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 instaed of all simultaneously. - aeb, 2002-11-01
26 #include <sys/types.h>
43 #include "closestream.h"
46 #include "exitcodes.h"
48 #define XALLOC_EXIT_CODE MKFS_EX_ERROR
51 /* The kernel only supports PAD_SIZE of 0 and 512. */
54 static int verbose
= 0;
56 static unsigned int blksize
= 0; /* settable via -b option, default page size */
57 static long total_blocks
= 0, total_nodes
= 1; /* pre-count the root node */
58 static int image_length
= 0;
59 static int cramfs_is_big_endian
= 0; /* target is big endian */
62 * If opt_holes is set, then mkcramfs can create explicit holes in the
63 * data, which saves 26 bytes per hole (which is a lot smaller a
64 * saving than for most filesystems).
66 * Note that kernels up to at least 2.3.39 don't support cramfs holes,
67 * which is why this is turned off by default.
69 static unsigned int opt_edition
= 0;
70 static int opt_errors
= 0;
71 static int opt_holes
= 0;
72 static int opt_pad
= 0;
73 static char *opt_image
= NULL
;
74 static char *opt_name
= NULL
;
76 static int warn_dev
= 0;
77 static int warn_gid
= 0;
78 static int warn_namelen
= 0;
79 static int warn_skip
= 0;
80 static int warn_size
= 0;
81 static int warn_uid
= 0;
84 #define CRAMFS_EFLAG_MD5 1
85 #define CRAMFS_EFLAG_INVALID 2
87 /* In-core version of inode / directory entry. */
91 unsigned int mode
, size
, uid
, gid
;
92 unsigned char md5sum
[MD5LENGTH
];
93 unsigned char flags
; /* CRAMFS_EFLAG_* */
97 int fd
; /* temporarily open files while mmapped */
98 struct entry
*same
; /* points to other identical file */
99 unsigned int offset
; /* pointer to compressed data in archive */
100 unsigned int dir_offset
; /* offset of directory entry in archive */
103 struct entry
*child
; /* NULL for non-directory and empty dir */
108 * Width of various bitfields in struct cramfs_inode.
109 * Used only to generate warnings.
111 #define CRAMFS_SIZE_WIDTH 24
112 #define CRAMFS_UID_WIDTH 16
113 #define CRAMFS_GID_WIDTH 8
114 #define CRAMFS_OFFSET_WIDTH 26
116 /* Input status of 0 to print help and exit without an error. */
119 FILE *stream
= status
? stderr
: stdout
;
122 _("usage: %s [-h] [-v] [-b blksize] [-e edition] [-N endian] [-i file] "
123 "[-n name] dirname outfile\n"
124 " -h print this help\n"
126 " -E make all warnings errors "
127 "(non-zero exit status)\n"
128 " -b blksize use this blocksize, must equal page size\n"
129 " -e edition set edition number (part of fsid)\n"
130 " -N endian set cramfs endianness (big|little|host), default host\n"
131 " -i file insert a file image into the filesystem "
132 "(requires >= 2.4.0)\n"
133 " -n name set name of cramfs filesystem\n"
134 " -p pad by %d bytes for boot code\n"
135 " -s sort directory entries (old option, ignored)\n"
136 " -z make explicit holes (requires >= 2.3.39)\n"
