1 /* 2 * Copyright (c) 2013-2024, Arm Limited and Contributors. All rights reserved. 3 * 4 * SPDX-License-Identifier: BSD-3-Clause 5 */ 6 7 #include <assert.h> 8 #include <errno.h> 9 #include <string.h> 10 11 #include <arch.h> 12 #include <arch_features.h> 13 #include <arch_helpers.h> 14 #include <common/bl_common.h> 15 #include <common/build_message.h> 16 #include <common/debug.h> 17 #include <drivers/auth/auth_mod.h> 18 #include <drivers/io/io_storage.h> 19 #include <lib/utils.h> 20 #include <lib/xlat_tables/xlat_tables_defs.h> 21 #include <plat/common/platform.h> 22 23 #if TRUSTED_BOARD_BOOT 24 # ifdef DYN_DISABLE_AUTH 25 static int disable_auth; 26 27 /****************************************************************************** 28 * API to dynamically disable authentication. Only meant for development 29 * systems. This is only invoked if DYN_DISABLE_AUTH is defined. 30 *****************************************************************************/ 31 void dyn_disable_auth(void) 32 { 33 INFO("Disabling authentication of images dynamically\n"); 34 disable_auth = 1; 35 } 36 # endif /* DYN_DISABLE_AUTH */ 37 38 /****************************************************************************** 39 * Function to determine whether the authentication is disabled dynamically. 40 *****************************************************************************/ 41 static int dyn_is_auth_disabled(void) 42 { 43 # ifdef DYN_DISABLE_AUTH 44 return disable_auth; 45 # else 46 return 0; 47 # endif 48 } 49 #endif /* TRUSTED_BOARD_BOOT */ 50 51 uintptr_t page_align(uintptr_t value, unsigned dir) 52 { 53 /* Round up the limit to the next page boundary */ 54 if ((value & PAGE_SIZE_MASK) != 0U) { 55 value &= ~PAGE_SIZE_MASK; 56 if (dir == UP) 57 value += PAGE_SIZE; 58 } 59 60 return value; 61 } 62 63 /******************************************************************************* 64 * Internal function to load an image at a specific address given 65 * an image ID and extents of free memory. 66 * 67 * If the load is successful then the image information is updated. 68 * 69 * Returns 0 on success, a negative error code otherwise. 70 ******************************************************************************/ 71 static int load_image(unsigned int image_id, image_info_t *image_data) 72 { 73 uintptr_t dev_handle; 74 uintptr_t image_handle; 75 uintptr_t image_spec; 76 uintptr_t image_base; 77 size_t image_size; 78 size_t bytes_read; 79 int io_result; 80 81 assert(image_data != NULL); 82 assert(image_data->h.version >= VERSION_2); 83 84 image_base = image_data->image_base; 85 86 /* Obtain a reference to the image by querying the platform layer */ 87 io_result = plat_get_image_source(image_id, &dev_handle, &image_spec); 88 if (io_result != 0) { 89 WARN("Failed to obtain reference to image id=%u (%i)\n", 90 image_id, io_result); 91 return io_result; 92 } 93 94 /* Attempt to access the image */ 95 io_result = io_open(dev_handle, image_spec, &image_handle); 96 if (io_result != 0) { 97 WARN("Failed to access image id=%u (%i)\n", 98 image_id, io_result); 99 return io_result; 100 } 101 102 INFO("Loading image id=%u at address 0x%lx\n", image_id, image_base); 103 104 /* Find the size of the image */ 105 io_result = io_size(image_handle, &image_size); 106 if ((io_result != 0) || (image_size == 0U)) { 107 WARN("Failed to determine the size of the image id=%u (%i)\n", 108 image_id, io_result); 109 goto exit; 110 } 111 112 /* Check that the image size to load is within limit */ 113 if (image_size > image_data->image_max_size) { 114 WARN("Image id=%u size out of bounds\n", image_id); 115 io_result = -EFBIG; 116 goto exit; 117 } 118 119 /* 120 * image_data->image_max_size is a uint32_t so image_size will always 121 * fit in image_data->image_size. 122 */ 123 image_data->image_size = (uint32_t)image_size; 124 125 /* We have enough space so load the image now */ 126 /* TODO: Consider whether to try to recover/retry a partially successful read */ 127 io_result = io_read(image_handle, image_base, image_size, &bytes_read); 128 if ((io_result != 0) || (bytes_read < image_size)) { 129 WARN("Failed to load image id=%u (%i)\n", image_id, io_result); 130 goto exit; 131 } 132 133 INFO("Image id=%u loaded: 0x%lx - 0x%lx\n", image_id, image_base, 134 (uintptr_t)(image_base + image_size)); 135 136 exit: 137 (void)io_close(image_handle); 138 /* Ignore improbable/unrecoverable error in 'close' */ 139 140 /* TODO: Consider maintaining open device connection from this bootloader stage */ 141 (void)io_dev_close(dev_handle); 142 /* Ignore improbable/unrecoverable error in 'dev_close' */ 143 144 return io_result; 145 } 146 147 #if TRUSTED_BOARD_BOOT 148 /* 149 * This function uses recursion to authenticate the parent images up to the root 150 * of trust. 