Add newfs_msdos: extensive newfs-style support for creating FAT12,

FAT16, and FAT32 file systems in all their various horriblenesses.

Approved-in-concept by: joerg

3 files changed, 1103 insertions, 0 deletions

diff --git a/sbin/newfs_msdos/Makefile b/sbin/newfs_msdos/Makefile
new file mode 100644
index 0000000..bb9c6e5
--- /dev/null
+++ b/sbin/newfs_msdos/Makefile
@@ -0,0 +1,6 @@
+#	$Id$
+
+PROG=	newfs_msdos
+MAN8=	newfs_msdos.8
+
+.include <bsd.prog.mk>
diff --git a/sbin/newfs_msdos/newfs_msdos.8 b/sbin/newfs_msdos/newfs_msdos.8
new file mode 100644
index 0000000..3119b97
--- /dev/null
+++ b/sbin/newfs_msdos/newfs_msdos.8
@@ -0,0 +1,173 @@
+.\" Copyright (c) 1998 Robert Nordier
+.\" All rights reserved.
+.\"
+.\" 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 AUTHOR(S) ``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 AUTHOR(S) 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.
+.\"
+.\"	$Id$
+.\"
+.Dd July 6, 1998
+.Dt NEWFS_MSDOS 8
+.Os
+.Sh NAME
+.Nm newfs_msdos
+.Nd construct a new MS-DOS (FAT) file system
+.Sh SYNOPSIS
+.Nm
+.Op Fl N
+.Op Fl B Ar boot
+.Op Fl F Ar FAT-type
+.Op Fl I Ar volid
+.Op Fl L Ar label
+.Op Fl O Ar OEM
+.Op Fl S Ar sector-size
+.Op Fl a Ar FAT-size
+.Op Fl b Ar block-size
+.Op Fl c Ar cluster-size
+.Op Fl e Ar dirents
+.Op Fl f Ar format
+.Op Fl h Ar heads
+.Op Fl i Ar info
+.Op Fl k Ar backup
+.Op Fl m Ar media
+.Op Fl n Ar FATs
+.Op Fl o Ar hidden
+.Op Fl r Ar reserved
+.Op Fl s Ar total
+.Op Fl u Ar track-size
+.Ar special
+.Op Ar disktype
+.Sh DESCRIPTION
+The
+.Nm
+utility creates a FAT12, FAT16, or FAT32 file system on device
+.Ar special ,
+using
+.Xr disktab 5
+entry
+.Ar disktype
+to determine geometry, if required.
+.Pp
+The options are as follow:
+.Bl -tag -width Fl
+.It Fl N
+Don't create a file system: just print out parameters.
+.It Fl B Ar boot
+Get bootstrap from file.
+.It Fl F Ar FAT-type
+FAT type (one of 12, 16, or 32).
+.It Fl I Ar volid
+Volume ID.
+.It Fl L Ar label
+Volume label (up to 11 characters).  The label should consist of
+only those characters permitted in regular DOS (8+3) filenames.
+.It Fl O Ar OEM
+OEM string (up to 8 characters).  The default is
+"BSD  4.4".
+.It Fl S Ar sector-size
+Number of bytes per sector.  Acceptable values are powers of 2
+in the range 128 through 32768.
+.It Fl a Ar FAT-size
+Number of sectors per FAT.
+.It Fl b Ar block-size.
+File system block size (bytes per cluster).  This should resolve to an
+acceptable number of sectors per cluster (see below).
+.It Fl c Ar cluster-size
+Sectors per cluster.  Acceptable values are powers of 2 in the range
+1 through 128.
+.It Fl e Ar dirents
+Number of root directory entries (FAT12 and FAT16 only).
+.It Fl f Ar format
+Specify a standard (floppy disk) format.  The eight standard formats
+are (capacities in kilobytes): 160, 180, 320, 360, 720, 1200, 1440,
+2880.
+.It Fl h Ar heads
+Number of drive heads.
+.It Fl i Ar info
+Location of the file system info sector (FAT32 only).
+A value of 0xffff signifies no info sector.
+.It Fl k Ar backup
+Location of the backup boot sector (FAT32 only).  A value
+of 0xffff signifies no backup sector.
+.It Fl m Ar media
+Media descriptor (acceptable range 0xf0 to 0xff).
+.It Fl n Ar FATs
+Number of FATs.  Acceptable values are 1 to 16 inclusive. The default
+is 2.
+.It Fl o Ar hidden
+Number of hidden sectors.
+.It Fl r Ar reserved
+Number of reserved sectors.
+.It Fl s Ar total
+File system size.
+.It Fl u Ar track-size
+Number of sectors per track.
+.El
+.Sh NOTES
+FAT file system parameters occupy a "Boot Sector BPB (BIOS Parameter
+Block)" in the first of the "reserved" sectors which precede the actual
+file system.  For reference purposes, this structure is presented
+below.
+.Bd -literal
+struct bsbpb {
+    u_int16_t	bps;		/* [-S] bytes per sector */
+    u_int8_t	spc;		/* [-c] sectors per cluster */
+    u_int16_t	res;		/* [-r] reserved sectors */
+    u_int8_t	nft;		/* [-n] number of FATs */
+    u_int16_t	rde;		/* [-e] root directory entries */
+    u_int16_t	sec;		/* [-s] total sectors */
+    u_int8_t	mid;		/* [-m] media descriptor */
+    u_int16_t	spf;		/* [-a] sectors per FAT */
+    u_int16_t	spt;		/* [-u] sectors per track */
+    u_int16_t	hds;		/* [-h] drive heads */
+    u_int32_t	hid;		/* [-o] hidden sectors */
+    u_int32_t	bsec;		/* [-s] big total sectors */
+};
+/* FAT32 extensions */
+struct bsxbpb {
+    u_int32_t	bspf;		/* [-a] big sectors per FAT */
+    u_int16_t	xflg;		/* control flags */
+    u_int16_t	vers;		/* file system version */
+    u_int32_t	rdcl;		/* root directory start cluster */
+    u_int16_t	infs;		/* [-i] file system info sector */
+    u_int16_t	bkbs;		/* [-k] backup boot sector */
+};
+.Ed
+.Sh EXAMPLES
+
+	newfs_msdos /dev/rwd0s1
+
+Create a file system, using default parameters, on /dev/rwd0s1.
