Merge https://gitlab.denx.de/u-boot/custodians/u-boot-marvell
[oweals/u-boot.git] / tools / mkimage.c
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * (C) Copyright 2008 Semihalf
4  *
5  * (C) Copyright 2000-2009
6  * DENX Software Engineering
7  * Wolfgang Denk, wd@denx.de
8  */
9
10 #include "mkimage.h"
11 #include "imximage.h"
12 #include <image.h>
13 #include <version.h>
14
15 static void copy_file(int, const char *, int);
16
17 /* parameters initialized by core will be used by the image type code */
18 static struct image_tool_params params = {
19         .os = IH_OS_LINUX,
20         .arch = IH_ARCH_PPC,
21         .type = IH_TYPE_KERNEL,
22         .comp = IH_COMP_GZIP,
23         .dtc = MKIMAGE_DEFAULT_DTC_OPTIONS,
24         .imagename = "",
25         .imagename2 = "",
26 };
27
28 static enum ih_category cur_category;
29
30 static int h_compare_category_name(const void *vtype1, const void *vtype2)
31 {
32         const int *type1 = vtype1;
33         const int *type2 = vtype2;
34         const char *name1 = genimg_get_cat_short_name(cur_category, *type1);
35         const char *name2 = genimg_get_cat_short_name(cur_category, *type2);
36
37         return strcmp(name1, name2);
38 }
39
40 static int show_valid_options(enum ih_category category)
41 {
42         int *order;
43         int count;
44         int item;
45         int i;
46
47         count = genimg_get_cat_count(category);
48         order = calloc(count, sizeof(*order));
49         if (!order)
50                 return -ENOMEM;
51
52         /* Sort the names in order of short name for easier reading */
53         for (item = 0; item < count; item++)
54                 order[item] = item;
55         cur_category = category;
56         qsort(order, count, sizeof(int), h_compare_category_name);
57
58         fprintf(stderr, "\nInvalid %s, supported are:\n",
59                 genimg_get_cat_desc(category));
60         for (i = 0; i < count; i++) {
61                 item = order[i];
62                 fprintf(stderr, "\t%-15s  %s\n",
63                         genimg_get_cat_short_name(category, item),
64                         genimg_get_cat_name(category, item));
65         }
66         fprintf(stderr, "\n");
67         free(order);
68
69         return 0;
70 }
71
72 static void usage(const char *msg)
73 {
74         fprintf(stderr, "Error: %s\n", msg);
75         fprintf(stderr, "Usage: %s -l image\n"
76                          "          -l ==> list image header information\n",
77                 params.cmdname);
78         fprintf(stderr,
79                 "       %s [-x] -A arch -O os -T type -C comp -a addr -e ep -n name -d data_file[:data_file...] image\n"
80                 "          -A ==> set architecture to 'arch'\n"
81                 "          -O ==> set operating system to 'os'\n"
82                 "          -T ==> set image type to 'type'\n"
83                 "          -C ==> set compression type 'comp'\n"
84                 "          -a ==> set load address to 'addr' (hex)\n"
85                 "          -e ==> set entry point to 'ep' (hex)\n"
86                 "          -n ==> set image name to 'name'\n"
87                 "          -d ==> use image data from 'datafile'\n"
88                 "          -x ==> set XIP (execute in place)\n",
89                 params.cmdname);
90         fprintf(stderr,
91                 "       %s [-D dtc_options] [-f fit-image.its|-f auto|-F] [-b <dtb> [-b <dtb>]] [-i <ramdisk.cpio.gz>] fit-image\n"
92                 "           <dtb> file is used with -f auto, it may occur multiple times.\n",
93                 params.cmdname);
94         fprintf(stderr,
95                 "          -D => set all options for device tree compiler\n"
96                 "          -f => input filename for FIT source\n"
97                 "          -i => input filename for ramdisk file\n");
