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/* $NetBSD: disk.c,v 1.13 1995/03/12 12:09:18 mycroft Exp $ */
/*
* Ported to boot 386BSD by Julian Elischer (julian@tfs.com) Sept 1992
*
* 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.
*/
#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)
#ifdef DOSREAD
char *devs[] = {"wd", "hd", "fd", "wt", "sd", "dos", 0};
#else
char *devs[] = {"wd", "hd", "fd", "wt", "sd", 0};
#endif
#ifdef DO_BAD144
struct dkbad dkb;
int do_bad144;
int bsize;
#endif DO_BAD144
char *iodest;
struct fs *fs;
struct inode inode;
int spt, spc;
int dosdev, unit, part, maj, boff, poff, bnum, cnt;
extern struct disklabel disklabel;
extern char iobuf[];
devopen()
{
struct dos_partition *dptr;
struct disklabel *lp;
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 {
Bread(0, iobuf);
dptr = (struct dos_partition *)&iobuf[DOSPARTOFF];
sector = LABELSECTOR;
for (i = 0; i < NDOSPART; i++, dptr++)
if (dptr->dp_typ == DOSPTYP_386BSD) {
sector = dptr->dp_start + LABELSECTOR;
break;
}
lp = &disklabel;
Bread(sector++, lp);
if (lp->d_magic != DISKMAGIC) {
printf("bad disklabel");
return 1;
}
if (maj == 4 || maj == 0 || maj == 1) {
if (lp->d_type == DTYPE_SCSI)
maj = 4; /* use scsi as boot dev */
else
maj = 0; /* must be ESDI/IDE */
}
boff = lp->d_partitions[part].p_offset;
#ifdef DO_BAD144
bsize = lp->d_partitions[part].p_size;
do_bad144 = 0;
if (lp->d_flags & D_BADSECT) {
/* this disk uses bad144 */
int i;
int dkbbnum;
struct dkbad *dkbptr;
/* find the first readable bad144 sector */
dkbbnum = lp->d_secperunit - lp->d_nsectors;
if (lp->d_secsize > DEV_BSIZE)
dkbbnum *= lp->d_secsize / DEV_BSIZE;
do_bad144 = 0;
for (i = 5; i; i--) {
/* XXX: what if the "DOS sector" < 512 bytes ??? */
Bread(dkbbnum, iobuf);
dkbptr = (struct dkbad *)&iobuf[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;
}
dkbbnum += 2;
}
if (!do_bad144)
printf("Bad badsect table\n");
else
printf("Using bad144 bad sector at %d\n",
dkbbnum);
}
#endif DO_BAD144
}
return 0;
}
devread()
{
int offset, sector = bnum;
for (offset = 0; offset < cnt; offset += BPS)
Bread(badsect(sector++), iodest + offset);
}
#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;
static int ra_sectors;
static int ra_skip;
Bread(sector, addr)
int sector;
void *addr;
{
extern int ourseg;
int dmalimit = ((((ourseg<<4)+(int)ra_buf)+65536) & ~65535)
- ((ourseg<<4)+ (int)ra_buf);
if (dmalimit<RA_SECTORS*BPS) {
if (dmalimit*2<RA_SECTORS*BPS) {
ra_sectors = (RA_SECTORS*BPS-dmalimit)/BPS;
ra_skip = RA_SECTORS - ra_sectors;
} else {
ra_sectors = dmalimit/BPS;
ra_skip = 0;
}
} else {
ra_sectors = RA_SECTORS;
ra_skip=0;
}
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();
while (biosread(dosdev, cyl, head, sec, nsec, ra_buf+ra_skip*BPS)) {
printf("Error: C:%d H:%d S:%d\n", cyl, head, sec);
nsec = 1;
twiddle();
}
ra_dev = dosdev;
ra_first = sector;
ra_end = sector + nsec;
}
bcopy(ra_buf + (sector - ra_first+ra_skip) * BPS, addr, BPS);
}
badsect(sector)
int sector;
{
int i;
#ifdef DO_BAD144
if (do_bad144) {
u_short cyl, head, 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;
/* now, look in the table for a possible bad sector */
for (i = 0; i < 126; i++) {
if (dkb.bt_bad[i].bt_cyl == cyl &&
dkb.bt_bad[i].bt_trksec == sec) {
/* found same sector */
goto remap;
} else if (dkb.bt_bad[i].bt_cyl > cyl) {
goto no_remap;
}
}
goto no_remap;
remap:
/* otherwise find replacement sector */
newsec = dl->d_secperunit - dl->d_nsectors - i -1;
return newsec;
}
#endif DO_BAD144
no_remap:
return sector;
}
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