tools/mkimage.c

   1 /*
   2  * (C) Copyright 2008 Semihalf
   3  *
   4  * (C) Copyright 2000-2009
   5  * DENX Software Engineering
   6  * Wolfgang Denk, wd@denx.de
   7  *
   8  * SPDX-License-Identifier:     GPL-2.0+
   9  */
  10
  11 #include "mkimage.h"
  12 #include "imximage.h"
  13 #include <image.h>
  14 #include <version.h>
  15
  16 static void copy_file(int, const char *, int);
  17
  18 /* parameters initialized by core will be used by the image type code */
  19 static struct image_tool_params params = {
  20         .os = IH_OS_LINUX,
  21         .arch = IH_ARCH_PPC,
  22         .type = IH_TYPE_KERNEL,
  23         .comp = IH_COMP_GZIP,
  24         .dtc = MKIMAGE_DEFAULT_DTC_OPTIONS,
  25         .imagename = "",
  26         .imagename2 = "",
  27 };
  28
  29 static enum ih_category cur_category;
  30
  31 static int h_compare_category_name(const void *vtype1, const void *vtype2)
  32 {
  33         const int *type1 = vtype1;
  34         const int *type2 = vtype2;
  35         const char *name1 = genimg_get_cat_short_name(cur_category, *type1);
  36         const char *name2 = genimg_get_cat_short_name(cur_category, *type2);
  37
  38         return strcmp(name1, name2);
  39 }
  40
  41 static int show_valid_options(enum ih_category category)
  42 {
  43         int *order;
  44         int count;
  45         int item;
  46         int i;
  47
  48         count = genimg_get_cat_count(category);
  49         order = calloc(count, sizeof(*order));
  50         if (!order)
  51                 return -ENOMEM;
  52
  53         /* Sort the names in order of short name for easier reading */
  54         for (item = 0; item < count; item++)
  55                 order[item] = item;
  56         cur_category = category;
  57         qsort(order, count, sizeof(int), h_compare_category_name);
  58
  59         fprintf(stderr, "\nInvalid %s, supported are:\n",
  60                 genimg_get_cat_desc(category));
  61         for (i = 0; i < count; i++) {
  62                 item = order[i];
  63                 fprintf(stderr, "\t%-15s  %s\n",
  64                         genimg_get_cat_short_name(category, item),
  65                         genimg_get_cat_name(category, item));
  66         }
  67         fprintf(stderr, "\n");
  68         free(order);
  69
  70         return 0;
  71 }
  72
  73 static void usage(const char *msg)
  74 {
  75         fprintf(stderr, "Error: %s\n", msg);
  76         fprintf(stderr, "Usage: %s -l image\n"
  77                          "          -l ==> list image header information\n",
  78                 params.cmdname);
  79         fprintf(stderr,
  80                 "       %s [-x] -A arch -O os -T type -C comp -a addr -e ep -n name -d data_file[:data_file...] image\n"
  81                 "          -A ==> set architecture to 'arch'\n"
  82                 "          -O ==> set operating system to 'os'\n"
  83                 "          -T ==> set image type to 'type'\n"
  84                 "          -C ==> set compression type 'comp'\n"
  85                 "          -a ==> set load address to 'addr' (hex)\n"
  86                 "          -e ==> set entry point to 'ep' (hex)\n"
  87                 "          -n ==> set image name to 'name'\n"
  88                 "          -d ==> use image data from 'datafile'\n"
  89                 "          -x ==> set XIP (execute in place)\n",
  90                 params.cmdname);
  91         fprintf(stderr,
  92                 "       %s [-D dtc_options] [-f fit-image.its|-f auto|-F] [-b <dtb> [-b <dtb>]] [-i <ramdisk.cpio.gz>] fit-image\n"
  93                 "           <dtb> file is used with -f auto, it may occur multiple times.\n",
  94                 params.cmdname);
  95         fprintf(stderr,
  96                 "          -D => set all options for device tree compiler\n"
  97                 "          -f => input filename for FIT source\n"
  98                 "          -i => input filename for ramdisk file\n");
  99 #ifdef CONFIG_FIT_SIGNATURE
 100         fprintf(stderr,
 101                 "Signing / verified boot options: [-E] [-k keydir] [-K dtb] [ -c <comment>] [-p addr] [-r]\n"
 102                 "          -E => place data outside of the FIT structure\n"
 103                 "          -k => set directory containing private keys\n"
 104                 "          -K => write public keys to this .dtb file\n"
 105                 "          -c => add comment in signature node\n"
 106                 "          -F => re-sign existing FIT image\n"
 107                 "          -p => place external data at a static position\n"
 108                 "          -r => mark keys used as 'required' in dtb\n");
 109 #else
 110         fprintf(stderr,
 111                 "Signing / verified boot not supported (CONFIG_FIT_SIGNATURE undefined)\n");
 112 #endif
 113         fprintf(stderr, "       %s -V ==> print version information and exit\n",
 114                 params.cmdname);
 115         fprintf(stderr, "Use -T to see a list of available image types\n");
 116
 117         exit(EXIT_FAILURE);
 118 }
 119
 120 static int add_content(int type, const char *fname)
 121 {
 122         struct content_info *cont;
 123
 124         cont = calloc(1, sizeof(*cont));
 125         if (!cont)
 126                 return -1;
 127         cont->type = type;
 128         cont->fname = fname;
 129         if (params.content_tail)
 130                 params.content_tail->next = cont;
