minix/sys/arch/i386/stand/lib/test/biosdisk_user.c

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/* $NetBSD: biosdisk_user.c,v 1.7 2008/12/14 18:46:33 christos Exp $ */
/*
* Copyright (c) 1998
* Matthias Drochner. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#include "sanamespace.h"
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <err.h>
#include "biosdisk_ll.h"
#include "biosdisk_user.h"
/*
* Replacement for i386/stand/lib/bios_disk.S.
* Allows to map BIOS-like device numbers to character
* device nodes or plain files.
* The actual mapping is defined in the external table
* "emuldisktab".
*/
static int currentdev, currentdte;
static int fd = -1;
int
get_diskinfo(int dev)
{
int i, retval;
if (fd != -1) {
close(fd);
fd = -1;
}
i = 0;
for (;;) {
if (emuldisktab[i].biosdev == -1)
break;
if (emuldisktab[i].biosdev == dev)
goto ok;
i++;
}
warnx("unknown device %x", dev);
return 0; /* triggers error in set_geometry() */
ok:
fd = open(emuldisktab[i].name, O_RDONLY, 0);
if (fd < 0) {
warn("open %s", emuldisktab[i].name);
return 0;
}
currentdev = dev;
currentdte = i;
retval = ((emuldisktab[i].cyls - 1) & 0xff) << 16;
retval |= ((emuldisktab[i].cyls - 1) & 0x300) << 6;
retval |= emuldisktab[i].spt << 8;
retval |= emuldisktab[i].heads - 1;
return retval;
}
int
biosread(int dev, int cyl, int head, int sec, int nsec, char *buf)
{
if (dev != currentdev) {
warnx("biosread: unexpected device %x", dev);
return -1;
}
if (lseek(fd, ((cyl * emuldisktab[currentdte].heads + head)
* emuldisktab[currentdte].spt + sec) * 512,
SEEK_SET) == -1) {
warn("lseek");
return -1;
}
if (read(fd, buf, nsec * 512) != nsec * 512) {
warn("read");
return -1;
}
return 0;
}
int
int13_extension(int dev)
{
return 0;
}
void
int13_getextinfo(int dev, struct biosdisk_ext13info *info)
{
}
struct ext {
int8_t size;
int8_t resvd;
int16_t cnt;
int16_t off;
int16_t seg;
int64_t sec;
};
int
biosextread(int dev, struct ext *ext)
{
return -1;
}