[unix-history] / sys / i386 / boot / disk.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;
}
Commit	Line	Data
15637ed4	1	/*
15637ed4 RG	2	* Mach Operating System
	3	* Copyright (c) 1992, 1991 Carnegie Mellon University
	4	* All Rights Reserved.
	5	*
	6	* Permission to use, copy, modify and distribute this software and its
	7	* documentation is hereby granted, provided that both the copyright
	8	* notice and this permission notice appear in all copies of the
	9	* software, derivative works or modified versions, and any portions
	10	* thereof, and that both notices appear in supporting documentation.
	11	*
	12	* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
	13	* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
	14	* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
	15	*
	16	* Carnegie Mellon requests users of this software to return to
	17	*
	18	* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
	19	* School of Computer Science
	20	* Carnegie Mellon University
	21	* Pittsburgh PA 15213-3890
	22	*
	23	* any improvements or extensions that they make and grant Carnegie Mellon
	24	* the rights to redistribute these changes.
a27f4645	25	*
e4270b63	26	* from: Mach, Revision 2.2 92/04/04 11:35:49 rpd
091a0361 AC	27	* $Id: disk.c,v 1.4 1994/02/22 22:59:40 rgrimes Exp $
	28	*/
	29
	30	/*
	31	* 93/10/08 bde
	32	* If there is no 386BSD partition, initialize the label sector with
	33	* LABELSECTOR instead of with garbage.
	34	*
	35	* 93/08/22 bde
	36	* Fixed reading of bad sector table. It is at the end of the 'c'
	37	* partition, which is not always at the end of the disk.
15637ed4 RG	38	*/
	39
	40	#include "boot.h"
	41	#ifdef DO_BAD144
	42	#include <sys/dkbad.h>
	43	#endif DO_BAD144
	44	#include <sys/disklabel.h>
	45
	46	#define BIOS_DEV_FLOPPY 0x0
	47	#define BIOS_DEV_WIN 0x80
	48
	49	#define BPS 512
	50	#define SPT(di) ((di)&0xff)
	51	#define HEADS(di) ((((di)>>8)&0xff)+1)
	52
	53	char *devs[] = {"wd", "hd", "fd", "wt", "sd", 0};
	54
	55	#ifdef DO_BAD144
	56	struct dkbad dkb;
	57	int do_bad144;
	58	int bsize;
	59	#endif DO_BAD144
	60
	61	int spt, spc;
	62
	63	char *iodest;
	64	struct fs *fs;
	65	struct inode inode;
	66	int dosdev, unit, part, maj, boff, poff, bnum, cnt;
	67
	68	/#define EMBEDDED_DISKLABEL 1/
	69	extern struct disklabel disklabel;
	70	/struct disklabel disklabel;/
	71
	72	devopen()
	73	{
	74	struct dos_partition *dptr;
	75	struct disklabel *dl;
	76	int dosdev = inode.i_dev;
	77	int i, sector, di;
	78
	79	di = get_diskinfo(dosdev);
	80	spc = (spt = SPT(di)) * HEADS(di);
	81	if (dosdev == 2)
	82	{
	83	boff = 0;
	84	part = (spt == 15 ? 3 : 1);
	85	}
	86	else
	87	{
	88	#ifdef EMBEDDED_DISKLABEL
	89	dl = &disklabel;
	90	#else EMBEDDED_DISKLABEL
	91	Bread(dosdev, 0);
	92	dptr = (struct dos_partition )(((char )0)+DOSPARTOFF);
091a0361	93	sector = LABELSECTOR;
15637ed4	94	for (i = 0; i < NDOSPART; i++, dptr++)
091a0361 AC	95	if (dptr->dp_typ == DOSPTYP_386BSD) {
091a0361 AC	96	sector = dptr->dp_start + LABELSECTOR;
15637ed4	97	break;
091a0361	98	}
15637ed4 RG	99	Bread(dosdev, sector++);
	100	dl=((struct disklabel *)0);
	101	disklabel = dl; / structure copy (maybe useful later)*/
	102	#endif EMBEDDED_DISKLABEL
	103	if (dl->d_magic != DISKMAGIC) {
	104	printf("bad disklabel");
	105	return 1;
	106	}
	107	if( (maj == 4) \|\| (maj == 0) \|\| (maj == 1))
	108	{
	109	if (dl->d_type == DTYPE_SCSI)
	110	{
	111	maj = 4; /* use scsi as boot dev */
	112	}
	113	else
	114	{
	115	maj = 0; /* must be ESDI/IDE */
	116	}
	117	}
	118	boff = dl->d_partitions[part].p_offset;
	119	#ifdef DO_BAD144
	120	bsize = dl->d_partitions[part].p_size;
	121	do_bad144 = 0;
	122	if (dl->d_flags & D_BADSECT) {
	123	/* this disk uses bad144 */
	124	int i;
	125	int dkbbnum;
	126	struct dkbad *dkbptr;
	127
091a0361 AC	128	/* find the first readable bad sector table */
	129	/* some of this code is copied from ufs/ufs_disksubr.c */
	130	/* including the bugs :-( */
15637ed4	131	/* read a bad sector table */
091a0361 AC	132
	133	#define BAD144_PART 2 /* XXX scattered magic numbers */
	134	#define BSD_PART 0 /* XXX should be 2 but bad144.c uses 0 */
