1 /* 2 * Copyright (C) 2016 Marvell International Ltd. 3 * 4 * SPDX-License-Identifier: GPL-2.0 5 * https://spdx.org/licenses 6 */ 7 8 #include <config.h> 9 #include <common.h> 10 #include <command.h> 11 #include <vsprintf.h> 12 #include <errno.h> 13 #include <dm.h> 14 15 #include <spi_flash.h> 16 #include <spi.h> 17 #include <nand.h> 18 #include <usb.h> 19 #include <fs.h> 20 #include <mmc.h> 21 #ifdef CONFIG_BLK 22 #include <blk.h> 23 #endif 24 #include <u-boot/sha1.h> 25 #include <u-boot/sha256.h> 26 27 #ifndef CONFIG_SYS_MMC_ENV_DEV 28 #define CONFIG_SYS_MMC_ENV_DEV 0 29 #endif 30 31 #if defined(CONFIG_ARMADA_8K) 32 #define MAIN_HDR_MAGIC 0xB105B002 33 34 struct mvebu_image_header { 35 u32 magic; /* 0-3 */ 36 u32 prolog_size; /* 4-7 */ 37 u32 prolog_checksum; /* 8-11 */ 38 u32 boot_image_size; /* 12-15 */ 39 u32 boot_image_checksum; /* 16-19 */ 40 u32 rsrvd0; /* 20-23 */ 41 u32 load_addr; /* 24-27 */ 42 u32 exec_addr; /* 28-31 */ 43 u8 uart_cfg; /* 32 */ 44 u8 baudrate; /* 33 */ 45 u8 ext_count; /* 34 */ 46 u8 aux_flags; /* 35 */ 47 u32 io_arg_0; /* 36-39 */ 48 u32 io_arg_1; /* 40-43 */ 49 u32 io_arg_2; /* 43-47 */ 50 u32 io_arg_3; /* 48-51 */ 51 u32 rsrvd1; /* 52-55 */ 52 u32 rsrvd2; /* 56-59 */ 53 u32 rsrvd3; /* 60-63 */ 54 }; 55 #elif defined(CONFIG_ARMADA_3700) /* A3700 */ 56 #define HASH_SUM_LEN 16 57 #define IMAGE_VERSION_3_6_0 0x030600 58 #define IMAGE_VERSION_3_5_0 0x030500 59 60 struct common_tim_data { 61 u32 version; 62 u32 identifier; 63 u32 trusted; 64 u32 issue_date; 65 u32 oem_unique_id; 66 u32 reserved[5]; /* Reserve 20 bytes */ 67 u32 boot_flash_sign; 68 u32 num_images; 69 u32 num_keys; 70 u32 size_of_reserved; 71 }; 72 73 struct mvebu_image_info { 74 u32 image_id; 75 u32 next_image_id; 76 u32 flash_entry_addr; 77 u32 load_addr; 78 u32 image_size; 79 u32 image_size_to_hash; 80 u32 hash_algorithm_id; 81 u32 hash[HASH_SUM_LEN]; /* Reserve 512 bits for the hash */ 82 u32 partition_number; 83 u32 enc_algorithm_id; 84 u32 encrypt_start_offset; 85 u32 encrypt_size; 86 }; 87 #endif /* CONFIG_ARMADA_XXX */ 88 89 struct bubt_dev { 90 char name[8]; 91 size_t (*read)(const char *file_name); 92 int (*write)(size_t image_size); 93 int (*active)(void); 94 }; 95 96 static ulong get_load_addr(void) 97 { 98 const char *addr_str; 99 unsigned long addr; 100 101 addr_str = getenv("loadaddr"); 102 if (addr_str) 103 addr = simple_strtoul(addr_str, NULL, 16); 104 else 105 addr = CONFIG_SYS_LOAD_ADDR; 106 107 return addr; 108 } 109 110 /******************************************************************** 111 * eMMC services 112 ********************************************************************/ 113 #ifdef CONFIG_DM_MMC 114 static int mmc_burn_image(size_t image_size) 115 { 116 struct mmc *mmc; 117 lbaint_t start_lba; 118 lbaint_t blk_count; 119 ulong blk_written; 120 int err; 121 const u8 mmc_dev_num = CONFIG_SYS_MMC_ENV_DEV; 122 #ifdef CONFIG_BLK 123 struct blk_desc *blk_desc; 124 #endif 125 mmc = find_mmc_device(mmc_dev_num); 126 if (!mmc) { 127 printf("No SD/MMC/eMMC card found\n"); 128 return -ENOMEDIUM; 129 } 130 131 err = mmc_init(mmc); 132 if (err) { 133 printf("%s(%d) init failed\n", IS_SD(mmc) ? "SD" : "MMC", 134 mmc_dev_num); 135 return err; 136 } 137 138 #ifdef CONFIG_SYS_MMC_ENV_PART 139 if (mmc->part_num != CONFIG_SYS_MMC_ENV_PART) { 140 err = mmc_switch_part(mmc_dev_num, CONFIG_SYS_MMC_ENV_PART); 141 if (err) { 142 printf("MMC partition switch failed\n"); 143 return err; 144 } 145 } 146 #endif 147 148 /* SD reserves LBA-0 for MBR and boots from LBA-1, 149 * MMC/eMMC boots from LBA-0 150 */ 151 start_lba = IS_SD(mmc) ? 