stack /* --------------------------------------------- * Perform platform specific early arch. setup * --------------------------------------------- */ #if RESET_TO_BL31 mov x0, 0 mov x1, 0 #else mov x0, x20 mov x1, x21 #endif bl bl31_early_platform_setup bl bl31_plat_arch_setup /* --------------------------------------------- * Jump to main function. * --------------------------------------------- */ bl bl31_main b el3_exit _panic: wfi b _panic