23fb8cd807422da4597d610401266f5bef175de5
[oweals/u-boot.git] / cmd / mvebu / bubt.c
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 = env_get("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 #if CONFIG_IS_ENABLED(DM_MMC) && CONFIG_IS_ENABLED(MMC_WRITE)
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 *mtd;
315
316         mtd = get_nand_dev_by_index(nand_curr_device);
317         if (!mtd) {
318                 puts("\nno devices available\n");
319                 return -ENOMEDIUM;
320         }
321         block_size = mtd->erasesize;
322
323         /* Align U-Boot size to currently used blocksize */
324         image_size = ((image_size + (block_size - 1)) & (~(block_size - 1)));
325
326         /* Erase the U-BOOT image space */
327         printf("Erasing 0x%x - 0x%x:...", 0, (int)image_size);
328         ret = nand_erase(mtd, 0, image_size);
329         if (ret) {
330                 printf("Error!\n");
331                 goto error;
332         }
333         printf("Done!\n");
334
335         /* Write the image to flash */
336         printf("Writing %d bytes from 0x%lx to offset 0 ... ",
337                (int)image_size, get_load_addr());
338         ret = nand_write(mtd, 0, &image_size, (void *)get_load_addr());
339         if (ret)
340                 printf("Error!\n");
341         else
342                 printf("Done!\n");
343
344 error:
345         return ret;
346 }
347
348 static int is_nand_active(void)
349 {
350         return 1;
351 }
352
353 #else /* CONFIG_CMD_NAND */
354 static int nand_burn_image(size_t image_size)
355 {
356         return -ENODEV;
357 }
358
359 static int is_nand_active(void)
360 {
361         return 0;
362 }
363 #endif /* CONFIG_CMD_NAND */
364
365 /********************************************************************
366  *     USB services
367  ********************************************************************/
368 #if defined(CONFIG_USB_STORAGE) && defined(CONFIG_BLK)
369 static size_t usb_read_file(const char *file_name)
370 {
371         loff_t act_read = 0;
372         struct udevice *dev;
373         int rc;
374
375         usb_stop();
376
377         if (usb_init() < 0) {
378                 printf("Error: usb_init failed\n");
379                 return 0;
380         }
381
382         /* Try to recognize storage devices immediately */
383         blk_first_device(IF_TYPE_USB, &dev);
384         if (!dev) {
385                 printf("Error: USB storage device not found\n");
386                 return 0;
387         }
388
389         /* Always load from usb 0 */
390         if (fs_set_blk_dev("usb", "0", FS_TYPE_ANY)) {
391                 printf("Error: USB 0 not found\n");
392                 return 0;
393         }
394
395         /* Perfrom file read */
396         rc = fs_read(file_name, get_load_addr(), 0, 0, &act_read);
397         if (rc)
398                 return 0;
399
400         return act_read;
401 }
402
403 static int is_usb_active(void)
404 {
405         return 1;
406 }
407
408 #else /* defined(CONFIG_USB_STORAGE) && defined (CONFIG_BLK) */
409 static size_t usb_read_file(const char *file_name)
410 {
411         return 0;
412 }
413
414 static int is_usb_active(void)
415 {
416         return 0;
417 }
418 #endif /* defined(CONFIG_USB_STORAGE) && defined (CONFIG_BLK) */
419
420 /********************************************************************
421  *     Network services
422  ********************************************************************/
423 #ifdef CONFIG_CMD_NET
424 static size_t tftp_read_file(const char *file_name)
425 {
426         /* update global variable load_addr before tftp file from network */
427         load_addr = get_load_addr();
428         return net_loop(TFTPGET);
429 }
430
431 static int is_tftp_active(void)
432 {
433         return 1;
434 }
435
436 #else
437 static size_t tftp_read_file(const char *file_name)
438 {
439         return 0;
440 }
441
442 static int is_tftp_active(void)
443 {
444         return 0;
445 }
446 #endif /* CONFIG_CMD_NET */
447
448 enum bubt_devices {
449         BUBT_DEV_NET = 0,
450         BUBT_DEV_USB,
451         BUBT_DEV_MMC,
452         BUBT_DEV_SPI,
453         BUBT_DEV_NAND,
454
455         BUBT_MAX_DEV
456 };
457
458 struct bubt_dev bubt_devs[BUBT_MAX_DEV] = {
459         {"tftp", tftp_read_file, NULL, is_tftp_active},