137 " dirname root of the filesystem to be compressed\n"
138 " outfile output file\n"),
139 program_invocation_short_name
, PAD_SIZE
);
145 do_mmap(char *path
, unsigned int size
, unsigned int mode
){
153 start
= xmalloc(size
);
154 if (readlink(path
, start
, size
) < 0) {
155 warn(_("readlink failed: %s"), path
);
162 fd
= open(path
, O_RDONLY
);
164 warn(_("cannot open %s"), path
);
169 start
= mmap(NULL
, size
, PROT_READ
, MAP_PRIVATE
, fd
, 0);
170 if (-1 == (int) (long) start
) {
172 err(MKFS_EX_ERROR
, "mmap");
182 do_munmap(char *start
, unsigned int size
, unsigned int mode
){
189 /* compute md5sums, so that we do not have to compare every pair of files */
191 mdfile(struct entry
*e
) {
195 start
= do_mmap(e
->path
, e
->size
, e
->mode
);
197 e
->flags
|= CRAMFS_EFLAG_INVALID
;
200 MD5Update(&ctx
, (unsigned char *) start
, e
->size
);
201 MD5Final(e
->md5sum
, &ctx
);
203 do_munmap(start
, e
->size
, e
->mode
);
205 e
->flags
|= CRAMFS_EFLAG_MD5
;
209 /* md5 digests are equal; files are almost certainly the same,
210 but just to be sure, do the comparison */
212 identical_file(struct entry
*e1
, struct entry
*e2
){
213 char *start1
, *start2
;
216 start1
= do_mmap(e1
->path
, e1
->size
, e1
->mode
);
219 start2
= do_mmap(e2
->path
, e2
->size
, e2
->mode
);
221 do_munmap(start1
, e1
->size
, e1
->mode
);
224 equal
= !memcmp(start1
, start2
, e1
->size
);
225 do_munmap(start1
, e1
->size
, e1
->mode
);
226 do_munmap(start2
, e2
->size
, e2
->mode
);
231 * The longest file name component to allow for in the input directory tree.
232 * Ext2fs (and many others) allow up to 255 bytes. A couple of filesystems
233 * allow longer (e.g. smbfs 1024), but there isn't much use in supporting
234 * >255-byte names in the input directory tree given that such names get
235 * truncated to 255 bytes when written to cramfs.
237 #define MAX_INPUT_NAMELEN 255
239 static int find_identical_file(struct entry
*orig
, struct entry
*new, loff_t
*fslen_ub
)
245 if (orig
->size
== new->size
&& orig
->path
) {
251 if ((orig
->flags
& CRAMFS_EFLAG_MD5
) &&
252 (new->flags
& CRAMFS_EFLAG_MD5
) &&
253 !memcmp(orig
->md5sum
, new->md5sum
, MD5LENGTH
) &&
254 identical_file(orig
, new)) {
256 *fslen_ub
-= new->size
;
260 return find_identical_file(orig
->child
, new, fslen_ub
) ||
261 find_identical_file(orig
->next
, new, fslen_ub
);
264 static void eliminate_doubles(struct entry
*root
, struct entry
*orig
, loff_t
*fslen_ub
) {
266 if (orig
->size
&& orig
->path
)
267 find_identical_file(root
,orig
, fslen_ub
);
268 eliminate_doubles(root
,orig
->child
, fslen_ub
);
269 eliminate_doubles(root
,orig
->next
, fslen_ub
);
274 * We define our own sorting function instead of using alphasort which
275 * uses strcoll and changes ordering based on locale information.