98 #ifdef CONFIG_FIT_SIGNATURE
99         fprintf(stderr,
100                 "Signing / verified boot options: [-E] [-k keydir] [-K dtb] [ -c <comment>] [-p addr] [-r] [-N engine]\n"
101                 "          -E => place data outside of the FIT structure\n"
102                 "          -k => set directory containing private keys\n"
103                 "          -K => write public keys to this .dtb file\n"
104                 "          -c => add comment in signature node\n"
105                 "          -F => re-sign existing FIT image\n"
106                 "          -p => place external data at a static position\n"
107                 "          -r => mark keys used as 'required' in dtb\n"
108                 "          -N => openssl engine to use for signing\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 list' 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:N: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 'N':
228                         params.engine_id = optarg;
229                         break;
230                 case 'O':
231                         params.os = genimg_get_os_id(optarg);
232                         if (params.os < 0) {
233                                 show_valid_options(IH_OS);
234                                 usage("Invalid operating system");
235                         }
236                         break;
237                 case 'p':
238                         params.external_offset = strtoull(optarg, &ptr, 16);
239                         if (*ptr) {
240                                 fprintf(stderr, "%s: invalid offset size %s\n",
241                                         params.cmdname, optarg);
242                                 exit(EXIT_FAILURE);
243                         }
244                         break;
245                 case 'q':
246                         params.quiet = 1;
247                         break;
248                 case 'r':
249                         params.require_keys = 1;
250                         break;
251                 case 'R':
252                         /*
253                          * This entry is for the second configuration
254                          * file, if only one is not enough.
255                          */
256                         params.imagename2 = optarg;
257                         break;
258                 case 's':
259                         params.skipcpy = 1;
260                         break;
261                 case 'T':
262                         if (strcmp(optarg, "list") == 0) {
263                                 show_valid_options(IH_TYPE);
264                                 exit(EXIT_SUCCESS);
265                         }
266                         type = genimg_get_type_id(optarg);
267                         if (type < 0) {
268                                 show_valid_options(IH_TYPE);
269                                 usage("Invalid image type");
270                         }
271                         break;
272                 case 'v':
273                         params.vflag++;
274                         break;
275                 case 'V':
276                         printf("mkimage version %s\n", PLAIN_VERSION);
277                         exit(EXIT_SUCCESS);
278                 case 'x':
279                         params.xflag++;
280                         break;
281                 default:
282                         usage("Invalid option");
283                 }
284         }
285
286         /* The last parameter is expected to be the imagefile */
287         if (optind < argc)
288                 params.imagefile = argv[optind];
289
290         /*
291          * For auto-generated FIT images we need to know the image type to put
292          * in the FIT, which is separate from the file's image type (which
293          * will always be IH_TYPE_FLATDT in this case).
