1 /* 2 * Copyright (c) 2013-2015, 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 <debug.h> 38 #include <platform.h> 39 #include <runtime_svc.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 = NON_SECURE; 55 56 /******************************************************************************* 57 * Simple function to initialise all BL31 helper libraries. 58 ******************************************************************************/ 59 void bl31_lib_init(void) 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 NOTICE("BL31: %s\n", version_string); 75 NOTICE("BL31: %s\n", build_message); 76 77 /* Perform remaining generic architectural setup from EL3 */ 78 bl31_arch_setup(); 79 80 /* Perform platform setup in BL31 */ 81 bl31_platform_setup(); 82 83 /* Initialise helper libraries */ 84 bl31_lib_init(); 85 86 /* Initialize the runtime services e.g. psci */ 87 INFO("BL31: Initializing runtime services\n"); 88 runtime_svc_init(); 89 90 /* 91 * All the cold boot actions on the primary cpu are done. We now need to 92 * decide which is the next image (BL32 or BL33) and how to execute it. 93 * If the SPD runtime service is present, it would want to pass control 94 * to BL32 first in S-EL1. In that case, SPD would have registered a 95 * function to intialize bl32 where it takes responsibility of entering 96 * S-EL1 and returning control back to bl31_main. Once this is done we 97 * can prepare entry into BL33 as normal. 98 */ 99 100 /* 101 * If SPD had registerd an init hook, invoke it. 102 */ 103 if (bl32_init) { 104 INFO("BL31: Initializing BL32\n"); 105 (*bl32_init)(); 106 } 107 /* 108 * We are ready to enter the next EL. Prepare entry into the image 109 * corresponding to the desired security state after the next ERET. 110 */ 111 bl31_prepare_next_image_entry(); 112 113 /* 114 * Perform any platform specific runtime setup prior to cold boot exit 115 * from BL31 116 */ 117 bl31_plat_runtime_setup(); 118 } 119 120 /******************************************************************************* 121 * Accessor functions to help runtime services decide which image should be 122 * executed after BL31. This is BL33 or the non-secure bootloader image by 123 * default but the Secure payload dispatcher could override this by requesting 124 * an entry into BL32 (Secure payload) first. If it does so then it should use 125 * the same API to program an entry into BL33 once BL32 initialisation is 126 * complete. 127 ******************************************************************************/ 128 void bl31_set_next_image_type(uint32_t security_state) 129 { 130 assert(sec_state_is_valid(security_state)); 131 next_image_type = security_state; 132 } 133 134 uint32_t bl31_get_next_image_type(void) 135 { 136 return next_image_type; 137 } 138 139 /******************************************************************************* 140 * This function programs EL3 registers and performs other setup to enable entry 141 * into the next image after BL31 at the next ERET. 142 ******************************************************************************/ 143 void bl31_prepare_next_image_entry(void) 144 { 145 entry_point_info_t *next_image_info; 146 uint32_t image_type; 147 148 /* Determine which image to execute next */ 149 image_type = bl31_get_next_image_type(); 150 151 /* Program EL3 registers to enable entry into the next EL */ 152 next_image_info = bl31_plat_get_next_image_ep_info(image_type); 153 assert(next_image_info); 154 assert(image_type == GET_SECURITY_STATE(next_image_info->h.attr)); 155 156 INFO("BL31: Preparing for EL3 exit to %s world\n", 157 (image_type == SECURE) ? "secure" : "normal"); 158 print_entry_point_info(next_image_info); 159 cm_init_my_context(next_image_info); 160 cm_prepare_el3_exit(image_type); 161 } 162 163 /******************************************************************************* 164 * This function initializes the pointer to BL32 init function. This is expected 165 * to be called by the SPD after it finishes all its initialization 166 ******************************************************************************/ 167 void bl31_register_bl32_init(int32_t (*func)(void)) 168 { 169 bl32_init = func; 170 } 171