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 <stdio.h> 32 #include <string.h> 33 #include <errno.h> 34 #include <assert.h> 35 #include <arch_helpers.h> 36 #include <console.h> 37 #include <platform.h> 38 #include <semihosting.h> 39 #include <bl_common.h> 40 #include "io_storage.h" 41 #include "debug.h" 42 43 unsigned long page_align(unsigned long value, unsigned dir) 44 { 45 unsigned long page_size = 1 << FOUR_KB_SHIFT; 46 47 /* Round up the limit to the next page boundary */ 48 if (value & (page_size - 1)) { 49 value &= ~(page_size - 1); 50 if (dir == UP) 51 value += page_size; 52 } 53 54 return value; 55 } 56 57 static inline unsigned int is_page_aligned (unsigned long addr) { 58 const unsigned long page_size = 1 << FOUR_KB_SHIFT; 59 60 return (addr & (page_size - 1)) == 0; 61 } 62 63 void change_security_state(unsigned int target_security_state) 64 { 65 unsigned long scr = read_scr(); 66 67 if (target_security_state == SECURE) 68 scr &= ~SCR_NS_BIT; 69 else if (target_security_state == NON_SECURE) 70 scr |= SCR_NS_BIT; 71 else 72 assert(0); 73 74 write_scr(scr); 75 } 76 77 void __dead2 drop_el(aapcs64_params *args, 78 unsigned long spsr, 79 unsigned long entrypoint) 80 { 81 write_spsr(spsr); 82 write_elr(entrypoint); 83 eret(args->arg0, 84 args->arg1, 85 args->arg2, 86 args->arg3, 87 args->arg4, 88 args->arg5, 89 args->arg6, 90 args->arg7); 91 } 92 93 void __dead2 raise_el(aapcs64_params *args) 94 { 95 smc(args->arg0, 96 args->arg1, 97 args->arg2, 98 args->arg3, 99 args->arg4, 100 args->arg5, 101 args->arg6, 102 args->arg7); 103 } 104 105 /* 106 * TODO: If we are not EL3 then currently we only issue an SMC. 107 * Add support for dropping into EL0 etc. Consider adding support 108 * for switching from S-EL1 to S-EL0/1 etc. 109 */ 110 void __dead2 change_el(el_change_info *info) 111 { 112 unsigned long current_el = read_current_el(); 113 114 if (GET_EL(current_el) == MODE_EL3) { 115 /* 116 * We can go anywhere from EL3. So find where. 117 * TODO: Lots to do if we are going non-secure. 118 * Flip the NS bit. Restore NS registers etc. 119 * Just doing the bare minimal for now. 120 */ 121 122 if (info->security_state == NON_SECURE) 123 change_security_state(info->security_state); 124 125 drop_el(&info->args, info->spsr, info->entrypoint); 126 } else 127 raise_el(&info->args); 128 } 129 130 /* TODO: add a parameter for DAIF. not needed right now */ 131 unsigned long make_spsr(unsigned long target_el, 132 unsigned long target_sp, 133 unsigned long target_rw) 134 { 135 unsigned long spsr; 136 137 /* Disable all exceptions & setup the EL */ 138 spsr = (DAIF_FIQ_BIT | DAIF_IRQ_BIT | DAIF_ABT_BIT | DAIF_DBG_BIT) 139 << PSR_DAIF_SHIFT; 140 spsr |= PSR_MODE(target_rw, target_el, target_sp); 141 142 return spsr; 143 } 144 145 /******************************************************************************* 146 * The next two functions are the weak definitions. Platform specific 147 * code can override them if it wishes to. 148 ******************************************************************************/ 149 150 /******************************************************************************* 151 * Function that takes a memory layout into which BL31 has been either top or 152 * bottom loaded. Using this information, it populates bl31_mem_layout to tell 153 * BL31 how much memory it has access to and how much is available for use. It 154 * does not need the address where BL31 has been loaded as BL31 will reclaim 155 * all the memory used by BL2. 156 * TODO: Revisit if this and init_bl2_mem_layout can be replaced by a single 157 * routine. 