294          */
295         if (params.type == IH_TYPE_FLATDT) {
296                 params.fit_image_type = type ? type : IH_TYPE_KERNEL;
297                 /* For auto_its, datafile is always 'auto' */
298                 if (!params.auto_its)
299                         params.datafile = datafile;
300                 else if (!params.datafile)
301                         usage("Missing data file for auto-FIT (use -d)");
302         } else if (type != IH_TYPE_INVALID) {
303                 if (type == IH_TYPE_SCRIPT && !params.datafile)
304                         usage("Missing data file for script (use -d)");
305                 params.type = type;
306         }
307
308         if (!params.imagefile)
309                 usage("Missing output filename");
310 }
311
312 int main(int argc, char **argv)
313 {
314         int ifd = -1;
315         struct stat sbuf;
316         char *ptr;
317         int retval = 0;
318         struct image_type_params *tparams = NULL;
319         int pad_len = 0;
320         int dfd;
321         size_t map_len;
322
323         params.cmdname = *argv;
324         params.addr = 0;
325         params.ep = 0;
326
327         process_args(argc, argv);
328
329         /* set tparams as per input type_id */
330         tparams = imagetool_get_type(params.type);
331         if (tparams == NULL) {
332                 fprintf (stderr, "%s: unsupported type %s\n",
333                         params.cmdname, genimg_get_type_name(params.type));
334                 exit (EXIT_FAILURE);
335         }
336
337         /*
338          * check the passed arguments parameters meets the requirements
339          * as per image type to be generated/listed
340          */
341         if (tparams->check_params)
342                 if (tparams->check_params (&params))
343                         usage("Bad parameters for image type");
344
345         if (!params.eflag) {
346                 params.ep = params.addr;
347                 /* If XIP, entry point must be after the U-Boot header */
348                 if (params.xflag)
349                         params.ep += tparams->header_size;
350         }
351
352         if (params.fflag){
353                 if (tparams->fflag_handle)
354                         /*
355                          * in some cases, some additional processing needs
356                          * to be done if fflag is defined
357                          *
358                          * For ex. fit_handle_file for Fit file support
359                          */
360                         retval = tparams->fflag_handle(&params);
361
362                 if (retval != EXIT_SUCCESS)
363                         exit (retval);
364         }
365
366         if (params.lflag || params.fflag) {
367                 ifd = open (params.imagefile, O_RDONLY|O_BINARY);
368         } else {
369                 ifd = open (params.imagefile,
370                         O_RDWR|O_CREAT|O_TRUNC|O_BINARY, 0666);
371         }
372
373         if (ifd < 0) {
374                 fprintf (stderr, "%s: Can't open %s: %s\n",
375                         params.cmdname, params.imagefile,
376                         strerror(errno));
377                 exit (EXIT_FAILURE);
378         }
379
380         if (params.lflag || params.fflag) {
381                 /*
382                  * list header information of existing image
383                  */
384                 if (fstat(ifd, &sbuf) < 0) {
385                         fprintf (stderr, "%s: Can't stat %s: %s\n",
386                                 params.cmdname, params.imagefile,
387                                 strerror(errno));
388                         exit (EXIT_FAILURE);
389                 }
390
391                 if ((unsigned)sbuf.st_size < tparams->header_size) {
392                         fprintf (stderr,
393                                 "%s: Bad size: \"%s\" is not valid image\n",
394                                 params.cmdname, params.imagefile);
395                         exit (EXIT_FAILURE);
396                 }
397
398                 ptr = mmap(0, sbuf.st_size, PROT_READ, MAP_SHARED, ifd, 0);
399                 if (ptr == MAP_FAILED) {
400                         fprintf (stderr, "%s: Can't read %s: %s\n",
401                                 params.cmdname, params.imagefile,
402                                 strerror(errno));
403                         exit (EXIT_FAILURE);
404                 }
405
406                 if (params.fflag) {
407                         /*
408                          * Verifies the header format based on the expected header for image
409                          * type in tparams
410                          */
411                         retval = imagetool_verify_print_header_by_type(ptr, &sbuf,
412                                         tparams, &params);
413                 } else {
414                         /**
415                          * When listing the image, we are not given the image type. Simply check all
416                          * image types to find one that matches our header
417                          */
418                         retval = imagetool_verify_print_header(ptr, &sbuf,
419                                         tparams, &params);
420                 }
421
422                 (void) munmap((void *)ptr, sbuf.st_size);
423                 (void) close (ifd);
424
425                 exit (retval);
426         }
427
428         if ((params.type != IH_TYPE_MULTI) && (params.type != IH_TYPE_SCRIPT)) {
429                 dfd = open(params.datafile, O_RDONLY | O_BINARY);
430                 if (dfd < 0) {
431                         fprintf(stderr, "%s: Can't open %s: %s\n",
432                                 params.cmdname, params.datafile,
433                                 strerror(errno));
434                         exit(EXIT_FAILURE);
435                 }
436
437                 if (fstat(dfd, &sbuf) < 0) {
438                         fprintf(stderr, "%s: Can't stat %s: %s\n",
439                                 params.cmdname, params.datafile,
440                                 strerror(errno));
441                         exit(EXIT_FAILURE);
442                 }
443
444                 params.file_size = sbuf.st_size + tparams->header_size;
445                 close(dfd);
446         }
447
448         /*
449          * In case there an header with a variable
450          * length will be added, the corresponding
451          * function is called. This is responsible to
452          * allocate memory for the header itself.