277 static int cramsort (const struct dirent
**a
, const struct dirent
**b
)
279 return strcmp((*a
)->d_name
, (*b
)->d_name
);
282 static unsigned int parse_directory(struct entry
*root_entry
, const char *name
, struct entry
**prev
, loff_t
*fslen_ub
)
284 struct dirent
**dirlist
;
285 int totalsize
= 0, dircount
, dirindex
;
286 char *path
, *endpath
;
287 size_t len
= strlen(name
);
289 /* Set up the path. */
290 /* TODO: Reuse the parent's buffer to save memcpy'ing and duplication. */
291 path
= xmalloc(len
+ 1 + MAX_INPUT_NAMELEN
+ 1);
292 memcpy(path
, name
, len
);
293 endpath
= path
+ len
;
297 /* read in the directory and sort */
298 dircount
= scandir(name
, &dirlist
, 0, cramsort
);
301 err(MKFS_EX_ERROR
, _("could not read directory %s"), name
);
303 /* process directory */
304 for (dirindex
= 0; dirindex
< dircount
; dirindex
++) {
305 struct dirent
*dirent
;
311 dirent
= dirlist
[dirindex
];
313 /* Ignore "." and ".." - we won't be adding them
315 if (dirent
->d_name
[0] == '.') {
316 if (dirent
->d_name
[1] == '\0')
318 if (dirent
->d_name
[1] == '.') {
319 if (dirent
->d_name
[2] == '\0')
323 namelen
= strlen(dirent
->d_name
);
324 if (namelen
> MAX_INPUT_NAMELEN
)
326 _("Very long (%zu bytes) filename `%s' found.\n"
327 " Please increase MAX_INPUT_NAMELEN in "
328 "mkcramfs.c and recompile. Exiting."),
329 namelen
, dirent
->d_name
);
330 memcpy(endpath
, dirent
->d_name
, namelen
+ 1);
332 if (lstat(path
, &st
) < 0) {
337 entry
= xcalloc(1, sizeof(struct entry
));
338 entry
->name
= (unsigned char *)xstrdup(dirent
->d_name
);
340 /* Can't happen when reading from ext2fs. */
342 /* TODO: we ought to avoid chopping in half
343 multi-byte UTF8 characters. */
344 entry
->name
[namelen
= 255] = '\0';
347 entry
->mode
= st
.st_mode
;
348 entry
->size
= st
.st_size
;
349 entry
->uid
= st
.st_uid
;
350 if (entry
->uid
>= 1 << CRAMFS_UID_WIDTH
)
352 entry
->gid
= st
.st_gid
;
353 if (entry
->gid
>= 1 << CRAMFS_GID_WIDTH
)
354 /* TODO: We ought to replace with a default
355 gid instead of truncating; otherwise there
356 are security problems. Maybe mode should
357 be &= ~070. Same goes for uid once Linux
358 supports >16-bit uids. */
360 size
= sizeof(struct cramfs_inode
) + ((namelen
+ 3) & ~3);
362 if (S_ISDIR(st
.st_mode
)) {
363 entry
->size
= parse_directory(root_entry
, path
, &entry
->child
, fslen_ub
);
364 } else if (S_ISREG(st
.st_mode
)) {
365 entry
->path
= xstrdup(path
);
367 if (entry
->size
>= (1 << CRAMFS_SIZE_WIDTH
)) {
369 entry
->size
= (1 << CRAMFS_SIZE_WIDTH
) - 1;
372 } else if (S_ISLNK(st
.st_mode
)) {
373 entry
->path
= xstrdup(path
);
374 } else if (S_ISFIFO(st
.st_mode
) || S_ISSOCK(st
.st_mode
)) {
375 /* maybe we should skip sockets */
378 entry
->size
= st
.st_rdev
;
379 if (entry
->size
& -(1<<CRAMFS_SIZE_WIDTH
))
383 if (S_ISREG(st
.st_mode
) || S_ISLNK(st
.st_mode
)) {
384 int blocks
= ((entry
->size
- 1) / blksize
+ 1);
386 /* block pointers & data expansion allowance + data */
388 *fslen_ub
+= (4+26)*blocks
+ entry
->size
+ 3;
391 /* Link it into the list */
397 free(dirlist
); /* allocated by scandir() with malloc() */
401 /* Returns sizeof(struct cramfs_super), which includes the root inode. */
402 static unsigned int write_superblock(struct entry
*root
, char *base
, int size
)
404 struct cramfs_super
*super
= (struct cramfs_super
*) base
;
405 unsigned int offset
= sizeof(struct cramfs_super
) + image_length
;
411 super
->magic
= CRAMFS_MAGIC
;
412 super
->flags
= CRAMFS_FLAG_FSID_VERSION_2
| CRAMFS_FLAG_SORTED_DIRS
;
414 super
->flags
|= CRAMFS_FLAG_HOLES
;
415 if (image_length