158 ******************************************************************************/ 159 void init_bl31_mem_layout(const meminfo *bl2_mem_layout, 160 meminfo *bl31_mem_layout, 161 unsigned int load_type) 162 { 163 if (load_type == BOT_LOAD) { 164 /* 165 * ------------ ^ 166 * | BL2 | | 167 * |----------| ^ | BL2 168 * | | | BL2 free | total 169 * | | | size | size 170 * |----------| BL2 free base v | 171 * | BL31 | | 172 * ------------ BL2 total base v 173 */ 174 unsigned long bl31_size; 175 176 bl31_mem_layout->free_base = bl2_mem_layout->free_base; 177 178 bl31_size = bl2_mem_layout->free_base - bl2_mem_layout->total_base; 179 bl31_mem_layout->free_size = bl2_mem_layout->total_size - bl31_size; 180 } else { 181 /* 182 * ------------ ^ 183 * | BL31 | | 184 * |----------| ^ | BL2 185 * | | | BL2 free | total 186 * | | | size | size 187 * |----------| BL2 free base v | 188 * | BL2 | | 189 * ------------ BL2 total base v 190 */ 191 unsigned long bl2_size; 192 193 bl31_mem_layout->free_base = bl2_mem_layout->total_base; 194 195 bl2_size = bl2_mem_layout->free_base - bl2_mem_layout->total_base; 196 bl31_mem_layout->free_size = bl2_mem_layout->free_size + bl2_size; 197 } 198 199 bl31_mem_layout->total_base = bl2_mem_layout->total_base; 200 bl31_mem_layout->total_size = bl2_mem_layout->total_size; 201 bl31_mem_layout->attr = load_type; 202 203 flush_dcache_range((unsigned long) bl31_mem_layout, sizeof(meminfo)); 204 return; 205 } 206 207 /******************************************************************************* 208 * Function that takes a memory layout into which BL2 has been either top or 209 * bottom loaded along with the address where BL2 has been loaded in it. Using 210 * this information, it populates bl2_mem_layout to tell BL2 how much memory 211 * it has access to and how much is available for use. 212 ******************************************************************************/ 213 void init_bl2_mem_layout(meminfo *bl1_mem_layout, 214 meminfo *bl2_mem_layout, 215 unsigned int load_type, 216 unsigned long bl2_base) 217 { 218 unsigned tmp; 219 220 if (load_type == BOT_LOAD) { 221 bl2_mem_layout->total_base = bl2_base; 222 tmp = bl1_mem_layout->free_base - bl2_base; 223 bl2_mem_layout->total_size = bl1_mem_layout->free_size + tmp; 224 225 } else { 226 bl2_mem_layout->total_base = bl1_mem_layout->free_base; 227 tmp = bl1_mem_layout->total_base + bl1_mem_layout->total_size; 228 bl2_mem_layout->total_size = tmp - bl1_mem_layout->free_base; 229 } 230 231 bl2_mem_layout->free_base = bl1_mem_layout->free_base; 232 bl2_mem_layout->free_size = bl1_mem_layout->free_size; 233 bl2_mem_layout->attr = load_type; 234 235 flush_dcache_range((unsigned long) bl2_mem_layout, sizeof(meminfo)); 236 return; 237 } 238 239 static void dump_load_info(unsigned long image_load_addr, 240 unsigned long image_size, 241 const meminfo *mem_layout) 242 { 243 #if DEBUG 244 printf("Trying to load image at address 0x%lx, size = 0x%lx\r\n", 245 image_load_addr, image_size); 246 printf("Current memory layout:\r\n"); 247 printf(" total region = [0x%lx, 0x%lx]\r\n", mem_layout->total_base, 248 mem_layout->total_base + mem_layout->total_size); 249 printf(" free region = [0x%lx, 0x%lx]\r\n", mem_layout->free_base, 250 mem_layout->free_base + mem_layout->free_size); 251 #endif 252 } 253 254 /******************************************************************************* 255 * Generic function to load an image into the trusted RAM, 256 * given a name, extents of free memory & whether the image should be loaded at 257 * the bottom or top of the free memory. It updates the memory layout if the 258 * load is successful. 259 ******************************************************************************/ 260 unsigned long load_image(meminfo *mem_layout, 261 const char *image_name, 262 unsigned int load_type, 263 unsigned long fixed_addr) 264 { 265 io_dev_handle dev_handle; 266 io_handle image_handle; 267 void *image_spec; 268 unsigned long temp_image_base = 0; 269 unsigned long image_base = 0; 270 long offset = 0; 271 size_t image_size = 0; 272 size_t bytes_read = 0; 273 int io_result = IO_FAIL; 274 275 assert(mem_layout != NULL); 276 assert(image_name != NULL); 277 278 /* Obtain a reference to the image by querying the platform layer */ 279 io_result = plat_get_image_source(image_name, &dev_handle, &image_spec); 280 if (io_result != IO_SUCCESS) { 281 WARN("Failed to obtain reference to image '%s' (%i)\n", 282 image_name, io_result); 283 return 0; 284 } 285 286 /* Attempt to access the image */ 287 io_result = io_open(dev_handle, image_spec, &image_handle); 288 if (io_result != IO_SUCCESS) { 289 WARN("Failed to access image '%s' (%i)\n", 290 image_name, io_result); 291 return 0; 292 } 293 294 /* Find the size of the image */ 295 io_result = io_size(image_handle, &image_size); 296 if ((io_result != IO_SUCCESS) || (image_size == 0)) { 297 WARN("Failed to determine the size of the image '%s' file (%i)\n", 298 image_name, io_result); 299 goto fail; 300 } 301 302 /* See if we have enough space */ 303 if (image_size > mem_layout->free_size) { 304 WARN("Cannot load '%s' file: Not enough space.