com32/gpllib/disk/util.c

   1 /* ----------------------------------------------------------------------- *
   2  *
   3  *   Copyright 2009 Pierre-Alexandre Meyer
   4  *
   5  *   Some parts borrowed from chain.c32:
   6  *
   7  *   Copyright 2003-2009 H. Peter Anvin - All Rights Reserved
   8  *   Copyright 2009 Intel Corporation; author: H. Peter Anvin
   9  *
  10  *   This file is part of Syslinux, and is made available under
  11  *   the terms of the GNU General Public License version 2.
  12  *
  13  * ----------------------------------------------------------------------- */
  14
  15 #include <com32.h>
  16 #include <stdlib.h>
  17 #include <string.h>
  18 #include <disk/geom.h>
  19
  20 #define MAX_NB_RETRIES 6
  21
  22 /**
  23  * int13_retry - int13h with error handling
  24  * @inreg:      int13h function parameters
  25  * @outreg:     output registers
  26  *
  27  * Call int 13h, but with retry on failure.  Especially floppies need this.
  28  **/
  29 int int13_retry(const com32sys_t * inreg, com32sys_t * outreg)
  30 {
  31     int retry = MAX_NB_RETRIES; /* Number of retries */
  32     com32sys_t tmpregs;
  33
  34     if (!outreg)
  35         outreg = &tmpregs;
  36
  37     while (retry--) {
  38         __intcall(0x13, inreg, outreg);
  39         if (!(outreg->eflags.l & EFLAGS_CF))
  40             return 0;           /* CF=0 => OK */
  41     }
  42
  43     /* If we get here: error */
  44     return -1;
  45 }