 131         else
 132                 params.content_head = cont;
 133         params.content_tail = cont;
 134
 135         return 0;
 136 }
 137
 138 static void process_args(int argc, char **argv)
 139 {
 140         char *ptr;
 141         int type = IH_TYPE_INVALID;
 142         char *datafile = NULL;
 143         int opt;
 144
 145         while ((opt = getopt(argc, argv,
 146                              "a:A:b:c:C:d:D:e:Ef:Fk:i:K:ln:p:O:rR:qsT:vVx")) != -1) {
 147                 switch (opt) {
 148                 case 'a':
 149                         params.addr = strtoull(optarg, &ptr, 16);
 150                         if (*ptr) {
 151                                 fprintf(stderr, "%s: invalid load address %s\n",
 152                                         params.cmdname, optarg);
 153                                 exit(EXIT_FAILURE);
 154                         }
 155                         break;
 156                 case 'A':
 157                         params.arch = genimg_get_arch_id(optarg);
 158                         if (params.arch < 0) {
 159                                 show_valid_options(IH_ARCH);
 160                                 usage("Invalid architecture");
 161                         }
 162                         break;
 163                 case 'b':
 164                         if (add_content(IH_TYPE_FLATDT, optarg)) {
 165                                 fprintf(stderr,
 166                                         "%s: Out of memory adding content '%s'",
 167                                         params.cmdname, optarg);
 168                                 exit(EXIT_FAILURE);
 169                         }
 170                         break;
 171                 case 'c':
 172                         params.comment = optarg;
 173                         break;
 174                 case 'C':
 175                         params.comp = genimg_get_comp_id(optarg);
 176                         if (params.comp < 0) {
 177                                 show_valid_options(IH_COMP);
 178                                 usage("Invalid compression type");
 179                         }
 180                         break;
 181                 case 'd':
 182                         params.datafile = optarg;
 183                         params.dflag = 1;
 184                         break;
 185                 case 'D':
 186                         params.dtc = optarg;
 187                         break;
 188                 case 'e':
 189                         params.ep = strtoull(optarg, &ptr, 16);
 190                         if (*ptr) {
 191                                 fprintf(stderr, "%s: invalid entry point %s\n",
 192                                         params.cmdname, optarg);
 193                                 exit(EXIT_FAILURE);
 194                         }
 195                         params.eflag = 1;
 196                         break;
 197                 case 'E':
 198                         params.external_data = true;
 199                         break;
 200                 case 'f':
 201                         datafile = optarg;
 202                         params.auto_its = !strcmp(datafile, "auto");
 203                         /* no break */
 204                 case 'F':
 205                         /*
 206                          * The flattened image tree (FIT) format
 207                          * requires a flattened device tree image type
 208                          */
 209                         params.type = IH_TYPE_FLATDT;
 210                         params.fflag = 1;
 211                         break;
 212                 case 'i':
 213                         params.fit_ramdisk = optarg;
 214                         break;
 215                 case 'k':
 216                         params.keydir = optarg;
 217                         break;
 218                 case 'K':
 219                         params.keydest = optarg;
 220                         break;
 221                 case 'l':
 222                         params.lflag = 1;
 223                         break;
 224                 case 'n':
 225                         params.imagename = optarg;
 226                         break;
 227                 case 'O':
 228                         params.os = genimg_get_os_id(optarg);
 229                         if (params.os < 0) {
 230                                 show_valid_options(IH_OS);
 231                                 usage("Invalid operating system");
 232                         }
 233                         break;
 234                 case 'p':
 235                         params.external_offset = strtoull(optarg, &ptr, 16);
 236                         if (*ptr) {
 237                                 fprintf(stderr, "%s: invalid offset size %s\n",
 238                                         params.cmdname, optarg);
 239                                 exit(EXIT_FAILURE);
 240                         }
 241                         break;
 242                 case 'q':
 243                         params.quiet = 1;
 244                         break;
 245                 case 'r':
 246                         params.require_keys = 1;
 247                         break;
 248                 case 'R':
 249                         /*
 250                          * This entry is for the second configuration
 251                          * file, if only one is not enough.
