2 * mkcramfs - make a cramfs file system
4 * Copyright (C) 1999-2002 Transmeta Corporation
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License along
17 * with this program; if not, write to the Free Software Foundation, Inc.,
18 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
22 * Old version would die on largish filesystems. Change to mmap the
23 * files one by one instead of all simultaneously. - aeb, 2002-11-01
26 #include <sys/types.h>
40 /* We don't use our include/crc32.h, but crc32 from zlib!
42 * The zlib implementation performs pre/post-conditioning. The util-linux
43 * imlemenation requires post-conditioning (xor) in the applications.
51 #include "exitcodes.h"
54 #define CLOSE_EXIT_CODE MKFS_EX_ERROR
55 #include "closestream.h"
57 #define XALLOC_EXIT_CODE MKFS_EX_ERROR
60 /* The kernel only supports PAD_SIZE of 0 and 512. */
63 static int verbose
= 0;
65 static unsigned int blksize
= 0; /* settable via -b option, default page size */
66 static long total_blocks
= 0, total_nodes
= 1; /* pre-count the root node */
67 static int image_length
= 0;
68 static int cramfs_is_big_endian
= 0; /* target is big endian */
71 * If opt_holes is set, then mkcramfs can create explicit holes in the
72 * data, which saves 26 bytes per hole (which is a lot smaller a
73 * saving than for most filesystems).
75 * Note that kernels up to at least 2.3.39 don't support cramfs holes,
76 * which is why this is turned off by default.
78 static unsigned int opt_edition
= 0;
79 static int opt_errors
= 0;
80 static int opt_holes
= 0;
81 static int opt_pad
= 0;
82 static char *opt_image
= NULL
;
83 static char *opt_name
= NULL
;
85 static int warn_dev
= 0;
86 static int warn_gid
= 0;
87 static int warn_namelen
= 0;
88 static int warn_skip
= 0;
89 static int warn_size
= 0;
90 static int warn_uid
= 0;
93 #define CRAMFS_EFLAG_MD5 1
94 #define CRAMFS_EFLAG_INVALID 2
96 /* In-core version of inode / directory entry. */
100 unsigned int mode
, size
, uid
, gid
;
101 unsigned char md5sum
[UL_MD5LENGTH
];
102 unsigned char flags
; /* CRAMFS_EFLAG_* */
106 int fd
; /* temporarily open files while mmapped */
107 struct entry
*same
; /* points to other identical file */
108 unsigned int offset
; /* pointer to compressed data in archive */
109 unsigned int dir_offset
; /* offset of directory entry in archive */
112 struct entry
*child
; /* NULL for non-directory and empty dir */
117 * Width of various bitfields in struct cramfs_inode.
118 * Used only to generate warnings.
120 #define CRAMFS_SIZE_WIDTH 24
121 #define CRAMFS_UID_WIDTH 16
122 #define CRAMFS_GID_WIDTH 8
123 #define CRAMFS_OFFSET_WIDTH 26
125 static void __attribute__((__noreturn__
)) usage(void)
127 fputs(USAGE_HEADER
, stdout
);
128 printf(_(" %s [-h] [-v] [-b blksize] [-e edition] [-N endian] [-i file] [-n name] dirname outfile\n"),
129 program_invocation_short_name
);
130 fputs(USAGE_SEPARATOR
, stdout
);
131 puts(_("Make compressed ROM file system."));
132 fputs(USAGE_OPTIONS
, stdout
);
133 puts(_( " -v be verbose"));
134 puts(_( " -E make all warnings errors (non-zero exit status)"));
135 puts(_( " -b blksize use this blocksize, must equal page size"));
136 puts(_( " -e edition set edition number (part of fsid)"));