1 : 0; 152 #ifdef CONFIG_BLK 153 blk_count = image_size / mmc->write_bl_len; 154 if (image_size % mmc->write_bl_len) 155 blk_count += 1; 156 157 blk_desc = mmc_get_blk_desc(mmc); 158 if (!blk_desc) { 159 printf("Error - failed to obtain block descriptor\n"); 160 return -ENODEV; 161 } 162 blk_written = blk_dwrite(blk_desc, start_lba, blk_count, 163 (void *)get_load_addr()); 164 #else 165 blk_count = image_size / mmc->block_dev.blksz; 166 if (image_size % mmc->block_dev.blksz) 167 blk_count += 1; 168 169 blk_written = mmc->block_dev.block_write(mmc_dev_num, 170 start_lba, blk_count, 171 (void *)get_load_addr()); 172 #endif /* CONFIG_BLK */ 173 if (blk_written != blk_count) { 174 printf("Error - written %#lx blocks\n", blk_written); 175 return -ENOSPC; 176 } 177 printf("Done!\n"); 178 179 #ifdef CONFIG_SYS_MMC_ENV_PART 180 if (mmc->part_num != CONFIG_SYS_MMC_ENV_PART) 181 mmc_switch_part(mmc_dev_num, mmc->part_num); 182 #endif 183 184 return 0; 185 } 186 187 static size_t mmc_read_file(const char *file_name) 188 { 189 loff_t act_read = 0; 190 int rc; 191 struct mmc *mmc; 192 const u8 mmc_dev_num = CONFIG_SYS_MMC_ENV_DEV; 193 194 mmc = find_mmc_device(mmc_dev_num); 195 if (!mmc) { 196 printf("No SD/MMC/eMMC card found\n"); 197 return 0; 198 } 199 200 if (mmc_init(mmc)) { 201 printf("%s(%d) init failed\n", IS_SD(mmc) ? "SD" : "MMC", 202 mmc_dev_num); 203 return 0; 204 } 205 206 /* Load from data partition (0) */ 207 if (fs_set_blk_dev("mmc", "0", FS_TYPE_ANY)) { 208 printf("Error: MMC 0 not found\n"); 209 return 0; 210 } 211 212 /* Perfrom file read */ 213 rc = fs_read(file_name, get_load_addr(), 0, 0, &act_read); 214 if (rc) 215 return 0; 216 217 return act_read; 218 } 219 220 static int is_mmc_active(void) 221 { 222 return 1; 223 } 224 #else /* CONFIG_DM_MMC */ 225 static int mmc_burn_image(size_t image_size) 226 { 227 return -ENODEV; 228 } 229 230 static size_t mmc_read_file(const char *file_name) 231 { 232 return 0; 233 } 234 235 static int is_mmc_active(void) 236 { 237 return 0; 238 } 239 #endif /* CONFIG_DM_MMC */ 240 241 /******************************************************************** 242 * SPI services 243 ********************************************************************/ 244 #ifdef CONFIG_SPI_FLASH 245 static int spi_burn_image(size_t image_size) 246 { 247 int ret; 248 struct spi_flash *flash; 249 u32 erase_bytes; 250 251 /* Probe the SPI bus to get the flash device */ 252 flash = spi_flash_probe(CONFIG_ENV_SPI_BUS, 253 CONFIG_ENV_SPI_CS, 254 CONFIG_SF_DEFAULT_SPEED, 255 CONFIG_SF_DEFAULT_MODE); 256 if (!flash) { 257 printf("Failed to probe SPI Flash\n"); 258 return -ENOMEDIUM; 259 } 260 261 #ifdef CONFIG_SPI_FLASH_PROTECTION 262 spi_flash_protect(flash, 0); 263 #endif 264 erase_bytes = image_size + 265 (flash->erase_size - image_size % flash->erase_size); 266 printf("Erasing %d bytes (%d blocks) at offset 0 ...", 267 erase_bytes, erase_bytes / flash->erase_size); 268 ret = spi_flash_erase(flash, 0, erase_bytes); 269 if (ret) 270 printf("Error!\n"); 271 else 272 printf("Done!