sys/arch/i386/stand/lib/diskbuf.h

   1 /*      $NetBSD: diskbuf.h,v 1.4 2005/12/11 12:17:48 christos Exp $     */
   2
   3 /*
   4  * Copyright (c) 1996
   5  *      Matthias Drochner.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  26  *
  27  */
  28
  29 /* data buffer for BIOS disk / DOS I/O */
  30
  31 #ifndef DISKBUFSIZE
  32 /* Read ahead buffer large enough for one track on a 1440K floppy.
  33  */
  34 #define DISKBUFSIZE (18*512)
  35 #endif
  36
  37 extern char *diskbufp;          /* allocated from heap... */
  38 extern const void *diskbuf_user; /* using function sets it to unique
  39                             value to allow check if overwritten*/
  40 char *alloc_diskbuf(const void *);