137 printf(_(" -N endian set cramfs endianness (%s|%s|%s), default %s\n"), "big", "little", "host", "host");
138 puts(_( " -i file insert a file image into the filesystem"));
139 puts(_( " -n name set name of cramfs filesystem"));
140 printf(_(" -p pad by %d bytes for boot code\n"), PAD_SIZE
);
141 puts(_( " -s sort directory entries (old option, ignored)"));
142 puts(_( " -z make explicit holes"));
143 puts(_( " dirname root of the filesystem to be compressed"));
144 puts(_( " outfile output file"));
145 fputs(USAGE_SEPARATOR
, stdout
);
146 printf(USAGE_HELP_OPTIONS(16));
147 printf(USAGE_MAN_TAIL("mkfs.cramfs(8)"));
152 do_mmap(char *path
, unsigned int size
, unsigned int mode
){
160 start
= xmalloc(size
);
161 if (readlink(path
, start
, size
) < 0) {
162 warn(_("readlink failed: %s"), path
);
169 fd
= open(path
, O_RDONLY
);
171 warn(_("cannot open %s"), path
);
176 start
= mmap(NULL
, size
, PROT_READ
, MAP_PRIVATE
, fd
, 0);
178 if (start
== MAP_FAILED
)
179 err(MKFS_EX_ERROR
, "mmap");
187 do_munmap(char *start
, unsigned int size
, unsigned int mode
){
194 /* compute md5sums, so that we do not have to compare every pair of files */
196 mdfile(struct entry
*e
) {
199 start
= do_mmap(e
->path
, e
->size
, e
->mode
);
201 e
->flags
|= CRAMFS_EFLAG_INVALID
;
206 ul_MD5Update(&ctx
, (unsigned char *) start
, e
->size
);
207 ul_MD5Final(e
->md5sum
, &ctx
);
209 do_munmap(start
, e
->size
, e
->mode
);
211 e
->flags
|= CRAMFS_EFLAG_MD5
;
215 /* md5 digests are equal; files are almost certainly the same,
216 but just to be sure, do the comparison */
218 identical_file(struct entry
*e1
, struct entry
*e2
){
219 char *start1
, *start2
;
222 start1
= do_mmap(e1
->path
, e1
->size
, e1
->mode
);
225 start2
= do_mmap(e2
->path
, e2
->size
, e2
->mode
);
227 do_munmap(start1
, e1
->size
, e1
->mode
);
230 equal
= !memcmp(start1
, start2
, e1
->size
);
231 do_munmap(start1
, e1
->size
, e1
->mode
);
232 do_munmap(start2
, e2
->size
, e2
->mode
);
237 * The longest file name component to allow for in the input directory tree.
238 * Ext2fs (and many others) allow up to 255 bytes. A couple of filesystems
239 * allow longer (e.g. smbfs 1024), but there isn't much use in supporting
240 * >255-byte names in the input directory tree given that such names get
241 * truncated to 255 bytes when written to cramfs.
243 #define MAX_INPUT_NAMELEN 255
245 static int find_identical_file(struct entry
*orig
, struct entry
*new, loff_t
*fslen_ub
)
251 if (orig
->size
== new->size
&& orig
->path
) {
257 if ((orig
->flags
& CRAMFS_EFLAG_MD5
) &&
258 (new->flags
& CRAMFS_EFLAG_MD5
) &&
259 !memcmp(orig
->md5sum
, new->md5sum
, UL_MD5LENGTH
) &&
260 identical_file(orig
, new)) {
262 *fslen_ub
-= new->size
;
266 return find_identical_file(orig
->child
, new, fslen_ub
) ||
267 find_identical_file(orig
->next
, new, fslen_ub
);
270 static void eliminate_doubles(struct entry
*root
, struct entry
*orig
, loff_t
*fslen_ub
) {
272 if (orig
->size
&& orig
->path
)
273 find_identical_file(root
,orig
, fslen_ub
);
274 eliminate_doubles(root
,orig
->child
, fslen_ub
);
275 eliminate_doubles(root
,orig
->next
, fslen_ub
);
280 * We define our own sorting function instead of using alphasort which
281 * uses strcoll and changes ordering based on locale information.