\n"); 273 274 printf("Writing %d bytes from 0x%lx to offset 0 ...", 275 (int)image_size, get_load_addr()); 276 ret = spi_flash_write(flash, 0, image_size, (void *)get_load_addr()); 277 if (ret) 278 printf("Error!\n"); 279 else 280 printf("Done!\n"); 281 282 #ifdef CONFIG_SPI_FLASH_PROTECTION 283 spi_flash_protect(flash, 1); 284 #endif 285 286 return ret; 287 } 288 289 static int is_spi_active(void) 290 { 291 return 1; 292 } 293 294 #else /* CONFIG_SPI_FLASH */ 295 static int spi_burn_image(size_t image_size) 296 { 297 return -ENODEV; 298 } 299 300 static int is_spi_active(void) 301 { 302 return 0; 303 } 304 #endif /* CONFIG_SPI_FLASH */ 305 306 /******************************************************************** 307 * NAND services 308 ********************************************************************/ 309 #ifdef CONFIG_CMD_NAND 310 static int nand_burn_image(size_t image_size) 311 { 312 int ret; 313 uint32_t block_size; 314 struct mtd_info *nand; 315 int dev = nand_curr_device; 316 317 if ((dev < 0) || (dev >= CONFIG_SYS_MAX_NAND_DEVICE) || 318 (!nand_info[dev]->name)) { 319 puts("\nno devices available\n"); 320 return -ENOMEDIUM; 321 } 322 nand = nand_info[dev]; 323 block_size = nand->erasesize; 324 325 /* Align U-Boot size to currently used blocksize */ 326 image_size = ((image_size + (block_size - 1)) & (~(block_size - 1))); 327 328 /* Erase the U-BOOT image space */ 329 printf("Erasing 0x%x - 0x%x:...", 0, (int)image_size); 330 ret = nand_erase(nand, 0, image_size); 331 if (ret) { 332 printf("Error!\n"); 333 goto error; 334 } 335 printf("Done!\n"); 336 337 /* Write the image to flash */ 338 printf("Writing %d bytes from 0x%lx to offset 0 ... ", 339 (int)image_size, get_load_addr()); 340 ret = nand_write(nand, 0, &image_size, (void *)get_load_addr()); 341 if (ret) 342 printf("Error!\n"); 343 else 344 printf("Done!\n"); 345 346 error: 347 return ret; 348 } 349 350 static int is_nand_active(void) 351 { 352 return 1; 353 } 354 355 #else /* CONFIG_CMD_NAND */ 356 static int nand_burn_image(size_t image_size) 357 { 358 return -ENODEV; 359 } 360 361 static int is_nand_active(void) 362 { 363 return 0; 364 } 365 #endif /* CONFIG_CMD_NAND */ 366 367 /******************************************************************** 368 * USB services 369 ********************************************************************/ 370 #if defined(CONFIG_USB_STORAGE) && defined(CONFIG_BLK) 371 static size_t usb_read_file(const char *file_name) 372 { 373 loff_t act_read = 0; 374 struct udevice *dev; 375 int rc; 376 377 usb_stop(); 378 379 if (usb_init() < 0) { 380 printf("Error: usb_init failed\n"); 381 return 0; 382 } 383 384 /* Try to recognize storage devices immediately */ 385 blk_first_device(IF_TYPE_USB, &dev); 386 if (!dev) { 387 printf("Error: USB storage device not found\n"); 388 return 0; 389 } 390 391 /* Always load from usb 0 */ 392 if (fs_set_blk_dev("usb", "0", FS_TYPE_ANY)) { 393 printf("Error: USB 0 not found\n"); 394 return 0; 395 } 396 397 /* Perfrom file read */ 398 rc = fs_read(file_name, get_load_addr(), 0, 0, &act_read); 399 if (rc) 400 return 0; 401 402 return act_read; 403 } 404 405 static int is_usb_active(void) 406 { 407 return 1; 408 } 409 410 #else /* defined(CONFIG_USB_STORAGE) && defined (CONFIG_BLK) */ 411 static size_t usb_read_file(const char *file_name) 412 { 413 return 0; 414 } 415 416 static int is_usb_active(void) 