> 0)
416 super
->flags
|= CRAMFS_FLAG_SHIFTED_ROOT_OFFSET
;
418 memcpy(super
->signature
, CRAMFS_SIGNATURE
, sizeof(super
->signature
));
420 super
->fsid
.crc
= crc32(0L, Z_NULL
, 0);
421 super
->fsid
.edition
= opt_edition
;
422 super
->fsid
.blocks
= total_blocks
;
423 super
->fsid
.files
= total_nodes
;
425 memset(super
->name
, 0x00, sizeof(super
->name
));
427 strncpy((char *)super
->name
, opt_name
, sizeof(super
->name
));
429 strncpy((char *)super
->name
, "Compressed", sizeof(super
->name
));
431 super
->root
.mode
= root
->mode
;
432 super
->root
.uid
= root
->uid
;
433 super
->root
.gid
= root
->gid
;
434 super
->root
.size
= root
->size
;
435 super
->root
.offset
= offset
>> 2;
437 super_toggle_endianness(cramfs_is_big_endian
, super
);
438 inode_from_host(cramfs_is_big_endian
, &super
->root
, &super
->root
);
443 static void set_data_offset(struct entry
*entry
, char *base
, unsigned long offset
)
445 struct cramfs_inode
*inode
= (struct cramfs_inode
*) (base
+ entry
->dir_offset
);
446 inode_to_host(cramfs_is_big_endian
, inode
, inode
);
447 if (offset
>= (1 << (2 + CRAMFS_OFFSET_WIDTH
)))
448 errx(MKFS_EX_ERROR
, _("filesystem too big. Exiting."));
449 inode
->offset
= (offset
>> 2);
450 inode_from_host(cramfs_is_big_endian
, inode
, inode
);
455 * We do a width-first printout of the directory
456 * entries, using a stack to remember the directories
459 static unsigned int write_directory_structure(struct entry
*entry
, char *base
, unsigned int offset
)
461 int stack_entries
= 0;
463 struct entry
**entry_stack
;
465 entry_stack
= xmalloc(stack_size
* sizeof(struct entry
*));
468 int dir_start
= stack_entries
;
470 struct cramfs_inode
*inode
=
471 (struct cramfs_inode
*) (base
+ offset
);
472 size_t len
= strlen((const char *)entry
->name
);
474 entry
->dir_offset
= offset
;
476 inode
->mode
= entry
->mode
;
477 inode
->uid
= entry
->uid
;
478 inode
->gid
= entry
->gid
;
479 inode
->size
= entry
->size
;
481 /* Non-empty directories, regfiles and symlinks will
482 write over inode->offset later. */
484 offset
+= sizeof(struct cramfs_inode
);
485 total_nodes
++; /* another node */
486 memcpy(base
+ offset
, entry
->name
, len
);
487 /* Pad up the name to a 4-byte boundary */
489 *(base
+ offset
+ len
) = '\0';
492 inode
->namelen
= len
>> 2;
496 printf(" %s\n", entry
->name
);
498 if (stack_entries
>= stack_size
) {
500 entry_stack
= xrealloc(entry_stack
, stack_size
* sizeof(struct entry
*));
502 entry_stack
[stack_entries
] = entry
;
505 inode_from_host(cramfs_is_big_endian
, inode
, inode
);
510 * Reverse the order the stack entries pushed during
511 * this directory, for a small optimization of disk
512 * access in the created fs. This change makes things
516 struct entry
**lo
= entry_stack
+ dir_start
;
517 struct entry
**hi
= entry_stack
+ stack_entries
;
527 /* Pop a subdirectory entry from the stack, and recurse. */
531 entry
= entry_stack
[stack_entries
];
533 set_data_offset(entry
, base
, offset
);
535 printf("'%s':\n", entry
->name
);
536 entry
= entry
->child
;
542 static int is_zero(unsigned char const *begin
, unsigned len
)
545 /* Returns non-zero iff the first LEN bytes from BEGIN are
547 return (len
-- == 0 ||
555 memcmp(begin
, begin
+ 4, len
) == 0))))))));
557 /* Never create holes. */
562 * One 4-byte pointer per block and then the actual blocked
563 * output. The first block does not need an offset pointer,
564 * as it will start immediately after the pointer block;
565 * so the i'th pointer points to the end of the i'th block
566 * (i.e. the start of the (i+1)'th block or past EOF).
