freebsd-skq/usr.sbin/mkdosfs/mkdosfs.c
1997-03-31 05:11:47 +00:00

310 lines
8.6 KiB
C

/*
* Copyright (c) 1995, 1996 Joerg Wunsch
*
* All rights reserved.
*
* This program is free software.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE DEVELOPERS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
* Create an MS-DOS (FAT) file system.
*
* $Id: mkdosfs.c,v 1.4 1997/02/22 16:06:38 peter Exp $
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <unistd.h>
#include <memory.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include "bootcode.h"
#include "dosfs.h"
struct descrip
{
/* our database key */
unsigned kilobytes;
/* MSDOS 3.3 BPB fields */
u_short sectsiz;
u_char clustsiz;
u_short ressecs;
u_char fatcnt;
u_short rootsiz;
u_short totsecs;
u_char media;
u_short fatsize;
u_short trksecs;
u_short headcnt;
u_short hidnsec;
/* MSDOS 4 BPB extensions */
u_long ext_totsecs;
u_short ext_physdrv;
u_char ext_extboot;
char ext_label[11];
char ext_fsysid[8];
};
static struct descrip
table[] =
{
/* NB: must be sorted, starting with the largest format! */
/*
* kilobytes
* sec cls res fat rot tot med fsz spt hds hid
* tot phs ebt label fsysid
*/
{1440,
512, 1, 1, 2, 224, 2880, 0xf0, 9, 18, 2, 0,
0, 0, 0, "4.4BSD ", "FAT12 "},
{1200,
512, 1, 1, 2, 224, 2400, 0xf9, 7, 15, 2, 0,
0, 0, 0, "4.4BSD ", "FAT12 "},
{ 720,
512, 2, 1, 2, 112, 1440, 0xf9, 3, 9, 2, 0,
0, 0, 0, "4.4BSD ", "FAT12 "},
{ 360,
512, 2, 1, 2, 112, 720, 0xfd, 2, 9, 2, 0,
0, 0, 0, "4.4BSD ", "FAT12 "},
};
void
usage(void)
{
fprintf(stderr, "usage: ");
errx(2, "[-f kbytes] [-L label] device");
}
unsigned
findformat(int fd)
{
struct stat sb;
/*
* This is a bit tricky. If the argument is a regular file, we can
* lseek() to its end and get the size reported. If it's a device
* however, lseeking doesn't report us any useful number. Instead,
* we try to seek just to the end of the device and try reading a
* block there. In the case where we've hit exactly the device
* boundary, we get a zero read, and thus have found the size.
* Since our knowledge of distinct formats is limited anyway, this
* is not a big deal at all.
*/
if(fstat(fd, &sb) == -1)
err(1, "Huh? Cannot fstat()"); /* Cannot happen */
if(S_ISREG(sb.st_mode))
{
off_t o;
if(lseek(fd, (off_t)0, SEEK_END) == -1 ||
(o = lseek(fd, (off_t)0, SEEK_CUR)) == -1)
/* Hmm, hmm. Hard luck. */
return 0;
return (int)(o / 1024);
}
else if(S_ISCHR(sb.st_mode) || S_ISBLK(sb.st_mode))
{
char b[512];
int i, rv;
struct descrip *dp;
for(i = 0, dp = table;
i < sizeof table / sizeof(struct descrip);
i++, dp++)
{
if(lseek(fd, (off_t)(dp->kilobytes * 1024), SEEK_SET) == 1)
/* Uh-oh, lseek() is not supposed to fail. */
return 0;
if((rv = read(fd, b, 512)) == 0)
break;
/* XXX The ENOSPC is for the bogus fd(4) driver return value. */
if(rv == -1 && errno != EINVAL && errno != ENOSPC)
return 0;
/* else: continue */
}
if(i == sizeof table / sizeof(struct descrip))
return 0;
(void)lseek(fd, (off_t)0, SEEK_SET);
return dp->kilobytes;
}
else
/* Outta luck. */
return 0;
}
void
setup_boot_sector_from_template(union bootsector *bs, struct descrip *dp)
{
memcpy((void *)bs->raw, (void *)bootcode, 512);
/* historical part of BPB */
s_to_little_s(bs->bsec.sectsiz, dp->sectsiz);
bs->bsec.clustsiz = dp->clustsiz;
s_to_little_s(bs->bsec.ressecs, dp->ressecs);
bs->bsec.fatcnt = dp->fatcnt;
s_to_little_s(bs->bsec.rootsiz, dp->rootsiz);
s_to_little_s(bs->bsec.totsecs, dp->totsecs);
bs->bsec.media = dp->media;