453          */
454         if (tparams->vrec_header)
455                 pad_len = tparams->vrec_header(&params, tparams);
456         else
457                 memset(tparams->hdr, 0, tparams->header_size);
458
459         if (write(ifd, tparams->hdr, tparams->header_size)
460                                         != tparams->header_size) {
461                 fprintf (stderr, "%s: Write error on %s: %s\n",
462                         params.cmdname, params.imagefile, strerror(errno));
463                 exit (EXIT_FAILURE);
464         }
465
466         if (!params.skipcpy) {
467                 if (params.type == IH_TYPE_MULTI ||
468                     params.type == IH_TYPE_SCRIPT) {
469                         char *file = params.datafile;
470                         uint32_t size;
471
472                         for (;;) {
473                                 char *sep = NULL;
474
475                                 if (file) {
476                                         if ((sep = strchr(file, ':')) != NULL) {
477                                                 *sep = '\0';
478                                         }
479
480                                         if (stat (file, &sbuf) < 0) {
481                                                 fprintf (stderr, "%s: Can't stat %s: %s\n",
482                                                          params.cmdname, file, strerror(errno));
483                                                 exit (EXIT_FAILURE);
484                                         }
485                                         size = cpu_to_uimage (sbuf.st_size);
486                                 } else {
487                                         size = 0;
488                                 }
489
490                                 if (write(ifd, (char *)&size, sizeof(size)) != sizeof(size)) {
491                                         fprintf (stderr, "%s: Write error on %s: %s\n",
492                                                  params.cmdname, params.imagefile,
493                                                  strerror(errno));
494                                         exit (EXIT_FAILURE);
495                                 }
496
497                                 if (!file) {
498                                         break;
499                                 }
500
501                                 if (sep) {
502                                         *sep = ':';
503                                         file = sep + 1;
504                                 } else {
505                                         file = NULL;
506                                 }
507                         }
508
509                         file = params.datafile;
510
511                         for (;;) {
512                                 char *sep = strchr(file, ':');
513                                 if (sep) {
514                                         *sep = '\0';
515                                         copy_file (ifd, file, 1);
516                                         *sep++ = ':';
517                                         file = sep;
518                                 } else {
519                                         copy_file (ifd, file, 0);
520                                         break;
521                                 }
522                         }
523                 } else if (params.type == IH_TYPE_PBLIMAGE) {
524                         /* PBL has special Image format, implements its' own */
525                         pbl_load_uboot(ifd, &params);
526                 } else if (params.type == IH_TYPE_ZYNQMPBIF) {
527                         /* Image file is meta, walk through actual targets */
528                         int ret;
529
530                         ret = zynqmpbif_copy_image(ifd, &params);
531                         if (ret)
532                                 return ret;
533                 } else if (params.type == IH_TYPE_IMX8IMAGE) {
534                         /* i.MX8/8X has special Image format */
535                         int ret;
536
537                         ret = imx8image_copy_image(ifd, &params);
538                         if (ret)
539                                 return ret;
540                 } else if (params.type == IH_TYPE_IMX8MIMAGE) {
541                         /* i.MX8M has special Image format */
542                         int ret;
543
544                         ret = imx8mimage_copy_image(ifd, &params);
