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 * This function pointer is used to initialise the BL32 image. It's initialized 42 * by SPD calling bl31_register_bl32_init after setting up all things necessary 43 * for SP execution. In cases where both SPD and SP are absent, or when SPD 44 * finds it impossible to execute SP, this pointer is left as NULL 45 ******************************************************************************/ 46 static int32_t (*bl32_init)(meminfo_t *); 47 48 /******************************************************************************* 49 * Variable to indicate whether next image to execute after BL31 is BL33 50 * (non-secure & default) or BL32 (secure). 51 ******************************************************************************/ 52 static uint32_t next_image_type; 53 54 /******************************************************************************* 55 * Simple function to initialise all BL31 helper libraries. 56 ******************************************************************************/ 57 void bl31_lib_init() 58 { 59 cm_init(); 60 } 61 62 /******************************************************************************* 63 * BL31 is responsible for setting up the runtime services for the primary cpu 64 * before passing control to the bootloader or an Operating System. This 65 * function calls runtime_svc_init() which initializes all registered runtime 66 * services. The run time services would setup enough context for the core to 67 * swtich to the next exception level. When this function returns, the core will 68 * switch to the programmed exception level via. an ERET. 69 ******************************************************************************/ 70 void bl31_main(void) 71 { 72 #if DEBUG 73 unsigned long mpidr = read_mpidr(); 74 #endif 75 76 /* Perform remaining generic architectural setup from EL3 */ 77 bl31_arch_setup(); 78 79 /* Perform platform setup in BL1 */ 80 bl31_platform_setup(); 81 82 printf("BL31 %s\n\r", build_message); 83 84 /* Initialise helper libraries */ 85 bl31_lib_init(); 86 87 /* Initialize the runtime services e.g. psci */ 88 runtime_svc_init(); 89 90 /* Clean caches before re-entering normal world */ 91 dcsw_op_all(DCCSW); 92 93 /* 94 * Use the more complex exception vectors now that context 95 * management is setup. SP_EL3 should point to a 'cpu_context' 96 * structure which has an exception stack allocated. The PSCI 97 * service should have set the context. 98 */ 99 assert(cm_get_context(mpidr, NON_SECURE)); 100 cm_set_next_eret_context(NON_SECURE); 101 cm_init_pcpu_ptr_cache(); 102 write_vbar_el3((uint64_t) runtime_exceptions); 103 isb(); 104 next_image_type = NON_SECURE; 105 106 /* 107 * All the cold boot actions on the primary cpu are done. We now need to 108 * decide which is the next image (BL32 or BL33) and how to execute it. 109 * If the SPD runtime service is present, it would want to pass control 110 * to BL32 first in S-EL1. In that case, SPD would have registered a 111 * function to intialize bl32 where it takes responsibility of entering 112 * S-EL1 and returning control back to bl31_main. Once this is done we 113 * can prepare entry into BL33 as normal. 114 */ 115 116 /* 117 * If SPD had registerd an init hook, invoke it. Pass it the information 118 * about memory extents 119 */ 120 if (bl32_init) 121 (*bl32_init)(bl31_plat_get_bl32_mem_layout()); 122 123 /* 124 * We are ready to enter the next EL. Prepare entry into the image 125 * corresponding to the desired security state after the next ERET. 126 */ 127 bl31_prepare_next_image_entry(); 128 } 129 130 /******************************************************************************* 131 * Accessor functions to help runtime services decide which image should be 132 * executed after BL31. This is BL33 or the non-secure bootloader image by 133 * default but the Secure payload dispatcher could override this by requesting 134 * an entry into BL32 (Secure payload) first. If it does so then it should use 135 * the same API to program an entry into BL33 once BL32 initialisation is 136 * complete. 137 ******************************************************************************/ 138 void bl31_set_next_image_type(uint32_t security_state) 139 { 140 assert(security_state == NON_SECURE || security_state == SECURE); 141 next_image_type = security_state; 142 } 143 144 uint32_t bl31_get_next_image_type(void) 145 { 146 return next_image_type; 147 } 148 149 /******************************************************************************* 150 * This function programs EL3 registers and performs other setup to enable entry 151 * into the next image after BL31 at the next ERET. 152 ******************************************************************************/ 153 void bl31_prepare_next_image_entry() 154 { 155 el_change_info_t *next_image_info; 156 uint32_t scr, image_type; 157 158 /* Determine which image to execute next */ 159 image_type = bl31_get_next_image_type(); 160 161 /* 162 * Setup minimal architectural state of the next highest EL to 163 * allow execution in it immediately upon entering it. 164 */ 165 bl31_next_el_arch_setup(image_type); 166 167 /* Program EL3 registers to enable entry into the next EL */ 168 next_image_info = bl31_get_next_image_info(image_type); 169 assert(next_image_info); 170 171 scr = read_scr(); 172 scr &= ~SCR_NS_BIT; 173 if (image_type == NON_SECURE) 174 scr |= SCR_NS_BIT; 175 176 scr &= ~SCR_RW_BIT; 177 if ((next_image_info->spsr & (1 << MODE_RW_SHIFT)) == 178 (MODE_RW_64 << MODE_RW_SHIFT)) 179 scr |= SCR_RW_BIT; 180 181 /* 182 * Tell the context mgmt. library to ensure that SP_EL3 points to 183 * the right context to exit from EL3 correctly. 184 */ 185 cm_set_el3_eret_context(next_image_info->security_state, 186 next_image_info->entrypoint, 187 next_image_info->spsr, 188 scr); 189 190 /* Finally set the next context */ 191 cm_set_next_eret_context(next_image_info->security_state); 192 } 193 194 /******************************************************************************* 195 * This function initializes the pointer to BL32 init function. This is expected 196 * to be called by the SPD after it finishes all its initialization 197 ******************************************************************************/ 198 void bl31_register_bl32_init(int32_t (*func)(meminfo_t *)) 199 { 200 bl32_init = func; 201 } 202