460         {"usb",  usb_read_file,  NULL, is_usb_active},
461         {"mmc",  mmc_read_file,  mmc_burn_image, is_mmc_active},
462         {"spi",  NULL, spi_burn_image,  is_spi_active},
463         {"nand", NULL, nand_burn_image, is_nand_active},
464 };
465
466 static int bubt_write_file(struct bubt_dev *dst, size_t image_size)
467 {
468         if (!dst->write) {
469                 printf("Error: Write not supported on device %s\n", dst->name);
470                 return -ENOTSUPP;
471         }
472
473         return dst->write(image_size);
474 }
475
476 #if defined(CONFIG_ARMADA_8K)
477 u32 do_checksum32(u32 *start, int32_t len)
478 {
479         u32 sum = 0;
480         u32 *startp = start;
481
482         do {
483                 sum += *startp;
484                 startp++;
485                 len -= 4;
486         } while (len > 0);
487
488         return sum;
489 }
490
491 static int check_image_header(void)
492 {
493         struct mvebu_image_header *hdr =
494                         (struct mvebu_image_header *)get_load_addr();
495         u32 header_len = hdr->prolog_size;
496         u32 checksum;
497         u32 checksum_ref = hdr->prolog_checksum;
498
499         /*
500          * For now compare checksum, and magic. Later we can
501          * verify more stuff on the header like interface type, etc
502          */
503         if (hdr->magic != MAIN_HDR_MAGIC) {
504                 printf("ERROR: Bad MAGIC 0x%08x != 0x%08x\n",
505                        hdr->magic, MAIN_HDR_MAGIC);
506                 return -ENOEXEC;
507         }
508
509         /* The checksum value is discarded from checksum calculation */
510         hdr->prolog_checksum = 0;
511
512         checksum = do_checksum32((u32 *)hdr, header_len);
513         if (checksum != checksum_ref) {
514                 printf("Error: Bad Image checksum. 0x%x != 0x%x\n",
515                        checksum, checksum_ref);
516                 return -ENOEXEC;
517         }
518
519         /* Restore the checksum before writing */
520         hdr->prolog_checksum = checksum_ref;
521         printf("Image checksum...OK!\n");
522
523         return 0;
524 }
525 #elif defined(CONFIG_ARMADA_3700) /* Armada 3700 */
526 static int check_image_header(void)
527 {
528         struct common_tim_data *hdr = (struct common_tim_data *)get_load_addr();
529         int image_num;
530         u8 hash_160_output[SHA1_SUM_LEN];
531         u8 hash_256_output[SHA256_SUM_LEN];
532         sha1_context hash1_text;
533         sha256_context hash256_text;
534         u8 *hash_output;
535         u32 hash_algorithm_id;
536         u32 image_size_to_hash;
537         u32 flash_entry_addr;
538         u32 *hash_value;
539         u32 internal_hash[HASH_SUM_LEN];
540         const u8 *buff;
541         u32 num_of_image = hdr->num_images;
542         u32 version = hdr->version;
543         u32 trusted = hdr->trusted;
544
545         /* bubt checksum validation only supports nontrusted images */
546         if (trusted == 1) {
547                 printf("bypass image validation, ");
548                 printf("only untrusted image is supported now\n");
549                 return 0;
550         }
551         /* only supports image version 3.5 and 3.6 */
552         if (version != IMAGE_VERSION_3_5_0 && version != IMAGE_VERSION_3_6_0) {
553                 printf("Error: Unsupported Image version = 0x%08x\n", version);
554                 return -ENOEXEC;
555         }
556         /* validate images hash value */
557         for (image_num = 0; image_num < num_of_image; image_num++) {
558                 struct mvebu_image_info *info =
559                                 (struct mvebu_image_info *)(get_load_addr() +
560                                 sizeof(struct common_tim_data) +
561                                 image_num * sizeof(struct mvebu_image_info));
562                 hash_algorithm_id = info->hash_algorithm_id;
563                 image_size_to_hash = info->image_size_to_hash;
564                 flash_entry_addr = info->flash_entry_addr;
565                 hash_value = info->hash;
566                 buff = (const u8 *)(get_load_addr() + flash_entry_addr);
567
568                 if (image_num == 0) {
569                         /*
570                          * The first image includes hash values in its content.