\n", 305 image_name); 306 dump_load_info(0, image_size, mem_layout); 307 goto fail; 308 } 309 310 switch (load_type) { 311 312 case TOP_LOAD: 313 314 /* Load the image in the top of free memory */ 315 temp_image_base = mem_layout->free_base + mem_layout->free_size; 316 temp_image_base -= image_size; 317 318 /* Page align base address and check whether the image still fits */ 319 image_base = page_align(temp_image_base, DOWN); 320 assert(image_base <= temp_image_base); 321 322 if (image_base < mem_layout->free_base) { 323 WARN("Cannot load '%s' file: Not enough space.\n", 324 image_name); 325 dump_load_info(image_base, image_size, mem_layout); 326 goto fail; 327 } 328 329 /* Calculate the amount of extra memory used due to alignment */ 330 offset = temp_image_base - image_base; 331 332 break; 333 334 case BOT_LOAD: 335 336 /* Load the BL2 image in the bottom of free memory */ 337 temp_image_base = mem_layout->free_base; 338 image_base = page_align(temp_image_base, UP); 339 assert(image_base >= temp_image_base); 340 341 /* Page align base address and check whether the image still fits */ 342 if (image_base + image_size > 343 mem_layout->free_base + mem_layout->free_size) { 344 WARN("Cannot load '%s' file: Not enough space.\n", 345 image_name); 346 dump_load_info(image_base, image_size, mem_layout); 347 goto fail; 348 } 349 350 /* Calculate the amount of extra memory used due to alignment */ 351 offset = image_base - temp_image_base; 352 353 break; 354 355 default: 356 assert(0); 357 358 } 359 360 /* 361 * Some images must be loaded at a fixed address, not a dynamic one. 362 * 363 * This has been implemented as a hack on top of the existing dynamic 364 * loading mechanism, for the time being. If the 'fixed_addr' function 365 * argument is different from zero, then it will force the load address. 366 * So we still have this principle of top/bottom loading but the code 367 * determining the load address is bypassed and the load address is 368 * forced to the fixed one. 369 * 370 * This can result in quite a lot of wasted space because we still use 371 * 1 sole meminfo structure to represent the extents of free memory, 372 * where we should use some sort of linked list. 373 * 374 * E.g. we want to load BL2 at address 0x04020000, the resulting memory 375 * layout should look as follows: 376 * ------------ 0x04040000 377 * | | <- Free space (1) 378 * |----------| 379 * | BL2 | 380 * |----------| 0x04020000 381 * | | <- Free space (2) 382 * |----------| 383 * | BL1 | 384 * ------------ 0x04000000 385 * 386 * But in the current hacky implementation, we'll need to specify 387 * whether BL2 is loaded at the top or bottom of the free memory. 388 * E.g. if BL2 is considered as top-loaded, the meminfo structure 389 * will give the following view of the memory, hiding the chunk of 390 * free memory above BL2: 391 * ------------ 0x04040000 392 * | | 393 * | | 394 * | BL2 | 395 * |----------| 0x04020000 396 * | | <- Free space (2) 397 * |----------| 398 * | BL1 | 399 * ------------ 0x04000000 400 */ 401 if (fixed_addr != 0) { 402 /* Load the image at the given address. */ 403 image_base = fixed_addr; 404 405 /* Check whether the image fits. */ 406 if ((image_base < mem_layout->free_base) || 407 (image_base + image_size > 408 mem_layout->free_base + mem_layout->free_size)) { 409 WARN("Cannot load '%s' file: Not enough space.