Add libtar to TWRP instead of using busybox tar
Add proper mkdosfs tool
Add fuse to TWRP
Add experimental exfat-fuse to TWRP
Convert all system() functions to use new Exec_Cmd function
diff --git a/dosfstools/src/mkdosfs.c b/dosfstools/src/mkdosfs.c
new file mode 100644
index 0000000..9456ccd
--- /dev/null
+++ b/dosfstools/src/mkdosfs.c
@@ -0,0 +1,1733 @@
+/* mkdosfs.c - utility to create FAT/MS-DOS filesystems
+
+   Copyright (C) 1991 Linus Torvalds <torvalds@klaava.helsinki.fi>
+   Copyright (C) 1992-1993 Remy Card <card@masi.ibp.fr>
+   Copyright (C) 1993-1994 David Hudson <dave@humbug.demon.co.uk>
+   Copyright (C) 1998 H. Peter Anvin <hpa@zytor.com>
+   Copyright (C) 1998-2005 Roman Hodek <Roman.Hodek@informatik.uni-erlangen.de>
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+   On Debian systems, the complete text of the GNU General Public License
+   can be found in /usr/share/common-licenses/GPL-3 file.
+*/
+
+/* Description: Utility to allow an MS-DOS filesystem to be created
+   under Linux.  A lot of the basic structure of this program has been
+   borrowed from Remy Card's "mke2fs" code.
+
+   As far as possible the aim here is to make the "mkdosfs" command
+   look almost identical to the other Linux filesystem make utilties,
+   eg bad blocks are still specified as blocks, not sectors, but when
+   it comes down to it, DOS is tied to the idea of a sector (512 bytes
+   as a rule), and not the block.  For example the boot block does not
+   occupy a full cluster.
+
+   Fixes/additions May 1998 by Roman Hodek
+   <Roman.Hodek@informatik.uni-erlangen.de>:
+   - Atari format support
+   - New options -A, -S, -C
+   - Support for filesystems > 2GB
+   - FAT32 support */
+
+/* Include the header files */
+
+#include "version.h"
+
+#include <fcntl.h>
+#include <linux/hdreg.h>
+#if defined(_USING_BIONIC_)
+#include <linux/fs.h>
+#else
+#include <sys/mount.h>
+#endif
+#include <linux/fd.h>
+#include <endian.h>
+#include <mntent.h>
+#include <signal.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <time.h>
+#include <errno.h>
+
+#include <asm/types.h>
+
+#if __BYTE_ORDER == __BIG_ENDIAN
+
+#include <asm/byteorder.h>
+#ifdef __le16_to_cpu
+/* ++roman: 2.1 kernel headers define these function, they're probably more
+ * efficient then coding the swaps machine-independently. */
+#define CF_LE_W	__le16_to_cpu
+#define CF_LE_L	__le32_to_cpu
+#define CT_LE_W	__cpu_to_le16
+#define CT_LE_L	__cpu_to_le32
+#else
+#define CF_LE_W(v) ((((v) & 0xff) << 8) | (((v) >> 8) & 0xff))
+#define CF_LE_L(v) (((unsigned)(v)>>24) | (((unsigned)(v)>>8)&0xff00) | \
+               (((unsigned)(v)<<8)&0xff0000) | ((unsigned)(v)<<24))
+#define CT_LE_W(v) CF_LE_W(v)
+#define CT_LE_L(v) CF_LE_L(v)
+#endif /* defined(__le16_to_cpu) */
+
+#else
+
+#define CF_LE_W(v) (v)
+#define CF_LE_L(v) (v)
+#define CT_LE_W(v) (v)
+#define CT_LE_L(v) (v)
+
+#endif /* __BIG_ENDIAN */
+
+/* In earlier versions, an own llseek() was used, but glibc lseek() is
+ * sufficient (or even better :) for 64 bit offsets in the meantime */
+#define llseek lseek
+
+/* Constant definitions */
+
+#define TRUE 1			/* Boolean constants */
+#define FALSE 0
+
+#define TEST_BUFFER_BLOCKS 16
+#define HARD_SECTOR_SIZE   512
+#define SECTORS_PER_BLOCK ( BLOCK_SIZE / HARD_SECTOR_SIZE )
+
+/* Macro definitions */
+
+/* Report a failure message and return a failure error code */
+
+#define die( str ) fatal_error( "%s: " str "\n" )
+
+/* Mark a cluster in the FAT as bad */
+
+#define mark_sector_bad( sector ) mark_FAT_sector( sector, FAT_BAD )
+
+/* Compute ceil(a/b) */
+
+inline int cdiv(int a, int b)
+{
+    return (a + b - 1) / b;
+}
+
+/* MS-DOS filesystem structures -- I included them here instead of
+   including linux/msdos_fs.h since that doesn't include some fields we
+   need */
+
+#define ATTR_RO      1		/* read-only */
+#define ATTR_HIDDEN  2		/* hidden */
+#define ATTR_SYS     4		/* system */
+#define ATTR_VOLUME  8		/* volume label */
+#define ATTR_DIR     16		/* directory */
+#define ATTR_ARCH    32		/* archived */
+
+#define ATTR_NONE    0		/* no attribute bits */
+#define ATTR_UNUSED  (ATTR_VOLUME | ATTR_ARCH | ATTR_SYS | ATTR_HIDDEN)
+	/* attribute bits that are copied "as is" */
+
+/* FAT values */
+#define FAT_EOF      (atari_format ? 0x0fffffff : 0x0ffffff8)
+#define FAT_BAD      0x0ffffff7
+
+#define MSDOS_EXT_SIGN 0x29	/* extended boot sector signature */
+#define MSDOS_FAT12_SIGN "FAT12   "	/* FAT12 filesystem signature */
+#define MSDOS_FAT16_SIGN "FAT16   "	/* FAT16 filesystem signature */
+#define MSDOS_FAT32_SIGN "FAT32   "	/* FAT32 filesystem signature */
+
+#define BOOT_SIGN 0xAA55	/* Boot sector magic number */
+
+#define MAX_CLUST_12	((1 << 12) - 16)
+#define MAX_CLUST_16	((1 << 16) - 16)
+#define MIN_CLUST_32    65529
+/* M$ says the high 4 bits of a FAT32 FAT entry are reserved and don't belong
+ * to the cluster number. So the max. cluster# is based on 2^28 */
+#define MAX_CLUST_32	((1 << 28) - 16)
+
+#define FAT12_THRESHOLD	4085
+
+#define OLDGEMDOS_MAX_SECTORS	32765
+#define GEMDOS_MAX_SECTORS	65531
+#define GEMDOS_MAX_SECTOR_SIZE	(16*1024)
+
+#define BOOTCODE_SIZE		448
+#define BOOTCODE_FAT32_SIZE	420
+
+/* __attribute__ ((packed)) is used on all structures to make gcc ignore any
+ * alignments */
+
+struct msdos_volume_info {
+    __u8 drive_number;		/* BIOS drive number */
+    __u8 RESERVED;		/* Unused */
+    __u8 ext_boot_sign;		/* 0x29 if fields below exist (DOS 3.3+) */
+    __u8 volume_id[4];		/* Volume ID number */
+    __u8 volume_label[11];	/* Volume label */
+    __u8 fs_type[8];		/* Typically FAT12 or FAT16 */
+} __attribute__ ((packed));
+
+struct msdos_boot_sector {
+    __u8 boot_jump[3];		/* Boot strap short or near jump */
+    __u8 system_id[8];		/* Name - can be used to special case
+				   partition manager volumes */
+    __u8 sector_size[2];	/* bytes per logical sector */
+    __u8 cluster_size;		/* sectors/cluster */
+    __u16 reserved;		/* reserved sectors */
+    __u8 fats;			/* number of FATs */
+    __u8 dir_entries[2];	/* root directory entries */
+    __u8 sectors[2];		/* number of sectors */
+    __u8 media;			/* media code (unused) */
+    __u16 fat_length;		/* sectors/FAT */
+    __u16 secs_track;		/* sectors per track */
+    __u16 heads;		/* number of heads */
+    __u32 hidden;		/* hidden sectors (unused) */
+    __u32 total_sect;		/* number of sectors (if sectors == 0) */
+    union {
+	struct {
+	    struct msdos_volume_info vi;
+	    __u8 boot_code[BOOTCODE_SIZE];
+	} __attribute__ ((packed)) _oldfat;
+	struct {
+	    __u32 fat32_length;	/* sectors/FAT */
+	    __u16 flags;	/* bit 8: fat mirroring, low 4: active fat */
+	    __u8 version[2];	/* major, minor filesystem version */
+	    __u32 root_cluster;	/* first cluster in root directory */
+	    __u16 info_sector;	/* filesystem info sector */
+	    __u16 backup_boot;	/* backup boot sector */
+	    __u16 reserved2[6];	/* Unused */
+	    struct msdos_volume_info vi;
+	    __u8 boot_code[BOOTCODE_FAT32_SIZE];
+	} __attribute__ ((packed)) _fat32;
+    } __attribute__ ((packed)) fstype;
+    __u16 boot_sign;
+} __attribute__ ((packed));
+#define fat32	fstype._fat32
+#define oldfat	fstype._oldfat
+
+struct fat32_fsinfo {
+    __u32 reserved1;		/* Nothing as far as I can tell */
+    __u32 signature;		/* 0x61417272L */
+    __u32 free_clusters;	/* Free cluster count.  -1 if unknown */
+    __u32 next_cluster;		/* Most recently allocated cluster.