545                         if (ret)
546                                 return ret;
547                 } else if ((params.type == IH_TYPE_RKSD) ||
548                                 (params.type == IH_TYPE_RKSPI)) {
549                         /* Rockchip has special Image format */
550                         int ret;
551
552                         ret = rockchip_copy_image(ifd, &params);
553                         if (ret)
554                                 return ret;
555                 } else {
556                         copy_file(ifd, params.datafile, pad_len);
557                 }
558                 if (params.type == IH_TYPE_FIRMWARE_IVT) {
559                         /* Add alignment and IVT */
560                         uint32_t aligned_filesize = (params.file_size + 0x1000
561                                         - 1) & ~(0x1000 - 1);
562                         flash_header_v2_t ivt_header = { { 0xd1, 0x2000, 0x40 },
563                                         params.addr, 0, 0, 0, params.addr
564                                                         + aligned_filesize
565                                                         - tparams->header_size,
566                                         params.addr + aligned_filesize
567                                                         - tparams->header_size
568                                                         + 0x20, 0 };
569                         int i = params.file_size;
570                         for (; i < aligned_filesize; i++) {
571                                 if (write(ifd, (char *) &i, 1) != 1) {
572                                         fprintf(stderr,
573                                                         "%s: Write error on %s: %s\n",
574                                                         params.cmdname,
575                                                         params.imagefile,
576                                                         strerror(errno));
577                                         exit(EXIT_FAILURE);
578                                 }
579                         }
580                         if (write(ifd, &ivt_header, sizeof(flash_header_v2_t))
581                                         != sizeof(flash_header_v2_t)) {
582                                 fprintf(stderr, "%s: Write error on %s: %s\n",
583                                                 params.cmdname,
584                                                 params.imagefile,
585                                                 strerror(errno));
586                                 exit(EXIT_FAILURE);
587                         }
588                 }
589         }
590
591         /* We're a bit of paranoid */
592 #if defined(_POSIX_SYNCHRONIZED_IO) && \
593    !defined(__sun__) && \
594    !defined(__FreeBSD__) && \
595    !defined(__OpenBSD__) && \
596    !defined(__APPLE__)
597         (void) fdatasync (ifd);
598 #else
599         (void) fsync (ifd);
600 #endif
601
602         if (fstat(ifd, &sbuf) < 0) {
603                 fprintf (stderr, "%s: Can't stat %s: %s\n",
604                         params.cmdname, params.imagefile, strerror(errno));
605                 exit (EXIT_FAILURE);
606         }
607         params.file_size = sbuf.st_size;
608
609         map_len = sbuf.st_size;
610         ptr = mmap(0, map_len, PROT_READ | PROT_WRITE, MAP_SHARED, ifd, 0);
611         if (ptr == MAP_FAILED) {
612                 fprintf (stderr, "%s: Can't map %s: %s\n",
613                         params.cmdname, params.imagefile, strerror(errno));
614                 exit (EXIT_FAILURE);
615         }
616
617         /* Setup the image header as per input image type*/
618         if (tparams->set_header)
619                 tparams->set_header (ptr, &sbuf, ifd, &params);
620         else {
621                 fprintf (stderr, "%s: Can't set header for %s: %s\n",
622                         params.cmdname, tparams->name, strerror(errno));
623                 exit (EXIT_FAILURE);
624         }
625
626         /* Print the image information by processing image header */
627         if (tparams->print_header)
628                 tparams->print_header (ptr);
629         else {
630                 fprintf (stderr, "%s: Can't print header for %s\n",
631                         params.cmdname, tparams->name);
632         }
633
634         (void)munmap((void *)ptr, map_len);
635
636         /* We're a bit of paranoid */
637 #if defined(_POSIX_SYNCHRONIZED_IO) && \
