/****************************************************************/
/*                                                              */
/*                            dcb.h                             */
/*                                                              */
/*                DOS Device Control Block Structure            */
/*                                                              */
/*                       November 20, 1991                      */
/*                                                              */
/*                      Copyright (c) 1995                      */
/*                      Pasquale J. Villani                     */
/*                      All Rights Reserved                     */
/*                                                              */
/* This file is part of DOS-C.                                  */
/*                                                              */
/* DOS-C 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 */
/* 2, or (at your option) any later version.                    */
/*                                                              */
/* DOS-C 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 DOS-C; see the file COPYING.  If not,     */
/* write to the Free Software Foundation, 675 Mass Ave,         */
/* Cambridge, MA 02139, USA.                                    */
/****************************************************************/

#ifdef MAIN
#ifdef VERSION_STRINGS
static BYTE *clock_hRcsId = "$Id$";
#endif
#endif

/*
 * $Log$
 * Revision 1.5  2001/09/23 20:39:44  bartoldeman
 * FAT32 support, misc fixes, INT2F/AH=12 support, drive B: handling
 *
 * Revision 1.4  2001/04/15 03:21:50  bartoldeman
 * See history.txt for the list of fixes.
 *
 * Revision 1.3  2000/05/25 20:56:19  jimtabor
 * Fixed project history
 *
 * Revision 1.2  2000/05/08 04:28:22  jimtabor
 * Update CVS to 2020
 *
 * Revision 1.1.1.1  2000/05/06 19:34:53  jhall1
 * The FreeDOS Kernel.  A DOS kernel that aims to be 100% compatible with
 * MS-DOS.  Distributed under the GNU GPL.
 *
 * Revision 1.3  2000/03/09 06:06:38  kernel
 * 2017f updates by James Tabor
 *
 * Revision 1.2  1999/04/16 00:52:09  jprice
 * Optimized FAT handling
 *
 * Revision 1.1.1.1  1999/03/29 15:39:23  jprice
 * New version without IPL.SYS
 *
 * Revision 1.3  1999/02/01 01:40:06  jprice
 * Clean up
 *
 * Revision 1.2  1999/01/22 04:17:40  jprice
 * Formating
 *
 * Revision 1.1.1.1  1999/01/20 05:51:01  jprice
 * Imported sources
 *
 *
 *         Rev 1.5   04 Jan 1998 23:14:18   patv
 *      Changed Log for strip utility
 *
 *         Rev 1.4   29 May 1996 21:25:20   patv
 *      bug fixes for v0.91a
 *
 *         Rev 1.3   19 Feb 1996  3:15:30   patv
 *      Added NLS, int2f and config.sys processing
 *
 *         Rev 1.2   01 Sep 1995 17:35:40   patv
 *      First GPL release.
 *
 *         Rev 1.1   30 Jul 1995 20:43:48   patv
 *      Eliminated version strings in ipl
 *
 *         Rev 1.0   02 Jul 1995 10:39:30   patv
 *      Initial revision.
 */

/* Internal drive parameter block                               */
struct dpb
{
  BYTE dpb_unit;                /* unit for error reporting     */
  BYTE dpb_subunit;             /* the sub-unit for driver      */
  UWORD dpb_secsize;            /* sector size                  */
  UBYTE dpb_clsmask;            /* mask (sectors/cluster-1)     */
  UBYTE dpb_shftcnt;            /* log base 2 of cluster size   */
  UWORD dpb_fatstrt;            /* FAT start sector             */
  UBYTE dpb_fats;               /* # of FAT copies              */
  UWORD dpb_dirents;            /* # of dir entries             */
#ifdef WITHFAT32
  UWORD dpb_wdata;              /* start of data area           */
  UWORD dpb_wsize;              /* # of clusters+1 on media     */
  UWORD dpb_wfatsize;           /* # of sectors / FAT           */
#else
  UWORD dpb_data;               /* start of data area           */
  UWORD dpb_size;               /* # of clusters+1 on media     */
  UWORD dpb_fatsize;            /* # of sectors / FAT           */
#define dpb_wdata dpb_data
#define dpb_wsize dpb_size
#define dpb_wfatsize dpb_fatsize  
#endif
  UWORD dpb_dirstrt;            /* start sec. of root dir       */
  struct dhdr FAR *             /* pointer to device header     */
    dpb_device;
  UBYTE dpb_mdb;                /* media descr. byte            */
  BYTE dpb_flags;               /* -1 = force MEDIA CHK         */
  struct dpb FAR *              /* next dpb in chain            */
    dpb_next;                   /* -1 = end                     */
#ifdef WITHFAT32
  UWORD dpb_wcluster;           /* cluster # of first free      */
                                /* -1 if not known              */
  ULONG dpb_nfreeclst;          /* number of free clusters      */
                                /* -1 if not known              */
  UWORD dpb_xflags;             /* extended flags, see bpb      */
  UWORD dpb_xfsinfosec;         /* FS info sector number,       */
                                /* 0xFFFF if unknown            */
  UWORD dpb_xbackupsec;         /* backup boot sector number    */
                                /* 0xFFFF if unknown            */
  ULONG dpb_data;
  ULONG dpb_size;               /* # of clusters+1 on media     */
  ULONG dpb_fatsize;            /* # of sectors / FAT           */
  ULONG dpb_xrootclst;          /* starting cluster of root dir */
  ULONG dpb_cluster;            /* cluster # of first free      */
                                /* -1 if not known              */
#else
  UWORD dpb_cluster;            /* cluster # of first free      */
                                /* -1 if not known              */
#define dpb_wcluster dpb_cluster
  UWORD dpb_nfreeclst;          /* number of free clusters      */
                                /* -1 if not known              */
#endif
};

#define UNKNCLUSTER      0x0000      /* see RBIL INT 21/AH=52 entry */
#ifdef WITHFAT32
#define UNKNCLSTFREE     0xffffffffl  /* unknown for DOS */
#else
#define UNKNCLSTFREE     0xffff      /* unknown for DOS */
#endif
#define UNKNCLSTFREE16   0xffff      /* unknown for DOS */