+
+	newfs_msdos -f 1440 -L foo fd0
+
+Create a standard 1.44M file system, with volume label "foo", on
+/dev/rfd0.
+.Sh SEE ALSO
+.Xr disklabel 8 ,
+.Xr disktab 5 ,
+.Xr fdisk 8 ,
+.Xr newfs 8
+.Sh DIAGNOSTICS
+Exit status is 0 on success and 1 on error.
+.Sh AUTHORS
+.An Robert Nordier Aq rnordier@FreeBSD.ORG .
diff --git a/sbin/newfs_msdos/newfs_msdos.c b/sbin/newfs_msdos/newfs_msdos.c
new file mode 100644
index 0000000..220cbcf
--- /dev/null
+++ b/sbin/newfs_msdos/newfs_msdos.c
@@ -0,0 +1,924 @@
+/*
+ * Copyright (c) 1998 Robert Nordier
+ * All rights reserved.
+ *
+ * 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 AUTHOR(S) ``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 AUTHOR(S) 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.
+ */
+
+#ifndef lint
+static const char rcsid[] =
+	"$Id$";
+#endif /* not lint */
+
+#include <sys/param.h>
+#include <sys/stat.h>
+#include <sys/diskslice.h>
+#include <sys/disklabel.h>
+#include <sys/mount.h>
+
+#include <ctype.h>
+#include <err.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <paths.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#define MAXU16	  0xffff	/* maximum unsigned 16-bit quantity */
+#define BPN	  4		/* bits per nibble */
+#define NPB	  2		/* nibbles per byte */
+
+#define DOSMAGIC  0xaa55	/* DOS magic number */
+#define MINBPS	  128		/* minimum bytes per sector */
+#define MAXSPC	  128		/* maximum sectors per cluster */
+#define MAXNFT	  16		/* maximum number of FATs */
+#define DEFBLK	  4096		/* default block size */
+#define DEFBLK16  2048		/* default block size FAT16 */
+#define DEFRDE	  512		/* default root directory entries */
+#define RESFTE	  2		/* reserved FAT entries */
+#define MINCLS12  1		/* minimum FAT12 clusters */
+#define MINCLS16  0x1000	/* minimum FAT16 clusters */
+#define MINCLS32  2		/* minimum FAT32 clusters */
+#define MAXCLS12  0xfed 	/* maximum FAT12 clusters */
+#define MAXCLS16  0xfff5	/* maximum FAT16 clusters */
+#define MAXCLS32  0xffffff5	/* maximum FAT32 clusters */
+
+#define mincls(fat)  ((fat) == 12 ? MINCLS12 :	\
+		      (fat) == 16 ? MINCLS16 :	\
+				    MINCLS32)
+
+#define maxcls(fat)  ((fat) == 12 ? MAXCLS12 :	\
+		      (fat) == 16 ? MAXCLS16 :	\
+				    MAXCLS32)
+
+#define mk1(p, x)				\
+    (p) = (u_int8_t)(x)
+
+#define mk2(p, x)				\
+    (p)[0] = (u_int8_t)(x),			\
+    (p)[1] = (u_int8_t)((x) >> 010)
+
+#define mk4(p, x)				\
+    (p)[0] = (u_int8_t)(x),			\
+    (p)[1] = (u_int8_t)((x) >> 010),		\
+    (p)[2] = (u_int8_t)((x) >> 020),		\
+    (p)[3] = (u_int8_t)((x) >> 030)
+
+#define argto1(arg, lo, msg)  argtou(arg, lo, 0xff, msg)
+#define argto2(arg, lo, msg)  argtou(arg, lo, 0xffff, msg)
+#define argto4(arg, lo, msg)  argtou(arg, lo, 0xffffffff, msg)
+#define argtox(arg, lo, msg)  argtou(arg, lo, UINT_MAX, msg)
+
+struct bs {
+    u_int8_t jmp[3];		/* bootstrap entry point */
+    u_int8_t oem[8];		/* OEM name and version */
+};
+
+struct bsbpb {
+    u_int8_t bps[2];		/* bytes per sector */
+    u_int8_t spc;		/* sectors per cluster */
+    u_int8_t res[2];		/* reserved sectors */
+    u_int8_t nft;		/* number of FATs */
+    u_int8_t rde[2];		/* root directory entries */
+    u_int8_t sec[2];		/* total sectors */
+    u_int8_t mid;		/* media descriptor */
+    u_int8_t spf[2];		/* sectors per FAT */
+    u_int8_t spt[2];		/* sectors per track */
+    u_int8_t hds[2];		/* drive heads */
+    u_int8_t hid[4];		/* hidden sectors */
+    u_int8_t bsec[4];		/* big total sectors */
+};
+
+struct bsxbpb {
+    u_int8_t bspf[4];		/* big sectors per FAT */
+    u_int8_t xflg[2];		/* FAT control flags */
+    u_int8_t vers[2];		/* file system version */