638    !defined(__sun__) && \
639    !defined(__FreeBSD__) && \
640    !defined(__OpenBSD__) && \
641    !defined(__APPLE__)
642         (void) fdatasync (ifd);
643 #else
644         (void) fsync (ifd);
645 #endif
646
647         if (close(ifd)) {
648                 fprintf (stderr, "%s: Write error on %s: %s\n",
649                         params.cmdname, params.imagefile, strerror(errno));
650                 exit (EXIT_FAILURE);
651         }
652
653         exit (EXIT_SUCCESS);
654 }
655
656 static void
657 copy_file (int ifd, const char *datafile, int pad)
658 {
659         int dfd;
660         struct stat sbuf;
661         unsigned char *ptr;
662         int tail;
663         int zero = 0;
664         uint8_t zeros[4096];
665         int offset = 0;
666         int size;
667         struct image_type_params *tparams = imagetool_get_type(params.type);
668
669         memset(zeros, 0, sizeof(zeros));
670
671         if (params.vflag) {
672                 fprintf (stderr, "Adding Image %s\n", datafile);
673         }
674
675         if ((dfd = open(datafile, O_RDONLY|O_BINARY)) < 0) {
676                 fprintf (stderr, "%s: Can't open %s: %s\n",
677                         params.cmdname, datafile, strerror(errno));
678                 exit (EXIT_FAILURE);
679         }
680
681         if (fstat(dfd, &sbuf) < 0) {
682                 fprintf (stderr, "%s: Can't stat %s: %s\n",
683                         params.cmdname, datafile, strerror(errno));
684                 exit (EXIT_FAILURE);
685         }
686
687         ptr = mmap(0, sbuf.st_size, PROT_READ, MAP_SHARED, dfd, 0);
688         if (ptr == MAP_FAILED) {
689                 fprintf (stderr, "%s: Can't read %s: %s\n",
690                         params.cmdname, datafile, strerror(errno));
691                 exit (EXIT_FAILURE);
692         }
693
694         if (params.xflag) {
695                 unsigned char *p = NULL;
696                 /*
697                  * XIP: do not append the image_header_t at the
698                  * beginning of the file, but consume the space
699                  * reserved for it.
700                  */
701
702                 if ((unsigned)sbuf.st_size < tparams->header_size) {
703                         fprintf (stderr,
704                                 "%s: Bad size: \"%s\" is too small for XIP\n",
705                                 params.cmdname, datafile);
706                         exit (EXIT_FAILURE);
707                 }
708
709                 for (p = ptr; p < ptr + tparams->header_size; p++) {
710                         if ( *p != 0xff ) {
711                                 fprintf (stderr,
712                                         "%s: Bad file: \"%s\" has invalid buffer for XIP\n",
713                                         params.cmdname, datafile);
714                                 exit (EXIT_FAILURE);
715                         }
716                 }
717
718                 offset = tparams->header_size;
719         }
720
721         size = sbuf.st_size - offset;
722         if (write(ifd, ptr + offset, size) != size) {
723                 fprintf (stderr, "%s: Write error on %s: %s\n",
724                         params.cmdname, params.imagefile, strerror(errno));
725                 exit (EXIT_FAILURE);
726         }
727
728         tail = size % 4;
729         if ((pad == 1) && (tail != 0)) {
730
731                 if (write(ifd, (char *)&zero, 4-tail) != 4-tail) {
732                         fprintf (stderr, "%s: Write error on %s: %s\n",
733                                 params.cmdname, params.imagefile,
734                                 strerror(errno));
735                         exit (EXIT_FAILURE);
736                 }
737         } else if (pad > 1) {
738                 while (pad > 0) {
739                         int todo = sizeof(zeros);
740
741                         if (todo > pad)
742                                 todo = pad;
743                         if (write(ifd, (char *)&zeros, todo) != todo) {
744                                 fprintf(stderr, "%s: Write error on %s: %s\n",
745                                         params.cmdname, params.imagefile,
746                                         strerror(errno));
747                                 exit(EXIT_FAILURE);
748                         }
749                         pad -= todo;
750                 }
751         }
752
753         (void) munmap((void *)ptr, sbuf.st_size);
754         (void) close (dfd);
755 }