151 */ 152 static int load_auth_image_recursive(unsigned int image_id, 153 image_info_t *image_data) 154 { 155 int rc; 156 unsigned int parent_id; 157 158 /* Use recursion to authenticate parent images */ 159 rc = auth_mod_get_parent_id(image_id, &parent_id); 160 if (rc == 0) { 161 rc = load_auth_image_recursive(parent_id, image_data); 162 if (rc != 0) { 163 return rc; 164 } 165 } 166 167 /* Load the image */ 168 rc = load_image(image_id, image_data); 169 if (rc != 0) { 170 return rc; 171 } 172 173 /* Authenticate it */ 174 rc = auth_mod_verify_img(image_id, 175 (void *)image_data->image_base, 176 image_data->image_size); 177 if (rc != 0) { 178 /* Authentication error, zero memory and flush it right away. */ 179 zero_normalmem((void *)image_data->image_base, 180 image_data->image_size); 181 flush_dcache_range(image_data->image_base, 182 image_data->image_size); 183 return -EAUTH; 184 } 185 186 return 0; 187 } 188 #endif /* TRUSTED_BOARD_BOOT */ 189 190 static int load_auth_image_internal(unsigned int image_id, 191 image_info_t *image_data) 192 { 193 #if TRUSTED_BOARD_BOOT 194 if (dyn_is_auth_disabled() == 0) { 195 return load_auth_image_recursive(image_id, image_data); 196 } 197 #endif 198 199 return load_image(image_id, image_data); 200 } 201 202 /******************************************************************************* 203 * Generic function to load and authenticate an image. The image is actually 204 * loaded by calling the 'load_image()' function. Therefore, it returns the 205 * same error codes if the loading operation failed, or -EAUTH if the 206 * authentication failed. In addition, this function uses recursion to 207 * authenticate the parent images up to the root of trust (if TBB is enabled). 208 ******************************************************************************/ 209 int load_auth_image(unsigned int image_id, image_info_t *image_data) 210 { 211 int err; 212 213 if ((plat_try_img_ops == NULL) || (plat_try_img_ops->next_instance == NULL)) { 214 err = load_auth_image_internal(image_id, image_data); 215 } else { 216 do { 217 err = load_auth_image_internal(image_id, image_data); 218 if (err != 0) { 219 if (plat_try_img_ops->next_instance(image_id) != 0) { 220 return err; 221 } 222 } 223 } while (err != 0); 224 } 225 226 if (err == 0) { 227 /* 228 * If loading of the image gets passed (along with its 229 * authentication in case of Trusted-Boot flow) then measure 230 * it (if MEASURED_BOOT flag is enabled). 231 */ 232 err = plat_mboot_measure_image(image_id, image_data); 233 if (err != 0) { 234 return err; 235 } 236 237 /* 238 * Flush the image to main memory so that it can be executed 239 * later by any CPU, regardless of cache and MMU state. 240 */ 241 flush_dcache_range(image_data->image_base, 242 image_data->image_size); 243 } 244 245 return err; 246 } 247 248 /******************************************************************************* 249 * Print the content of an entry_point_info_t structure. 250 ******************************************************************************/ 251 void print_entry_point_info(const entry_point_info_t *ep_info) 252 { 253 INFO("Entry point address = 0x%lx\n", ep_info->pc); 254 INFO("SPSR = 0x%x\n", ep_info->spsr); 255 256 #define PRINT_IMAGE_ARG(n) \ 257 VERBOSE("Argument #" #n " = 0x%llx\n", \ 258 (unsigned long long) ep_info->args.arg##n) 259 260 PRINT_IMAGE_ARG(0); 261 PRINT_IMAGE_ARG(1); 262 PRINT_IMAGE_ARG(2); 263 PRINT_IMAGE_ARG(3); 264 #ifdef __aarch64__ 265 PRINT_IMAGE_ARG(4); 266 PRINT_IMAGE_ARG(5); 267 PRINT_IMAGE_ARG(6); 268 PRINT_IMAGE_ARG(7); 269 #endif 270 #undef PRINT_IMAGE_ARG 271 } 272 273 /* 274 * This function is for returning the TF-A version 275 */ 276 const char *get_version(void) 277 { 278 return build_version; 279 } 280