1/* 2 * Copyright (c) 2013-2014, ARM Limited and Contributors. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions are met: 6 * 7 * Redistributions of source code must retain the above copyright notice, this 8 * list of conditions and the following disclaimer. 9 * 10 * Redistributions in binary form must reproduce the above copyright notice, 11 * this list of conditions and the following disclaimer in the documentation 12 * and/or other materials provided with the distribution. 13 * 14 * Neither the name of ARM nor the names of its contributors may be used 15 * to endorse or promote products derived from this software without specific 16 * prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 19 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE 22 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 28 * POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31#include <arch.h> 32#include <asm_macros.S> 33#include <bl_common.h> 34 35 .globl bl31_entrypoint 36 37 38 /* ----------------------------------------------------- 39 * bl31_entrypoint() is the cold boot entrypoint, 40 * executed only by the primary cpu. 41 * ----------------------------------------------------- 42 */ 43 44func bl31_entrypoint 45 /* --------------------------------------------------------------- 46 * Preceding bootloader has populated x0 with a pointer to a 47 * 'bl31_params' structure & x1 with a pointer to platform 48 * specific structure 49 * --------------------------------------------------------------- 50 */ 51#if !RESET_TO_BL31 52 mov x20, x0 53 mov x21, x1 54#else 55 /* --------------------------------------------- 56 * Set the CPU endianness before doing anything 57 * that might involve memory reads or writes. 58 * --------------------------------------------- 59 */ 60 mrs x0, sctlr_el3 61 bic x0, x0, #SCTLR_EE_BIT 62 msr sctlr_el3, x0 63 isb 64 65 /* ----------------------------------------------------- 66 * Perform any processor specific actions upon reset 67 * e.g. cache, tlb invalidations etc. Override the 68 * Boot ROM(BL0) programming sequence 69 * ----------------------------------------------------- 70 */ 71 bl cpu_reset_handler 72#endif 73 /* --------------------------------------------- 74 * Enable the instruction cache, stack pointer 75 * and data access alignment checks 76 * --------------------------------------------- 77 */ 78 mov x1, #(SCTLR_I_BIT | SCTLR_A_BIT | SCTLR_SA_BIT) 79 mrs x0, sctlr_el3 80 orr x0, x0, x1 81 msr sctlr_el3, x0 82 isb 83 84 /* --------------------------------------------- 85 * Initialise cpu_data early to enable crash 86 * reporting to have access to crash stack. 87 * Since crash reporting depends on cpu_data to 88 * report the unhandled exception, not 89 * doing so can lead to recursive exceptions due 90 * to a NULL TPIDR_EL3 91 * --------------------------------------------- 92 */ 93 bl init_cpu_data_ptr 94 95 /* --------------------------------------------- 96 * Set the exception vector. 97 * --------------------------------------------- 98 */ 99 adr x1, runtime_exceptions 100 msr vbar_el3, x1 101 102 /* --------------------------------------------------------------------- 103 * The initial state of the Architectural feature trap register 104 * (CPTR_EL3) is unknown and it must be set to a known state. All 105 * feature traps are disabled. Some bits in this register are marked as 106 * Reserved and should not be modified. 107 * 108 * CPTR_EL3.TCPAC: This causes a direct access to the CPACR_EL1 from EL1 109 * or the CPTR_EL2 from EL2 to trap to EL3 unless it is trapped at EL2. 110 * CPTR_EL3.TTA: This causes access to the Trace functionality to trap 111 * to EL3 when executed from EL0, EL1, EL2, or EL3. If system register 112 * access to trace functionality is not supported, this bit is RES0. 113 * CPTR_EL3.TFP: This causes instructions that access the registers 114 * associated with Floating Point and Advanced SIMD execution to trap 115 * to EL3 when executed from any exception level, unless trapped to EL1 116 * or EL2. 117 * --------------------------------------------------------------------- 118 */ 119 mrs x1, cptr_el3 120 bic w1, w1, #TCPAC_BIT 121 bic w1, w1, #TTA_BIT 122 bic w1, w1, #TFP_BIT 123 msr cptr_el3, x1 124 125#if RESET_TO_BL31 126 /* ------------------------------------------------------- 127 * Will not return from this macro if it is a warm boot. 128 * ------------------------------------------------------- 129 */ 130 wait_for_entrypoint 131 bl platform_mem_init 132#else 133 /* --------------------------------------------- 134 * This is BL31 which is expected to be executed 135 * only by the primary cpu (at least for now). 136 * So, make sure no secondary has lost its way. 137 * --------------------------------------------- 138 */ 139 mrs x0, mpidr_el1 140 bl platform_is_primary_cpu 141 cbz x0, _panic 142#endif 143 144 /* --------------------------------------------- 145 * Zero out NOBITS sections. There are 2 of them: 146 * - the .bss section; 147 * - the coherent memory section. 148 * --------------------------------------------- 149 */ 150 ldr x0, =__BSS_START__ 151 ldr x1, =__BSS_SIZE__ 152 bl zeromem16 153 154 ldr x0, =__COHERENT_RAM_START__ 155 ldr x1, =__COHERENT_RAM_UNALIGNED_SIZE__ 156 bl zeromem16 157 158 /* --------------------------------------------- 159 * Use SP_EL0 for the C runtime stack. 160 * --------------------------------------------- 161 */ 162 msr spsel, #0 163 164 /* -------------------------------------------- 165 * Allocate a stack whose memory will be marked 166 * as Normal-IS-WBWA when the MMU is enabled. 167 * There is no risk of reading stale stack 168 * memory after enabling the MMU as only the 169 * primary cpu is running at the moment. 170 * -------------------------------------------- 171 */ 172 mrs x0, mpidr_el1 173 bl platform_set_stack 174 175 /* --------------------------------------------- 176 * Perform platform specific early arch. setup 177 * --------------------------------------------- 178 */ 179#if RESET_TO_BL31 180 mov x0, 0 181 mov x1, 0 182#else 183 mov x0, x20 184 mov x1, x21 185#endif 186 187 bl bl31_early_platform_setup 188 bl bl31_plat_arch_setup 189 190 /* --------------------------------------------- 191 * Jump to main function. 192 * --------------------------------------------- 193 */ 194 bl bl31_main 195 196 b el3_exit 197 198_panic: 199 wfi 200 b _panic 201