283 static int cramsort (const struct dirent
**a
, const struct dirent
**b
)
285 return strcmp((*a
)->d_name
, (*b
)->d_name
);
288 static unsigned int parse_directory(struct entry
*root_entry
, const char *name
, struct entry
**prev
, loff_t
*fslen_ub
)
290 struct dirent
**dirlist
;
291 int totalsize
= 0, dircount
, dirindex
;
292 char *path
, *endpath
;
293 size_t len
= strlen(name
);
295 /* Set up the path. */
296 /* TODO: Reuse the parent's buffer to save memcpy'ing and duplication. */
297 path
= xmalloc(len
+ 1 + MAX_INPUT_NAMELEN
+ 1);
298 memcpy(path
, name
, len
);
299 endpath
= path
+ len
;
303 /* read in the directory and sort */
304 dircount
= scandir(name
, &dirlist
, NULL
, cramsort
);
307 err(MKFS_EX_ERROR
, _("could not read directory %s"), name
);
309 /* process directory */
310 for (dirindex
= 0; dirindex
< dircount
; dirindex
++) {
311 struct dirent
*dirent
;
317 dirent
= dirlist
[dirindex
];
319 /* Ignore "." and ".." - we won't be adding them
321 if (dirent
->d_name
[0] == '.') {
322 if (dirent
->d_name
[1] == '\0')
324 if (dirent
->d_name
[1] == '.' &&
325 dirent
->d_name
[2] == '\0')
328 namelen
= strlen(dirent
->d_name
);
329 if (namelen
> MAX_INPUT_NAMELEN
) {
330 namelen
= MAX_INPUT_NAMELEN
;
334 memcpy(endpath
, dirent
->d_name
, namelen
+ 1);
336 if (lstat(path
, &st
) < 0) {
337 warn(_("stat of %s failed"), endpath
);
341 entry
= xcalloc(1, sizeof(struct entry
));
342 entry
->name
= (unsigned char *)xstrndup(dirent
->d_name
, namelen
);
343 entry
->mode
= st
.st_mode
;
344 entry
->size
= st
.st_size
;
345 entry
->uid
= st
.st_uid
;
346 if (entry
->uid
>= 1 << CRAMFS_UID_WIDTH
)
348 entry
->gid
= st
.st_gid
;
349 if (entry
->gid
>= 1 << CRAMFS_GID_WIDTH
)
350 /* TODO: We ought to replace with a default
351 gid instead of truncating; otherwise there
352 are security problems. Maybe mode should
353 be &= ~070. Same goes for uid once Linux
354 supports >16-bit uids. */
356 size
= sizeof(struct cramfs_inode
) + ((namelen
+ 3) & ~3);
358 if (S_ISDIR(st
.st_mode
)) {
359 entry
->size
= parse_directory(root_entry
, path
, &entry
->child
, fslen_ub
);
360 } else if (S_ISREG(st
.st_mode
)) {
361 entry
->path
= xstrdup(path
);
362 if (entry
->size
>= (1 << CRAMFS_SIZE_WIDTH
)) {
364 entry
->size
= (1 << CRAMFS_SIZE_WIDTH
) - 1;
366 } else if (S_ISLNK(st
.st_mode
)) {
367 entry
->path
= xstrdup(path
);
368 } else if (S_ISFIFO(st
.st_mode
) || S_ISSOCK(st
.st_mode
)) {
369 /* maybe we should skip sockets */
372 entry
->size
= st
.st_rdev
;
373 if (entry
->size
& -(1<<CRAMFS_SIZE_WIDTH
))
377 if (S_ISREG(st
.st_mode
) || S_ISLNK(st
.st_mode
)) {
378 int blocks
= ((entry
->size
- 1) / blksize
+ 1);
380 /* block pointers & data expansion allowance + data */
382 *fslen_ub
+= (4+26)*blocks
+ entry
->size
+ 3;
385 /* Link it into the list */
391 free(dirlist
); /* allocated by scandir() with malloc() */
395 /* Returns sizeof(struct cramfs_super), which includes the root inode. */
396 static unsigned int write_superblock(struct entry
*root
, char *base
, int size
)
398 struct cramfs_super
*super
= (struct cramfs_super
*) base
;
399 unsigned int offset
= sizeof(struct cramfs_super
) + image_length
;
405 super
->magic
= CRAMFS_MAGIC
;
406 super
->flags
= CRAMFS_FLAG_FSID_VERSION_2
| CRAMFS_FLAG_SORTED_DIRS
;
408 super
->flags
|= CRAMFS_FLAG_HOLES
;
409 if (image_length
> 0)
410 super
->flags
|= CRAMFS_FLAG_SHIFTED_ROOT_OFFSET
;
412 memcpy(super
->signature
, CRAMFS_SIGNATURE
, sizeof(super
