source: bootcd/isolinux/syslinux-6.03/diag/geodsp/mk-lba-img.c

/* ----------------------------------------------------------------------- *
 *
 *   Copyright 2010 Gene Cumm
 *
 *   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, Inc., 53 Temple Place Ste 330,
 *   Boston MA 02111-1307, USA; either version 2 of the License, or
 *   (at your option) any later version; incorporated herein by reference.
 *
 * ----------------------------------------------------------------------- */

/*
 * mk-lba-img.c
 *
 * Makes an image that contains the LBA in every *word of every sector
 */

#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <unistd.h>

#define NUM_SECT (256*63+1)
#define BPS (512)
#define SECT_INT (BPS / sizeof(unsigned int))

typedef unsigned char uint8_t;
typedef unsigned int uint32_t;

const char DEF_FN[] = "-";

int main(int argc, char *argv[])
{
        int i, rv = 0, one = 0;
        unsigned int lba, b[SECT_INT];
        int len;
        FILE *f;
        uint8_t tt = 0;
        const char *fn;

        if (argc >= 2) {
                if (argc >= 3) {
                        if (strcasecmp("-1", argv[1]) == 0) {
                                fn = argv[2];
                                one = 1;
                        } else {
                                fn = argv[1];
                        }
                } else {
                        fn = argv[1];
                }
        } else {
                fn = DEF_FN;
        }

        if (!strcmp(fn, "-"))
                f = stdout;
        else
                f = fopen(fn, "w");

        if (!f) {
                fprintf(stderr, "%s: %s: unable to open for writing: %s\n",
                        argv[0], fn, strerror(errno));
                return 1;
        }

        lba = 0;
        while ((len = fread(b, 1, BPS, stdin))) {
                if (len < BPS)
                        memset((char *)b + len, 0, BPS - len);
                fwrite(b, 1, BPS, f);
                lba++;
        }

        memset(b, 0, sizeof b);

        while (lba < NUM_SECT) {
                if (one) {
                        b[0] = lba;
                } else {
                        for (i = 0; i < SECT_INT; i++)
                                b[i] = lba;
                }
                fwrite(b, 1, BPS, f);
                lba++;
        }

        if (f != stdout)
                fclose(f);

        return rv;
}