417 { 418 return 0; 419 } 420 #endif /* defined(CONFIG_USB_STORAGE) && defined (CONFIG_BLK) */ 421 422 /******************************************************************** 423 * Network services 424 ********************************************************************/ 425 #ifdef CONFIG_CMD_NET 426 static size_t tftp_read_file(const char *file_name) 427 { 428 /* update global variable load_addr before tftp file from network */ 429 load_addr = get_load_addr(); 430 return net_loop(TFTPGET); 431 } 432 433 static int is_tftp_active(void) 434 { 435 return 1; 436 } 437 438 #else 439 static size_t tftp_read_file(const char *file_name) 440 { 441 return 0; 442 } 443 444 static int is_tftp_active(void) 445 { 446 return 0; 447 } 448 #endif /* CONFIG_CMD_NET */ 449 450 enum bubt_devices { 451 BUBT_DEV_NET = 0, 452 BUBT_DEV_USB, 453 BUBT_DEV_MMC, 454 BUBT_DEV_SPI, 455 BUBT_DEV_NAND, 456 457 BUBT_MAX_DEV 458 }; 459 460 struct bubt_dev bubt_devs[BUBT_MAX_DEV] = { 461 {"tftp", tftp_read_file, NULL, is_tftp_active}, 462 {"usb", usb_read_file, NULL, is_usb_active}, 463 {"mmc", mmc_read_file, mmc_burn_image, is_mmc_active}, 464 {"spi", NULL, spi_burn_image, is_spi_active}, 465 {"nand", NULL, nand_burn_image, is_nand_active}, 466 }; 467 468 static int bubt_write_file(struct bubt_dev *dst, size_t image_size) 469 { 470 if (!dst->write) { 471 printf("Error: Write not supported on device %s\n", dst->name); 472 return -ENOTSUPP; 473 } 474 475 return dst->write(image_size); 476 } 477 478 #if defined(CONFIG_ARMADA_8K) 479 u32 do_checksum32(u32 *start, int32_t len) 480 { 481 u32 sum = 0; 482 u32 *startp = start; 483 484 do { 485 sum += *startp; 486 startp++; 487 len -= 4; 488 } while (len > 0); 489 490 return sum; 491 } 492 493 static int check_image_header(void) 494 { 495 struct mvebu_image_header *hdr = 496 (struct mvebu_image_header *)get_load_addr(); 497 u32 header_len = hdr->prolog_size; 498 u32 checksum; 499 u32 checksum_ref = hdr->prolog_checksum; 500 501 /* 502 * For now compare checksum, and magic. Later we can 503 * verify more stuff on the header like interface type, etc 504 */ 505 if (hdr->magic != MAIN_HDR_MAGIC) { 506 printf("ERROR: Bad MAGIC 0x%08x != 0x%08x\n", 507 hdr->magic, MAIN_HDR_MAGIC); 508 return -ENOEXEC; 509 } 510 511 /* The checksum value is discarded from checksum calculation */ 512 hdr->prolog_checksum = 0; 513 514 checksum = do_checksum32((u32 *)hdr, header_len); 515 if (checksum != checksum_ref) { 516 printf("Error: Bad Image checksum. 0x%x != 0x%x\n", 517 checksum, checksum_ref); 518 return -ENOEXEC; 519 } 520 521 /* Restore the checksum before writing */ 522 hdr->prolog_checksum = checksum_ref; 523 printf("Image checksum...OK!\n"); 524 525 return 0; 526 } 527 #elif defined(CONFIG_ARMADA_3700) /* Armada 3700 */ 528 static int check_image_header(void) 529 { 530 struct common_tim_data *hdr = (struct common_tim_data *)get_load_addr(); 531 int image_num; 532 u8 hash_160_output[SHA1_SUM_LEN]; 533 u8 hash_256_output[SHA256_SUM_LEN]; 534 sha1_context hash1_text; 535 sha256_context hash256_text; 536 u8 *hash_output; 537 u32 hash_algorithm_id; 538 u32 image_size_to_hash; 539 u32 flash_entry_addr; 540 u32 *hash_value; 541 u32 internal_hash[HASH_SUM_LEN]; 542 const u8 *buff; 543 u32 num_of_image = hdr->num_images; 544 u32 version = hdr->version; 545 u32 trusted = hdr->trusted; 