->signature
));
414 super
->fsid
.crc
= crc32(0L, NULL
, 0);
415 super
->fsid
.edition
= opt_edition
;
416 super
->fsid
.blocks
= total_blocks
;
417 super
->fsid
.files
= total_nodes
;
419 memset(super
->name
, 0x00, sizeof(super
->name
));
421 str2memcpy((char *)super
->name
, opt_name
, sizeof(super
->name
));
423 str2memcpy((char *)super
->name
, "Compressed", sizeof(super
->name
));
425 super
->root
.mode
= root
->mode
;
426 super
->root
.uid
= root
->uid
;
427 super
->root
.gid
= root
->gid
;
428 super
->root
.size
= root
->size
;
429 super
->root
.offset
= offset
>> 2;
431 super_toggle_endianness(cramfs_is_big_endian
, super
);
432 inode_from_host(cramfs_is_big_endian
, &super
->root
, &super
->root
);
437 static void set_data_offset(struct entry
*entry
, char *base
, unsigned long offset
)
439 struct cramfs_inode
*inode
= (struct cramfs_inode
*) (base
+ entry
->dir_offset
);
440 inode_to_host(cramfs_is_big_endian
, inode
, inode
);
441 if (offset
>= (1 << (2 + CRAMFS_OFFSET_WIDTH
)))
442 errx(MKFS_EX_ERROR
, _("filesystem too big. Exiting."));
443 inode
->offset
= (offset
>> 2);
444 inode_from_host(cramfs_is_big_endian
, inode
, inode
);
449 * We do a width-first printout of the directory
450 * entries, using a stack to remember the directories
453 static unsigned int write_directory_structure(struct entry
*entry
, char *base
, unsigned int offset
)
455 int stack_entries
= 0;
457 struct entry
**entry_stack
;
459 entry_stack
= xmalloc(stack_size
* sizeof(struct entry
*));
462 int dir_start
= stack_entries
;
464 struct cramfs_inode
*inode
=
465 (struct cramfs_inode
*) (base
+ offset
);
466 size_t len
= strlen((const char *)entry
->name
);
468 entry
->dir_offset
= offset
;
470 inode
->mode
= entry
->mode
;
471 inode
->uid
= entry
->uid
;
472 inode
->gid
= entry
->gid
;
473 inode
->size
= entry
->size
;
475 /* Non-empty directories, regfiles and symlinks will
476 write over inode->offset later. */
478 offset
+= sizeof(struct cramfs_inode
);
479 total_nodes
++; /* another node */
480 memcpy(base
+ offset
, entry
->name
, len
);
481 /* Pad up the name to a 4-byte boundary */
483 *(base
+ offset
+ len
) = '\0';
486 inode
->namelen
= len
>> 2;
490 printf(" %s\n", entry
->name
);
492 if (stack_entries
>= stack_size
) {
494 entry_stack
= xrealloc(entry_stack
, stack_size
* sizeof(struct entry
*));
496 entry_stack
[stack_entries
] = entry
;
499 inode_from_host(cramfs_is_big_endian
, inode
, inode
);
504 * Reverse the order the stack entries pushed during
505 * this directory, for a small optimization of disk
506 * access in the created fs. This change makes things
510 struct entry
**lo
= entry_stack
+ dir_start
;
511 struct entry
**hi
= entry_stack
+ stack_entries
;
521 /* Pop a subdirectory entry from the stack, and recurse. */
525 entry
= entry_stack
[stack_entries
];
527 set_data_offset(entry
, base
, offset
);
529 printf("'%s':\n", entry
->name
);
530 entry
= entry
->child
;
536 static int is_zero(unsigned char const *begin
, unsigned len
)
539 /* Returns non-zero iff the first LEN bytes from BEGIN are
541 return (len
-- == 0 ||
549 memcmp(begin
, begin
+ 4, len
) == 0))))))));
551 /* Never create holes. */
556 * One 4-byte pointer per block and then the actual blocked
557 * output. The first block does not need an offset pointer,
558 * as it will start immediately after the pointer block;
559 * so the i'th pointer points to the end of the i'th block
560 * (i.e. the start of the (i+1)'th block or past EOF).