+				 * Unused under Linux. */
+    __u32 reserved2[4];
+};
+
+struct msdos_dir_entry {
+    char name[8], ext[3];	/* name and extension */
+    __u8 attr;			/* attribute bits */
+    __u8 lcase;			/* Case for base and extension */
+    __u8 ctime_ms;		/* Creation time, milliseconds */
+    __u16 ctime;		/* Creation time */
+    __u16 cdate;		/* Creation date */
+    __u16 adate;		/* Last access date */
+    __u16 starthi;		/* high 16 bits of first cl. (FAT32) */
+    __u16 time, date, start;	/* time, date and first cluster */
+    __u32 size;			/* file size (in bytes) */
+} __attribute__ ((packed));
+
+/* The "boot code" we put into the filesystem... it writes a message and
+   tells the user to try again */
+
+char dummy_boot_jump[3] = { 0xeb, 0x3c, 0x90 };
+
+char dummy_boot_jump_m68k[2] = { 0x60, 0x1c };
+
+#define MSG_OFFSET_OFFSET 3
+char dummy_boot_code[BOOTCODE_SIZE] = "\x0e"	/* push cs */
+    "\x1f"			/* pop ds */
+    "\xbe\x5b\x7c"		/* mov si, offset message_txt */
+    /* write_msg: */
+    "\xac"			/* lodsb */
+    "\x22\xc0"			/* and al, al */
+    "\x74\x0b"			/* jz key_press */
+    "\x56"			/* push si */
+    "\xb4\x0e"			/* mov ah, 0eh */
+    "\xbb\x07\x00"		/* mov bx, 0007h */
+    "\xcd\x10"			/* int 10h */
+    "\x5e"			/* pop si */
+    "\xeb\xf0"			/* jmp write_msg */
+    /* key_press: */
+    "\x32\xe4"			/* xor ah, ah */
+    "\xcd\x16"			/* int 16h */
+    "\xcd\x19"			/* int 19h */
+    "\xeb\xfe"			/* foo: jmp foo */
+    /* message_txt: */
+    "This is not a bootable disk.  Please insert a bootable floppy and\r\n"
+    "press any key to try again ... \r\n";
+
+#define MESSAGE_OFFSET 29	/* Offset of message in above code */
+
+/* Global variables - the root of all evil :-) - see these and weep! */
+
+static char *program_name = "mkdosfs";	/* Name of the program */
+static char *device_name = NULL;	/* Name of the device on which to create the filesystem */
+static int atari_format = 0;	/* Use Atari variation of MS-DOS FS format */
+static int check = FALSE;	/* Default to no readablity checking */
+static int verbose = 0;		/* Default to verbose mode off */
+static long volume_id;		/* Volume ID number */
+static time_t create_time;	/* Creation time */
+static struct timeval create_timeval;	/* Creation time */
+static char volume_name[] = "           ";	/* Volume name */
+static unsigned long long blocks;	/* Number of blocks in filesystem */
+static int sector_size = 512;	/* Size of a logical sector */
+static int sector_size_set = 0;	/* User selected sector size */
+static int backup_boot = 0;	/* Sector# of backup boot sector */
+static int reserved_sectors = 0;	/* Number of reserved sectors */
+static int badblocks = 0;	/* Number of bad blocks in the filesystem */
+static int nr_fats = 2;		/* Default number of FATs to produce */
+static int size_fat = 0;	/* Size in bits of FAT entries */
+static int size_fat_by_user = 0;	/* 1 if FAT size user selected */
+static int dev = -1;		/* FS block device file handle */
+static int ignore_full_disk = 0;	/* Ignore warning about 'full' disk devices */
+static off_t currently_testing = 0;	/* Block currently being tested (if autodetect bad blocks) */
+static struct msdos_boot_sector bs;	/* Boot sector data */
+static int start_data_sector;	/* Sector number for the start of the data area */
+static int start_data_block;	/* Block number for the start of the data area */
+static unsigned char *fat;	/* File allocation table */
+static unsigned alloced_fat_length;	/* # of FAT sectors we can keep in memory */
+static unsigned char *info_sector;	/* FAT32 info sector */
+static struct msdos_dir_entry *root_dir;	/* Root directory */
+static int size_root_dir;	/* Size of the root directory in bytes */
+static int sectors_per_cluster = 0;	/* Number of sectors per disk cluster */
+static int root_dir_entries = 0;	/* Number of root directory entries */
+static char *blank_sector;	/* Blank sector - all zeros */
+static int hidden_sectors = 0;	/* Number of hidden sectors */
+static int malloc_entire_fat = FALSE;	/* Whether we should malloc() the entire FAT or not */
+static int align_structures = TRUE;	/* Whether to enforce alignment */
+static int orphaned_sectors = 0;	/* Sectors that exist in the last block of filesystem */
+
+/* Function prototype definitions */
+
+static void fatal_error(const char *fmt_string) __attribute__ ((noreturn));
+static void mark_FAT_cluster(int cluster, unsigned int value);
+static void mark_FAT_sector(int sector, unsigned int value);
+static long do_check(char *buffer, int try, off_t current_block);
+static void alarm_intr(int alnum);
+static void check_blocks(void);
+static void get_list_blocks(char *filename);
+static int valid_offset(int fd, loff_t offset);
+static unsigned long long count_blocks(char *filename, int *remainder);
+static void check_mount(char *device_name);
+static void establish_params(int device_num, int size);
+static void setup_tables(void);
+static void write_tables(void);
+
+/* The function implementations */
+
+/* Handle the reporting of fatal errors.  Volatile to let gcc know that this doesn't return */
+
+static void fatal_error(const char *fmt_string)
+{
+    fprintf(stderr, fmt_string, program_name, device_name);
+    exit(1);			/* The error exit code is 1! */
+}
+
+/* Mark the specified cluster as having a particular value */
+
+static void mark_FAT_cluster(int cluster, unsigned int value)
+{
+    switch (size_fat) {
+    case 12:
+	value &= 0x0fff;
+	if (((cluster * 3) & 0x1) == 0) {
+	    fat[3 * cluster / 2] = (unsigned char)(value & 0x00ff);
+	    fat[(3 * cluster / 2) + 1] =
+		(unsigned char)((fat[(3 * cluster / 2) + 1] & 0x00f0)
+				| ((value & 0x0f00) >> 8));
+	} else {
+	    fat[3 * cluster / 2] =
+		(unsigned char)((fat[3 * cluster / 2] & 0x000f) |
+				((value & 0x000f) << 4));
+	    fat[(3 * cluster / 2) + 1] = (unsigned char)((value & 0x0ff0) >> 4);
+	}
+	break;
+
+    case 16:
+	value &= 0xffff;
+	fat[2 * cluster] = (unsigned char)(value & 0x00ff);
+	fat[(2 * cluster) + 1] = (unsigned char)(value >> 8);
+	break;
+
+    case 32:
+	value &= 0xfffffff;
+	fat[4 * cluster] = (unsigned char)(value & 0x000000ff);
+	fat[(4 * cluster) + 1] = (unsigned char)((value & 0x0000ff00) >> 8);
+	fat[(4 * cluster) + 2] = (unsigned char)((value & 0x00ff0000) >> 16);
+	fat[(4 * cluster) + 3] = (unsigned char)((value & 0xff000000) >> 24);
+	break;
+
+    default:
+	die("Bad FAT size (not 12, 16, or 32)");
+    }
+}
+
+/* Mark a specified sector as having a particular value in it's FAT entry */
+
+static void mark_FAT_sector(int sector, unsigned int value)
+{
+    int cluster;
+
+    cluster = (sector - start_data_sector) / (int)(bs.cluster_size) /
+	(sector_size / HARD_SECTOR_SIZE);
+    if (cluster < 0)
+	die("Invalid cluster number in mark_FAT_sector: probably bug!");
+
+    mark_FAT_cluster(cluster, value);
+}
+
+/* Perform a test on a block.  Return the number of blocks that could be read successfully */
+
+static long do_check(char *buffer, int try, off_t current_block)
+{
+    long got;
+