 252                          */
 253                         params.imagename2 = optarg;
 254                         break;
 255                 case 's':
 256                         params.skipcpy = 1;
 257                         break;
 258                 case 'T':
 259                         type = genimg_get_type_id(optarg);
 260                         if (type < 0) {
 261                                 show_valid_options(IH_TYPE);
 262                                 usage("Invalid image type");
 263                         }
 264                         break;
 265                 case 'v':
 266                         params.vflag++;
 267                         break;
 268                 case 'V':
 269                         printf("mkimage version %s\n", PLAIN_VERSION);
 270                         exit(EXIT_SUCCESS);
 271                 case 'x':
 272                         params.xflag++;
 273                         break;
 274                 default:
 275                         usage("Invalid option");
 276                 }
 277         }
 278
 279         /* The last parameter is expected to be the imagefile */
 280         if (optind < argc)
 281                 params.imagefile = argv[optind];
 282
 283         /*
 284          * For auto-generated FIT images we need to know the image type to put
 285          * in the FIT, which is separate from the file's image type (which
 286          * will always be IH_TYPE_FLATDT in this case).
 287          */
 288         if (params.type == IH_TYPE_FLATDT) {
 289                 params.fit_image_type = type ? type : IH_TYPE_KERNEL;
 290                 /* For auto_its, datafile is always 'auto' */
 291                 if (!params.auto_its)
 292                         params.datafile = datafile;
 293                 else if (!params.datafile)
 294                         usage("Missing data file for auto-FIT (use -d)");
 295         } else if (type != IH_TYPE_INVALID) {
 296                 params.type = type;
 297         }
 298
 299         if (!params.imagefile)
 300                 usage("Missing output filename");
 301 }
 302
 303 int main(int argc, char **argv)
 304 {
 305         int ifd = -1;
 306         struct stat sbuf;
 307         char *ptr;
 308         int retval = 0;
 309         struct image_type_params *tparams = NULL;
 310         int pad_len = 0;
 311         int dfd;
 312
 313         params.cmdname = *argv;
 314         params.addr = 0;
 315         params.ep = 0;
 316
 317         process_args(argc, argv);
 318
 319         /* set tparams as per input type_id */
 320         tparams = imagetool_get_type(params.type);
 321         if (tparams == NULL) {
 322                 fprintf (stderr, "%s: unsupported type %s\n",
 323                         params.cmdname, genimg_get_type_name(params.type));
 324                 exit (EXIT_FAILURE);
 325         }
 326
 327         /*
 328          * check the passed arguments parameters meets the requirements
 329          * as per image type to be generated/listed
 330          */
 331         if (tparams->check_params)
 332                 if (tparams->check_params (&params))
 333                         usage("Bad parameters for image type");
 334
 335         if (!params.eflag) {
 336                 params.ep = params.addr;
 337                 /* If XIP, entry point must be after the U-Boot header */
 338                 if (params.xflag)
 339                         params.ep += tparams->header_size;
 340         }
 341
 342         if (params.fflag){
 343                 if (tparams->fflag_handle)
 344                         /*
 345                          * in some cases, some additional processing needs
 346                          * to be done if fflag is defined
 347                          *
 348                          * For ex. fit_handle_file for Fit file support
 349                          */
 350                         retval = tparams->fflag_handle(&params);
 351
 352                 if (retval != EXIT_SUCCESS)
 353                         exit (retval);
 354         }
 355
 356         if (params.lflag || params.fflag) {
 357                 ifd = open (params.imagefile, O_RDONLY|O_BINARY);
 358         } else {
 359                 ifd = open (params.imagefile,
 360                         O_RDWR|O_CREAT|O_TRUNC|O_BINARY, 0666);
 361         }
 362
 363         if (ifd < 0) {
 364                 fprintf (stderr, "%s: Can't open %s: %s\n",
 365                         params.cmdname, params.imagefile,
 366                         strerror(errno));
 367                 exit (EXIT_FAILURE);
 368         }
 369
 370         if (params.lflag || params.fflag) {
 371                 /*
 372                  * list header information of existing image
 373                  */
 374                 if (fstat(ifd, &sbuf) < 0) {
 375                         fprintf (stderr, "%s: Can't stat %s: %s\n",
 376                                 params.cmdname, params.imagefile,
