freebsd-dev/sys/i386/boot/biosboot/disk.c
Charlie Root f7710986e2 New boot blocks, from Bruce Evans, and NetBSD fixes. Allows kernel to
be loaded above 1MB.  Same boot code for floppies now.  Speed improvements.
etc etc etc. (I don't have much history on this, but then have been tested)
1993-07-13 18:15:32 +00:00

281 lines
7.0 KiB
C

/*
* 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.
*/
/*
* HISTORY
* $Log: disk.c,v $
* Revision 1.3 1993/07/11 12:02:23 andrew
* Fixes from bde, including support for loading @ any MB boundary (e.g. a
* kernel linked for 0xfe100000 will load at the 1MB mark) and read-ahead
* buffering to speed booting from floppies. Also works with aha174x
* controllers in enhanced mode.
*
* Revision 1.2 1993/06/18 02:28:58 cgd
* make it *do* something when loading the kernel, a la sun twiddling-thing
*
* Revision 1.1 1993/03/21 18:08:36 cgd
* after 0.2.2 "stable" patches applied
*
* Revision 2.2 92/04/04 11:35:49 rpd
* Fabricated from 3.0 bootstrap and 2.5 boot disk.c:
* with support for scsi
* [92/03/30 mg32]
*
*/
/*
* 9/20/92
* Peng-Toh Sim. sim@cory.berkeley.edu
* Added bad144 support under 386bsd for wd's
* So, bad block remapping is done when loading the kernel.
*/
#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);
for (i = 0; i < NDOSPART; i++, dptr++)
if (dptr->dp_typ == DOSPTYP_386BSD)
break;
sector = dptr->dp_start + LABELSECTOR;
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 bad144 sector */
/* some of this code is copied from ufs/disk_subr.c */
/* read a bad sector table */
dkbbnum = dl->d_secperunit - 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 badsect table\n");
else
printf("Using bad144 bad sector 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_end;
static int ra_first;
Bread(dosdev,sector)
int dosdev,sector;
{
if (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_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 */
newsec = dl->d_secperunit - dl->d_nsectors - i -1;
return newsec;
}
#endif DO_BAD144
no_remap:
return sector;
}