s_to_little_s(bs->bsec.fatsize, dp->fatsize);
s_to_little_s(bs->bsec.trksecs, dp->trksecs);
s_to_little_s(bs->bsec.headcnt, dp->headcnt);
s_to_little_s(bs->bsec.hidnsec, dp->hidnsec);
/* MSDOS 4 extensions */
l_to_little_l(bs->bsec.variable_part.extended.totsecs, dp->ext_totsecs);
s_to_little_s(bs->bsec.variable_part.extended.physdrv, dp->ext_physdrv);
bs->bsec.variable_part.extended.extboot = dp->ext_extboot;
/* assign a "serial number" :) */
srandom((unsigned)time((time_t)0));
l_to_little_l(bs->bsec.variable_part.extended.serial, random());
memcpy((void *)bs->bsec.variable_part.extended.label,
(void *)dp->ext_label, 11);
memcpy((void *)bs->bsec.variable_part.extended.fsysid,
(void *)dp->ext_fsysid, 8);
}
#define roundup(dst, limit) dst = (((dst) | ((limit) - 1)) & ~(limit)) + 1
int
main(int argc, char **argv)
{
union bootsector bs;
struct descrip *dp;
struct fat *fat;
struct direntry *rootdir;
struct tm *tp;
time_t now;
int c, i, fd, format = 0, rootdirsize;
const char *label = 0;
while((c = getopt(argc, argv, "f:L:")) != -1)
switch(c)
{
case 'f':
format = atoi(optarg);
break;
case 'L':
label = optarg;
break;
case '?':
default:
usage();
}
argc -= optind;
argv += optind;
if(argc != 1)
usage();
if((fd = open(argv[0], O_RDWR|O_EXCL, 0)) == -1)
err(1, "open(%s)", argv[0]);
if(format == 0)
{
/*
* No format specified, try to figure it out.
*/
if((format = findformat(fd)) == 0)
errx(1, "cannot determine size, must use -f format");
}
for(i = 0, dp = table; i < sizeof table / sizeof(struct descrip); i++, dp++)
if(dp->kilobytes == format)
break;
if(i == sizeof table / sizeof(struct descrip))
errx(1, "cannot find format description for %d KB", format);
/* prepare and write the boot sector */
setup_boot_sector_from_template(&bs, dp);
/* if we've got an explicit label, use it */
if(label)
strncpy(bs.bsec.variable_part.extended.label, label, 11);
if(write(fd, (char *)bs.raw, sizeof bs) != sizeof bs)
err(1, "boot sector write()");
/* now, go on with the FATs */
if((fat = (struct fat *)malloc(dp->sectsiz * dp->fatsize)) == 0)
abort();
memset((void *)fat, 0, dp->sectsiz * dp->fatsize);
fat->media = dp->media;
fat->padded = 0xff;
fat->contents[0] = 0xff;
if(dp->totsecs > 20740 || (dp->totsecs == 0 && dp->ext_totsecs > 20740))
/* 16-bit FAT */
fat->contents[1] = 0xff;
for(i = 0; i < dp->fatcnt; i++)
if(write(fd, (char *)fat, dp->sectsiz * dp->fatsize)
!= dp->sectsiz * dp->fatsize)
err(1, "FAT write()");
free((void *)fat);
/* finally, build the root dir */
rootdirsize = dp->rootsiz * sizeof(struct direntry);
roundup(rootdirsize, dp->clustsiz * dp->sectsiz);
if((rootdir = (struct direntry *)malloc(rootdirsize)) == 0)
abort();
memset((void *)fat, 0, rootdirsize);
/* set up a volume label inside the root dir :) */
if(label)
strncpy(rootdir[0].name, label, 11);
else
memcpy(rootdir[0].name, dp->ext_label, 11);
rootdir[0].attr = FA_VOLLABEL;
now = time((time_t)0);
tp = localtime(&now);
rootdir[0].fdate.time[0] = tp->tm_sec / 2;
rootdir[0].fdate.time[0] |= (tp->tm_min & 7) << 5;
rootdir[0].fdate.time[1] = ((tp->tm_min >> 3) & 7);
rootdir[0].fdate.time[1] |= tp->tm_hour << 3;
rootdir[0].fdate.date[0] = tp->tm_mday;
rootdir[0].fdate.date[0] |= ((tp->tm_mon + 1) & 7) << 5;
rootdir[0].fdate.date[1] = ((tp->tm_mon + 1) >> 3) & 1;
rootdir[0].fdate.date[1] |= (tp->tm_year - 80) << 1;
if(write(fd, (char *)rootdir, rootdirsize) != rootdirsize)
err(1, "root dir write()");
(void)close(fd);
return 0;
}