+    u_int8_t rdcl[4];		/* root directory start cluster */
+    u_int8_t infs[2];		/* file system info sector */
+    u_int8_t bkbs[2];		/* backup boot sector */
+    u_int8_t rsvd[12];		/* reserved */
+};
+
+struct bsx {
+    u_int8_t drv;		/* drive number */
+    u_int8_t rsvd;		/* reserved */
+    u_int8_t sig;		/* extended boot signature */
+    u_int8_t volid[4];		/* volume ID number */
+    u_int8_t label[11]; 	/* volume label */
+    u_int8_t type[8];		/* file system type */
+};
+
+struct de {
+    u_int8_t namext[11];	/* name and extension */
+    u_int8_t attr;		/* attributes */
+    u_int8_t rsvd[10];		/* reserved */
+    u_int8_t time[2];		/* creation time */
+    u_int8_t date[2];		/* creation date */
+    u_int8_t clus[2];		/* starting cluster */
+    u_int8_t size[4];		/* size */
+};
+
+struct bpb {
+    u_int bps;			/* bytes per sector */
+    u_int spc;			/* sectors per cluster */
+    u_int res;			/* reserved sectors */
+    u_int nft;			/* number of FATs */
+    u_int rde;			/* root directory entries */
+    u_int sec;			/* total sectors */
+    u_int mid;			/* media descriptor */
+    u_int spf;			/* sectors per FAT */
+    u_int spt;			/* sectors per track */
+    u_int hds;			/* drive heads */
+    u_int hid;			/* hidden sectors */
+    u_int bsec; 		/* big total sectors */
+    u_int bspf; 		/* big sectors per FAT */
+    u_int rdcl; 		/* root directory start cluster */
+    u_int infs; 		/* file system info sector */
+    u_int bkbs; 		/* backup boot sector */
+};
+
+static struct {
+    const char *name;
+    struct bpb bpb;
+} stdfmt[] = {
+    {"160",  {512, 1, 1, 2,  64,  320, 0xfe, 1,  8, 1}},
+    {"180",  {512, 1, 1, 2,  64,  360, 0xfc, 2,  9, 1}},
+    {"320",  {512, 2, 1, 2, 112,  640, 0xff, 1,  8, 2}},
+    {"360",  {512, 2, 1, 2, 112,  720, 0xfd, 2,  9, 2}},
+    {"720",  {512, 2, 1, 2, 112, 1440, 0xf9, 3,  9, 2}},
+    {"1200", {512, 1, 1, 2, 224, 2400, 0xf9, 7, 15, 2}},
+    {"1440", {512, 1, 1, 2, 224, 2880, 0xf0, 9, 18, 2}},
+    {"2880", {512, 2, 1, 2, 240, 5760, 0xf0, 9, 36, 2}}
+};
+
+static u_int8_t bootcode[] = {
+    0xfa,			/* cli		    */
+    0x31, 0xc0, 		/* xor	   ax,ax    */
+    0x8e, 0xd0, 		/* mov	   ss,ax    */
+    0xbc, 0x00, 0x7c,		/* mov	   sp,7c00h */
+    0xfb,			/* sti		    */
+    0x8e, 0xd8, 		/* mov	   ds,ax    */
+    0xe8, 0x00, 0x00,		/* call    $ + 3    */
+    0x5e,			/* pop	   si	    */
+    0x83, 0xc6, 0x19,		/* add	   si,+19h  */
+    0xbb, 0x07, 0x00,		/* mov	   bx,0007h */
+    0xfc,			/* cld		    */
+    0xac,			/* lodsb	    */
+    0x84, 0xc0, 		/* test    al,al    */
+    0x74, 0x06, 		/* jz	   $ + 8    */
+    0xb4, 0x0e, 		/* mov	   ah,0eh   */
+    0xcd, 0x10, 		/* int	   10h	    */
+    0xeb, 0xf5, 		/* jmp	   $ - 9    */
+    0x30, 0xe4, 		/* xor	   ah,ah    */
+    0xcd, 0x16, 		/* int	   16h	    */
+    0xcd, 0x19, 		/* int	   19h	    */
+    0x0d, 0x0a,
+    'N', 'o', 'n', '-', 's', 'y', 's', 't',
+    'e', 'm', ' ', 'd', 'i', 's', 'k',
+    0x0d, 0x0a,
+    'P', 'r', 'e', 's', 's', ' ', 'a', 'n',
+    'y', ' ', 'k', 'e', 'y', ' ', 't', 'o',
+    ' ', 'r', 'e', 'b', 'o', 'o', 't',
+    0x0d, 0x0a,
+    0
+};
+
+static void check_mounted(const char *, mode_t);
+static void getstdfmt(const char *, struct bpb *);
+static void getdiskinfo(int, const char *, const char *, int,
+			struct bpb *);
+static void print_bpb(struct bpb *);
+static u_int ckgeom(const char *, u_int, const char *);
+static u_int argtou(const char *, u_int, u_int, const char *);
+static int oklabel(const char *);
+static void mklabel(u_int8_t *, const char *);
+static void setstr(u_int8_t *, const char *, size_t);
+static void usage(void);
+
+/*
+ * Construct a FAT12, FAT16, or FAT32 file system.
