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)(void); 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. 118 */ 119 if (bl32_init) 120 (*bl32_init)(); 121 122 /* 123 * We are ready to enter the next EL. Prepare entry into the image 124 * corresponding to the desired security state after the next ERET. 125 */ 126 bl31_prepare_next_image_entry(); 127 } 128 129 /******************************************************************************* 130 * Accessor functions to help runtime services decide which image should be 131 * executed after BL31. This is BL33 or the non-secure bootloader image by 132 * default but the Secure payload dispatcher could override this by requesting 133 * an entry into BL32 (Secure payload) first. If it does so then it should use 134 * the same API to program an entry into BL33 once BL32 initialisation is 135 * complete. 136 ******************************************************************************/ 137 void bl31_set_next_image_type(uint32_t security_state) 138 { 139 assert(security_state == NON_SECURE || security_state == SECURE); 140 next_image_type = security_state; 141 } 142 143 uint32_t bl31_get_next_image_type(void) 144 { 145 return next_image_type; 146 } 147 148 /******************************************************************************* 149 * This function programs EL3 registers and performs other setup to enable entry 150 * into the next image after BL31 at the next ERET. 151 ******************************************************************************/ 152 void bl31_prepare_next_image_entry() 153 { 154 entry_point_info_t *next_image_info; 155 uint32_t scr, image_type; 156 157 /* Determine which image to execute next */ 158 image_type = bl31_get_next_image_type(); 159 160 /* 161 * Setup minimal architectural state of the next highest EL to 162 * allow execution in it immediately upon entering it. 163 */ 164 bl31_next_el_arch_setup(image_type); 165 166 /* Program EL3 registers to enable entry into the next EL */ 167 next_image_info = bl31_get_next_image_info(image_type); 168 assert(next_image_info); 169 170 scr = read_scr(); 171 scr &= ~SCR_NS_BIT; 172 if (image_type == NON_SECURE) 173 scr |= SCR_NS_BIT; 174 175 scr &= ~SCR_RW_BIT; 176 if ((next_image_info->spsr & (1 << MODE_RW_SHIFT)) == 177 (MODE_RW_64 << MODE_RW_SHIFT)) 178 scr |= SCR_RW_BIT; 179 180 /* 181 * Tell the context mgmt. library to ensure that SP_EL3 points to 182 * the right context to exit from EL3 correctly. 183 */ 184 cm_set_el3_eret_context(GET_SECURITY_STATE(next_image_info->h.attr), 185 next_image_info->pc, 186 next_image_info->spsr, 187 scr); 188 189 /* Finally set the next context */ 190 cm_set_next_eret_context(GET_SECURITY_STATE(next_image_info->h.attr)); 191 } 192 193 /******************************************************************************* 194 * This function initializes the pointer to BL32 init function. This is expected 195 * to be called by the SPD after it finishes all its initialization 196 ******************************************************************************/ 197 void bl31_register_bl32_init(int32_t (*func)(void)) 198 { 199 bl32_init = func; 200 } 201