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freebsd/sys/i386/boot/disk.c
Andrey A. Chernov 7b5cad487c From Bruce:
*	If there is no 386BSD partition, initialize the label sector with
 *	LABELSECTOR instead of with garbage.
 *	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.
1994-05-16 03:06:00 +00:00

282 lines
7.0 KiB
C

/*
* 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
* $Id: disk.c,v 1.4 1994/02/22 22:59:40 rgrimes Exp $
*/
/*
* 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"
#ifdef DO_BAD144
#include <sys/dkbad.h>
#endif DO_BAD144
#include <sys/disklabel.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)
char *devs[] = {"wd", "hd", "fd", "wt", "sd", 0};
#ifdef DO_BAD144
struct dkbad dkb;
int do_bad144;
int bsize;
#endif DO_BAD144
int spt, spc;
char *iodest;
struct fs *fs;
struct inode inode;
int dosdev, unit, part, maj, boff, poff, bnum, cnt;
/*#define EMBEDDED_DISKLABEL 1*/
extern struct disklabel disklabel;
/*struct disklabel disklabel;*/
devopen()
{
struct dos_partition *dptr;
struct disklabel *dl;
int dosdev = inode.i_dev;
int i, sector, di;
di = get_diskinfo(dosdev);
spc = (spt = SPT(di)) * 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 *)0)+DOSPARTOFF);
sector = LABELSECTOR;
for (i = 0; i < NDOSPART; i++, dptr++)
if (dptr->dp_typ == DOSPTYP_386BSD) {
sector = dptr->dp_start + LABELSECTOR;
break;
}
Bread(dosdev, sector++);
dl=((struct disklabel *)0);
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;
#ifdef DO_BAD144
bsize = dl->d_partitions[part].p_size;
do_bad144 = 0;
if (dl->d_flags & D_BADSECT) {
/* this disk uses bad144 */
int i;
int dkbbnum;
struct dkbad *dkbptr;
/* find the first readable bad sector table */
/* some of this code is copied from ufs/ufs_disksubr.c */
/* including the bugs :-( */
/* read a bad sector table */
#define BAD144_PART 2 /* XXX scattered magic numbers */
#define BSD_PART 0 /* XXX should be 2 but bad144.c uses 0 */
if (dl->d_partitions[BSD_PART].p_offset != 0)
dkbbnum = dl->d_partitions[BAD144_PART].p_offset
+ dl->d_partitions[BAD144_PART].p_size;
else
dkbbnum = dl->d_secperunit;
dkbbnum -= dl->d_nsectors;
if (dl->d_secsize > DEV_BSIZE)
dkbbnum *= dl->d_secsize / DEV_BSIZE;
else
dkbbnum /= DEV_BSIZE / dl->d_secsize;
i = 0;
do_bad144 = 0;
do {
/* XXX: what if the "DOS sector" < 512 bytes ??? */
Bread(dosdev, dkbbnum + i);
dkbptr = (struct dkbad *) 0;
/* XXX why is this not in <sys/dkbad.h> ??? */
#define DKBAD_MAGIC 0x4321
if (dkbptr->bt_mbz == 0 &&
dkbptr->bt_flag == DKBAD_MAGIC) {
dkb = *dkbptr; /* structure copy */
do_bad144 = 1;
break;
}
i += 2;
} while (i < 10 && i < dl->d_nsectors);
if (!do_bad144)
printf("Bad bad sector table\n");
else
printf("Using bad sector table at %d\n", dkbbnum+i);
}
#endif DO_BAD144
}
return 0;
}
devread()
{
int offset, sector = bnum;
int dosdev = inode.i_dev;
for (offset = 0; offset < cnt; offset += BPS)
{
Bread(dosdev, badsect(dosdev, sector++));
bcopy(0, iodest+offset, BPS);
}
}
#define I_ADDR ((void *) 0) /* XXX where all reads go */
/* 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;
Bread(dosdev,sector)
int dosdev,sector;
{
if (dosdev != ra_dev || sector < ra_first || sector >= ra_end)
{
int cyl, head, sec, nsec;
cyl = sector/spc;
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: C:%d H:%d S:%d\n", cyl, head, sec);
twiddle();
}
}
ra_dev = dosdev;
ra_first = sector;
ra_end = sector + nsec;
}
bcopy(ra_buf + (sector - ra_first) * BPS, I_ADDR, BPS);
}
badsect(dosdev, sector)
int dosdev, sector;
{
int i;
#ifdef DO_BAD144
if (do_bad144) {
u_short cyl;
u_short head;
u_short sec;
int newsec;
struct disklabel *dl = &disklabel;
/* XXX */
/* from wd.c */
/* bt_cyl = cylinder number in sorted order */
/* bt_trksec is actually (head << 8) + sec */
/* only remap sectors in the partition */
if (sector < boff || sector >= boff + bsize) {
goto no_remap;
}
cyl = sector / dl->d_secpercyl;
head = (sector % dl->d_secpercyl) / dl->d_nsectors;
sec = sector % dl->d_nsectors;
sec = (head<<8) + sec;
/* now, look in the table for a possible bad sector */
for (i=0; i<126; i++) {
if (dkb.bt_bad[i].bt_cyl == cyl) {
/* found same cylinder */
if (dkb.bt_bad[i].bt_trksec == sec) {
/* FOUND! */
break;
}
} else if (dkb.bt_bad[i].bt_cyl > cyl) {
i = 126;
break;
}
}
if (i == 126) {
/* didn't find bad sector */
goto no_remap;
}
/* otherwise find replacement sector */
if (dl->d_partitions[BSD_PART].p_offset != 0)
newsec = dl->d_partitions[BAD144_PART].p_offset
+ dl->d_partitions[BAD144_PART].p_size;
else
newsec = dl->d_secperunit;
newsec -= dl->d_nsectors + i + 1;
return newsec;
}
#endif DO_BAD144
no_remap:
return sector;
}