\n", 410 image_name); 411 dump_load_info(image_base, image_size, mem_layout); 412 goto fail; 413 } 414 415 /* Check whether the fixed load address is page-aligned. */ 416 if (!is_page_aligned(image_base)) { 417 WARN("Cannot load '%s' file at unaligned address 0x%lx\n", 418 image_name, fixed_addr); 419 goto fail; 420 } 421 422 /* 423 * Calculate the amount of extra memory used due to fixed 424 * loading. 425 */ 426 if (load_type == TOP_LOAD) { 427 unsigned long max_addr, space_used; 428 /* 429 * ------------ max_addr 430 * | /wasted/ | | offset 431 * |..........|.............................. 432 * | image | | image_flen 433 * |----------| fixed_addr 434 * | | 435 * | | 436 * ------------ total_base 437 */ 438 max_addr = mem_layout->total_base + mem_layout->total_size; 439 /* 440 * Compute the amount of memory used by the image. 441 * Corresponds to all space above the image load 442 * address. 443 */ 444 space_used = max_addr - fixed_addr; 445 /* 446 * Calculate the amount of wasted memory within the 447 * amount of memory used by the image. 448 */ 449 offset = space_used - image_size; 450 } else /* BOT_LOAD */ 451 /* 452 * ------------ 453 * | | 454 * | | 455 * |----------| 456 * | image | 457 * |..........| fixed_addr 458 * | /wasted/ | | offset 459 * ------------ total_base 460 */ 461 offset = fixed_addr - mem_layout->total_base; 462 } 463 464 /* We have enough space so load the image now */ 465 /* TODO: Consider whether to try to recover/retry a partially successful read */ 466 io_result = io_read(image_handle, (void *)image_base, image_size, &bytes_read); 467 if ((io_result != IO_SUCCESS) || (bytes_read < image_size)) { 468 WARN("Failed to load '%s' file (%i)\n", image_name, io_result); 469 goto fail; 470 } 471 472 /* 473 * File has been successfully loaded. Update the free memory 474 * data structure & flush the contents of the TZRAM so that 475 * the next EL can see it. 476 */ 477 /* Update the memory contents */ 478 flush_dcache_range(image_base, image_size); 479 480 mem_layout->free_size -= image_size + offset; 481 482 /* Update the base of free memory since its moved up */ 483 if (load_type == BOT_LOAD) 484 mem_layout->free_base += offset + image_size; 485 486 exit: 487 io_result = io_close(image_handle); 488 /* Ignore improbable/unrecoverable error in 'close' */ 489 490 /* TODO: Consider maintaining open device connection from this bootloader stage */ 491 io_result = io_dev_close(dev_handle); 492 /* Ignore improbable/unrecoverable error in 'dev_close' */ 493 494 return image_base; 495 496 fail: image_base = 0; 497 goto exit; 498 } 499 500 /******************************************************************************* 501 * Run a loaded image from the given entry point. This could result in either 502 * dropping into a lower exception level or jumping to a higher exception level. 503 * The only way of doing the latter is through an SMC. In either case, setup the 504 * parameters for the EL change request correctly. 505 ******************************************************************************/ 506 void __dead2 run_image(unsigned long entrypoint, 507 unsigned long spsr, 508 unsigned long target_security_state, 509 void *first_arg, 510 void *second_arg) 511 { 512 el_change_info run_image_info; 513 unsigned long current_el = read_current_el(); 514 515 /* Tell next EL what we want done */ 516 run_image_info.args.arg0 = RUN_IMAGE; 517 run_image_info.entrypoint = entrypoint; 518 run_image_info.spsr = spsr; 519 run_image_info.security_state = target_security_state; 520 521 /* 522 * If we are EL3 then only an eret can take us to the desired 523 * exception level. Else for the time being assume that we have 524 * to jump to a higher EL and issue an SMC. Contents of argY 525 * will go into the general purpose register xY e.g. arg0->x0 526 */ 527 if (GET_EL(current_el) == MODE_EL3) { 528 run_image_info.args.arg1 = (unsigned long) first_arg; 529 run_image_info.args.arg2 = (unsigned long) second_arg; 530 } else { 531 run_image_info.args.arg1 = entrypoint; 532 run_image_info.args.arg2 = spsr; 533 run_image_info.args.arg3 = (unsigned long) first_arg; 534 run_image_info.args.arg4 = (unsigned long) second_arg; 535 } 536 537 change_el(&run_image_info); 538 } 539