 377                                 strerror(errno));
 378                         exit (EXIT_FAILURE);
 379                 }
 380
 381                 if ((unsigned)sbuf.st_size < tparams->header_size) {
 382                         fprintf (stderr,
 383                                 "%s: Bad size: \"%s\" is not valid image\n",
 384                                 params.cmdname, params.imagefile);
 385                         exit (EXIT_FAILURE);
 386                 }
 387
 388                 ptr = mmap(0, sbuf.st_size, PROT_READ, MAP_SHARED, ifd, 0);
 389                 if (ptr == MAP_FAILED) {
 390                         fprintf (stderr, "%s: Can't read %s: %s\n",
 391                                 params.cmdname, params.imagefile,
 392                                 strerror(errno));
 393                         exit (EXIT_FAILURE);
 394                 }
 395
 396                 /*
 397                  * scan through mkimage registry for all supported image types
 398                  * and verify the input image file header for match
 399                  * Print the image information for matched image type
 400                  * Returns the error code if not matched
 401                  */
 402                 retval = imagetool_verify_print_header(ptr, &sbuf,
 403                                 tparams, &params);
 404
 405                 (void) munmap((void *)ptr, sbuf.st_size);
 406                 (void) close (ifd);
 407
 408                 exit (retval);
 409         }
 410
 411         if ((params.type != IH_TYPE_MULTI) && (params.type != IH_TYPE_SCRIPT)) {
 412                 dfd = open(params.datafile, O_RDONLY | O_BINARY);
 413                 if (dfd < 0) {
 414                         fprintf(stderr, "%s: Can't open %s: %s\n",
 415                                 params.cmdname, params.datafile,
 416                                 strerror(errno));
 417                         exit(EXIT_FAILURE);
 418                 }
 419
 420                 if (fstat(dfd, &sbuf) < 0) {
 421                         fprintf(stderr, "%s: Can't stat %s: %s\n",
 422                                 params.cmdname, params.datafile,
 423                                 strerror(errno));
 424                         exit(EXIT_FAILURE);
 425                 }
 426
 427                 params.file_size = sbuf.st_size + tparams->header_size;
 428                 close(dfd);
 429         }
 430
 431         /*
 432          * In case there an header with a variable
 433          * length will be added, the corresponding
 434          * function is called. This is responsible to
 435          * allocate memory for the header itself.
 436          */
 437         if (tparams->vrec_header)
 438                 pad_len = tparams->vrec_header(&params, tparams);
 439         else
 440                 memset(tparams->hdr, 0, tparams->header_size);
 441
 442         if (write(ifd, tparams->hdr, tparams->header_size)
 443                                         != tparams->header_size) {
 444                 fprintf (stderr, "%s: Write error on %s: %s\n",
 445                         params.cmdname, params.imagefile, strerror(errno));
 446                 exit (EXIT_FAILURE);
 447         }
 448
 449         if (!params.skipcpy) {
 450                 if (params.type == IH_TYPE_MULTI ||
 451                     params.type == IH_TYPE_SCRIPT) {
 452                         char *file = params.datafile;
 453                         uint32_t size;
 454
 455                         for (;;) {
 456                                 char *sep = NULL;
 457
 458                                 if (file) {
 459                                         if ((sep = strchr(file, ':')) != NULL) {
 460                                                 *sep = '\0';
 461                                         }
 462
 463                                         if (stat (file, &sbuf) < 0) {
 464                                                 fprintf (stderr, "%s: Can't stat %s: %s\n",
 465                                                          params.cmdname, file, strerror(errno));
 466                                                 exit (EXIT_FAILURE);
 467                                         }
 468                                         size = cpu_to_uimage (sbuf.st_size);
 469                                 } else {
 470                                         size = 0;
 471                                 }
 472
 473                                 if (write(ifd, (char *)&size, sizeof(size)) != sizeof(size)) {
 474                                         fprintf (stderr, "%s: Write error on %s: %s\n",
 475                                                  params.cmdname, params.imagefile,
 476                                                  strerror(errno));
 477                                         exit (EXIT_FAILURE);
 478                                 }
 479
 480                                 if (!file) {
 481                                         break;