+    if (llseek(dev, current_block * BLOCK_SIZE, SEEK_SET)	/* Seek to the correct location */
+	!=current_block * BLOCK_SIZE)
+	die("seek failed during testing for blocks");
+
+    got = read(dev, buffer, try * BLOCK_SIZE);	/* Try reading! */
+    if (got < 0)
+	got = 0;
+
+    if (got & (BLOCK_SIZE - 1))
+	printf("Unexpected values in do_check: probably bugs\n");
+    got /= BLOCK_SIZE;
+
+    return got;
+}
+
+/* Alarm clock handler - display the status of the quest for bad blocks!  Then retrigger the alarm for five senconds
+   later (so we can come here again) */
+
+static void alarm_intr(int alnum)
+{
+    if (currently_testing >= blocks)
+	return;
+
+    signal(SIGALRM, alarm_intr);
+    alarm(5);
+    if (!currently_testing)
+	return;
+
+    printf("%lld... ", (unsigned long long)currently_testing);
+    fflush(stdout);
+}
+
+static void check_blocks(void)
+{
+    int try, got;
+    int i;
+    static char blkbuf[BLOCK_SIZE * TEST_BUFFER_BLOCKS];
+
+    if (verbose) {
+	printf("Searching for bad blocks ");
+	fflush(stdout);
+    }
+    currently_testing = 0;
+    if (verbose) {
+	signal(SIGALRM, alarm_intr);
+	alarm(5);
+    }
+    try = TEST_BUFFER_BLOCKS;
+    while (currently_testing < blocks) {
+	if (currently_testing + try > blocks)
+	    try = blocks - currently_testing;
+	got = do_check(blkbuf, try, currently_testing);
+	currently_testing += got;
+	if (got == try) {
+	    try = TEST_BUFFER_BLOCKS;
+	    continue;
+	} else
+	    try = 1;
+	if (currently_testing < start_data_block)
+	    die("bad blocks before data-area: cannot make fs");
+
+	for (i = 0; i < SECTORS_PER_BLOCK; i++)	/* Mark all of the sectors in the block as bad */
+	    mark_sector_bad(currently_testing * SECTORS_PER_BLOCK + i);
+	badblocks++;
+	currently_testing++;
+    }
+
+    if (verbose)
+	printf("\n");
+
+    if (badblocks)
+	printf("%d bad block%s\n", badblocks, (badblocks > 1) ? "s" : "");
+}
+
+static void get_list_blocks(char *filename)
+{
+    int i;
+    FILE *listfile;
+    unsigned long blockno;
+
+    listfile = fopen(filename, "r");
+    if (listfile == (FILE *) NULL)
+	die("Can't open file of bad blocks");
+
+    while (!feof(listfile)) {
+	fscanf(listfile, "%ld\n", &blockno);
+	for (i = 0; i < SECTORS_PER_BLOCK; i++)	/* Mark all of the sectors in the block as bad */
+	    mark_sector_bad(blockno * SECTORS_PER_BLOCK + i);
+	badblocks++;
+    }
+    fclose(listfile);
+
+    if (badblocks)
+	printf("%d bad block%s\n", badblocks, (badblocks > 1) ? "s" : "");
+}
+
+/* Given a file descriptor and an offset, check whether the offset is a valid offset for the file - return FALSE if it
+   isn't valid or TRUE if it is */
+
+static int valid_offset(int fd, loff_t offset)
+{
+    char ch;
+
+    if (llseek(fd, offset, SEEK_SET) < 0)
+	return FALSE;
+    if (read(fd, &ch, 1) < 1)
+	return FALSE;
+    return TRUE;
+}
+
+/* Given a filename, look to see how many blocks of BLOCK_SIZE are present, returning the answer */
+
+static unsigned long long count_blocks(char *filename, int *remainder)
+
+{
+    loff_t high, low;
+    int fd;
+
+    if ((fd = open(filename, O_RDONLY)) < 0) {
+	perror(filename);
+	exit(1);
+    }
+
+    /* first try SEEK_END, which should work on most devices nowadays */
+    if ((low = llseek(fd, 0, SEEK_END)) <= 0) {
+	low = 0;
+	for (high = 1; valid_offset(fd, high); high *= 2)
+	    low = high;
+	while (low < high - 1) {
+	    const loff_t mid = (low + high) / 2;
+	    if (valid_offset(fd, mid))
+		low = mid;
+	    else
+		high = mid;
+	}
+	++low;
+    }
+
+    close(fd);
+    *remainder = (low%BLOCK_SIZE)/sector_size;
+    return(low / BLOCK_SIZE);
+}
+
+/* Check to see if the specified device is currently mounted - abort if it is */
+
+static void check_mount(char *device_name)
+{
+#if ! defined(_USING_BIONIC_)
+    FILE *f;
+    struct mntent *mnt;
+
+    if ((f = setmntent(MOUNTED, "r")) == NULL)
+	return;
+    while ((mnt = getmntent(f)) != NULL)
+	if (strcmp(device_name, mnt->mnt_fsname) == 0)
+	    die("%s contains a mounted file system.");
+    endmntent(f);
+#endif
+}
+
+/* Establish the geometry and media parameters for the device */
+
+static void establish_params(int device_num, int size)
+{
+    long loop_size;
+    struct hd_geometry geometry;
+    struct floppy_struct param;
+    int def_root_dir_entries = 512;
+
+    if ((0 == device_num) || ((device_num & 0xff00) == 0x0200))
+	/* file image or floppy disk */
+    {
+	if (0 == device_num) {
+	    param.size = size / 512;
+	    switch (param.size) {
+	    case 720:
+		param.sect = 9;
+		param.head = 2;
+		break;
+	    case 1440:
+		param.sect = 9;
+		param.head = 2;
+		break;
+	    case 2400:
+		param.sect = 15;
+		param.head = 2;
+		break;
+	    case 2880:
+		param.sect = 18;
+		param.head = 2;
+		break;
+	    case 5760:
+		param.sect = 36;
+		param.head = 2;
+		break;
+	    default:
+		/* fake values */
+		param.sect = 32;
+		param.head = 64;
+		break;
+	    }
+
+	} else {		/* is a floppy diskette */
+
+	    if (ioctl(dev, FDGETPRM, &param))	/*  Can we get the diskette geometry? */
+		die("unable to get diskette geometry for '%s'");
+	}
+	bs.secs_track = CT_LE_W(param.sect);	/*  Set up the geometry information */
+	bs.heads = CT_LE_W(param.head);
+	switch (param.size) {	/*  Set up the media descriptor byte */
+	case 720:		/* 5.25", 2, 9, 40 - 360K */
+	    bs.media = (char)0xfd;
+	    bs.cluster_size = (char)2;
+	    def_root_dir_entries = 112;
+	    break;
+
+	case 1440:		/* 3.5", 2, 9, 80 - 720K */
+	    bs.media = (char)0xf9;
+	    bs.cluster_size = (char)2;
+	    def_root_dir_entries = 112;
+	    break;
+
+	case 2400:		/* 5.25", 2, 15, 80 - 1200K */
+	    bs.media = (char)0xf9;
+	    bs.cluster_size = (char)(atari_format ? 2 : 1);
+	    def_root_dir_entries = 224;
+	    break;
+
+	case 5760:		/* 3.5", 2, 36, 80 - 2880K */
+	    bs.media = (char)0xf0;
+	    bs.cluster_size = (char)2;
+	    def_root_dir_entries = 224;
+	    break;
+
+	case 2880:		/* 3.5", 2, 18, 80 - 1440K */
+floppy_default:
+	    bs.media = (char)0xf0;
+	    bs.cluster_size = (char)(atari_format ? 2 : 1);
+	    def_root_dir_entries = 224;
+	    break;
+
+	default:		/* Anything else */
+	    if (0 == device_num)
+		goto def_hd_params;
+	    else
+		goto floppy_default;
+	}
+    } else if ((device_num & 0xff00) == 0x0700) {	/* This is a loop device */
+	if (ioctl(dev, BLKGETSIZE, &loop_size))
+	    die("unable to get loop device size");
+
+	switch (loop_size) {	/* Assuming the loop device -> floppy later */
+	case 720:		/* 5.25", 2, 9, 40 - 360K */
+	    bs.secs_track = CF_LE_W(9);
+	    bs.heads = CF_LE_W(2);
+	    bs.media = (char)0xfd;
+	    bs.cluster_size = (char)2;
+	    def_root_dir_entries = 112;
+	    break;
+
+	case 1440:		/* 3.5", 2, 9, 80 - 720K */
+	    bs.secs_track = CF_LE_W(9);
+	    bs.heads = CF_LE_W(2);
+	    bs.media = (char)0xf9;
+	    bs.cluster_size = (char)2;
+	    def_root_dir_entries = 112;
+	    break;
+
+	case 2400:		/* 5.25", 2, 15, 80 - 1200K */
+	    bs.secs_track = CF_LE_W(15);
+	    bs.heads = CF_LE_W(2);
+	    bs.media = (char)0xf9;
+	    bs.cluster_size = (char)(atari_format ? 2 : 1);
