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/*
* Mach Operating System
* Copyright (c) 1992, 1991 Carnegie Mellon University
* All Rights Reserved.
*
* Permission to use, copy, modify and distribute this software and its
* documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie Mellon
* the rights to redistribute these changes.
*
* from: Mach, Revision 2.2 92/04/04 11:35:49 rpd
* $FreeBSD$
*/
#include <stdio.h>
#include <memory.h>
#define bcopy(a,b,c) memcpy(b,a,c)
#include "boot.h"
#include "disklabe.h"
#include "diskslic.h"
#define BIOS_DEV_FLOPPY 0x0
#define BIOS_DEV_WIN 0x80
#define BPS 512
#define SPT(di) ((di)&0xff)
#define HEADS(di) ((((di)>>8)&0xff)+1)
static char i_buf[BPS];
#define I_ADDR ((void *) i_buf) /* XXX where all reads go */
static int spt, spc;
char *iodest;
struct fs *fs;
struct inode inode;
long dosdev, slice, unit, part, maj, boff, poff, bnum, cnt;
extern int biosread(int dev, int track, int head, int sector, int cnt, unsigned char far *buffer);
struct disklabel disklabel;
static void Bread(int dosdev, long sector);
unsigned long get_diskinfo(int drive)
{
char dr = (char) drive;
unsigned long rt;
_asm {
mov ah,8 ; get diskinfo
mov dl,dr ; drive
int 13h
cmp ah,0
je ok
;
; Failure! We assume it's a floppy!
;
sub ax,ax
mov bh,ah
mov bl,2
mov ch,79
mov cl,15
mov dh,1
mov dl,1
ok:
mov ah,dh
mov al,cl
and al,3fh
mov word ptr rt,ax
xor bx,bx
mov bl,cl
and bl,0c0h
shl bx,2
mov bl,ch
mov word ptr rt+2,bx
}
return rt;
}
int devopen(void)
{
struct dos_partition *dptr;
struct disklabel *dl;
int dosdev = (int) inode.i_dev;
int i;
long di, sector;
di = get_diskinfo(dosdev);
spc = (spt = (int)SPT(di)) * (int)HEADS(di);
if (dosdev == 2)
{
boff = 0;
part = (spt == 15 ? 3 : 1);
}
else
{
#ifdef EMBEDDED_DISKLABEL
dl = &disklabel;
#else EMBEDDED_DISKLABEL
Bread(dosdev, 0);
dptr = (struct dos_partition *)(((char *)I_ADDR)+DOSPARTOFF);
sector = LABELSECTOR;
slice = WHOLE_DISK_SLICE;
for (i = 0; i < NDOSPART; i++, dptr++)
if (dptr->dp_typ == DOSPTYP_386BSD) {
slice = BASE_SLICE + i;
sector = dptr->dp_start + LABELSECTOR;
break;
}
Bread(dosdev, sector++);
dl=((struct disklabel *)I_ADDR);
disklabel = *dl; /* structure copy (maybe useful later)*/
#endif EMBEDDED_DISKLABEL
if (dl->d_magic != DISKMAGIC) {
printf("bad disklabel");
return 1;
}
if( (maj == 4) || (maj == 0) || (maj == 1)) {
if (dl->d_type == DTYPE_SCSI)
maj = 4; /* use scsi as boot dev */
else
maj = 0; /* must be ESDI/IDE */
}
boff = dl->d_partitions[part].p_offset;
}
return 0;
}
void devread(void)
{
long offset, sector = bnum;
int dosdev = (int) inode.i_dev;
for (offset = 0; offset < cnt; offset += BPS)
{
Bread(dosdev, sector++);
bcopy(I_ADDR, iodest+offset, BPS);
}
}
/* Read ahead buffer large enough for one track on a 1440K floppy. For
* reading from floppies, the bootstrap has to be loaded on a 64K boundary
* to ensure that this buffer doesn't cross a 64K DMA boundary.
*/
#define RA_SECTORS 18
static char ra_buf[RA_SECTORS * BPS];
static int ra_dev;
static long ra_end;
static long ra_first;
static void Bread(int dosdev, long sector)
{
if (dosdev != ra_dev || sector < ra_first || sector >= ra_end)
{
int cyl, head, sec, nsec;
cyl = (int) (sector/(long)spc);
head = (int) ((sector % (long) spc) / (long) spt);
sec = (int) (sector % (long) spt);
nsec = spt - sec;
if (nsec > RA_SECTORS)
nsec = RA_SECTORS;
if (biosread(dosdev, cyl, head, sec, nsec, ra_buf) != 0)
{
nsec = 1;
while (biosread(dosdev, cyl, head, sec, nsec, ra_buf) != 0)
printf("Error: C:%d H:%d S:%d\n", cyl, head, sec);
}
ra_dev = dosdev;
ra_first = sector;
ra_end = sector + nsec;
}
bcopy(ra_buf + (sector - ra_first) * BPS, I_ADDR, BPS);
}
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