+ */
+int
+main(int argc, char *argv[])
+{
+    static char opts[] = "NB:F:I:L:O:S:a:b:c:e:f:h:i:k:m:n:o:r:s:u:";
+    static const char *opt_B, *opt_L, *opt_O, *opt_f;
+    static u_int opt_F, opt_I, opt_S, opt_a, opt_b, opt_c, opt_e;
+    static u_int opt_h, opt_i, opt_k, opt_m, opt_n, opt_o, opt_r;
+    static u_int opt_s, opt_u;
+    static int opt_N;
+    static int Iflag, mflag, oflag;
+    char buf[MAXPATHLEN];
+    struct stat sb;
+    struct timeval tv;
+    struct bpb bpb;
+    struct tm *tm;
+    struct bs *bs;
+    struct bsbpb *bsbpb;
+    struct bsxbpb *bsxbpb;
+    struct bsx *bsx;
+    struct de *de;
+    u_int8_t *img;
+    const char *fname, *dtype, *bname;
+    ssize_t n;
+    u_int fat, bss, rds, cls, dir, lsn, x, x1, x2;
+    int ch, fd, fd1;
+
+    while ((ch = getopt(argc, argv, opts)) != -1)
+	switch (ch) {
+	case 'N':
+	    opt_N = 1;
+	    break;
+	case 'B':
+	    opt_B = optarg;
+	    break;
+	case 'F':
+	    if (strcmp(optarg, "12") &&
+		strcmp(optarg, "16") &&
+		strcmp(optarg, "32"))
+		errx(1, "%s: bad FAT type", optarg);
+	    opt_F = atoi(optarg);
+	    break;
+	case 'I':
+	    opt_I = argto4(optarg, 0, "volume ID");
+	    Iflag = 1;
+	    break;
+	case 'L':
+	    if (!oklabel(optarg))
+		errx(1, "%s: bad volume label", optarg);
+	    opt_L = optarg;
+	    break;
+	case 'O':
+	    if (strlen(optarg) > 8)
+		errx(1, "%s: bad OEM string", optarg);
+	    opt_O = optarg;
+	    break;
+	case 'S':
+	    opt_S = argto2(optarg, 1, "bytes/sector");
+	    break;
+	case 'a':
+	    opt_a = argto4(optarg, 1, "sectors/FAT");
+	    break;
+	case 'b':
+	    opt_b = argtox(optarg, 1, "block size");
+	    opt_c = 0;
+	    break;
+	case 'c':
+	    opt_c = argto1(optarg, 1, "sectors/cluster");
+	    opt_b = 0;
+	    break;
+	case 'e':
+	    opt_e = argto2(optarg, 1, "directory entries");
+	    break;
+	case 'f':
+	    opt_f = optarg;
+	    break;
+	case 'h':
+	    opt_h = argto2(optarg, 1, "drive heads");
+	    break;
+	case 'i':
+	    opt_i = argto2(optarg, 1, "info sector");
+	    break;
+	case 'k':
+	    opt_k = argto2(optarg, 1, "backup sector");
+	    break;
+	case 'm':
+	    opt_m = argto1(optarg, 0, "media descriptor");
+	    mflag = 1;
+	    break;
+	case 'n':
+	    opt_n = argto1(optarg, 1, "number of FATs");
+	    break;
+	case 'o':
+	    opt_o = argto4(optarg, 0, "hidden sectors");
+	    oflag = 1;
+	    break;
+	case 'r':
+	    opt_r = argto2(optarg, 1, "reserved sectors");
+	    break;
+	case 's':
+	    opt_s = argto4(optarg, 1, "file system size");
+	    break;
+	case 'u':
+	    opt_u = argto2(optarg, 1, "sectors/track");
+	    break;
+	default:
+	    usage();
+	}
+    argc -= optind;
+    argv += optind;
+    if (argc < 1 || argc > 2)
+	usage();
+    fname = *argv++;
+    if (!strchr(fname, '/')) {
+	snprintf(buf, sizeof(buf), "%sr%s", _PATH_DEV, fname);
+	if (stat(buf, &sb))
+	    snprintf(buf, sizeof(buf), "%s%s", _PATH_DEV, fname);
+	if (!(fname = strdup(buf)))
+	    err(1, NULL);
+    }
+    dtype = *argv;
+    if ((fd = open(fname, opt_N ? O_RDONLY : O_RDWR)) == -1 ||
+	fstat(fd, &sb))
+	err(1, "%s", fname);
+    if (!opt_N)
+	check_mounted(fname, sb.st_mode);
+    if (!S_ISCHR(sb.st_mode))
+	warnx("warning: %s is not a character device", fname);
+    memset(&bpb, 0, sizeof(bpb));
+    if (opt_f) {
+	getstdfmt(opt_f, &bpb);
+	bpb.bsec = bpb.sec;
+	bpb.sec = 0;
+	bpb.bspf = bpb.spf;
+	bpb.spf = 0;
+    }
+    if (opt_h)
+	bpb.hds = opt_h;
+    if (opt_u)
+	bpb.spt = opt_u;
+    if (opt_S)
+	bpb.bps = opt_S;
+    if (opt_s)
+	bpb.bsec = opt_s;
+    if (oflag)
+	bpb.hid = opt_o;
+    if (!(opt_f || (opt_h && opt_u && opt_S && opt_s && oflag)))
+	getdiskinfo(fd, fname, dtype, oflag, &bpb);
+    if (!powerof2(bpb.bps))
+	errx(1, "bytes/sector (%u) is not a power of 2", bpb.bps);
+    if (bpb.bps < MINBPS)
+	errx(1, "bytes/sector (%u) is too small; minimum is %u",
+	     bpb.bps, MINBPS);
+    if (!(fat = opt_F))
+	if (opt_f)
+	    fat = 12;
+	else if (!opt_e && (opt_i || opt_k))
+	    fat = 32;
+    if ((fat == 32 && opt_e) || (fat != 32 && (opt_i || opt_k)))
+	errx(1, "-%c is not a legal FAT%s option",
+	     fat == 32 ? 'e' : opt_i ? 'i' : 'k',
+	     fat == 32 ? "32" : "12/16");