568 * Note that size > 0, as a zero-sized file wouldn't ever
569 * have gotten here in the first place.
572 do_compress(char *base
, unsigned int offset
, unsigned char const *name
,
573 char *path
, unsigned int size
, unsigned int mode
)
575 unsigned long original_size
, original_offset
, new_size
, blocks
, curr
;
580 /* get uncompressed data */
581 start
= do_mmap(path
, size
, mode
);
586 original_size
= size
;
587 original_offset
= offset
;
588 blocks
= (size
- 1) / blksize
+ 1;
589 curr
= offset
+ 4 * blocks
;
591 total_blocks
+= blocks
;
594 uLongf len
= 2 * blksize
;
599 if (!is_zero (p
, input
)) {
600 compress((Bytef
*)(base
+ curr
), &len
, p
, input
);
605 if (len
> blksize
*2) {
606 /* (I don't think this can happen with zlib.) */
607 printf(_("AIEEE: block \"compressed\" to > "
608 "2*blocklength (%ld)\n"),
613 *(uint32_t *) (base
+ offset
) = u32_toggle_endianness(cramfs_is_big_endian
, curr
);
617 do_munmap(start
, original_size
, mode
);
619 curr
= (curr
+ 3) & ~3;
620 new_size
= curr
- original_offset
;
621 /* TODO: Arguably, original_size in these 2 lines should be
622 st_blocks * 512. But if you say that, then perhaps
623 administrative data should also be included in both. */
624 change
= new_size
- original_size
;
626 printf(_("%6.2f%% (%+ld bytes)\t%s\n"),
627 (change
* 100) / (double) original_size
, change
, name
);
634 * Traverse the entry tree, writing data for every item that has
635 * non-null entry->path (i.e. every symlink and non-empty
639 write_data(struct entry
*entry
, char *base
, unsigned int offset
) {
642 for (e
= entry
; e
; e
= e
->next
) {
645 set_data_offset(e
, base
, e
->same
->offset
);
646 e
->offset
= e
->same
->offset
;
647 } else if (e
->size
) {
648 set_data_offset(e
, base
, offset
);
650 offset
= do_compress(base
, offset
, e
->name
,
651 e
->path
, e
->size
,e
->mode
);
654 offset
= write_data(e
->child
, base
, offset
);
659 static unsigned int write_file(char *file
, char *base
, unsigned int offset
)
664 fd
= open(file
, O_RDONLY
);
666 err(MKFS_EX_ERROR
, _("cannot open %s"), file
);
667 buf
= mmap(NULL
, image_length
, PROT_READ
, MAP_PRIVATE
, fd
, 0);
668 memcpy(base
+ offset
, buf
, image_length
);
669 munmap(buf
, image_length
);
671 err(MKFS_EX_ERROR
, _("cannot close file %s"), file
);
672 /* Pad up the image_length to a 4-byte boundary */
673 while (image_length
& 3) {
674 *(base
+ offset
+ image_length
) = '\0';
677 return (offset
+ image_length
);
681 * Maximum size fs you can create is roughly 256MB. (The last file's
682 * data must begin within 256MB boundary but can extend beyond that.)
684 * Note that if you want it to fit in a ROM then you're limited to what the
685 * hardware and kernel can support (64MB?).