+	    def_root_dir_entries = 224;
+	    break;
+
+	case 5760:		/* 3.5", 2, 36, 80 - 2880K */
+	    bs.secs_track = CF_LE_W(36);
+	    bs.heads = CF_LE_W(2);
+	    bs.media = (char)0xf0;
+	    bs.cluster_size = (char)2;
+	    bs.dir_entries[0] = (char)224;
+	    bs.dir_entries[1] = (char)0;
+	    break;
+
+	case 2880:		/* 3.5", 2, 18, 80 - 1440K */
+	    bs.secs_track = CF_LE_W(18);
+	    bs.heads = CF_LE_W(2);
+	    bs.media = (char)0xf0;
+	    bs.cluster_size = (char)(atari_format ? 2 : 1);
+	    def_root_dir_entries = 224;
+	    break;
+
+	default:		/* Anything else: default hd setup */
+	    printf("Loop device does not match a floppy size, using "
+		   "default hd params\n");
+	    bs.secs_track = CT_LE_W(32);	/* these are fake values... */
+	    bs.heads = CT_LE_W(64);
+	    goto def_hd_params;
+	}
+    } else
+	/* Must be a hard disk then! */
+    {
+	/* Can we get the drive geometry? (Note I'm not too sure about */
+	/* whether to use HDIO_GETGEO or HDIO_REQ) */
+	if (ioctl(dev, HDIO_GETGEO, &geometry) || geometry.sectors == 0
+	    || geometry.heads == 0) {
+	    printf("unable to get drive geometry, using default 255/63\n");
+	    bs.secs_track = CT_LE_W(63);
+	    bs.heads = CT_LE_W(255);
+	} else {
+	    bs.secs_track = CT_LE_W(geometry.sectors);	/* Set up the geometry information */
+	    bs.heads = CT_LE_W(geometry.heads);
+	}
+def_hd_params:
+	bs.media = (char)0xf8;	/* Set up the media descriptor for a hard drive */
+	if (!size_fat && blocks * SECTORS_PER_BLOCK > 1064960) {
+	    if (verbose)
+		printf("Auto-selecting FAT32 for large filesystem\n");
+	    size_fat = 32;
+	}
+	if (size_fat == 32) {
+	    /* For FAT32, try to do the same as M$'s format command
+	     * (see http://www.win.tue.nl/~aeb/linux/fs/fat/fatgen103.pdf p. 20):
+	     * fs size <= 260M: 0.5k clusters
+	     * fs size <=   8G: 4k clusters
+	     * fs size <=  16G: 8k clusters
+	     * fs size >   16G: 16k clusters
+	     */
+	    unsigned long sz_mb =
+		(blocks + (1 << (20 - BLOCK_SIZE_BITS)) - 1) >> (20 -
+								 BLOCK_SIZE_BITS);
+	    bs.cluster_size =
+		sz_mb > 16 * 1024 ? 32 : sz_mb > 8 * 1024 ? 16 : sz_mb >
+		260 ? 8 : 1;
+	} else {
+	    /* FAT12 and FAT16: start at 4 sectors per cluster */
+	    bs.cluster_size = (char)4;
+	}
+    }
+
+    if (!root_dir_entries)
+	root_dir_entries = def_root_dir_entries;
+}
+
+/*
+ * If alignment is enabled, round the first argument up to the second; the
+ * latter must be a power of two.
+ */
+static unsigned int align_object(unsigned int sectors, unsigned int clustsize)
+{
+    if (align_structures)
+	return (sectors + clustsize - 1) & ~(clustsize - 1);
+    else
+	return sectors;
+}
+
+/* Create the filesystem data tables */
+
+static void setup_tables(void)
+{
+    unsigned num_sectors;
+    unsigned cluster_count = 0, fat_length;
+    struct tm *ctime;
+    struct msdos_volume_info *vi =
+	(size_fat == 32 ? &bs.fat32.vi : &bs.oldfat.vi);
+
+    if (atari_format)
+	/* On Atari, the first few bytes of the boot sector are assigned
+	 * differently: The jump code is only 2 bytes (and m68k machine code
+	 * :-), then 6 bytes filler (ignored), then 3 byte serial number. */
+	memcpy(bs.system_id - 1, "mkdosf", 6);
+    else
+	strcpy((char *)bs.system_id, "mkdosfs");
+    if (sectors_per_cluster)
+	bs.cluster_size = (char)sectors_per_cluster;
+    if (size_fat == 32) {
+	/* Under FAT32, the root dir is in a cluster chain, and this is
+	 * signalled by bs.dir_entries being 0. */
+	root_dir_entries = 0;
+    }
+
+    if (atari_format) {
+	bs.system_id[5] = (unsigned char)(volume_id & 0x000000ff);
+	bs.system_id[6] = (unsigned char)((volume_id & 0x0000ff00) >> 8);
+	bs.system_id[7] = (unsigned char)((volume_id & 0x00ff0000) >> 16);
+    } else {
+	vi->volume_id[0] = (unsigned char)(volume_id & 0x000000ff);
+	vi->volume_id[1] = (unsigned char)((volume_id & 0x0000ff00) >> 8);
+	vi->volume_id[2] = (unsigned char)((volume_id & 0x00ff0000) >> 16);
+	vi->volume_id[3] = (unsigned char)(volume_id >> 24);
+    }
+
+    if (!atari_format) {
+	memcpy(vi->volume_label, volume_name, 11);
+
+	memcpy(bs.boot_jump, dummy_boot_jump, 3);
+	/* Patch in the correct offset to the boot code */
+	bs.boot_jump[1] = ((size_fat == 32 ?
+			    (char *)&bs.fat32.boot_code :
+			    (char *)&bs.oldfat.boot_code) - (char *)&bs) - 2;
+
+	if (size_fat == 32) {
+	    int offset = (char *)&bs.fat32.boot_code -
+		(char *)&bs + MESSAGE_OFFSET + 0x7c00;
+	    if (dummy_boot_code[BOOTCODE_FAT32_SIZE - 1])
+		printf("Warning: message too long; truncated\n");
+	    dummy_boot_code[BOOTCODE_FAT32_SIZE - 1] = 0;
+	    memcpy(bs.fat32.boot_code, dummy_boot_code, BOOTCODE_FAT32_SIZE);
+	    bs.fat32.boot_code[MSG_OFFSET_OFFSET] = offset & 0xff;
+	    bs.fat32.boot_code[MSG_OFFSET_OFFSET + 1] = offset >> 8;
+	} else {
+	    memcpy(bs.oldfat.boot_code, dummy_boot_code, BOOTCODE_SIZE);
+	}
+	bs.boot_sign = CT_LE_W(BOOT_SIGN);
+    } else {
+	memcpy(bs.boot_jump, dummy_boot_jump_m68k, 2);
+    }
+    if (verbose >= 2)
+	printf("Boot jump code is %02x %02x\n",
+	       bs.boot_jump[0], bs.boot_jump[1]);
+
+    if (!reserved_sectors)
+	reserved_sectors = (size_fat == 32) ? 32 : 1;
+    else {
+	if (size_fat == 32 && reserved_sectors < 2)
+	    die("On FAT32 at least 2 reserved sectors are needed.");
+    }
+    bs.reserved = CT_LE_W(reserved_sectors);
+    if (verbose >= 2)
+	printf("Using %d reserved sectors\n", reserved_sectors);
+    bs.fats = (char)nr_fats;
+    if (!atari_format || size_fat == 32)
+	bs.hidden = CT_LE_L(hidden_sectors);
+    else {
+	/* In Atari format, hidden is a 16 bit field */
+	__u16 hidden = CT_LE_W(hidden_sectors);
+	if (hidden_sectors & ~0xffff)
+	    die("#hidden doesn't fit in 16bit field of Atari format\n");
+	memcpy(&bs.hidden, &hidden, 2);
+    }
+
+    num_sectors = (long long)(blocks *BLOCK_SIZE / sector_size)+orphaned_sectors;
+
+    if (!atari_format) {
+	unsigned fatdata1216;	/* Sectors for FATs + data area (FAT12/16) */
+	unsigned fatdata32;	/* Sectors for FATs + data area (FAT32) */
+	unsigned fatlength12, fatlength16, fatlength32;
+	unsigned maxclust12, maxclust16, maxclust32;
+	unsigned clust12, clust16, clust32;
+	int maxclustsize;
+	unsigned root_dir_sectors = cdiv(root_dir_entries * 32, sector_size);
+
+	/*
+	 * If the filesystem is 8192 sectors or less (4 MB with 512-byte
+	 * sectors, i.e. floppy size), don't align the data structures.
+	 */
+	if (num_sectors <= 8192) {
+	    if (align_structures && verbose >= 2)
+		printf("Disabling alignment due to tiny filesystem\n");
+
+	    align_structures = FALSE;
+	}
+
+	if (sectors_per_cluster)
+	    bs.cluster_size = maxclustsize = sectors_per_cluster;
+	else
+	    /* An initial guess for bs.cluster_size should already be set */
+	    maxclustsize = 128;
+
+	do {
+	    fatdata32 = num_sectors
+		- align_object(reserved_sectors, bs.cluster_size);
+	    fatdata1216 = fatdata32
+		- align_object(root_dir_sectors, bs.cluster_size);
+
+	    if (verbose >= 2)
+		printf("Trying with %d sectors/cluster:\n", bs.cluster_size);
+
+	    /* The factor 2 below avoids cut-off errors for nr_fats == 1.