+    if (opt_f && fat == 32)
+	bpb.rde = 0;
+    if (opt_b) {
+	if (!powerof2(opt_b))
+	    errx(1, "block size (%u) is not a power of 2", opt_b);
+	if (opt_b < bpb.bps)
+	    errx(1, "block size (%u) is too small; minimum is %u",
+		 opt_b, bpb.bps);
+	if (opt_b > bpb.bps * MAXSPC)
+	    errx(1, "block size (%u) is too large; maximum is %u",
+		 opt_b, bpb.bps * MAXSPC);
+	bpb.spc = opt_b / bpb.bps;
+    }
+    if (opt_c) {
+	if (!powerof2(opt_c))
+	    errx(1, "sectors/cluster (%u) is not a power of 2", opt_c);
+	bpb.spc = opt_c;
+    }
+    if (opt_r)
+	bpb.res = opt_r;
+    if (opt_n) {
+	if (opt_n > MAXNFT)
+	    errx(1, "number of FATs (%u) is too large; maximum is %u",
+		 opt_n, MAXNFT);
+	bpb.nft = opt_n;
+    }
+    if (opt_e)
+	bpb.rde = opt_e;
+    if (mflag) {
+	if (opt_m < 0xf0)
+	    errx(1, "illegal media descriptor (0x%x)", opt_m);
+	bpb.mid = opt_m;
+    }
+    if (opt_a)
+	bpb.bspf = opt_a;
+    if (opt_i)
+	bpb.infs = opt_i;
+    if (opt_k)
+	bpb.bkbs = opt_k;
+    bss = 1;
+    bname = NULL;
+    fd1 = -1;
+    if (opt_B) {
+	bname = opt_B;
+	if (!strchr(bname, '/')) {
+	    snprintf(buf, sizeof(buf), "/usr/mdec/%s", bname);
+	    if (!(bname = strdup(buf)))
+		err(1, NULL);
+	}
+	if ((fd1 = open(bname, O_RDONLY)) == -1 || fstat(fd1, &sb))
+	    err(1, "%s", bname);
+	if (!S_ISREG(sb.st_mode) || sb.st_size % bpb.bps ||
+	    sb.st_size < bpb.bps || sb.st_size > bpb.bps * MAXU16)
+	    errx(1, "%s: inappropriate file type or format", bname);
+	bss = sb.st_size / bpb.bps;
+    }
+    if (!bpb.nft)
+	bpb.nft = 2;
+    if (!fat)
+	if (bpb.bsec < (bpb.res ? bpb.res : bss) +
+	    howmany((RESFTE + (bpb.spc ? MINCLS16 : MAXCLS12 + 1)) *
+		    ((bpb.spc ? 16 : 12) / BPN), bpb.bps * NPB) *
+	    bpb.nft +
+	    howmany(bpb.rde ? bpb.rde : DEFRDE,
+		    bpb.bps / sizeof(struct de)) +
+	    (bpb.spc ? MINCLS16 : MAXCLS12 + 1) *
+	    (bpb.spc ? bpb.spc : howmany(DEFBLK, bpb.bps)))
+	    fat = 12;
+	else if (bpb.rde || bpb.bsec <
+		 (bpb.res ? bpb.res : bss) +
+		 howmany((RESFTE + MAXCLS16) * 2, bpb.bps) * bpb.nft +
+		 howmany(DEFRDE, bpb.bps / sizeof(struct de)) +
+		 (MAXCLS16 + 1) *
+		 (bpb.spc ? bpb.spc : howmany(8192, bpb.bps)))
+	    fat = 16;
+	else
+	    fat = 32;
+    x = bss;
+    if (fat == 32) {
+	if (!bpb.infs) {
+	    if (x == MAXU16 || x == bpb.bkbs)
+		errx(1, "no room for info sector");
+	    bpb.infs = x;
+	}
+	if (bpb.infs != MAXU16 && x <= bpb.infs)
+	    x = bpb.infs + 1;
+	if (!bpb.bkbs) {
+	    if (x == MAXU16)
+		errx(1, "no room for backup sector");
+	    bpb.bkbs = x;
+	} else if (bpb.bkbs != MAXU16 && bpb.bkbs == bpb.infs)
+	    errx(1, "backup sector would overwrite info sector");
+	if (bpb.bkbs != MAXU16 && x <= bpb.bkbs)
+	    x = bpb.bkbs + 1;
+    }
+    if (!bpb.res)
+	bpb.res = fat == 32 ? MAX(x, MAX(16384 / bpb.bps, 4)) : x;
+    else if (bpb.res < x)
+	errx(1, "too few reserved sectors");
+    if (fat != 32 && !bpb.rde)
+	bpb.rde = DEFRDE;
+    rds = howmany(bpb.rde, bpb.bps / sizeof(struct de));
+    if (!bpb.spc)
+	for (bpb.spc = howmany(fat == 16 ? DEFBLK16 : DEFBLK, bpb.bps);
+	     bpb.spc < MAXSPC &&
+	     bpb.res +
+	     howmany((RESFTE + maxcls(fat)) * (fat / BPN),
+		     bpb.bps * NPB) * bpb.nft +
+	     rds +
+	     (u_int64_t)(maxcls(fat) + 1) * bpb.spc <= bpb.bsec;
+	     bpb.spc <<= 1);
+    if (fat != 32 && bpb.bspf > MAXU16)
+	errx(1, "too many sectors/FAT for FAT12/16");
+    x1 = bpb.res + rds;
+    x = bpb.bspf ? bpb.bspf : 1;
+    if (x1 + (u_int64_t)x * bpb.nft > bpb.bsec)
+	errx(1, "meta data exceeds file system size");
+    x1 += x * bpb.nft;
+    x = (u_int64_t)(bpb.bsec - x1) * bpb.bps * NPB /
+	(bpb.spc * bpb.bps * NPB + fat / BPN * bpb.nft);
+    x2 = howmany((RESFTE + MIN(x, maxcls(fat))) * (fat / BPN),
+		 bpb.bps * NPB);
+    if (!bpb.bspf) {
+	bpb.bspf = x2;
+	x1 += (bpb.bspf - 1) * bpb.nft;
+    }
+    cls = (bpb.bsec - x1) / bpb.spc;
+    x = (u_int64_t)bpb.bspf * bpb.bps * NPB / (fat / BPN) - RESFTE;
+    if (cls > x)
+	cls = x;
+    if (bpb.bspf < x2)
+	warnx("warning: sectors/FAT limits file system to %u clusters",
+	      cls);
+    if (cls < mincls(fat))
+	errx(1, "too few clusters for FAT%u", fat);
+    if (cls > maxcls(fat)) {