 482                                 }
 483
 484                                 if (sep) {
 485                                         *sep = ':';
 486                                         file = sep + 1;
 487                                 } else {
 488                                         file = NULL;
 489                                 }
 490                         }
 491
 492                         file = params.datafile;
 493
 494                         for (;;) {
 495                                 char *sep = strchr(file, ':');
 496                                 if (sep) {
 497                                         *sep = '\0';
 498                                         copy_file (ifd, file, 1);
 499                                         *sep++ = ':';
 500                                         file = sep;
 501                                 } else {
 502                                         copy_file (ifd, file, 0);
 503                                         break;
 504                                 }
 505                         }
 506                 } else if (params.type == IH_TYPE_PBLIMAGE) {
 507                         /* PBL has special Image format, implements its' own */
 508                         pbl_load_uboot(ifd, &params);
 509                 } else {
 510                         copy_file(ifd, params.datafile, pad_len);
 511                 }
 512                 if (params.type == IH_TYPE_FIRMWARE_IVT) {
 513                         /* Add alignment and IVT */
 514                         uint32_t aligned_filesize = (params.file_size + 0x1000
 515                                         - 1) & ~(0x1000 - 1);
 516                         flash_header_v2_t ivt_header = { { 0xd1, 0x2000, 0x40 },
 517                                         params.addr, 0, 0, 0, params.addr
 518                                                         + aligned_filesize
 519                                                         - tparams->header_size,
 520                                         params.addr + aligned_filesize
 521                                                         - tparams->header_size
 522                                                         + 0x20, 0 };
 523                         int i = params.file_size;
 524                         for (; i < aligned_filesize; i++) {
 525                                 if (write(ifd, &i, 1) != 1) {
 526                                         fprintf(stderr,
 527                                                         "%s: Write error on %s: %s\n",
 528                                                         params.cmdname,
 529                                                         params.imagefile,
 530                                                         strerror(errno));
 531                                         exit(EXIT_FAILURE);
 532                                 }
 533                         }
 534                         if (write(ifd, &ivt_header, sizeof(flash_header_v2_t))
 535                                         != sizeof(flash_header_v2_t)) {
 536                                 fprintf(stderr, "%s: Write error on %s: %s\n",
 537                                                 params.cmdname,
 538                                                 params.imagefile,
 539                                                 strerror(errno));
 540                                 exit(EXIT_FAILURE);
 541                         }
 542                 }
 543         }
 544
 545         /* We're a bit of paranoid */
 546 #if defined(_POSIX_SYNCHRONIZED_IO) && \
 547    !defined(__sun__) && \
 548    !defined(__FreeBSD__) && \
 549    !defined(__OpenBSD__) && \
 550    !defined(__APPLE__)
 551         (void) fdatasync (ifd);
 552 #else
 553         (void) fsync (ifd);
 554 #endif
 555
 556         if (fstat(ifd, &sbuf) < 0) {
 557                 fprintf (stderr, "%s: Can't stat %s: %s\n",
 558                         params.cmdname, params.imagefile, strerror(errno));
 559                 exit (EXIT_FAILURE);
 560         }
 561         params.file_size = sbuf.st_size;
 562
 563         ptr = mmap(0, sbuf.st_size, PROT_READ|PROT_WRITE, MAP_SHARED, ifd, 0);
 564         if (ptr == MAP_FAILED) {
 565                 fprintf (stderr, "%s: Can't map %s: %s\n",
 566                         params.cmdname, params.imagefile, strerror(errno));
 567                 exit (EXIT_FAILURE);
 568         }
 569
 570         /* Setup the image header as per input image type*/
 571         if (tparams->set_header)
 572                 tparams->set_header (ptr, &sbuf, ifd, &params);
 573         else {
 574                 fprintf (stderr, "%s: Can't set header for %s: %s\n",
 575                         params.cmdname, tparams->name, strerror(errno));
 576                 exit (EXIT_FAILURE);
 577         }
 578
 579         /* Print the image information by processing image header */
 580         if (tparams->print_header)
 581                 tparams->print_header (ptr);
