source: MondoRescue/branches/3.2/mindi-busybox/util-linux/fdformat.c

/* vi: set sw=4 ts=4: */
/* fdformat.c  -  Low-level formats a floppy disk - Werner Almesberger
 * 5 July 2003 -- modified for Busybox by Erik Andersen
 *
 * Licensed under GPLv2, see file LICENSE in this source tree.
 */

//usage:#define fdformat_trivial_usage
//usage:       "[-n] DEVICE"
//usage:#define fdformat_full_usage "\n\n"
//usage:       "Format floppy disk\n"
//usage:     "\n    -n  Don't verify after format"

#include "libbb.h"


/* Stuff extracted from linux/fd.h */
struct floppy_struct {
    unsigned int    size,       /* nr of sectors total */
            sect,       /* sectors per track */
            head,       /* nr of heads */
            track,      /* nr of tracks */
            stretch;    /* !=0 means double track steps */
#define FD_STRETCH 1
#define FD_SWAPSIDES 2

    unsigned char   gap,        /* gap1 size */

            rate,       /* data rate. |= 0x40 for perpendicular */
#define FD_2M 0x4
#define FD_SIZECODEMASK 0x38
#define FD_SIZECODE(floppy) (((((floppy)->rate&FD_SIZECODEMASK)>> 3)+ 2) %8)
#define FD_SECTSIZE(floppy) ( (floppy)->rate & FD_2M ? \
                 512 : 128 << FD_SIZECODE(floppy) )
#define FD_PERP 0x40

            spec1,      /* stepping rate, head unload time */
            fmt_gap;    /* gap2 size */
    const char  * name; /* used only for predefined formats */
};
struct format_descr {
    unsigned int device,head,track;
};
#define FDFMTBEG _IO(2,0x47)
#define FDFMTTRK _IOW(2,0x48, struct format_descr)
#define FDFMTEND _IO(2,0x49)
#define FDGETPRM _IOR(2, 0x04, struct floppy_struct)
#define FD_FILL_BYTE 0xF6 /* format fill byte. */

int fdformat_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int fdformat_main(int argc UNUSED_PARAM, char **argv)
{
    int fd, n, cyl, read_bytes, verify;
    unsigned char *data;
    struct stat st;
    struct floppy_struct param;
    struct format_descr descr;

    opt_complementary = "=1"; /* must have 1 param */
    verify = !getopt32(argv, "n");
    argv += optind;

    xstat(*argv, &st);
    if (!S_ISBLK(st.st_mode)) {
        bb_error_msg_and_die("%s: not a block device", *argv);
        /* do not test major - perhaps this was an USB floppy */
    }

    /* O_RDWR for formatting and verifying */
    fd = xopen(*argv, O_RDWR);

    /* original message was: "Could not determine current format type" */
    xioctl(fd, FDGETPRM, &param);

    printf("%s-sided, %d tracks, %d sec/track. Total capacity %d kB\n",
        (param.head == 2) ? "Double" : "Single",
        param.track, param.sect, param.size >> 1);

    /* FORMAT */
    printf("Formatting... ");
    xioctl(fd, FDFMTBEG, NULL);

    /* n == track */
    for (n = 0; n < param.track; n++) {
        descr.head = 0;
        descr.track = n;
        xioctl(fd, FDFMTTRK, &descr);
        printf("%3d\b\b\b", n);
        if (param.head == 2) {
            descr.head = 1;
            xioctl(fd, FDFMTTRK, &descr);
        }
    }

    xioctl(fd, FDFMTEND, NULL);
    printf("done\n");

    /* VERIFY */
    if (verify) {
        /* n == cyl_size */
        n = param.sect*param.head*512;

        data = xmalloc(n);
        printf("Verifying... ");
        for (cyl = 0; cyl < param.track; cyl++) {
            printf("%3d\b\b\b", cyl);
            read_bytes = safe_read(fd, data, n);
            if (read_bytes != n) {
                if (read_bytes < 0) {
                    bb_perror_msg(bb_msg_read_error);
                }
                bb_error_msg_and_die("problem reading cylinder %d, "
                    "expected %d, read %d", cyl, n, read_bytes);
                // FIXME: maybe better seek & continue??
            }
            /* Check backwards so we don't need a counter */
            while (--read_bytes >= 0) {
                if (data[read_bytes] != FD_FILL_BYTE) {
                    printf("bad data in cyl %d\nContinuing... ", cyl);
                }
            }
        }
        /* There is no point in freeing blocks at the end of a program, because
        all of the program's space is given back to the system when the process
        terminates.*/

        if (ENABLE_FEATURE_CLEAN_UP) free(data);

        printf("done\n");
    }

    if (ENABLE_FEATURE_CLEAN_UP) close(fd);

    /* Don't bother closing.  Exit does
     * that, so we can save a few bytes */
    return EXIT_SUCCESS;
}