+	     * The "nr_fats*3" is for the reserved first two FAT entries */
+	    clust12 = 2 * ((long long)fatdata1216 * sector_size + nr_fats * 3) /
+		(2 * (int)bs.cluster_size * sector_size + nr_fats * 3);
+	    fatlength12 = cdiv(((clust12 + 2) * 3 + 1) >> 1, sector_size);
+	    fatlength12 = align_object(fatlength12, bs.cluster_size);
+	    /* Need to recalculate number of clusters, since the unused parts of the
+	     * FATS and data area together could make up space for an additional,
+	     * not really present cluster. */
+	    clust12 = (fatdata1216 - nr_fats * fatlength12) / bs.cluster_size;
+	    maxclust12 = (fatlength12 * 2 * sector_size) / 3;
+	    if (maxclust12 > MAX_CLUST_12)
+		maxclust12 = MAX_CLUST_12;
+	    if (verbose >= 2)
+		printf("FAT12: #clu=%u, fatlen=%u, maxclu=%u, limit=%u\n",
+		       clust12, fatlength12, maxclust12, MAX_CLUST_12);
+	    if (clust12 > maxclust12 - 2) {
+		clust12 = 0;
+		if (verbose >= 2)
+		    printf("FAT12: too much clusters\n");
+	    }
+
+	    clust16 = ((long long)fatdata1216 * sector_size + nr_fats * 4) /
+		((int)bs.cluster_size * sector_size + nr_fats * 2);
+	    fatlength16 = cdiv((clust16 + 2) * 2, sector_size);
+	    fatlength16 = align_object(fatlength16, bs.cluster_size);
+	    /* Need to recalculate number of clusters, since the unused parts of the
+	     * FATS and data area together could make up space for an additional,
+	     * not really present cluster. */
+	    clust16 = (fatdata1216 - nr_fats * fatlength16) / bs.cluster_size;
+	    maxclust16 = (fatlength16 * sector_size) / 2;
+	    if (maxclust16 > MAX_CLUST_16)
+		maxclust16 = MAX_CLUST_16;
+	    if (verbose >= 2)
+		printf("FAT16: #clu=%u, fatlen=%u, maxclu=%u, limit=%u\n",
+		       clust16, fatlength16, maxclust16, MAX_CLUST_16);
+	    if (clust16 > maxclust16 - 2) {
+		if (verbose >= 2)
+		    printf("FAT16: too much clusters\n");
+		clust16 = 0;
+	    }
+	    /* The < 4078 avoids that the filesystem will be misdetected as having a
+	     * 12 bit FAT. */
+	    if (clust16 < FAT12_THRESHOLD
+		&& !(size_fat_by_user && size_fat == 16)) {
+		if (verbose >= 2)
+		    printf(clust16 < FAT12_THRESHOLD ?
+			   "FAT16: would be misdetected as FAT12\n" :
+			   "FAT16: too much clusters\n");
+		clust16 = 0;
+	    }
+
+	    clust32 = ((long long)fatdata32 * sector_size + nr_fats * 8) /
+		((int)bs.cluster_size * sector_size + nr_fats * 4);
+	    fatlength32 = cdiv((clust32 + 2) * 4, sector_size);
+	    fatlength32 = align_object(fatlength32, bs.cluster_size);
+	    /* Need to recalculate number of clusters, since the unused parts of the
+	     * FATS and data area together could make up space for an additional,
+	     * not really present cluster. */
+	    clust32 = (fatdata32 - nr_fats * fatlength32) / bs.cluster_size;
+	    maxclust32 = (fatlength32 * sector_size) / 4;
+	    if (maxclust32 > MAX_CLUST_32)
+		maxclust32 = MAX_CLUST_32;
+	    if (clust32 && clust32 < MIN_CLUST_32
+		&& !(size_fat_by_user && size_fat == 32)) {
+		clust32 = 0;
+		if (verbose >= 2)
+		    printf("FAT32: not enough clusters (%d)\n", MIN_CLUST_32);
+	    }
+	    if (verbose >= 2)
+		printf("FAT32: #clu=%u, fatlen=%u, maxclu=%u, limit=%u\n",
+		       clust32, fatlength32, maxclust32, MAX_CLUST_32);
+	    if (clust32 > maxclust32) {
+		clust32 = 0;
+		if (verbose >= 2)
+		    printf("FAT32: too much clusters\n");
+	    }
+
+	    if ((clust12 && (size_fat == 0 || size_fat == 12)) ||
+		(clust16 && (size_fat == 0 || size_fat == 16)) ||
+		(clust32 && size_fat == 32))
+		break;
+
+	    bs.cluster_size <<= 1;
+	} while (bs.cluster_size && bs.cluster_size <= maxclustsize);
+
+	/* Use the optimal FAT size if not specified;
+	 * FAT32 is (not yet) choosen automatically */
+	if (!size_fat) {
+	    size_fat = (clust16 > clust12) ? 16 : 12;
+	    if (verbose >= 2)
+		printf("Choosing %d bits for FAT\n", size_fat);
+	}
+
+	switch (size_fat) {
+	case 12:
+	    cluster_count = clust12;
+	    fat_length = fatlength12;
+	    bs.fat_length = CT_LE_W(fatlength12);
+	    memcpy(vi->fs_type, MSDOS_FAT12_SIGN, 8);
+	    break;
+
+	case 16:
+	    if (clust16 < FAT12_THRESHOLD) {
+		if (size_fat_by_user) {
+		    fprintf(stderr, "WARNING: Not enough clusters for a "
+			    "16 bit FAT! The filesystem will be\n"
+			    "misinterpreted as having a 12 bit FAT without "
+			    "mount option \"fat=16\".\n");
+		} else {
+		    fprintf(stderr, "This filesystem has an unfortunate size. "
+			    "A 12 bit FAT cannot provide\n"
+			    "enough clusters, but a 16 bit FAT takes up a little "
+			    "bit more space so that\n"
+			    "the total number of clusters becomes less than the "
+			    "threshold value for\n"
+			    "distinction between 12 and 16 bit FATs.\n");
+		    die("Make the file system a bit smaller manually.");
+		}
+	    }
+	    cluster_count = clust16;
+	    fat_length = fatlength16;
+	    bs.fat_length = CT_LE_W(fatlength16);
+	    memcpy(vi->fs_type, MSDOS_FAT16_SIGN, 8);
+	    break;
+
+	case 32:
+	    if (clust32 < MIN_CLUST_32)
+		fprintf(stderr,
+			"WARNING: Not enough clusters for a 32 bit FAT!\n");
+	    cluster_count = clust32;
+	    fat_length = fatlength32;
+	    bs.fat_length = CT_LE_W(0);
+	    bs.fat32.fat32_length = CT_LE_L(fatlength32);
+	    memcpy(vi->fs_type, MSDOS_FAT32_SIGN, 8);
+	    root_dir_entries = 0;
+	    break;
+
+	default:
+	    die("FAT not 12, 16 or 32 bits");
+	}
+
+	/* Adjust the reserved number of sectors for alignment */
+	reserved_sectors = align_object(reserved_sectors, bs.cluster_size);
+	bs.reserved = CT_LE_W(reserved_sectors);
+
+	/* Adjust the number of root directory entries to help enforce alignment */
+	if (align_structures) {
+	    root_dir_entries = align_object(root_dir_sectors, bs.cluster_size)
+		* (sector_size >> 5);
+	}
+    } else {
+	unsigned clusters, maxclust, fatdata;
+
+	/* GEMDOS always uses a 12 bit FAT on floppies, and always a 16 bit FAT on
+	 * hard disks. So use 12 bit if the size of the file system suggests that
+	 * this fs is for a floppy disk, if the user hasn't explicitly requested a
+	 * size.
+	 */
+	if (!size_fat)
+	    size_fat = (num_sectors == 1440 || num_sectors == 2400 ||
+			num_sectors == 2880 || num_sectors == 5760) ? 12 : 16;
+	if (verbose >= 2)
+	    printf("Choosing %d bits for FAT\n", size_fat);
+
+	/* Atari format: cluster size should be 2, except explicitly requested by
+	 * the user, since GEMDOS doesn't like other cluster sizes very much.
+	 * Instead, tune the sector size for the FS to fit.
