FreeDOS/hdr/buffer.h
2001-07-24 16:56:29 +00:00

88 lines
3.9 KiB
C

/****************************************************************/
/* */
/* buffer.h */
/* */
/* Sector buffer structure */
/* */
/* Copyright (c) 2001 */
/* Bart Oldeman */
/* */
/* Largely taken from globals.h: */
/* Copyright (c) 1995, 1996 */
/* 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 *buffer_hRcsId = "$Id$";
#endif
#endif
/*
* $Log$
* Revision 1.3 2001/07/24 16:56:29 bartoldeman
* fixes for FCBs, DJGPP ls, DBLBYTE, dyninit allocation (2024e).
*
* Revision 1.2 2001/06/03 14:16:17 bartoldeman
* BUFFERS tuning and misc bug fixes/cleanups (2024c).
*
* Revision 1.1 2001/04/21 22:32:53 bartoldeman
* Init DS=Init CS, fixed stack overflow problems and misc bugs.
*
* Rev 1.0 20 Apr 2001 17:30:00 Bart Oldeman
* Initial revision.
*/
#define BUFFERSIZE 512
struct buffer
{
struct buffer
FAR *b_next; /* form linked list for LRU */
BYTE b_unit; /* disk for this buffer */
BYTE b_flag; /* buffer flags */
ULONG b_blkno; /* block for this buffer */
/* DOS-C: 0xffff for huge block numbers */
BYTE b_copies; /* number of copies to write */
UBYTE b_offset_lo; /* span between copies (low) */
#if 0 /*TE*/
union
{
struct dpb FAR *_b_dpbp; /* pointer to DPB */
LONG _b_huge_blkno; /* DOS-C: actual block number if >= 0xffff */
}
_b;
#endif
UBYTE b_offset_hi; /* DOS-C: span between copies (high) */
UBYTE b_unused;
BYTE b_buffer[BUFFERSIZE]; /* 512 byte sectors for now */
};
#define b_dpbp _b._b_dpbp
#define b_huge_blkno _b._b_huge_blkno
#define BFR_UNCACHE 0x80 /* indication, not really used */
#define BFR_DIRTY 0x40 /* buffer modified */
#define BFR_VALID 0x20 /* buffer contains valid data */
#define BFR_DATA 0x08 /* buffer is from data area */
#define BFR_DIR 0x04 /* buffer is from dir area */
#define BFR_FAT 0x02 /* buffer is from fat area */
#define BFR_BOOT 0x01 /* buffer is boot disk */