1 /* 2 * Copyright (c) 2013-2022, 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/debug.h> 16 #include <drivers/auth/auth_mod.h> 17 #include <drivers/io/io_storage.h> 18 #include <lib/utils.h> 19 #include <lib/xlat_tables/xlat_tables_defs.h> 20 #include <plat/common/platform.h> 21 22 #if TRUSTED_BOARD_BOOT 23 # ifdef DYN_DISABLE_AUTH 24 static int disable_auth; 25 26 /****************************************************************************** 27 * API to dynamically disable authentication. Only meant for development 28 * systems. This is only invoked if DYN_DISABLE_AUTH is defined. 29 *****************************************************************************/ 30 void dyn_disable_auth(void) 31 { 32 INFO("Disabling authentication of images dynamically\n"); 33 disable_auth = 1; 34 } 35 # endif /* DYN_DISABLE_AUTH */ 36 37 /****************************************************************************** 38 * Function to determine whether the authentication is disabled dynamically. 39 *****************************************************************************/ 40 static int dyn_is_auth_disabled(void) 41 { 42 # ifdef DYN_DISABLE_AUTH 43 return disable_auth; 44 # else 45 return 0; 46 # endif 47 } 48 #endif /* TRUSTED_BOARD_BOOT */ 49 50 uintptr_t page_align(uintptr_t value, unsigned dir) 51 { 52 /* Round up the limit to the next page boundary */ 53 if ((value & PAGE_SIZE_MASK) != 0U) { 54 value &= ~PAGE_SIZE_MASK; 55 if (dir == UP) 56 value += PAGE_SIZE; 57 } 58 59 return value; 60 } 61 62 /******************************************************************************* 63 * Internal function to load an image at a specific address given 64 * an image ID and extents of free memory. 65 * 66 * If the load is successful then the image information is updated. 67 * 68 * Returns 0 on success, a negative error code otherwise. 69 ******************************************************************************/ 70 static int load_image(unsigned int image_id, image_info_t *image_data) 71 { 72 uintptr_t dev_handle; 73 uintptr_t image_handle; 74 uintptr_t image_spec; 75 uintptr_t image_base; 76 size_t image_size; 77 size_t bytes_read; 78 int io_result; 79 80 assert(image_data != NULL); 81 assert(image_data->h.version >= VERSION_2); 82 83 image_base = image_data->image_base; 84 85 /* Obtain a reference to the image by querying the platform layer */ 86 io_result = plat_get_image_source(image_id, &dev_handle, &image_spec); 87 if (io_result != 0) { 88 WARN("Failed to obtain reference to image id=%u (%i)\n", 89 image_id, io_result); 90 return io_result; 91 } 92 93 /* Attempt to access the image */ 94 io_result = io_open(dev_handle, image_spec, &image_handle); 95 if (io_result != 0) { 96 WARN("Failed to access image id=%u (%i)\n", 97 image_id, io_result); 98 return io_result; 99 } 100 101 INFO("Loading image id=%u at address 0x%lx\n", image_id, image_base); 102 103 /* Find the size of the image */ 104 io_result = io_size(image_handle, &image_size); 105 if ((io_result != 0) || (image_size == 0U)) { 106 WARN("Failed to determine the size of the image id=%u (%i)\n", 107 image_id, io_result); 108 goto exit; 109 } 110 111 /* Check that the image size to load is within limit */ 112 if (image_size > image_data->image_max_size) { 113 WARN("Image id=%u size out of bounds\n", image_id); 114 io_result = -EFBIG; 115 goto exit; 116 } 117 118 /* 119 * image_data->image_max_size is a uint32_t so image_size will always 120 * fit in image_data->image_size. 121 */ 122 image_data->image_size = (uint32_t)image_size; 123 124 /* We have enough space so load the image now */ 125 /* TODO: Consider whether to try to recover/retry a partially successful read */ 126 io_result = io_read(image_handle, image_base, image_size, &bytes_read); 127 if ((io_result != 0) || (bytes_read < image_size)) { 128 WARN("Failed to load image id=%u (%i)\n", image_id, io_result); 129 goto exit; 130 } 131 132 INFO("Image id=%u loaded: 0x%lx - 0x%lx\n", image_id, image_base, 133 (uintptr_t)(image_base + image_size)); 134 135 exit: 136 (void)io_close(image_handle); 137 /* Ignore improbable/unrecoverable error in 'close' */ 138 139 /* TODO: Consider maintaining open device connection from this bootloader stage */ 140 (void)io_dev_close(dev_handle); 141 /* Ignore improbable/unrecoverable error in 'dev_close' */ 142 143 return io_result; 144 } 145 146 #if TRUSTED_BOARD_BOOT 147 /* 148 * This function uses recursion to authenticate the parent images up to the root 149 * of trust. 150 */ 151 static int load_auth_image_recursive(unsigned int image_id, 152 image_info_t *image_data, 153 int is_parent_image) 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, 1); 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, 0); 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 /* 214 * All firmware banks should be part of the same non-volatile storage as per 215 * PSA FWU specification, hence don't check for any alternate boot source 216 * when PSA FWU is enabled. 217 */ 218 #if PSA_FWU_SUPPORT 219 err = load_auth_image_internal(image_id, image_data); 220 #else 221 do { 222 err = load_auth_image_internal(image_id, image_data); 223 } while ((err != 0) && (plat_try_next_boot_source() != 0)); 224 #endif /* PSA_FWU_SUPPORT */ 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 extern const char version[]; 279 return version; 280 } 281