+	cls = maxcls(fat);
+	bpb.bsec = x1 + (cls + 1) * bpb.spc - 1;
+	warnx("warning: FAT type limits file system to %u sectors",
+	      bpb.bsec);
+    }
+    printf("%s: %u sector%s in %u FAT%u cluster%s "
+	   "(%u bytes/cluster)\n", fname, cls * bpb.spc,
+	   cls * bpb.spc == 1 ? "" : "s", cls, fat,
+	   cls == 1 ? "" : "s", bpb.bps * bpb.spc);
+    if (!bpb.mid)
+	bpb.mid = !bpb.hid ? 0xf0 : 0xf8;
+    if (fat == 32)
+	bpb.rdcl = RESFTE;
+    if (bpb.bsec <= MAXU16 && bpb.hid <= MAXU16 &&
+	bpb.hid + bpb.bsec <= MAXU16) {
+	bpb.sec = bpb.bsec;
+	bpb.bsec = 0;
+    }
+    if (fat != 32) {
+	bpb.spf = bpb.bspf;
+	bpb.bspf = 0;
+    }
+    print_bpb(&bpb);
+    if (!opt_N) {
+	gettimeofday(&tv, NULL);
+	tm = localtime(&tv.tv_sec);
+	if (!(img = malloc(bpb.bps)))
+	    err(1, NULL);
+	dir = bpb.res + (bpb.spf ? bpb.spf : bpb.bspf) * bpb.nft;
+	for (lsn = 0; lsn < dir + (fat == 32 ? bpb.spc : rds); lsn++) {
+	    x = lsn;
+	    if (opt_B &&
+		fat == 32 && bpb.bkbs != MAXU16 &&
+		bss <= bpb.bkbs && x >= bpb.bkbs) {
+		x -= bpb.bkbs;
+		if (!x && lseek(fd1, 0, SEEK_SET))
+		    err(1, "%s", bname);
+	    }
+	    if (opt_B && x < bss) {
+		if ((n = read(fd1, img, bpb.bps)) == -1)
+		    err(1, "%s", bname);
+		if (n != bpb.bps)
+		    errx(1, "%s: can't read sector %u", bname, x);
+	    } else
+		memset(img, 0, bpb.bps);
+	    if (!lsn ||
+	      (fat == 32 && bpb.bkbs != MAXU16 && lsn == bpb.bkbs)) {
+		x1 = sizeof(struct bs);
+		bsbpb = (struct bsbpb *)(img + x1);
+		mk2(bsbpb->bps, bpb.bps);
+		mk1(bsbpb->spc, bpb.spc);
+		mk2(bsbpb->res, bpb.res);
+		mk1(bsbpb->nft, bpb.nft);
+		mk2(bsbpb->rde, bpb.rde);
+		mk2(bsbpb->sec, bpb.sec);
+		mk1(bsbpb->mid, bpb.mid);
+		mk2(bsbpb->spf, bpb.spf);
+		mk2(bsbpb->spt, bpb.spt);
+		mk2(bsbpb->hds, bpb.hds);
+		mk4(bsbpb->hid, bpb.hid);
+		mk4(bsbpb->bsec, bpb.bsec);
+		x1 += sizeof(struct bsbpb);
+		if (fat == 32) {
+		    bsxbpb = (struct bsxbpb *)(img + x1);
+		    mk4(bsxbpb->bspf, bpb.bspf);
+		    mk2(bsxbpb->xflg, 0);
+		    mk2(bsxbpb->vers, 0);
+		    mk4(bsxbpb->rdcl, bpb.rdcl);
+		    mk2(bsxbpb->infs, bpb.infs);
+		    mk2(bsxbpb->bkbs, bpb.bkbs);
+		    x1 += sizeof(struct bsxbpb);
+		}
+		bsx = (struct bsx *)(img + x1);
+		mk1(bsx->sig, 0x29);
+		if (Iflag)
+		    x = opt_I;
+		else
+		    x = (((u_int)(1 + tm->tm_mon) << 8 |
+			  (u_int)tm->tm_mday) +
+			 ((u_int)tm->tm_sec << 8 |
+			  (u_int)(tv.tv_usec / 10))) << 16 |
+			((u_int)(1900 + tm->tm_year) +
+			 ((u_int)tm->tm_hour << 8 |
+			  (u_int)tm->tm_min));
+		mk4(bsx->volid, x);
+		mklabel(bsx->label, opt_L ? opt_L : "NO NAME");
+		sprintf(buf, "FAT%u", fat);
+		setstr(bsx->type, buf, sizeof(bsx->type));
+		if (!opt_B) {
+		    x1 += sizeof(struct bsx);
+		    bs = (struct bs *)img;
+		    mk1(bs->jmp[0], 0xeb);
+		    mk1(bs->jmp[1], x1 - 2);
+		    mk1(bs->jmp[2], 0x90);
+		    setstr(bs->oem, opt_O ? opt_O : "BSD  4.4",
+			   sizeof(bs->oem));
+		    memcpy(img + x1, bootcode, sizeof(bootcode));
+		    mk2(img + bpb.bps - 2, DOSMAGIC);
+		}
+	    } else if (fat == 32 && bpb.infs != MAXU16 &&
+		       (lsn == bpb.infs ||
+			(bpb.bkbs != MAXU16 &&
+			 lsn == bpb.bkbs + bpb.infs))) {
+		mk4(img, 0x41615252);
+		mk4(img + bpb.bps - 28, 0x61417272);
+		mk4(img + bpb.bps - 24, 0xffffffff);
+		mk4(img + bpb.bps - 20, 2);
+		mk2(img + bpb.bps - 2, DOSMAGIC);
+	    } else if (lsn >= bpb.res && lsn < dir &&
+		       !((lsn - bpb.res) %
+			 (bpb.spf ? bpb.spf : bpb.bspf))) {
+		mk1(img[0], bpb.mid);
+		for (x = 1; x < fat * (fat == 32 ? 3 : 2) / 8; x++)
+		    mk1(img[x], fat == 32 && x % 4 == 3 ? 0x0f : 0xff);
+	    } else if (lsn == dir && opt_L) {
+		de = (struct de *) img;
+		mklabel(de->namext, opt_L);
+		mk1(de->attr, 050);
+		x = (u_int)tm->tm_hour << 11 |
+		    (u_int)tm->tm_min << 5 |
+		    (u_int)tm->tm_sec >> 1;
+		mk2(de->time, x);
+		x = (u_int)(tm->tm_year - 80) << 9 |
+		    (u_int)(tm->tm_mon + 1) << 5 |
+		    (u_int)tm->tm_mday;
+		mk2(de->date, x);
+	    }
+	    if ((n = write(fd, img, bpb.bps)) == -1)
+		err(1, "%s", fname);
+	    if (n != bpb.bps)
+		errx(1, "%s: can't write sector %u", fname, lsn);
+	}
+    }
+    return 0;
+}
+
+/*
+ * Exit with error if file system is mounted.