571                          * For hash calculation, we need to save the original
572                          * hash values to a local variable that will be
573                          * copied back for comparsion and set all zeros to
574                          * the orignal hash values for calculating new value.
575                          * First image original format :
576                          * x...x (datum1) x...x(orig. hash values) x...x(datum2)
577                          * Replaced first image format :
578                          * x...x (datum1) 0...0(hash values) x...x(datum2)
579                          */
580                         memcpy(internal_hash, hash_value,
581                                sizeof(internal_hash));
582                         memset(hash_value, 0, sizeof(internal_hash));
583                 }
584                 if (image_size_to_hash == 0) {
585                         printf("Warning: Image_%d hash checksum is disabled, ",
586                                image_num);
587                         printf("skip the image validation.\n");
588                         continue;
589                 }
590                 switch (hash_algorithm_id) {
591                 case SHA1_SUM_LEN:
592                         sha1_starts(&hash1_text);
593                         sha1_update(&hash1_text, buff, image_size_to_hash);
594                         sha1_finish(&hash1_text, hash_160_output);
595                         hash_output = hash_160_output;
596                         break;
597                 case SHA256_SUM_LEN:
598                         sha256_starts(&hash256_text);
599                         sha256_update(&hash256_text, buff, image_size_to_hash);
600                         sha256_finish(&hash256_text, hash_256_output);
601                         hash_output = hash_256_output;
602                         break;
603                 default:
604                         printf("Error: Unsupported hash_algorithm_id = %d\n",
605                                hash_algorithm_id);
606                         return -ENOEXEC;
607                 }
608                 if (image_num == 0)
609                         memcpy(hash_value, internal_hash,
610                                sizeof(internal_hash));
611                 if (memcmp(hash_value, hash_output, hash_algorithm_id) != 0) {
612                         printf("Error: Image_%d checksum is not correct\n",
613                                image_num);
614                         return -ENOEXEC;
615                 }
616         }
617         printf("Image checksum...OK!\n");
618
619         return 0;
620 }
621
622 #else /* Not ARMADA? */
623 static int check_image_header(void)
624 {
625         printf("bubt cmd does not support this SoC device or family!\n");
626         return -ENOEXEC;
627 }
628 #endif
629
630 static int bubt_verify(size_t image_size)
631 {
632         int err;
633
634         /* Check a correct image header exists */
635         err = check_image_header();
636         if (err) {
637                 printf("Error: Image header verification failed\n");
638                 return err;
639         }
640
641         return 0;
642 }
643
644 static int bubt_read_file(struct bubt_dev *src)
645 {
646         size_t image_size;
647
648         if (!src->read) {
649                 printf("Error: Read not supported on device \"%s\"\n",
650                        src->name);
651                 return 0;
652         }
653
654         image_size = src->read(net_boot_file_name);
655         if (image_size <= 0) {
656                 printf("Error: Failed to read file %s from %s\n",
657                        net_boot_file_name, src->name);
658                 return 0;
659         }
660
661         return image_size;
662 }
663
664 static int bubt_is_dev_active(struct bubt_dev *dev)
665 {
666         if (!dev->active) {