562 * Note that size > 0, as a zero-sized file wouldn't ever
563 * have gotten here in the first place.
566 do_compress(char *base
, unsigned int offset
, unsigned char const *name
,
567 char *path
, unsigned int size
, unsigned int mode
)
569 unsigned long original_size
, original_offset
, new_size
, blocks
, curr
;
574 /* get uncompressed data */
575 start
= do_mmap(path
, size
, mode
);
580 original_size
= size
;
581 original_offset
= offset
;
582 blocks
= (size
- 1) / blksize
+ 1;
583 curr
= offset
+ 4 * blocks
;
585 total_blocks
+= blocks
;
588 uLongf len
= 2 * blksize
;
593 if (!is_zero (p
, input
)) {
594 compress((Bytef
*)(base
+ curr
), &len
, p
, input
);
599 if (len
> blksize
*2) {
600 /* (I don't think this can happen with zlib.) */
601 printf(_("AIEEE: block \"compressed\" to > "
602 "2*blocklength (%ld)\n"),
607 *(uint32_t *) (base
+ offset
) = u32_toggle_endianness(cramfs_is_big_endian
, curr
);
611 do_munmap(start
, original_size
, mode
);
613 curr
= (curr
+ 3) & ~3;
614 new_size
= curr
- original_offset
;
615 /* TODO: Arguably, original_size in these 2 lines should be
616 st_blocks * 512. But if you say that, then perhaps
617 administrative data should also be included in both. */
618 change
= new_size
- original_size
;
620 printf(_("%6.2f%% (%+ld bytes)\t%s\n"),
621 (change
* 100) / (double) original_size
, change
, name
);
628 * Traverse the entry tree, writing data for every item that has
629 * non-null entry->path (i.e. every symlink and non-empty
633 write_data(struct entry
*entry
, char *base
, unsigned int offset
) {
636 for (e
= entry
; e
; e
= e
->next
) {
639 set_data_offset(e
, base
, e
->same
->offset
);
640 e
->offset
= e
->same
->offset
;
641 } else if (e
->size
) {
642 set_data_offset(e
, base
, offset
);
644 offset
= do_compress(base
, offset
, e
->name
,
645 e
->path
, e
->size
,e
->mode
);
648 offset
= write_data(e
->child
, base
, offset
);
653 static unsigned int write_file(char *file
, char *base
, unsigned int offset
)
658 fd
= open(file
, O_RDONLY
);
660 err(MKFS_EX_ERROR
, _("cannot open %s"), file
);
661 buf
= mmap(NULL
, image_length
, PROT_READ
, MAP_PRIVATE
, fd
, 0);
662 memcpy(base
+ offset
, buf
, image_length
);
663 munmap(buf
, image_length
);
665 err(MKFS_EX_ERROR
, _("cannot close file %s"), file
);
666 /* Pad up the image_length to a 4-byte boundary */
667 while (image_length
& 3) {
668 *(base
+ offset
+ image_length
) = '\0';
671 return (offset
+ image_length
);
675 * Maximum size fs you can create is roughly 256MB. (The last file's
676 * data must begin within 256MB boundary but can extend beyond that.)
678 * Note that if you want it to fit in a ROM then you're limited to what the
679 * hardware and kernel can support (64MB?).