+	 */
+	bs.cluster_size = sectors_per_cluster ? sectors_per_cluster : 2;
+	if (!sector_size_set) {
+	    while (num_sectors > GEMDOS_MAX_SECTORS) {
+		num_sectors >>= 1;
+		sector_size <<= 1;
+	    }
+	}
+	if (verbose >= 2)
+	    printf("Sector size must be %d to have less than %d log. sectors\n",
+		   sector_size, GEMDOS_MAX_SECTORS);
+
+	/* Check if there are enough FAT indices for how much clusters we have */
+	do {
+	    fatdata = num_sectors - cdiv(root_dir_entries * 32, sector_size) -
+		reserved_sectors;
+	    /* The factor 2 below avoids cut-off errors for nr_fats == 1 and
+	     * size_fat == 12
+	     * The "2*nr_fats*size_fat/8" is for the reserved first two FAT entries
+	     */
+	    clusters =
+		(2 *
+		 ((long long)fatdata * sector_size -
+		  2 * nr_fats * size_fat / 8)) / (2 * ((int)bs.cluster_size *
+						       sector_size +
+						       nr_fats * size_fat / 8));
+	    fat_length = cdiv((clusters + 2) * size_fat / 8, sector_size);
+	    /* Need to recalculate number of clusters, since the unused parts of the
+	     * FATS and data area together could make up space for an additional,
+	     * not really present cluster. */
+	    clusters = (fatdata - nr_fats * fat_length) / bs.cluster_size;
+	    maxclust = (fat_length * sector_size * 8) / size_fat;
+	    if (verbose >= 2)
+		printf("ss=%d: #clu=%d, fat_len=%d, maxclu=%d\n",
+		       sector_size, clusters, fat_length, maxclust);
+
+	    /* last 10 cluster numbers are special (except FAT32: 4 high bits rsvd);
+	     * first two numbers are reserved */
+	    if (maxclust <=
+		(size_fat == 32 ? MAX_CLUST_32 : (1 << size_fat) - 0x10)
+		&& clusters <= maxclust - 2)
+		break;
+	    if (verbose >= 2)
+		printf(clusters > maxclust - 2 ?
+		       "Too many clusters\n" : "FAT too big\n");
+
+	    /* need to increment sector_size once more to  */
+	    if (sector_size_set)
+		die("With this sector size, the maximum number of FAT entries "
+		    "would be exceeded.");
+	    num_sectors >>= 1;
+	    sector_size <<= 1;
+	} while (sector_size <= GEMDOS_MAX_SECTOR_SIZE);
+
+	if (sector_size > GEMDOS_MAX_SECTOR_SIZE)
+	    die("Would need a sector size > 16k, which GEMDOS can't work with");
+
+	cluster_count = clusters;
+	if (size_fat != 32)
+	    bs.fat_length = CT_LE_W(fat_length);
+	else {
+	    bs.fat_length = 0;
+	    bs.fat32.fat32_length = CT_LE_L(fat_length);
+	}
+    }
+
+    bs.sector_size[0] = (char)(sector_size & 0x00ff);
+    bs.sector_size[1] = (char)((sector_size & 0xff00) >> 8);
+
+    bs.dir_entries[0] = (char)(root_dir_entries & 0x00ff);
+    bs.dir_entries[1] = (char)((root_dir_entries & 0xff00) >> 8);
+
+    if (size_fat == 32) {
+	/* set up additional FAT32 fields */
+	bs.fat32.flags = CT_LE_W(0);
+	bs.fat32.version[0] = 0;
+	bs.fat32.version[1] = 0;
+	bs.fat32.root_cluster = CT_LE_L(2);
+	bs.fat32.info_sector = CT_LE_W(1);
+	if (!backup_boot)
+	    backup_boot = (reserved_sectors >= 7) ? 6 :
+		(reserved_sectors >= 2) ? reserved_sectors - 1 : 0;
+	else {
+	    if (backup_boot == 1)
+		die("Backup boot sector must be after sector 1");
+	    else if (backup_boot >= reserved_sectors)
+		die("Backup boot sector must be a reserved sector");
+	}
+	if (verbose >= 2)
+	    printf("Using sector %d as backup boot sector (0 = none)\n",
+		   backup_boot);
+	bs.fat32.backup_boot = CT_LE_W(backup_boot);
+	memset(&bs.fat32.reserved2, 0, sizeof(bs.fat32.reserved2));
+    }
+
+    if (atari_format) {
+	/* Just some consistency checks */
+	if (num_sectors >= GEMDOS_MAX_SECTORS)
+	    die("GEMDOS can't handle more than 65531 sectors");
+	else if (num_sectors >= OLDGEMDOS_MAX_SECTORS)
+	    printf("Warning: More than 32765 sector need TOS 1.04 "
+		   "or higher.\n");
+    }
+    if (num_sectors >= 65536) {
+	bs.sectors[0] = (char)0;
+	bs.sectors[1] = (char)0;
+	bs.total_sect = CT_LE_L(num_sectors);
+    } else {
+	bs.sectors[0] = (char)(num_sectors & 0x00ff);
+	bs.sectors[1] = (char)((num_sectors & 0xff00) >> 8);
+	if (!atari_format)
+	    bs.total_sect = CT_LE_L(0);
+    }
+
+    if (!atari_format)
+	vi->ext_boot_sign = MSDOS_EXT_SIGN;
+
+    if (!cluster_count) {
+	if (sectors_per_cluster)	/* If yes, die if we'd spec'd sectors per cluster */
+	    die("Too many clusters for file system - try more sectors per cluster");
+	else
+	    die("Attempting to create a too large file system");
+    }
+
+    /* The two following vars are in hard sectors, i.e. 512 byte sectors! */
+    start_data_sector = (reserved_sectors + nr_fats * fat_length) *
+	(sector_size / HARD_SECTOR_SIZE);
+    start_data_block = (start_data_sector + SECTORS_PER_BLOCK - 1) /
+	SECTORS_PER_BLOCK;
+
+    if (blocks < start_data_block + 32)	/* Arbitrary undersize file system! */
+	die("Too few blocks for viable file system");
+
+    if (verbose) {
+	printf("%s has %d head%s and %d sector%s per track,\n",
+	       device_name, CF_LE_W(bs.heads),
+	       (CF_LE_W(bs.heads) != 1) ? "s" : "", CF_LE_W(bs.secs_track),
+	       (CF_LE_W(bs.secs_track) != 1) ? "s" : "");
+	printf("logical sector size is %d,\n", sector_size);
+	printf("using 0x%02x media descriptor, with %d sectors;\n",
+	       (int)(bs.media), num_sectors);
+	printf("file system has %d %d-bit FAT%s and %d sector%s per cluster.\n",
+	       (int)(bs.fats), size_fat, (bs.fats != 1) ? "s" : "",
+	       (int)(bs.cluster_size), (bs.cluster_size != 1) ? "s" : "");
+	printf("FAT size is %d sector%s, and provides %d cluster%s.\n",
+	       fat_length, (fat_length != 1) ? "s" : "",
+	       cluster_count, (cluster_count != 1) ? "s" : "");
+	printf("There %s %u reserved sector%s.\n",
+	       (reserved_sectors != 1) ? "are" : "is",
+	       reserved_sectors, (reserved_sectors != 1) ? "s" : "");
+
+	if (size_fat != 32) {
+	    unsigned root_dir_entries =
+		bs.dir_entries[0] + ((bs.dir_entries[1]) * 256);
+	    unsigned root_dir_sectors =
+		cdiv(root_dir_entries * 32, sector_size);
+	    printf("Root directory contains %u slots and uses %u sectors.\n",
+		   root_dir_entries, root_dir_sectors);
+	}
+	printf("Volume ID is %08lx, ", volume_id &
+	       (atari_format ? 0x00ffffff : 0xffffffff));
+	if (strcmp(volume_name, "           "))
+	    printf("volume label %s.\n", volume_name);
+	else
+	    printf("no volume label.\n");
+    }
+
+    /* Make the file allocation tables! */
+
+    if (malloc_entire_fat)
+	alloced_fat_length = fat_length;
+    else
+	alloced_fat_length = 1;
+
+    if ((fat =
+	 (unsigned char *)malloc(alloced_fat_length * sector_size)) == NULL)
+	die("unable to allocate space for FAT image in memory");
+
+    memset(fat, 0, alloced_fat_length * sector_size);
+
+    mark_FAT_cluster(0, 0xffffffff);	/* Initial fat entries */
+    mark_FAT_cluster(1, 0xffffffff);
+    fat[0] = (unsigned char)bs.media;	/* Put media type in first byte! */
+    if (size_fat == 32) {
+	/* Mark cluster 2 as EOF (used for root dir) */
+	mark_FAT_cluster(2, FAT_EOF);
+    }
+
+    /* Make the root directory entries */
+
+    size_root_dir = (size_fat == 32) ?
