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 <auth_mod.h> 35 #include <bl_common.h> 36 #include <debug.h> 37 #include <errno.h> 38 #include <io_storage.h> 39 #include <platform.h> 40 #include <string.h> 41 42 unsigned long page_align(unsigned long value, unsigned dir) 43 { 44 unsigned long page_size = 1 << FOUR_KB_SHIFT; 45 46 /* Round up the limit to the next page boundary */ 47 if (value & (page_size - 1)) { 48 value &= ~(page_size - 1); 49 if (dir == UP) 50 value += page_size; 51 } 52 53 return value; 54 } 55 56 static inline unsigned int is_page_aligned (unsigned long addr) { 57 const unsigned long page_size = 1 << FOUR_KB_SHIFT; 58 59 return (addr & (page_size - 1)) == 0; 60 } 61 62 void change_security_state(unsigned int target_security_state) 63 { 64 unsigned long scr = read_scr(); 65 66 assert(sec_state_is_valid(target_security_state)); 67 if (target_security_state == SECURE) 68 scr &= ~SCR_NS_BIT; 69 else 70 scr |= SCR_NS_BIT; 71 72 write_scr(scr); 73 } 74 75 /****************************************************************************** 76 * Determine whether the memory region delimited by 'addr' and 'size' is free, 77 * given the extents of free memory. 78 * Return 1 if it is free, 0 otherwise. 79 *****************************************************************************/ 80 static int is_mem_free(uint64_t free_base, size_t free_size, 81 uint64_t addr, size_t size) 82 { 83 return (addr >= free_base) && (addr + size <= free_base + free_size); 84 } 85 86 /****************************************************************************** 87 * Inside a given memory region, determine whether a sub-region of memory is 88 * closer from the top or the bottom of the encompassing region. Return the 89 * size of the smallest chunk of free memory surrounding the sub-region in 90 * 'small_chunk_size'. 91 *****************************************************************************/ 92 static unsigned int choose_mem_pos(uint64_t mem_start, uint64_t mem_end, 93 uint64_t submem_start, uint64_t submem_end, 94 size_t *small_chunk_size) 95 { 96 size_t top_chunk_size, bottom_chunk_size; 97 98 assert(mem_start <= submem_start); 99 assert(submem_start <= submem_end); 100 assert(submem_end <= mem_end); 101 assert(small_chunk_size != NULL); 102 103 top_chunk_size = mem_end - submem_end; 104 bottom_chunk_size = submem_start - mem_start; 105 106 if (top_chunk_size < bottom_chunk_size) { 107 *small_chunk_size = top_chunk_size; 108 return TOP; 109 } else { 110 *small_chunk_size = bottom_chunk_size; 111 return BOTTOM; 112 } 113 } 114 115 /****************************************************************************** 116 * Reserve the memory region delimited by 'addr' and 'size'. The extents of free 117 * memory are passed in 'free_base' and 'free_size' and they will be updated to 118 * reflect the memory usage. 119 * The caller must ensure the memory to reserve is free. 120 *****************************************************************************/ 121 void reserve_mem(uint64_t *free_base, size_t *free_size, 122 uint64_t addr, size_t size) 123 { 124 size_t discard_size; 125 size_t reserved_size; 126 unsigned int pos; 127 128 assert(free_base != NULL); 129 assert(free_size != NULL); 130 assert(is_mem_free(*free_base, *free_size, addr, size)); 131 132 pos = choose_mem_pos(*free_base, *free_base + *free_size, 133 addr, addr + size, 134 &discard_size); 135 136 reserved_size = size + discard_size; 137 *free_size -= reserved_size; 138 139 if (pos == BOTTOM) 140 *free_base = addr + size; 141 142 VERBOSE("Reserved 0x%lx bytes (discarded 0x%lx bytes %s)\n", 143 reserved_size, discard_size, 144 pos == TOP ? "above" : "below"); 145 } 146 147 static void dump_load_info(unsigned long image_load_addr, 148 unsigned long