 582         else {
 583                 fprintf (stderr, "%s: Can't print header for %s: %s\n",
 584                         params.cmdname, tparams->name, strerror(errno));
 585                 exit (EXIT_FAILURE);
 586         }
 587
 588         (void) munmap((void *)ptr, sbuf.st_size);
 589
 590         /* We're a bit of paranoid */
 591 #if defined(_POSIX_SYNCHRONIZED_IO) && \
 592    !defined(__sun__) && \
 593    !defined(__FreeBSD__) && \
 594    !defined(__OpenBSD__) && \
 595    !defined(__APPLE__)
 596         (void) fdatasync (ifd);
 597 #else
 598         (void) fsync (ifd);
 599 #endif
 600
 601         if (close(ifd)) {
 602                 fprintf (stderr, "%s: Write error on %s: %s\n",
 603                         params.cmdname, params.imagefile, strerror(errno));
 604                 exit (EXIT_FAILURE);
 605         }
 606
 607         exit (EXIT_SUCCESS);
 608 }
 609
 610 static void
 611 copy_file (int ifd, const char *datafile, int pad)
 612 {
 613         int dfd;
 614         struct stat sbuf;
 615         unsigned char *ptr;
 616         int tail;
 617         int zero = 0;
 618         uint8_t zeros[4096];
 619         int offset = 0;
 620         int size;
 621         struct image_type_params *tparams = imagetool_get_type(params.type);
 622
 623         memset(zeros, 0, sizeof(zeros));
 624
 625         if (params.vflag) {
 626                 fprintf (stderr, "Adding Image %s\n", datafile);
 627         }
 628
 629         if ((dfd = open(datafile, O_RDONLY|O_BINARY)) < 0) {
 630                 fprintf (stderr, "%s: Can't open %s: %s\n",
 631                         params.cmdname, datafile, strerror(errno));
 632                 exit (EXIT_FAILURE);
 633         }
 634
 635         if (fstat(dfd, &sbuf) < 0) {
 636                 fprintf (stderr, "%s: Can't stat %s: %s\n",
 637                         params.cmdname, datafile, strerror(errno));
 638                 exit (EXIT_FAILURE);
 639         }
 640
 641         ptr = mmap(0, sbuf.st_size, PROT_READ, MAP_SHARED, dfd, 0);
 642         if (ptr == MAP_FAILED) {
 643                 fprintf (stderr, "%s: Can't read %s: %s\n",
 644                         params.cmdname, datafile, strerror(errno));
 645                 exit (EXIT_FAILURE);
 646         }
 647
 648         if (params.xflag) {
 649                 unsigned char *p = NULL;
 650                 /*
 651                  * XIP: do not append the image_header_t at the
 652                  * beginning of the file, but consume the space
 653                  * reserved for it.
 654                  */
 655
 656                 if ((unsigned)sbuf.st_size < tparams->header_size) {
 657                         fprintf (stderr,
 658                                 "%s: Bad size: \"%s\" is too small for XIP\n",
 659                                 params.cmdname, datafile);
 660                         exit (EXIT_FAILURE);
 661                 }
 662
 663                 for (p = ptr; p < ptr + tparams->header_size; p++) {
 664                         if ( *p != 0xff ) {
 665                                 fprintf (stderr,
 666                                         "%s: Bad file: \"%s\" has invalid buffer for XIP\n",
 667                                         params.cmdname, datafile);
 668                                 exit (EXIT_FAILURE);
 669                         }
 670                 }
 671
 672                 offset = tparams->header_size;
 673         }
 674
 675         size = sbuf.st_size - offset;
 676         if (write(ifd, ptr + offset, size) != size) {
 677                 fprintf (stderr, "%s: Write error on %s: %s\n",
 678                         params.cmdname, params.imagefile, strerror(errno));
 679                 exit (EXIT_FAILURE);
 680         }
 681
 682         tail = size % 4;
 683         if ((pad == 1) && (tail != 0)) {
 684
 685                 if (write(ifd, (char *)&zero, 4-tail) != 4-tail) {
 686                         fprintf (stderr, "%s: Write error on %s: %s\n",
 687                                 params.cmdname, params.imagefile,
 688                                 strerror(errno));
 689                         exit (EXIT_FAILURE);
 690                 }
 691         } else if (pad > 1) {
 692                 while (pad > 0) {
 693                         int todo = sizeof(zeros);
 694
 695                         if (todo > pad)
 696                                 todo = pad;
 697                         if (write(ifd, (char *)&zeros, todo) != todo) {
 698                                 fprintf(stderr, "%s: Write error on %s: %s\n",
 699                                         params.cmdname, params.imagefile,
 700                                         strerror(errno));
 701                                 exit(EXIT_FAILURE);
 702                         }
 703                         pad -= todo;
 704                 }
 705         }
 706
 707         (void) munmap((void *)ptr, sbuf.st_size);
 708         (void) close (dfd);
 709 }