source: bootcd/isolinux/syslinux-6.03/com32/gpllib/disk/util.c

/* ----------------------------------------------------------------------- *
 *
 *   Copyright 2009 Pierre-Alexandre Meyer
 *
 *   Some parts borrowed from chain.c32:
 *
 *   Copyright 2003-2009 H. Peter Anvin - All Rights Reserved
 *   Copyright 2009 Intel Corporation; author: H. Peter Anvin
 *
 *   This file is part of Syslinux, and is made available under
 *   the terms of the GNU General Public License version 2.
 *
 * ----------------------------------------------------------------------- */

#include <com32.h>
#include <stdlib.h>
#include <string.h>
#include <disk/geom.h>

#define MAX_NB_RETRIES 6

/**
 * int13_retry - int13h with error handling
 * @inreg:      int13h function parameters
 * @outreg:     output registers
 *
 * Call int 13h, but with retry on failure.  Especially floppies need this.
 **/
int int13_retry(const com32sys_t * inreg, com32sys_t * outreg)
{
    int retry = MAX_NB_RETRIES; /* Number of retries */
    com32sys_t tmpregs;

    if (!outreg)
        outreg = &tmpregs;

    while (retry--) {
        __intcall(0x13, inreg, outreg);
        if (!(outreg->eflags.l & EFLAGS_CF))
            return 0;           /* CF=0 => OK */
    }

    /* If we get here: error */
    return -1;
}