546 547 /* bubt checksum validation only supports nontrusted images */ 548 if (trusted == 1) { 549 printf("bypass image validation, "); 550 printf("only untrusted image is supported now\n"); 551 return 0; 552 } 553 /* only supports image version 3.5 and 3.6 */ 554 if (version != IMAGE_VERSION_3_5_0 && version != IMAGE_VERSION_3_6_0) { 555 printf("Error: Unsupported Image version = 0x%08x\n", version); 556 return -ENOEXEC; 557 } 558 /* validate images hash value */ 559 for (image_num = 0; image_num < num_of_image; image_num++) { 560 struct mvebu_image_info *info = 561 (struct mvebu_image_info *)(get_load_addr() + 562 sizeof(struct common_tim_data) + 563 image_num * sizeof(struct mvebu_image_info)); 564 hash_algorithm_id = info->hash_algorithm_id; 565 image_size_to_hash = info->image_size_to_hash; 566 flash_entry_addr = info->flash_entry_addr; 567 hash_value = info->hash; 568 buff = (const u8 *)(get_load_addr() + flash_entry_addr); 569 570 if (image_num == 0) { 571 /* 572 * The first image includes hash values in its content. 573 * For hash calculation, we need to save the original 574 * hash values to a local variable that will be 575 * copied back for comparsion and set all zeros to 576 * the orignal hash values for calculating new value. 577 * First image original format : 578 * x...x (datum1) x...x(orig. hash values) x...x(datum2) 579 * Replaced first image format : 580 * x...x (datum1) 0...0(hash values) x...x(datum2) 581 */ 582 memcpy(internal_hash, hash_value, 583 sizeof(internal_hash)); 584 memset(hash_value, 0, sizeof(internal_hash)); 585 } 586 if (image_size_to_hash == 0) { 587 printf("Warning: Image_%d hash checksum is disabled, ", 588 image_num); 589 printf("skip the image validation.\n"); 590 continue; 591 } 592 switch (hash_algorithm_id) { 593 case SHA1_SUM_LEN: 594 sha1_starts(&hash1_text); 595 sha1_update(&hash1_text, buff, image_size_to_hash); 596 sha1_finish(&hash1_text, hash_160_output); 597 hash_output = hash_160_output; 598 break; 599 case SHA256_SUM_LEN: 600 sha256_starts(&hash256_text); 601 sha256_update(&hash256_text, buff, image_size_to_hash); 602 sha256_finish(&hash256_text, hash_256_output); 603 hash_output = hash_256_output; 604 break; 605 default: 606 printf("Error: Unsupported hash_algorithm_id = %d\n", 607 hash_algorithm_id); 608 return -ENOEXEC; 609 } 610 if (image_num == 0) 611 memcpy(hash_value, internal_hash, 612 sizeof(internal_hash)); 613 if (memcmp(hash_value, hash_output, hash_algorithm_id) != 0) { 614 printf("Error: Image_%d checksum is not correct\n", 615 image_num); 616 return -ENOEXEC; 617 } 618 } 619 printf("Image checksum...OK!\n"); 620 621 return 0; 622 } 623 624 #else /* Not ARMADA? */ 625 static int check_image_header(void) 626 { 627 printf("bubt cmd does not support this SoC device or family!\n"); 628 return -ENOEXEC; 629 } 630 #endif 631 632 static int bubt_verify(size_t image_size) 633 { 634 int err; 635 636 /* Check a correct image header exists */ 637 err = check_image_header(); 638 if (err) { 639 printf("Error: Image header verification failed\n"); 640 return err; 641 } 642 643 return 0; 644 } 645 646 static int bubt_read_file(struct bubt_dev *src) 647 { 648 size_t image_size; 649 650 if (!src->read) { 651 printf("Error: Read not supported on device \"%s\"\n", 652 src->name); 653 return 0; 654 } 655 656 image_size = src->read(net_boot_file_name); 657 if (image_size <= 0) { 658 printf("Error: Failed to read file %s from %s\n", 659 net_boot_file_name, src->name); 660 return 0; 661 } 662 663 return image_size; 664 } 665 666 static int bubt_is_dev_active(struct bubt_dev *dev) 667 { 668 if (!dev->active) { 669 printf("Device \"%s\" not supported by U-BOOT image\n", 670 dev->name); 671 return 0; 672 } 673 674 if (!dev->active()) { 675 printf("Device \"%s\" is inactive\n", dev->name); 676 return 0; 677 } 678 679 return 1; 680 } 681 682 struct bubt_dev *find_bubt_dev(char *dev_name) 683 { 684 int dev; 685 686 for (dev = 0; dev < BUBT_MAX_DEV; dev++) { 687 if (strcmp(bubt_devs[dev].name, dev_name) == 0) 688 return &bubt_devs[dev]; 689 } 690 691 return 0; 692 } 693 694 #define DEFAULT_BUBT_SRC "tftp" 695 696 #ifndef DEFAULT_BUBT_DST 697 #ifdef CONFIG_MVEBU_SPI_BOOT 698 #define DEFAULT_BUBT_DST "spi" 699 #elif defined(CONFIG_MVEBU_NAND_BOOT) 700 #define DEFAULT_BUBT_DST "nand" 701 #elif defined(CONFIG_MVEBU_MMC_BOOT) 702 #define DEFAULT_BUBT_DST "mmc" 703 else 704 #define DEFAULT_BUBT_DST "error" 705 #endif 706 #endif /* DEFAULT_BUBT_DST */ 707 708 int do_bubt_cmd(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]) 709 { 710 struct bubt_dev *src, *dst; 711 size_t image_size; 712 char src_dev_name[8]; 713 char dst_dev_name[8]; 714 char *name; 715 int err; 716 717 if (argc < 2) 718 copy_filename(net_boot_file_name, 719 CONFIG_MVEBU_UBOOT_DFLT_NAME, 720 sizeof(net_boot_file_name)); 721 else 722 copy_filename(net_boot_file_name, argv[1], 723 sizeof(net_boot_file_name)); 724 725 if (argc >= 3) { 726 strncpy(dst_dev_name, argv[2], 8); 727 } else { 728 name = DEFAULT_BUBT_DST; 729 strncpy(dst_dev_name, name, 8); 730 } 731 732 if (argc >= 4) 733 strncpy(src_dev_name, argv[3], 8); 734 else 735 strncpy(src_dev_name, DEFAULT_BUBT_SRC, 8); 736 737 /* Figure out the destination device */ 738 dst = find_bubt_dev(dst_dev_name); 739 if (!dst) { 740 printf("Error: Unknown destination \"%s\"\n", dst_dev_name); 741 return -EINVAL; 742 } 743 744 if (!bubt_is_dev_active(dst)) 745 return -ENODEV; 746 747 /* Figure out the source device */ 748 src = find_bubt_dev(src_dev_name); 749 if (!src) { 750 printf("Error: Unknown source \"%s\"\n", src_dev_name); 751 return 1; 752 } 753 754 if (!bubt_is_dev_active(src)) 755 return -ENODEV; 756 757 printf("Burning U-BOOT image \"%s\" from \"%s\" to \"%s\"\n", 758 net_boot_file_name, src->name, dst->name); 759 760 image_size = bubt_read_file(src); 761 if (!image_size) 762 return -EIO; 763 764 err = bubt_verify(image_size); 765 if (err) 766 return err; 767 768 err = bubt_write_file(dst, image_size); 769 if (err) 770 return err; 771 772 return 0; 773 } 774 775 U_BOOT_CMD( 776 bubt, 4, 0, do_bubt_cmd, 777 "Burn a u-boot image to flash", 778 "[file-name] [destination [source]]\n" 779 "\t-file-name The image file name to burn. Default = flash-image.bin\n" 780 "\t-destination Flash to burn to [spi, nand, mmc]. Default = active boot device\n" 781 "\t-source The source to load image from [tftp, usb, mmc]. Default = tftp\n" 782 "Examples:\n" 783 "\tbubt - Burn flash-image.bin from tftp to active boot device\n" 784 "\tbubt flash-image-new.bin nand - Burn flash-image-new.bin from tftp to NAND flash\n" 785 "\tbubt backup-flash-image.bin mmc usb - Burn backup-flash-image.bin from usb to MMC\n" 786 787 ); 788