689 return (((1 << CRAMFS_OFFSET_WIDTH
) - 1) << 2) /* offset */
690 + (1 << CRAMFS_SIZE_WIDTH
) - 1 /* filesize */
691 + (1 << CRAMFS_SIZE_WIDTH
) * 4 / blksize
; /* block pointers */
697 * mkcramfs directory-name outfile
699 * where "directory-name" is simply the root of the directory
700 * tree that we want to generate a compressed filesystem out
703 int main(int argc
, char **argv
)
705 struct stat st
; /* used twice... */
706 struct entry
*root_entry
;
708 ssize_t offset
, written
;
710 /* initial guess (upper-bound) of required filesystem size */
711 loff_t fslen_ub
= sizeof(struct cramfs_super
);
712 unsigned int fslen_max
;
713 char const *dirname
, *outfile
;
714 uint32_t crc
= crc32(0L, Z_NULL
, 0);
716 cramfs_is_big_endian
= HOST_IS_BIG_ENDIAN
; /* default is to use host order */
720 setlocale(LC_ALL
, "");
721 bindtextdomain(PACKAGE
, LOCALEDIR
);
723 atexit(close_stdout
);
725 /* command line options */
726 while ((c
= getopt(argc
, argv
, "hb:Ee:i:n:N:psVvz")) != EOF
) {
731 blksize
= strtou32_or_err(optarg
, _("invalid blocksize argument"));
737 opt_edition
= strtou32_or_err(optarg
, _("invalid edition number argument"));
740 if (strcmp(optarg
, "big") == 0)
741 cramfs_is_big_endian
= 1;
742 else if (strcmp(optarg
, "little") == 0)
743 cramfs_is_big_endian
= 0;
744 else if (strcmp(optarg
, "host") == 0)
747 errx(MKFS_EX_USAGE
, _("invalid endianness given;"
748 " must be 'big', 'little', or 'host'"));
752 if (lstat(opt_image
, &st
) < 0)
753 err(MKFS_EX_USAGE
, _("stat failed %s"), opt_image
);
754 image_length
= st
.st_size
; /* may be padded later */
755 fslen_ub
+= (image_length
+ 3); /* 3 is for padding */
762 fslen_ub
+= PAD_SIZE
;
765 /* old option, ignored */
768 printf(UTIL_LINUX_VERSION
);
777 usage(FSCK_EX_USAGE
);
781 if ((argc
- optind
) != 2)
782 usage(MKFS_EX_USAGE
);
783 dirname
= argv
[optind
];
784 outfile
= argv
[optind
+ 1];
787 blksize
= getpagesize();
789 if (stat(dirname
, &st
) < 0)
790 err(MKFS_EX_USAGE
, _("stat failed %s"), dirname
);
791 fd
= open(outfile
, O_WRONLY
| O_CREAT
| O_TRUNC
, 0666);
793 err(MKFS_EX_USAGE
, _("cannot open %s"), outfile
);
795 root_entry
= xcalloc(1, sizeof(struct entry
));
796 root_entry
->mode
= st
.st_mode
;
797 root_entry
->uid
= st
.st_uid
;
798 root_entry
->gid
= st
.st_gid
;
800 root_entry
->size
= parse_directory(root_entry
, dirname
, &root_entry
->child
, &fslen_ub
);
802 /* find duplicate files */
803 eliminate_doubles(root_entry
,root_entry
, &fslen_ub
);
805 /* always allocate a multiple of blksize bytes because that's
806 what we're going to write later on */
807 fslen_ub
= ((fslen_ub
- 1) | (blksize
- 1)) + 1;
808 fslen_max
= maxfslen();
810 if (fslen_ub
> fslen_max
) {
811 warnx( _("warning: guestimate of required size (upper bound) "
812 "is %lldMB, but maximum image size is %uMB. "
813 "We might die prematurely."),
814 (long long)fslen_ub
>> 20,
816 fslen_ub
= fslen_max
;
819 /* TODO: Why do we use a private/anonymous mapping here
820 followed by a write below, instead of just a shared mapping
821 and a couple of ftruncate calls? Is it just to save us
