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 <arch_helpers.h> 33 #include <assert.h> 34 #include <bl_common.h> 35 #include <bl31.h> 36 #include <context_mgmt.h> 37 #include <platform.h> 38 #include <runtime_svc.h> 39 #include <stdio.h> 40 #include <string.h> 41 42 /******************************************************************************* 43 * This function pointer is used to initialise the BL32 image. It's initialized 44 * by SPD calling bl31_register_bl32_init after setting up all things necessary 45 * for SP execution. In cases where both SPD and SP are absent, or when SPD 46 * finds it impossible to execute SP, this pointer is left as NULL 47 ******************************************************************************/ 48 static int32_t (*bl32_init)(void); 49 50 /******************************************************************************* 51 * Variable to indicate whether next image to execute after BL31 is BL33 52 * (non-secure & default) or BL32 (secure). 53 ******************************************************************************/ 54 static uint32_t next_image_type; 55 56 /******************************************************************************* 57 * Simple function to initialise all BL31 helper libraries. 58 ******************************************************************************/ 59 void bl31_lib_init() 60 { 61 cm_init(); 62 } 63 64 /******************************************************************************* 65 * BL31 is responsible for setting up the runtime services for the primary cpu 66 * before passing control to the bootloader or an Operating System. This 67 * function calls runtime_svc_init() which initializes all registered runtime 68 * services. The run time services would setup enough context for the core to 69 * swtich to the next exception level. When this function returns, the core will 70 * switch to the programmed exception level via. an ERET. 71 ******************************************************************************/ 72 void bl31_main(void) 73 { 74 /* Perform remaining generic architectural setup from EL3 */ 75 bl31_arch_setup(); 76 77 /* Perform platform setup in BL1 */ 78 bl31_platform_setup(); 79 80 printf("BL31 %s\n\r", build_message); 81 82 /* Initialise helper libraries */ 83 bl31_lib_init(); 84 85 /* Initialize the runtime services e.g. psci */ 86 runtime_svc_init(); 87 88 /* Clean caches before re-entering normal world */ 89 dcsw_op_all(DCCSW); 90 91 /* By default run the non-secure BL3-3 image next */ 92 next_image_type = NON_SECURE; 93 94 /* 95 * All the cold boot actions on the primary cpu are done. We now need to 96 * decide which is the next image (BL32 or BL33) and how to execute it. 97 * If the SPD runtime service is present, it would want to pass control 98 * to BL32 first in S-EL1. In that case, SPD would have registered a 99 * function to intialize bl32 where it takes responsibility of entering 100 * S-EL1 and returning control back to bl31_main. Once this is done we 101 * can prepare entry into BL33 as normal. 102 */ 103 104 /* 105 * If SPD had registerd an init hook, invoke it. 106 */ 107 if (bl32_init) 108 (*bl32_init)(); 109 110 /* 111 * We are ready to enter the next EL. Prepare entry into the image 112 * corresponding to the desired security state after the next ERET. 113 */ 114 bl31_prepare_next_image_entry(); 115 } 116 117 /******************************************************************************* 118 * Accessor functions to help runtime services decide which image should be 119 * executed after BL31. This is BL33 or the non-secure bootloader image by 120 * default but the Secure payload dispatcher could override this by requesting 121 * an entry into BL32 (Secure payload) first. If it does so then it should use 122 * the same API to program an entry into BL33 once BL32 initialisation is 123 * complete. 124 ******************************************************************************/ 125 void bl31_set_next_image_type(uint32_t security_state) 126 { 127 assert(security_state == NON_SECURE || security_state == SECURE); 128 next_image_type = security_state; 129 } 130 131 uint32_t bl31_get_next_image_type(void) 132 { 133 return next_image_type; 134 } 135 136 /******************************************************************************* 137 * This function programs EL3 registers and performs other setup to enable entry 138 * into the next image after BL31 at the next ERET. 139 ******************************************************************************/ 140 void bl31_prepare_next_image_entry() 141 { 142 entry_point_info_t *next_image_info; 143 uint32_t scr, image_type; 144 cpu_context_t *ctx; 145 gp_regs_t *gp_regs; 146 147 /* Determine which image to execute next */ 148 image_type = bl31_get_next_image_type(); 149 150 /* 151 * Setup minimal architectural state of the next highest EL to 152 * allow execution in it immediately upon entering it. 153 */ 154 bl31_next_el_arch_setup(image_type); 155 156 /* Program EL3 registers to enable entry into the next EL */ 157 next_image_info = bl31_plat_get_next_image_ep_info(image_type); 158 assert(next_image_info); 159 assert(image_type == GET_SECURITY_STATE(next_image_info->h.attr)); 160 161 scr = read_scr(); 162 scr &= ~SCR_NS_BIT; 163 if (image_type == NON_SECURE) 164 scr |= SCR_NS_BIT; 165 166 scr &= ~SCR_RW_BIT; 167 if ((next_image_info->spsr & (1 << MODE_RW_SHIFT)) == 168 (MODE_RW_64 << MODE_RW_SHIFT)) 169 scr |= SCR_RW_BIT; 170 171 /* 172 * Tell the context mgmt. library to ensure that SP_EL3 points to 173 * the right context to exit from EL3 correctly. 174 */ 175 cm_set_el3_eret_context(image_type, 176 next_image_info->pc, 177 next_image_info->spsr, 178 scr); 179 180 /* 181 * Save the args generated in BL2 for the image in the right context 182 * used on its entry 183 */ 184 ctx = cm_get_context(image_type); 185 gp_regs = get_gpregs_ctx(ctx); 186 memcpy(gp_regs, (void *)&next_image_info->args, sizeof(aapcs64_params_t)); 187 188 /* Finally set the next context */ 189 cm_set_next_eret_context(image_type); 190 } 191 192 /******************************************************************************* 193 * This function initializes the pointer to BL32 init function. This is expected 194 * to be called by the SPD after it finishes all its initialization 195 ******************************************************************************/ 196 void bl31_register_bl32_init(int32_t (*func)(void)) 197 { 198 bl32_init = func; 199 } 200