667                 printf("Device \"%s\" not supported by U-BOOT image\n",
668                        dev->name);
669                 return 0;
670         }
671
672         if (!dev->active()) {
673                 printf("Device \"%s\" is inactive\n", dev->name);
674                 return 0;
675         }
676
677         return 1;
678 }
679
680 struct bubt_dev *find_bubt_dev(char *dev_name)
681 {
682         int dev;
683
684         for (dev = 0; dev < BUBT_MAX_DEV; dev++) {
685                 if (strcmp(bubt_devs[dev].name, dev_name) == 0)
686                         return &bubt_devs[dev];
687         }
688
689         return 0;
690 }
691
692 #define DEFAULT_BUBT_SRC "tftp"
693
694 #ifndef DEFAULT_BUBT_DST
695 #ifdef CONFIG_MVEBU_SPI_BOOT
696 #define DEFAULT_BUBT_DST "spi"
697 #elif defined(CONFIG_MVEBU_NAND_BOOT)
698 #define DEFAULT_BUBT_DST "nand"
699 #elif defined(CONFIG_MVEBU_MMC_BOOT)
700 #define DEFAULT_BUBT_DST "mmc"
701 else
702 #define DEFAULT_BUBT_DST "error"
703 #endif
704 #endif /* DEFAULT_BUBT_DST */
705
706 int do_bubt_cmd(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
707 {
708         struct bubt_dev *src, *dst;
709         size_t image_size;
710         char src_dev_name[8];
711         char dst_dev_name[8];
712         char *name;
713         int  err;
714
715         if (argc < 2)
716                 copy_filename(net_boot_file_name,
717                               CONFIG_MVEBU_UBOOT_DFLT_NAME,
718                               sizeof(net_boot_file_name));
719         else
720                 copy_filename(net_boot_file_name, argv[1],
721                               sizeof(net_boot_file_name));
722
723         if (argc >= 3) {
724                 strncpy(dst_dev_name, argv[2], 8);
725         } else {
726                 name = DEFAULT_BUBT_DST;
727                 strncpy(dst_dev_name, name, 8);
728         }
729
730         if (argc >= 4)
731                 strncpy(src_dev_name, argv[3], 8);
732         else
733                 strncpy(src_dev_name, DEFAULT_BUBT_SRC, 8);
734
735         /* Figure out the destination device */
736         dst = find_bubt_dev(dst_dev_name);
737         if (!dst) {
738                 printf("Error: Unknown destination \"%s\"\n", dst_dev_name);
739                 return -EINVAL;
740         }
741
742         if (!bubt_is_dev_active(dst))
743                 return -ENODEV;
744
745         /* Figure out the source device */
746         src = find_bubt_dev(src_dev_name);
747         if (!src) {
748                 printf("Error: Unknown source \"%s\"\n", src_dev_name);
749                 return 1;
750         }
751
752         if (!bubt_is_dev_active(src))
753                 return -ENODEV;
754
755         printf("Burning U-BOOT image \"%s\" from \"%s\" to \"%s\"\n",
756                net_boot_file_name, src->name, dst->name);
757
758         image_size = bubt_read_file(src);
759         if (!image_size)
760                 return -EIO;
761
762         err = bubt_verify(image_size);
763         if (err)
764                 return err;
765
766         err = bubt_write_file(dst, image_size);
767         if (err)
768                 return err;
769
770         return 0;
771 }
772
773 U_BOOT_CMD(
774         bubt, 4, 0, do_bubt_cmd,
775         "Burn a u-boot image to flash",
776         "[file-name] [destination [source]]\n"
777         "\t-file-name     The image file name to burn. Default = flash-image.bin\n"
778         "\t-destination   Flash to burn to [spi, nand, mmc]. Default = active boot device\n"
779         "\t-source        The source to load image from [tftp, usb, mmc]. Default = tftp\n"
780         "Examples:\n"
781         "\tbubt - Burn flash-image.bin from tftp to active boot device\n"
782         "\tbubt flash-image-new.bin nand - Burn flash-image-new.bin from tftp to NAND flash\n"
783         "\tbubt backup-flash-image.bin mmc usb - Burn backup-flash-image.bin from usb to MMC\n"
784
785 );