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 <runtime_svc.h> 38 #include <stdio.h> 39 40 41 /******************************************************************************* 42 * This function pointer is used to initialise the BL32 image. It's initialized 43 * by SPD calling bl31_register_bl32_init after setting up all things necessary 44 * for SP execution. In cases where both SPD and SP are absent, or when SPD 45 * finds it impossible to execute SP, this pointer is left as NULL 46 ******************************************************************************/ 47 static int32_t (*bl32_init)(meminfo_t *); 48 49 /******************************************************************************* 50 * Variable to indicate whether next image to execute after BL31 is BL33 51 * (non-secure & default) or BL32 (secure). 52 ******************************************************************************/ 53 static uint32_t next_image_type = NON_SECURE; 54 55 /******************************************************************************* 56 * Simple function to initialise all BL31 helper libraries. 57 ******************************************************************************/ 58 void bl31_lib_init() 59 { 60 cm_init(); 61 } 62 63 /******************************************************************************* 64 * BL31 is responsible for setting up the runtime services for the primary cpu 65 * before passing control to the bootloader or an Operating System. This 66 * function calls runtime_svc_init() which initializes all registered runtime 67 * services. The run time services would setup enough context for the core to 68 * swtich to the next exception level. When this function returns, the core will 69 * switch to the programmed exception level via. an ERET. 70 ******************************************************************************/ 71 void bl31_main(void) 72 { 73 #if DEBUG 74 unsigned long mpidr = read_mpidr(); 75 #endif 76 77 /* Perform remaining generic architectural setup from EL3 */ 78 bl31_arch_setup(); 79 80 /* Perform platform setup in BL1 */ 81 bl31_platform_setup(); 82 83 printf("BL31 %s\n\r", build_message); 84 85 /* Initialise helper libraries */ 86 bl31_lib_init(); 87 88 /* Initialize the runtime services e.g. psci */ 89 runtime_svc_init(); 90 91 /* Clean caches before re-entering normal world */ 92 dcsw_op_all(DCCSW); 93 94 /* 95 * Use the more complex exception vectors now that context 96 * management is setup. SP_EL3 should point to a 'cpu_context' 97 * structure which has an exception stack allocated. The PSCI 98 * service should have set the context. 99 */ 100 assert(cm_get_context(mpidr, NON_SECURE)); 101 cm_set_next_eret_context(NON_SECURE); 102 write_vbar_el3((uint64_t) runtime_exceptions); 103 104 /* 105 * All the cold boot actions on the primary cpu are done. We now need to 106 * decide which is the next image (BL32 or BL33) and how to execute it. 107 * If the SPD runtime service is present, it would want to pass control 108 * to BL32 first in S-EL1. In that case, SPD would have registered a 109 * function to intialize bl32 where it takes responsibility of entering 110 * S-EL1 and returning control back to bl31_main. Once this is done we 111 * can prepare entry into BL33 as normal. 112 */ 113 114 /* 115 * If SPD had registerd an init hook, invoke it. Pass it the information 116 * about memory extents 117 */ 118 if (bl32_init) 119 (*bl32_init)(bl31_plat_get_bl32_mem_layout()); 120 121 /* 122 * We are ready to enter the next EL. Prepare entry into the image 123 * corresponding to the desired security state after the next ERET. 124 */ 125 bl31_prepare_next_image_entry(); 126 } 127 128 /******************************************************************************* 129 * Accessor functions to help runtime services decide which image should be 130 * executed after BL31. This is BL33 or the non-secure bootloader image by 131 * default but the Secure payload dispatcher could override this by requesting 132 * an entry into BL32 (Secure payload) first. If it does so then it should use 133 * the same API to program an entry into BL33 once BL32 initialisation is 134 * complete. 135 ******************************************************************************/ 136 void bl31_set_next_image_type(uint32_t security_state) 137 { 138 assert(security_state == NON_SECURE || security_state == SECURE); 139 next_image_type = security_state; 140 } 141 142 uint32_t bl31_get_next_image_type(void) 143 { 144 return next_image_type; 145 } 146 147 /******************************************************************************* 148 * This function programs EL3 registers and performs other setup to enable entry 149 * into the next image after BL31 at the next ERET. 150 ******************************************************************************/ 151 void bl31_prepare_next_image_entry() 152 { 153 el_change_info_t *next_image_info; 154 uint32_t scr, image_type; 155 156 /* Determine which image to execute next */ 157 image_type = bl31_get_next_image_type(); 158 159 /* 160 * Setup minimal architectural state of the next highest EL to 161 * allow execution in it immediately upon entering it. 162 */ 163 bl31_next_el_arch_setup(image_type); 164 165 /* Program EL3 registers to enable entry into the next EL */ 166 next_image_info = bl31_get_next_image_info(image_type); 167 assert(next_image_info); 168 169 scr = read_scr(); 170 if (image_type == NON_SECURE) 171 scr |= SCR_NS_BIT; 172 173 /* 174 * Tell the context mgmt. library to ensure that SP_EL3 points to 175 * the right context to exit from EL3 correctly. 176 */ 177 cm_set_el3_eret_context(next_image_info->security_state, 178 next_image_info->entrypoint, 179 next_image_info->spsr, 180 scr); 181 182 /* Finally set the next context */ 183 cm_set_next_eret_context(next_image_info->security_state); 184 } 185 186 /******************************************************************************* 187 * This function initializes the pointer to BL32 init function. This is expected 188 * to be called by the SPD after it finishes all its initialization 189 ******************************************************************************/ 190 void bl31_register_bl32_init(int32_t (*func)(meminfo_t *)) 191 { 192 bl32_init = func; 193 } 194