	135	if (dl->d_partitions[BSD_PART].p_offset != 0)
	136	dkbbnum = dl->d_partitions[BAD144_PART].p_offset
	137	+ dl->d_partitions[BAD144_PART].p_size;
	138	else
	139	dkbbnum = dl->d_secperunit;
	140	dkbbnum -= dl->d_nsectors;
	141
15637ed4 RG	142	if (dl->d_secsize > DEV_BSIZE)
	143	dkbbnum *= dl->d_secsize / DEV_BSIZE;
	144	else
	145	dkbbnum /= DEV_BSIZE / dl->d_secsize;
	146	i = 0;
	147	do_bad144 = 0;
	148	do {
	149	/* XXX: what if the "DOS sector" < 512 bytes ??? */
	150	Bread(dosdev, dkbbnum + i);
	151	dkbptr = (struct dkbad *) 0;
	152	/* XXX why is this not in <sys/dkbad.h> ??? */
	153	#define DKBAD_MAGIC 0x4321
	154	if (dkbptr->bt_mbz == 0 &&
	155	dkbptr->bt_flag == DKBAD_MAGIC) {
	156	dkb = dkbptr; / structure copy */
	157	do_bad144 = 1;
	158	break;
	159	}
	160	i += 2;
	161	} while (i < 10 && i < dl->d_nsectors);
	162	if (!do_bad144)
091a0361	163	printf("Bad bad sector table\n");
15637ed4	164	else
091a0361	165	printf("Using bad sector table at %d\n", dkbbnum+i);
15637ed4 RG	166	}
	167	#endif DO_BAD144
	168	}
	169	return 0;
	170	}
	171
	172	devread()
	173	{
	174	int offset, sector = bnum;
	175	int dosdev = inode.i_dev;
	176	for (offset = 0; offset < cnt; offset += BPS)
	177	{
	178	Bread(dosdev, badsect(dosdev, sector++));
	179	bcopy(0, iodest+offset, BPS);
	180	}
	181	}
	182
a27f4645 RM	183	#define I_ADDR ((void ) 0) / XXX where all reads go */
	184
	185	/* Read ahead buffer large enough for one track on a 1440K floppy. For
	186	* reading from floppies, the bootstrap has to be loaded on a 64K boundary
	187	* to ensure that this buffer doesn't cross a 64K DMA boundary.
	188	*/
	189	#define RA_SECTORS 18
	190	static char ra_buf[RA_SECTORS * BPS];
2d95de23	191	static int ra_dev;
a27f4645 RM	192	static int ra_end;
	193	static int ra_first;
	194
15637ed4 RG	195	Bread(dosdev,sector)
	196	int dosdev,sector;
	197	{
2d95de23	198	if (dosdev != ra_dev \|\| sector < ra_first \|\| sector >= ra_end)
15637ed4	199	{
a27f4645 RM	200	int cyl, head, sec, nsec;
	201
	202	cyl = sector/spc;
	203	head = (sector % spc) / spt;
	204	sec = sector % spt;
	205	nsec = spt - sec;
	206	if (nsec > RA_SECTORS)
	207	nsec = RA_SECTORS;
	208	twiddle();
	209	if (biosread(dosdev, cyl, head, sec, nsec, ra_buf) != 0)
	210	{
	211	nsec = 1;
	212	twiddle();
	213	while (biosread(dosdev, cyl, head, sec, nsec, ra_buf) != 0) {
	214	printf("Error: C:%d H:%d S:%d\n", cyl, head, sec);
	215	twiddle();
	216	}
	217	}
2d95de23	218	ra_dev = dosdev;
a27f4645 RM	219	ra_first = sector;
a27f4645 RM	220	ra_end = sector + nsec;
15637ed4	221	}
a27f4645	222	bcopy(ra_buf + (sector - ra_first) * BPS, I_ADDR, BPS);
15637ed4 RG	223	}
	224
	225	badsect(dosdev, sector)
	226	int dosdev, sector;
	227	{
	228	int i;
	229	#ifdef DO_BAD144
	230	if (do_bad144) {
	231	u_short cyl;
	232	u_short head;
	233	u_short sec;
	234	int newsec;
	235	struct disklabel *dl = &disklabel;
	236
	237	/* XXX */
	238	/* from wd.c */
	239	/* bt_cyl = cylinder number in sorted order */
	240	/* bt_trksec is actually (head << 8) + sec */
	241
	242	/* only remap sectors in the partition */
	243	if (sector < boff \|\| sector >= boff + bsize) {
	244	goto no_remap;
	245	}
	246
	247	cyl = sector / dl->d_secpercyl;
	248	head = (sector % dl->d_secpercyl) / dl->d_nsectors;
	249	sec = sector % dl->d_nsectors;
	250	sec = (head<<8) + sec;
	251
	252	/* now, look in the table for a possible bad sector */
	253	for (i=0; i<126; i++) {
	254	if (dkb.bt_bad[i].bt_cyl == cyl) {
	255	/* found same cylinder */
	256	if (dkb.bt_bad[i].bt_trksec == sec) {
	257	/* FOUND! */
	258	break;
	259	}
	260	} else if (dkb.bt_bad[i].bt_cyl > cyl) {
	261	i = 126;
	262	break;
	263	}
	264	}
	265	if (i == 126) {
	266	/* didn't find bad sector */
	267	goto no_remap;
	268	}
	269	/* otherwise find replacement sector */
091a0361 AC	270	if (dl->d_partitions[BSD_PART].p_offset != 0)
	271	newsec = dl->d_partitions[BAD144_PART].p_offset
	272	+ dl->d_partitions[BAD144_PART].p_size;
	273	else
	274	newsec = dl->d_secperunit;
	275	newsec -= dl->d_nsectors + i + 1;
15637ed4 RG	276	return newsec;
	277	}
	278	#endif DO_BAD144
	279	no_remap:
	280	return sector;
	281	}