image_size, 149 const meminfo_t *mem_layout) 150 { 151 INFO("Trying to load image at address 0x%lx, size = 0x%lx\n", 152 image_load_addr, image_size); 153 INFO("Current memory layout:\n"); 154 INFO(" total region = [0x%lx, 0x%lx]\n", mem_layout->total_base, 155 mem_layout->total_base + mem_layout->total_size); 156 INFO(" free region = [0x%lx, 0x%lx]\n", mem_layout->free_base, 157 mem_layout->free_base + mem_layout->free_size); 158 } 159 160 /* Generic function to return the size of an image */ 161 unsigned long image_size(unsigned int image_id) 162 { 163 uintptr_t dev_handle; 164 uintptr_t image_handle; 165 uintptr_t image_spec; 166 size_t image_size = 0; 167 int io_result = IO_FAIL; 168 169 /* Obtain a reference to the image by querying the platform layer */ 170 io_result = plat_get_image_source(image_id, &dev_handle, &image_spec); 171 if (io_result != IO_SUCCESS) { 172 WARN("Failed to obtain reference to image id=%u (%i)\n", 173 image_id, io_result); 174 return 0; 175 } 176 177 /* Attempt to access the image */ 178 io_result = io_open(dev_handle, image_spec, &image_handle); 179 if (io_result != IO_SUCCESS) { 180 WARN("Failed to access image id=%u (%i)\n", 181 image_id, io_result); 182 return 0; 183 } 184 185 /* Find the size of the image */ 186 io_result = io_size(image_handle, &image_size); 187 if ((io_result != IO_SUCCESS) || (image_size == 0)) { 188 WARN("Failed to determine the size of the image id=%u (%i)\n", 189 image_id, io_result); 190 } 191 io_result = io_close(image_handle); 192 /* Ignore improbable/unrecoverable error in 'close' */ 193 194 /* TODO: Consider maintaining open device connection from this 195 * bootloader stage 196 */ 197 io_result = io_dev_close(dev_handle); 198 /* Ignore improbable/unrecoverable error in 'dev_close' */ 199 200 return image_size; 201 } 202 203 /******************************************************************************* 204 * Generic function to load an image at a specific address given a name and 205 * extents of free memory. It updates the memory layout if the load is 206 * successful, as well as the image information and the entry point information. 207 * The caller might pass a NULL pointer for the entry point if it is not 208 * interested in this information, e.g. because the image just needs to be 209 * loaded in memory but won't ever be executed. 210 * Returns 0 on success, a negative error code otherwise. 211 ******************************************************************************/ 212 int load_image(meminfo_t *mem_layout, 213 unsigned int image_id, 214 uintptr_t image_base, 215 image_info_t *image_data, 216 entry_point_info_t *entry_point_info) 217 { 218 uintptr_t dev_handle; 219 uintptr_t image_handle; 220 uintptr_t image_spec; 221 size_t image_size; 222 size_t bytes_read; 223 int io_result = IO_FAIL; 224 225 assert(mem_layout != NULL); 226 assert(image_data != NULL); 227 assert(image_data->h.version >= VERSION_1); 228 229 /* Obtain a reference to the image by querying the platform layer */ 230 io_result = plat_get_image_source(image_id, &dev_handle, &image_spec); 231 if (io_result != IO_SUCCESS) { 232 WARN("Failed to obtain reference to image id=%u (%i)\n", 233 image_id, io_result); 234 return io_result; 235 } 236 237 /* Attempt to access the image */ 238 io_result = io_open(dev_handle, image_spec, &image_handle); 239 if (io_result != IO_SUCCESS) { 240 WARN("Failed to access image id=%u (%i)\n", 241 image_id, io_result); 242 return io_result; 243 } 244 245 INFO("Loading image id=%u at address 0x%lx\n", image_id, image_base); 246 247 /* Find the size of the image */ 248 io_result = io_size(image_handle, &image_size); 249 if ((io_result != IO_SUCCESS) || (image_size == 0)) { 250 WARN("Failed to determine the size of the image id=%u (%i)\n", 