822 having to deal with removing the file afterwards? If we
823 really need this huge anonymous mapping, we ought to mmap
824 in smaller chunks, so that the user doesn't need nn MB of
825 RAM free. If the reason is to be able to write to
826 un-mmappable block devices, then we could try shared mmap
827 and revert to anonymous mmap if the shared mmap fails. */
828 rom_image
= mmap(NULL
,
830 PROT_READ
| PROT_WRITE
,
831 MAP_PRIVATE
| MAP_ANONYMOUS
,
834 if (-1 == (int) (long) rom_image
)
835 err(MKFS_EX_ERROR
, _("ROM image map"));
837 /* Skip the first opt_pad bytes for boot loader code */
839 memset(rom_image
, 0x00, opt_pad
);
841 /* Skip the superblock and come back to write it later. */
842 offset
+= sizeof(struct cramfs_super
);
844 /* Insert a file image. */
847 printf(_("Including: %s\n"), opt_image
);
848 offset
= write_file(opt_image
, rom_image
, offset
);
851 offset
= write_directory_structure(root_entry
->child
, rom_image
, offset
);
853 printf(_("Directory data: %zd bytes\n"), offset
);
855 offset
= write_data(root_entry
, rom_image
, offset
);
857 /* We always write a multiple of blksize bytes, so that
859 offset
= ((offset
- 1) | (blksize
- 1)) + 1;
861 printf(_("Everything: %zd kilobytes\n"), offset
>> 10);
863 /* Write the superblock now that we can fill in all of the fields. */
864 write_superblock(root_entry
, rom_image
+opt_pad
, offset
);
866 printf(_("Super block: %zd bytes\n"),
867 sizeof(struct cramfs_super
));
869 /* Put the checksum in. */
870 crc
= crc32(crc
, (unsigned char *) (rom_image
+opt_pad
), (offset
-opt_pad
));
871 ((struct cramfs_super
*) (rom_image
+opt_pad
))->fsid
.crc
= u32_toggle_endianness(cramfs_is_big_endian
, crc
);
873 printf(_("CRC: %x\n"), crc
);
875 /* Check to make sure we allocated enough space. */
876 if (fslen_ub
< offset
)
878 _("not enough space allocated for ROM image "
879 "(%lld allocated, %zu used)"),
880 (long long) fslen_ub
, offset
);
882 written
= write(fd
, rom_image
, offset
);
883 if (offset
!= written
)
884 errx(MKFS_EX_ERROR
, _("ROM image write failed (%zd %zd)"),
886 if (close_fd(fd
) != 0)
887 err(MKFS_EX_ERROR
, _("ROM image"));
890 * (These warnings used to come at the start, but they scroll off
891 * the screen too quickly.)
894 /* Can't happen when reading from ext2fs. */
895 /* Bytes, not chars: think UTF8. */
896 warnx(_("warning: filenames truncated to 255 bytes."));
898 warnx(_("warning: files were skipped due to errors."));
900 warnx(_("warning: file sizes truncated to %luMB "
901 "(minus 1 byte)."), 1L << (CRAMFS_SIZE_WIDTH
- 20));
903 /* (not possible with current Linux versions) */
904 warnx(_("warning: uids truncated to %u bits. "
905 "(This may be a security concern.)"), CRAMFS_UID_WIDTH
);
907 warnx(_("warning: gids truncated to %u bits. "
908 "(This may be a security concern.)"), CRAMFS_GID_WIDTH
);
910 warnx(_("WARNING: device numbers truncated to %u bits. "
911 "This almost certainly means\n"
912 "that some device files will be wrong."),
913 CRAMFS_OFFSET_WIDTH
);
915 (warn_namelen
|warn_skip
|warn_size
|warn_uid
|warn_gid
|warn_dev
))