+	bs.cluster_size * sector_size :
+	(((int)bs.dir_entries[1] * 256 + (int)bs.dir_entries[0]) *
+	 sizeof(struct msdos_dir_entry));
+    if ((root_dir = (struct msdos_dir_entry *)malloc(size_root_dir)) == NULL) {
+	free(fat);		/* Tidy up before we die! */
+	die("unable to allocate space for root directory in memory");
+    }
+
+    memset(root_dir, 0, size_root_dir);
+    if (memcmp(volume_name, "           ", 11)) {
+	struct msdos_dir_entry *de = &root_dir[0];
+	memcpy(de->name, volume_name, 8);
+	memcpy(de->ext, volume_name + 8, 3);
+	de->attr = ATTR_VOLUME;
+	ctime = localtime(&create_time);
+	de->time = CT_LE_W((unsigned short)((ctime->tm_sec >> 1) +
+					    (ctime->tm_min << 5) +
+					    (ctime->tm_hour << 11)));
+	de->date =
+	    CT_LE_W((unsigned short)(ctime->tm_mday +
+				     ((ctime->tm_mon + 1) << 5) +
+				     ((ctime->tm_year - 80) << 9)));
+	de->ctime_ms = 0;
+	de->ctime = de->time;
+	de->cdate = de->date;
+	de->adate = de->date;
+	de->starthi = CT_LE_W(0);
+	de->start = CT_LE_W(0);
+	de->size = CT_LE_L(0);
+    }
+
+    if (size_fat == 32) {
+	/* For FAT32, create an info sector */
+	struct fat32_fsinfo *info;
+
+	if (!(info_sector = malloc(sector_size)))
+	    die("Out of memory");
+	memset(info_sector, 0, sector_size);
+	/* fsinfo structure is at offset 0x1e0 in info sector by observation */
+	info = (struct fat32_fsinfo *)(info_sector + 0x1e0);
+
+	/* Info sector magic */
+	info_sector[0] = 'R';
+	info_sector[1] = 'R';
+	info_sector[2] = 'a';
+	info_sector[3] = 'A';
+
+	/* Magic for fsinfo structure */
+	info->signature = CT_LE_L(0x61417272);
+	/* We've allocated cluster 2 for the root dir. */
+	info->free_clusters = CT_LE_L(cluster_count - 1);
+	info->next_cluster = CT_LE_L(2);
+
+	/* Info sector also must have boot sign */
+	*(__u16 *) (info_sector + 0x1fe) = CT_LE_W(BOOT_SIGN);
+    }
+
+    if (!(blank_sector = malloc(sector_size)))
+	die("Out of memory");
+    memset(blank_sector, 0, sector_size);
+}
+
+/* Write the new filesystem's data tables to wherever they're going to end up! */
+
+#define error(str)				\
+  do {						\
+    free (fat);					\
+    if (info_sector) free (info_sector);	\
+    free (root_dir);				\
+    die (str);					\
+  } while(0)
+
+#define seekto(pos,errstr)						\
+  do {									\
+    loff_t __pos = (pos);						\
+    if (llseek (dev, __pos, SEEK_SET) != __pos)				\
+	error ("seek to " errstr " failed whilst writing tables");	\
+  } while(0)
+
+#define writebuf(buf,size,errstr)			\
+  do {							\
+    int __size = (size);				\
+    if (write (dev, buf, __size) != __size)		\
+	error ("failed whilst writing " errstr);	\
+  } while(0)
+
+static void write_tables(void)
+{
+    int x;
+    int fat_length;
+
+    fat_length = (size_fat == 32) ?
+	CF_LE_L(bs.fat32.fat32_length) : CF_LE_W(bs.fat_length);
+
+    seekto(0, "start of device");
+    /* clear all reserved sectors */
+    for (x = 0; x < reserved_sectors; ++x)
+	writebuf(blank_sector, sector_size, "reserved sector");
+    /* seek back to sector 0 and write the boot sector */
+    seekto(0, "boot sector");
+    writebuf((char *)&bs, sizeof(struct msdos_boot_sector), "boot sector");
+    /* on FAT32, write the info sector and backup boot sector */
+    if (size_fat == 32) {
+	seekto(CF_LE_W(bs.fat32.info_sector) * sector_size, "info sector");
+	writebuf(info_sector, 512, "info sector");
+	if (backup_boot != 0) {
+	    seekto(backup_boot * sector_size, "backup boot sector");
+	    writebuf((char *)&bs, sizeof(struct msdos_boot_sector),
+		     "backup boot sector");
+	}
+    }
+    /* seek to start of FATS and write them all */
+    seekto(reserved_sectors * sector_size, "first FAT");
+    for (x = 1; x <= nr_fats; x++) {
+	int y;
+	int blank_fat_length = fat_length - alloced_fat_length;
+	writebuf(fat, alloced_fat_length * sector_size, "FAT");
+	for (y = 0; y < blank_fat_length; y++)
+	    writebuf(blank_sector, sector_size, "FAT");
+    }
+    /* Write the root directory directly after the last FAT. This is the root
+     * dir area on FAT12/16, and the first cluster on FAT32. */
+    writebuf((char *)root_dir, size_root_dir, "root directory");
+
+    if (blank_sector)
+	free(blank_sector);
+    if (info_sector)
+	free(info_sector);
+    free(root_dir);		/* Free up the root directory space from setup_tables */
+    free(fat);			/* Free up the fat table space reserved during setup_tables */
+}
+
+/* Report the command usage and return a failure error code */
+
+void usage(void)
+{
+    fatal_error("\
+Usage: mkdosfs [-a][-A][-c][-C][-v][-I][-l bad-block-file][-b backup-boot-sector]\n\
+       [-m boot-msg-file][-n volume-name][-i volume-id]\n\
+       [-s sectors-per-cluster][-S logical-sector-size][-f number-of-FATs]\n\
+       [-h hidden-sectors][-F fat-size][-r root-dir-entries][-R reserved-sectors]\n\
+       /dev/name [blocks]\n");
+}
+
+/*
+ * ++roman: On m68k, check if this is an Atari; if yes, turn on Atari variant
+ * of MS-DOS filesystem by default.
+ */
+static void check_atari(void)
+{
+#ifdef __mc68000__
+    FILE *f;
+    char line[128], *p;
+
+    if (!(f = fopen("/proc/hardware", "r"))) {
+	perror("/proc/hardware");
+	return;
+    }
+
+    while (fgets(line, sizeof(line), f)) {
+	if (strncmp(line, "Model:", 6) == 0) {
+	    p = line + 6;
+	    p += strspn(p, " \t");
+	    if (strncmp(p, "Atari ", 6) == 0)
+		atari_format = 1;
+	    break;
+	}
+    }
+    fclose(f);
+#endif
+}
+
+/* The "main" entry point into the utility - we pick up the options and attempt to process them in some sort of sensible
+   way.  In the event that some/all of the options are invalid we need to tell the user so that something can be done! */
+
+int main(int argc, char **argv)
+{
+    int c;
+    char *tmp;
+    char *listfile = NULL;
+    FILE *msgfile;
+    struct stat statbuf;
+    int i = 0, pos, ch;
+    int create = 0;
+    unsigned long long cblocks = 0;
+    int min_sector_size;
+
+    if (argc && *argv) {	/* What's the program name? */
+	char *p;
+	program_name = *argv;
+	if ((p = strrchr(program_name, '/')))
+	    program_name = p + 1;
+    }
+
+    gettimeofday(&create_timeval, NULL);
+    create_time = create_timeval.tv_sec;
+    volume_id = (u_int32_t) ((create_timeval.tv_sec << 20) | create_timeval.tv_usec);	/* Default volume ID = creation time, fudged for more uniqueness */
+    check_atari();
+
+    printf("%s " VERSION " (" VERSION_DATE ")\n", program_name);
+
+    while ((c = getopt(argc, argv, "aAb:cCf:F:Ii:l:m:n:r:R:s:S:h:v")) != EOF)
+	/* Scan the command line for options */
+	switch (c) {
+	case 'A':		/* toggle Atari format */
+	    atari_format = !atari_format;
+	    break;
+
+	case 'a':		/* a : skip alignment */
+	    align_structures = FALSE;
+	    break;
+
+	case 'b':		/* b : location of backup boot sector */
+	    backup_boot = (int)strtol(optarg, &tmp, 0);
+	    if (*tmp || backup_boot < 2 || backup_boot > 0xffff) {
+		printf("Bad location for backup boot sector : %s\n", optarg);
+		usage();
+	    }
+	    break;
+
+	case 'c':		/* c : Check FS as we build it */
+	    check = TRUE;
+	    malloc_entire_fat = TRUE;	/* Need to be able to mark clusters bad */
+	    break;
+
+	case 'C':		/* C : Create a new file */
+	    create = TRUE;
+	    break;
+
+	case 'f':		/* f : Choose number of FATs */
+	    nr_fats = (int)strtol(optarg, &tmp, 0);
+	    if (*tmp || nr_fats < 1 || nr_fats > 4) {
+		printf("Bad number of FATs : %s\n", optarg);
+		usage();
+	    }
+	    break;
+
+	case 'F':		/* F : Choose FAT size */
+	    size_fat = (int)strtol(optarg, &tmp, 0);
+	    if (*tmp || (size_fat != 12 && size_fat != 16 && size_fat != 32)) {
+		printf("Bad FAT type : %s\n", optarg);