683 return (((1 << CRAMFS_OFFSET_WIDTH
) - 1) << 2) /* offset */
684 + (1 << CRAMFS_SIZE_WIDTH
) - 1 /* filesize */
685 + (1 << CRAMFS_SIZE_WIDTH
) * 4 / blksize
; /* block pointers */
691 * mkcramfs directory-name outfile
693 * where "directory-name" is simply the root of the directory
694 * tree that we want to generate a compressed filesystem out
697 int main(int argc
, char **argv
)
699 struct stat st
; /* used twice... */
700 struct entry
*root_entry
;
702 ssize_t offset
, written
;
704 /* initial guess (upper-bound) of required filesystem size */
705 loff_t fslen_ub
= sizeof(struct cramfs_super
);
706 unsigned int fslen_max
;
707 char const *dirname
, *outfile
;
708 uint32_t crc
= crc32(0L, NULL
, 0);
710 cramfs_is_big_endian
= HOST_IS_BIG_ENDIAN
; /* default is to use host order */
714 setlocale(LC_ALL
, "");
715 bindtextdomain(PACKAGE
, LOCALEDIR
);
717 close_stdout_atexit();
720 /* first arg may be one of our standard longopts */
721 if (!strcmp(argv
[1], "--help"))
723 if (!strcmp(argv
[1], "--version")) {
724 print_version(EXIT_SUCCESS
);
728 strutils_set_exitcode(MKFS_EX_USAGE
);
730 /* command line options */
731 while ((c
= getopt(argc
, argv
, "hb:Ee:i:n:N:psVvz")) != EOF
) {
736 blksize
= strtou32_or_err(optarg
, _("invalid blocksize argument"));
742 opt_edition
= strtou32_or_err(optarg
, _("invalid edition number argument"));
745 if (strcmp(optarg
, "big") == 0)
746 cramfs_is_big_endian
= 1;
747 else if (strcmp(optarg
, "little") == 0)
748 cramfs_is_big_endian
= 0;
749 else if (strcmp(optarg
, "host") == 0)
752 errx(MKFS_EX_USAGE
, _("invalid endianness given;"
753 " must be 'big', 'little', or 'host'"));
757 if (lstat(opt_image
, &st
) < 0)
758 err(MKFS_EX_USAGE
, _("stat of %s failed"), opt_image
);
759 image_length
= st
.st_size
; /* may be padded later */
760 fslen_ub
+= (image_length
+ 3); /* 3 is for padding */
767 fslen_ub
+= PAD_SIZE
;
770 /* old option, ignored */
773 print_version(MKFS_EX_OK
);
781 errtryhelp(MKFS_EX_USAGE
);
785 if ((argc
- optind
) != 2) {
786 warnx(_("bad usage"));
787 errtryhelp(MKFS_EX_USAGE
);
789 dirname
= argv
[optind
];
790 outfile
= argv
[optind
+ 1];
793 blksize
= getpagesize();
795 if (stat(dirname
, &st
) < 0)
796 err(MKFS_EX_USAGE
, _("stat of %s failed"), dirname
);
797 fd
= open(outfile
, O_WRONLY
| O_CREAT
| O_TRUNC
, 0666);
799 err(MKFS_EX_USAGE
, _("cannot open %s"), outfile
);
801 root_entry
= xcalloc(1, sizeof(struct entry
));
802 root_entry
->mode
= st
.st_mode
;
803 root_entry
->uid
= st
.st_uid
;
804 root_entry
->gid
= st
.st_gid
;
806 root_entry
->size
= parse_directory(root_entry
, dirname
, &root_entry
->child
, &fslen_ub
);
808 /* find duplicate files */
809 eliminate_doubles(root_entry
,root_entry
, &fslen_ub
);
811 /* always allocate a multiple of blksize bytes because that's
812 what we're going to write later on */
813 fslen_ub
= ((fslen_ub
- 1) | (blksize
- 1)) + 1;
814 fslen_max
= maxfslen();
816 if (fslen_ub
> fslen_max
) {
817 warnx( _("warning: guestimate of required size (upper bound) "
818 "is %lldMB, but maximum image size is %uMB. "
819 "We might die prematurely."),
820 (long long)fslen_ub
>> 20,
822 fslen_ub
= fslen_max
;
825 /* TODO: Why do we use a private/anonymous mapping here