+ */
+static void
+check_mounted(const char *fname, mode_t mode)
+{
+    struct statfs *mp;
+    const char *s1, *s2;
+    size_t len;
+    int n, r;
+
+    if (!(n = getmntinfo(&mp, MNT_NOWAIT)))
+	err(1, "getmntinfo");
+    len = strlen(_PATH_DEV);
+    s1 = fname;
+    if (!strncmp(s1, _PATH_DEV, len))
+	s1 += len;
+    r = S_ISCHR(mode) && s1 != fname && *s1 == 'r';
+    for (; n--; mp++) {
+	s2 = mp->f_mntfromname;
+	if (!strncmp(s2, _PATH_DEV, len))
+	    s2 += len;
+	if ((r && s2 != mp->f_mntfromname && !strcmp(s1 + 1, s2)) ||
+	    !strcmp(s1, s2))
+	    errx(1, "%s is mounted on %s", fname, mp->f_mntonname);
+    }
+}
+
+/*
+ * Get a standard format.
+ */
+static void
+getstdfmt(const char *fmt, struct bpb *bpb)
+{
+    u_int x, i;
+
+    x = sizeof(stdfmt) / sizeof(stdfmt[0]);
+    for (i = 0; i < x && strcmp(fmt, stdfmt[i].name); i++);
+    if (i == x)
+	errx(1, "%s: unknown standard format", fmt);
+    *bpb = stdfmt[i].bpb;
+}
+
+/*
+ * Get disk slice, partition, and geometry information.
+ */
+static void
+getdiskinfo(int fd, const char *fname, const char *dtype, int oflag,
+	    struct bpb *bpb)
+{
+    struct diskslices ds;
+    struct disklabel dl, *lp;
+    const char *s1, *s2;
+    char *s;
+    int slice, part, fd1, i, e;
+
+    slice = part = -1;
+    s1 = fname;
+    if ((s2 = strrchr(s1, '/')))
+	s1 = s2 + 1;
+    for (s2 = s1; *s2 && !isdigit(*s2); s2++);
+    if (!*s2 || s2 == s1)
+	s2 = NULL;
+    else
+	while (isdigit(*++s2));
+    s1 = s2;
+    if (s2 && *s2 == 's') {
+	slice = (int)strtol(s2 + 1, &s, 10);
+	if (slice < 1 || slice > MAX_SLICES - BASE_SLICE)
+	    s2 = NULL;
+	else {
+	    slice = BASE_SLICE + slice - 1;
+	    s2 = s;
+	}
+    }
+    if (s2 && *s2 >= 'a' && *s2 <= 'a' + MAXPARTITIONS - 1) {
+	if (slice == -1)
+	    slice = COMPATIBILITY_SLICE;
+	part = *s2++ - 'a';
+    }
+    if (!s2 || (*s2 && *s2 != '.'))
+	errx(1, "%s: can't figure out partition info", fname);
+    if (slice != -1 && (!oflag || (!bpb->bsec && part == -1))) {
+	if (ioctl(fd, DIOCGSLICEINFO, &ds) == -1) {
+	    warn("ioctl (GSLICEINFO)");
+	    errx(1, "%s: can't get slice info", fname);
+	}
+	if (slice >= ds.dss_nslices || !ds.dss_slices[slice].ds_size)
+	    errx(1, "%s: slice is unavailable", fname);
+	if (!oflag)
+	    bpb->hid = (u_int32_t)ds.dss_slices[slice].ds_offset;
+	if (!bpb->bsec && part == -1)
+	    bpb->bsec = (u_int32_t)ds.dss_slices[slice].ds_size;
+    }
+    if (((slice == -1 || part != -1) &&
+	 ((!oflag && part != -1) || !bpb->bsec)) ||
+	!bpb->bps || !bpb->spt || !bpb->hds) {
+	lp = &dl;
+	i = ioctl(fd, DIOCGDINFO, lp);
+	if (i == -1 && slice != -1 && part == -1) {
+	    e = errno;
+	    if (!(s = strdup(fname)))
+		err(1, NULL);
+	    s[s1 - fname] = 0;
+	    if ((fd1 = open(s, O_RDONLY)) != -1) {
+		i = ioctl(fd1, DIOCGDINFO, lp);
+		close(fd1);
+	    }
+	    free(s);
+	    errno = e;
+	}
+	if (i == -1)
+	    if (!dtype) {
+		warn("ioctl (GDINFO)");
+		errx(1, "%s: can't read disk label; "
+		     "disk type must be specified", fname);
+	    } else if (!(lp = getdiskbyname(dtype)))
+		errx(1, "%s: unknown disk type", dtype);
+	if (slice == -1 || part != -1) {
+	    if (part == -1)
+		part = RAW_PART;
+	    if (part >= lp->d_npartitions ||
+		!lp->d_partitions[part].p_size)
+		errx(1, "%s: partition is unavailable", fname);
+	    if (!oflag && part != -1)
+		bpb->hid += lp->d_partitions[part].p_offset;
+	    if (!bpb->bsec)
+		bpb->bsec = lp->d_partitions[part].p_size;
+	}
+	if (!bpb->bps)
+	    bpb->bps = ckgeom(fname, lp->d_secsize, "bytes/sector");
+	if (!bpb->spt)
+	    bpb->spt = ckgeom(fname, lp->d_nsectors, "sectors/track");
+	if (!bpb->hds)
+	    bpb->hds = ckgeom(fname, lp->d_ntracks, "drive heads");
+    }
+}
+
+/*
+ * Print out BPB values.