+		usage();
+	    }
+	    size_fat_by_user = 1;
+	    break;
+
+	case 'h':		/* h : number of hidden sectors */
+	    hidden_sectors = (int)strtol(optarg, &tmp, 0);
+	    if (*tmp || hidden_sectors < 0) {
+		printf("Bad number of hidden sectors : %s\n", optarg);
+		usage();
+	    }
+	    break;
+
+	case 'I':
+	    ignore_full_disk = 1;
+	    break;
+
+	case 'i':		/* i : specify volume ID */
+	    volume_id = strtoul(optarg, &tmp, 16);
+	    if (*tmp) {
+		printf("Volume ID must be a hexadecimal number\n");
+		usage();
+	    }
+	    break;
+
+	case 'l':		/* l : Bad block filename */
+	    listfile = optarg;
+	    malloc_entire_fat = TRUE;	/* Need to be able to mark clusters bad */
+	    break;
+
+	case 'm':		/* m : Set boot message */
+	    if (strcmp(optarg, "-")) {
+		msgfile = fopen(optarg, "r");
+		if (!msgfile)
+		    perror(optarg);
+	    } else
+		msgfile = stdin;
+
+	    if (msgfile) {
+		/* The boot code ends at offset 448 and needs a null terminator */
+		i = MESSAGE_OFFSET;
+		pos = 0;	/* We are at beginning of line */
+		do {
+		    ch = getc(msgfile);
+		    switch (ch) {
+		    case '\r':	/* Ignore CRs */
+		    case '\0':	/* and nulls */
+			break;
+
+		    case '\n':	/* LF -> CR+LF if necessary */
+			if (pos) {	/* If not at beginning of line */
+			    dummy_boot_code[i++] = '\r';
+			    pos = 0;
+			}
+			dummy_boot_code[i++] = '\n';
+			break;
+
+		    case '\t':	/* Expand tabs */
+			do {
+			    dummy_boot_code[i++] = ' ';
+			    pos++;
+			}
+			while (pos % 8 && i < BOOTCODE_SIZE - 1);
+			break;
+
+		    case EOF:
+			dummy_boot_code[i++] = '\0';	/* Null terminator */
+			break;
+
+		    default:
+			dummy_boot_code[i++] = ch;	/* Store character */
+			pos++;	/* Advance position */
+			break;
+		    }
+		}
+		while (ch != EOF && i < BOOTCODE_SIZE - 1);
+
+		/* Fill up with zeros */
+		while (i < BOOTCODE_SIZE - 1)
+		    dummy_boot_code[i++] = '\0';
+		dummy_boot_code[BOOTCODE_SIZE - 1] = '\0';	/* Just in case */
+
+		if (ch != EOF)
+		    printf("Warning: message too long; truncated\n");
+
+		if (msgfile != stdin)
+		    fclose(msgfile);
+	    }
+	    break;
+
+	case 'n':		/* n : Volume name */
+	    sprintf(volume_name, "%-11.11s", optarg);
+	    break;
+
+	case 'r':		/* r : Root directory entries */
+	    root_dir_entries = (int)strtol(optarg, &tmp, 0);
+	    if (*tmp || root_dir_entries < 16 || root_dir_entries > 32768) {
+		printf("Bad number of root directory entries : %s\n", optarg);
+		usage();
+	    }
+	    break;
+
+	case 'R':		/* R : number of reserved sectors */
+	    reserved_sectors = (int)strtol(optarg, &tmp, 0);
+	    if (*tmp || reserved_sectors < 1 || reserved_sectors > 0xffff) {
+		printf("Bad number of reserved sectors : %s\n", optarg);
+		usage();
+	    }
+	    break;
+
+	case 's':		/* s : Sectors per cluster */
+	    sectors_per_cluster = (int)strtol(optarg, &tmp, 0);
+	    if (*tmp || (sectors_per_cluster != 1 && sectors_per_cluster != 2
+			 && sectors_per_cluster != 4 && sectors_per_cluster != 8
+			 && sectors_per_cluster != 16
+			 && sectors_per_cluster != 32
+			 && sectors_per_cluster != 64
+			 && sectors_per_cluster != 128)) {
+		printf("Bad number of sectors per cluster : %s\n", optarg);
+		usage();
+	    }
+	    break;
+
+	case 'S':		/* S : Sector size */
+	    sector_size = (int)strtol(optarg, &tmp, 0);
+	    if (*tmp || (sector_size != 512 && sector_size != 1024 &&
+			 sector_size != 2048 && sector_size != 4096 &&
+			 sector_size != 8192 && sector_size != 16384 &&
+			 sector_size != 32768)) {
+		printf("Bad logical sector size : %s\n", optarg);
+		usage();
+	    }
+	    sector_size_set = 1;
+	    break;
+
+	case 'v':		/* v : Verbose execution */
+	    ++verbose;
+	    break;
+
+	default:
+	    printf("Unknown option: %c\n", c);
+	    usage();
+	}
+    if (optind < argc) {
+	device_name = argv[optind];	/* Determine the number of blocks in the FS */
+
+	if (!device_name) {
+	    printf("No device specified.\n");
+	    usage();
+	}
+
+	if (!create)
+	    cblocks = count_blocks(device_name, &orphaned_sectors);	/*  Have a look and see! */
+    }
+    if (optind == argc - 2) {	/*  Either check the user specified number */
+	blocks = strtoull(argv[optind + 1], &tmp, 0);
+	if (!create && blocks != cblocks) {
+	    fprintf(stderr, "Warning: block count mismatch: ");
+	    fprintf(stderr, "found %llu but assuming %llu.\n", cblocks, blocks);
+	}
+    } else if (optind == argc - 1) {	/*  Or use value found */
+	if (create)
+	    die("Need intended size with -C.");
+	blocks = cblocks;
+	tmp = "";
+    } else {
+	fprintf(stderr, "No device specified!\n");
+	usage();
+    }
+    if (*tmp) {
+	printf("Bad block count : %s\n", argv[optind + 1]);
+	usage();
+    }
+
+    if (check && listfile)	/* Auto and specified bad block handling are mutually */
+	die("-c and -l are incompatible");	/* exclusive of each other! */
+
+    if (!create) {
+	check_mount(device_name);	/* Is the device already mounted? */
+	dev = open(device_name, O_EXCL | O_RDWR);	/* Is it a suitable device to build the FS on? */
+	if (dev < 0) {
+	    fprintf(stderr, "%s: unable to open %s: %s\n", program_name,
+		    device_name, strerror(errno));
+	    exit(1);		/* The error exit code is 1! */
+	}
+    } else {
+	loff_t offset = blocks * BLOCK_SIZE - 1;
+	char null = 0;
+	/* create the file */
+	dev = open(device_name, O_EXCL | O_RDWR | O_CREAT | O_TRUNC, 0666);
+	if (dev < 0)
+	    die("unable to create %s");
+	/* seek to the intended end-1, and write one byte. this creates a
+	 * sparse-as-possible file of appropriate size. */
+	if (llseek(dev, offset, SEEK_SET) != offset)
+	    die("seek failed");
+	if (write(dev, &null, 1) < 0)
+	    die("write failed");
+	if (llseek(dev, 0, SEEK_SET) != 0)
+	    die("seek failed");
+    }
+
+    if (fstat(dev, &statbuf) < 0)
+	die("unable to stat %s");
+    if (!S_ISBLK(statbuf.st_mode)) {
+	statbuf.st_rdev = 0;
+	check = 0;
+    } else
+	/*
+	 * Ignore any 'full' fixed disk devices, if -I is not given.
+	 * On a MO-disk one doesn't need partitions.  The filesytem can go
+	 * directly to the whole disk.  Under other OSes this is known as
+	 * the 'superfloppy' format.  As I don't know how to find out if
+	 * this is a MO disk I introduce a -I (ignore) switch.  -Joey
+	 */
+	if (!ignore_full_disk && ((statbuf.st_rdev & 0xff3f) == 0x0300 ||	/* hda, hdb */
+				  (statbuf.st_rdev & 0xff0f) == 0x0800 ||	/* sd */
+				  (statbuf.st_rdev & 0xff3f) == 0x0d00 ||	/* xd */
+				  (statbuf.st_rdev & 0xff3f) == 0x1600)	/* hdc, hdd */
+	)
+	die("Device partition expected, not making filesystem on entire device '%s' (use -I to override)");
+
+    if (sector_size_set) {
+	if (ioctl(dev, BLKSSZGET, &min_sector_size) >= 0)
+	    if (sector_size < min_sector_size) {
+		sector_size = min_sector_size;
+		fprintf(stderr,
+			"Warning: sector size was set to %d (minimal for this device)\n",
+			sector_size);
+	    }
+    } else {
+	if (ioctl(dev, BLKSSZGET, &min_sector_size) >= 0) {
+	    sector_size = min_sector_size;
+	    sector_size_set = 1;
+	}
+    }
+
+    if (sector_size > 4096)
+	fprintf(stderr,
+		"Warning: sector size is set to %d > 4096, such filesystem will not propably mount\n",
+		sector_size);
+
+    establish_params(statbuf.st_rdev, statbuf.st_size);
+    /* Establish the media parameters */
+
+    setup_tables();		/* Establish the file system tables */
+
+    if (check)			/* Determine any bad block locations and mark them */
+	check_blocks();
+    else if (listfile)
+	get_list_blocks(listfile);
+
+    write_tables();		/* Write the file system tables away! */
+
+    exit(0);			/* Terminate with no errors! */
+}