826 followed by a write below, instead of just a shared mapping
827 and a couple of ftruncate calls? Is it just to save us
828 having to deal with removing the file afterwards? If we
829 really need this huge anonymous mapping, we ought to mmap
830 in smaller chunks, so that the user doesn't need nn MB of
831 RAM free. If the reason is to be able to write to
832 un-mmappable block devices, then we could try shared mmap
833 and revert to anonymous mmap if the shared mmap fails. */
834 rom_image
= mmap(NULL
,
836 PROT_READ
| PROT_WRITE
,
837 MAP_PRIVATE
| MAP_ANONYMOUS
,
840 if (-1 == (int) (long) rom_image
)
841 err(MKFS_EX_ERROR
, _("ROM image map"));
843 /* Skip the first opt_pad bytes for boot loader code */
845 memset(rom_image
, 0x00, opt_pad
);
847 /* Skip the superblock and come back to write it later. */
848 offset
+= sizeof(struct cramfs_super
);
850 /* Insert a file image. */
853 printf(_("Including: %s\n"), opt_image
);
854 offset
= write_file(opt_image
, rom_image
, offset
);
857 offset
= write_directory_structure(root_entry
->child
, rom_image
, offset
);
859 printf(_("Directory data: %zd bytes\n"), offset
);
861 offset
= write_data(root_entry
, rom_image
, offset
);
863 /* We always write a multiple of blksize bytes, so that
865 offset
= ((offset
- 1) | (blksize
- 1)) + 1;
867 printf(_("Everything: %zd kilobytes\n"), offset
>> 10);
869 /* Write the superblock now that we can fill in all of the fields. */
870 write_superblock(root_entry
, rom_image
+opt_pad
, offset
);
872 printf(_("Super block: %zd bytes\n"),
873 sizeof(struct cramfs_super
));
875 /* Put the checksum in. */
876 crc
= crc32(crc
, (unsigned char *) (rom_image
+opt_pad
), (offset
-opt_pad
));
877 ((struct cramfs_super
*) (rom_image
+opt_pad
))->fsid
.crc
= u32_toggle_endianness(cramfs_is_big_endian
, crc
);
879 printf(_("CRC: %x\n"), crc
);
881 /* Check to make sure we allocated enough space. */
882 if (fslen_ub
< offset
)
884 _("not enough space allocated for ROM image "
885 "(%lld allocated, %zu used)"),
886 (long long) fslen_ub
, offset
);
888 written
= write(fd
, rom_image
, offset
);
889 if (offset
!= written
)
890 errx(MKFS_EX_ERROR
, _("ROM image write failed (%zd %zd)"),
892 if (close_fd(fd
) != 0)
893 err(MKFS_EX_ERROR
, _("ROM image"));
896 * (These warnings used to come at the start, but they scroll off
897 * the screen too quickly.)
900 /* Can't happen when reading from ext2fs. */
901 /* Bytes, not chars: think UTF8. */
902 warnx(_("warning: filenames truncated to %u bytes."), MAX_INPUT_NAMELEN
);
904 warnx(_("warning: files were skipped due to errors."));
906 warnx(_("warning: file sizes truncated to %luMB "
907 "(minus 1 byte)."), 1L << (CRAMFS_SIZE_WIDTH
- 20));
909 /* (not possible with current Linux versions) */
910 warnx(_("warning: uids truncated to %u bits. "
911 "(This may be a security concern.)"), CRAMFS_UID_WIDTH
);
913 warnx(_("warning: gids truncated to %u bits. "
914 "(This may be a security concern.)"), CRAMFS_GID_WIDTH
);
916 warnx(_("WARNING: device numbers truncated to %u bits. "
917 "This almost certainly means\n"
918 "that some device files will be wrong."),
919 CRAMFS_OFFSET_WIDTH
);
921 (warn_namelen
|warn_skip
|warn_size
|warn_uid
|warn_gid
|warn_dev
))