+ */
+static void
+print_bpb(struct bpb *bpb)
+{
+    printf("bps=%u spc=%u res=%u nft=%u", bpb->bps, bpb->spc, bpb->res,
+	   bpb->nft);
+    if (bpb->rde)
+	printf(" rde=%u", bpb->rde);
+    if (bpb->sec)
+	printf(" sec=%u", bpb->sec);
+    printf(" mid=0x%x", bpb->mid);
+    if (bpb->spf)
+	printf(" spf=%u", bpb->spf);
+    printf(" spt=%u hds=%u hid=%u", bpb->spt, bpb->hds, bpb->hid);
+    if (bpb->bsec)
+	printf(" bsec=%u", bpb->bsec);
+    if (!bpb->spf) {
+	printf(" bspf=%u rdcl=%u", bpb->bspf, bpb->rdcl);
+	printf(" infs=");
+	printf(bpb->infs == MAXU16 ? "0x%x" : "%u", bpb->infs);
+	printf(" bkbs=");
+	printf(bpb->bkbs == MAXU16 ? "0x%x" : "%u", bpb->bkbs);
+    }
+    printf("\n");
+}
+
+/*
+ * Check a disk geometry value.
+ */
+static u_int
+ckgeom(const char *fname, u_int val, const char *msg)
+{
+    if (!val)
+	errx(1, "%s: no default %s", fname, msg);
+    if (val > MAXU16)
+	errx(1, "%s: illegal %s", fname, msg);
+    return val;
+}
+
+/*
+ * Convert and check a numeric option argument.
+ */
+static u_int
+argtou(const char *arg, u_int lo, u_int hi, const char *msg)
+{
+    char *s;
+    u_long x;
+
+    errno = 0;
+    x = strtoul(arg, &s, 0);
+    if (errno || !*arg || *s || x < lo || x > hi)
+	errx(1, "%s: bad %s", arg, msg);
+    return x;
+}
+
+/*
+ * Check a volume label.
+ */
+static int
+oklabel(const char *src)
+{
+    int c, i;
+
+    for (i = 0; i <= 11; i++) {
+	c = (u_char)*src++;
+	if (c < ' ' + !i || strchr("\"*+,./:;<=>?[\\]|", c))
+	    break;
+    }
+    return i && !c;
+}
+
+/*
+ * Make a volume label.
+ */
+static void
+mklabel(u_int8_t *dest, const char *src)
+{
+    int c, i;
+
+    for (i = 0; i < 11; i++) {
+	c = *src ? toupper(*src++) : ' ';
+	*dest++ = !i && c == '\xe5' ? 5 : c;
+    }
+}
+
+/*
+ * Copy string, padding with spaces.
+ */
+static void
+setstr(u_int8_t *dest, const char *src, size_t len)
+{
+    while (len--)
+	*dest++ = *src ? *src++ : ' ';
+}
+
+/*
+ * Print usage message.
+ */
+static void
+usage(void)
+{
+    fprintf(stderr,
+	    "usage: newfs_msdos [ -options ] special [disktype]\n");
+    fprintf(stderr, "where the options are:\n");
+    fprintf(stderr, "\t-N don't create file system: "
+	    "just print out parameters\n");
+    fprintf(stderr, "\t-B get bootstrap from file\n");
+    fprintf(stderr, "\t-F FAT type (12, 16, or 32)\n");
+    fprintf(stderr, "\t-I volume ID\n");
+    fprintf(stderr, "\t-L volume label\n");
+    fprintf(stderr, "\t-O OEM string\n");
+    fprintf(stderr, "\t-S bytes/sector\n");
+    fprintf(stderr, "\t-a sectors/FAT\n");
+    fprintf(stderr, "\t-b block size\n");
+    fprintf(stderr, "\t-c sectors/cluster\n");
+    fprintf(stderr, "\t-e root directory entries\n");
+    fprintf(stderr, "\t-f standard format\n");
+    fprintf(stderr, "\t-h drive heads\n");
+    fprintf(stderr, "\t-i file system info sector\n");
+    fprintf(stderr, "\t-k backup boot sector\n");
+    fprintf(stderr, "\t-m media descriptor\n");
+    fprintf(stderr, "\t-n number of FATs\n");
+    fprintf(stderr, "\t-o hidden sectors\n");
+    fprintf(stderr, "\t-r reserved sectors\n");
+    fprintf(stderr, "\t-s file system size (sectors)\n");
+    fprintf(stderr, "\t-u sectors/track\n");
+    exit(1);
+}