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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
* $FreeBSD$
*/
/*
* 93/10/08 bde
* If there is no 386BSD partition, initialize the label sector with
* LABELSECTOR instead of with garbage.
*
* 93/08/22 bde
* Fixed reading of bad sector table. It is at the end of the 'c'
* partition, which is not always at the end of the disk.
*/
#include "boot.h"
#include <sys/disklabel.h>
#include <sys/diskslice.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 int bsize;
static int spt, spc;
struct fs *fs;
struct inode inode;
int dosdev, unit, slice, part, maj, boff;
/*#define EMBEDDED_DISKLABEL 1*/
/* 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 int ra_end;
static int ra_first;
static char *Bread(int dosdev, int sector);
int
devopen(void)
{
struct dos_partition *dptr;
struct disklabel *dl;
char *p;
int i, sector = 0, di, dosdev_copy;
dosdev_copy = dosdev;
di = get_diskinfo(dosdev_copy);
spt = SPT(di);
/* Hack for 2.88MB floppy drives. */
if (!(dosdev_copy & 0x80) && spt == 36)
spt = 18;
spc = spt * HEADS(di);
#ifndef RAWBOOT
{
#ifdef EMBEDDED_DISKLABEL
dl = &disklabel;
#else EMBEDDED_DISKLABEL
p = Bread(dosdev_copy, 0);
dptr = (struct dos_partition *)(p+DOSPARTOFF);
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;
break;
}
p = Bread(dosdev_copy, sector + LABELSECTOR);
dl=((struct disklabel *)p);
disklabel = *dl; /* structure copy (maybe useful later)*/
#endif EMBEDDED_DISKLABEL
if (dl->d_magic != DISKMAGIC) {
printf("bad disklabel\n");
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 */
}
}
/* This little trick is for OnTrack DiskManager disks */
boff = dl->d_partitions[part].p_offset -
dl->d_partitions[2].p_offset + sector;
bsize = dl->d_partitions[part].p_size;
if (bsize == 0) {
printf("empty partition\n");
return 1;
}
}
#endif /* RAWBOOT */
return 0;
}
/*
* Be aware that cnt is rounded up to N*BPS
*/
void
devread(char *iodest, int sector, int cnt)
{
int offset;
char *p;
int dosdev_copy;
for (offset = 0; offset < cnt; offset += BPS)
{
dosdev_copy = dosdev;
p = Bread(dosdev_copy, sector++);
bcopy(p, iodest+offset, BPS);
}
}
static char *
Bread(int dosdev, int sector)
{
if (dosdev != ra_dev || sector < ra_first || sector >= ra_end)
{
int cyl, head, sec, nsec;
cyl = sector/spc;
if (cyl > 1023) {
printf("Error: C:%d > 1023 (BIOS limit)\n", cyl);
for(;;); /* loop forever */
}
head = (sector % spc) / spt;
sec = sector % spt;
nsec = spt - sec;
if (nsec > RA_SECTORS)
nsec = RA_SECTORS;
twiddle();
if (biosread(dosdev, cyl, head, sec, nsec, ra_buf) != 0)
{
nsec = 1;
twiddle();
while (biosread(dosdev, cyl, head, sec, nsec, ra_buf) != 0) {
printf("Error: D:0x%x C:%d H:%d S:%d\n",
dosdev, cyl, head, sec);
twiddle();
}
}
ra_dev = dosdev;
ra_first = sector;
ra_end = sector + nsec;
}
return (ra_buf + (sector - ra_first) * BPS);
}
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