251 image_id, io_result); 252 goto exit; 253 } 254 255 /* Check that the memory where the image will be loaded is free */ 256 if (!is_mem_free(mem_layout->free_base, mem_layout->free_size, 257 image_base, image_size)) { 258 WARN("Failed to reserve memory: 0x%lx - 0x%lx\n", 259 image_base, image_base + image_size); 260 dump_load_info(image_base, image_size, mem_layout); 261 io_result = -ENOMEM; 262 goto exit; 263 } 264 265 /* We have enough space so load the image now */ 266 /* TODO: Consider whether to try to recover/retry a partially successful read */ 267 io_result = io_read(image_handle, image_base, image_size, &bytes_read); 268 if ((io_result != IO_SUCCESS) || (bytes_read < image_size)) { 269 WARN("Failed to load image id=%u (%i)\n", image_id, io_result); 270 goto exit; 271 } 272 273 /* 274 * Update the memory usage info. 275 * This is done after the actual loading so that it is not updated when 276 * the load is unsuccessful. 277 * If the caller does not provide an entry point, bypass the memory 278 * reservation. 279 */ 280 if (entry_point_info != NULL) { 281 reserve_mem(&mem_layout->free_base, &mem_layout->free_size, 282 image_base, image_size); 283 } else { 284 INFO("Skip reserving memory: 0x%lx - 0x%lx\n", 285 image_base, image_base + image_size); 286 } 287 288 image_data->image_base = image_base; 289 image_data->image_size = image_size; 290 291 if (entry_point_info != NULL) 292 entry_point_info->pc = image_base; 293 294 /* 295 * File has been successfully loaded. 296 * Flush the image in TZRAM so that the next EL can see it. 297 */ 298 flush_dcache_range(image_base, image_size); 299 300 INFO("Image id=%u loaded: 0x%lx - 0x%lx\n", image_id, image_base, 301 image_base + image_size); 302 303 exit: 304 io_close(image_handle); 305 /* Ignore improbable/unrecoverable error in 'close' */ 306 307 /* TODO: Consider maintaining open device connection from this bootloader stage */ 308 io_dev_close(dev_handle); 309 /* Ignore improbable/unrecoverable error in 'dev_close' */ 310 311 return io_result; 312 } 313 314 /******************************************************************************* 315 * Generic function to load and authenticate an image. The image is actually 316 * loaded by calling the 'load_image()' function. In addition, this function 317 * uses recursion to authenticate the parent images up to the root of trust. 318 ******************************************************************************/ 319 int load_auth_image(meminfo_t *mem_layout, 320 unsigned int image_id, 321 uintptr_t image_base, 322 image_info_t *image_data, 323 entry_point_info_t *entry_point_info) 324 { 325 int rc; 326 327 #if TRUSTED_BOARD_BOOT 328 unsigned int parent_id; 329 330 /* Use recursion to authenticate parent images */ 331 rc = auth_mod_get_parent_id(image_id, &parent_id); 332 if (rc == 0) { 333 rc = load_auth_image(mem_layout, parent_id, image_base, 334 image_data, NULL); 335 if (rc != LOAD_SUCCESS) { 336 return rc; 337 } 338 } 339 #endif /* TRUSTED_BOARD_BOOT */ 340 341 /* Load the image */ 342 rc = load_image(mem_layout, image_id, image_base, image_data, 343 entry_point_info); 344 if (rc != IO_SUCCESS) { 345 return LOAD_ERR; 346 } 347 348 #if TRUSTED_BOARD_BOOT 349 /* Authenticate it */ 350 rc = auth_mod_verify_img(image_id, 351 (void *)image_data->image_base, 352 image_data->image_size); 353 if (rc != 0) { 354 memset((void *)image_data->image_base, 0x00, 355 image_data->image_size); 356 flush_dcache_range(image_data->image_base, 357 image_data->image_size); 358 return LOAD_AUTH_ERR; 359 } 360 361 /* After working with data, invalidate the data cache */ 362 inv_dcache_range(image_data->image_base, 363 (size_t)image_data->image_size); 364 #endif /* TRUSTED_BOARD_BOOT */ 365 366 return LOAD_SUCCESS; 367 } 368