[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
 *	$Id$
 */

#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;
}
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.
78ed81a3	25	*
	26	* from: Mach, Revision 2.2 92/04/04 11:35:49 rpd
	27	* $Id$
15637ed4 RG	28	*/
	29
	30	#include "boot.h"
	31	#ifdef DO_BAD144
	32	#include <sys/dkbad.h>
	33	#endif DO_BAD144
	34	#include <sys/disklabel.h>
	35
	36	#define BIOS_DEV_FLOPPY 0x0
	37	#define BIOS_DEV_WIN 0x80
	38
	39	#define BPS 512
	40	#define SPT(di) ((di)&0xff)
	41	#define HEADS(di) ((((di)>>8)&0xff)+1)
	42
	43	char *devs[] = {"wd", "hd", "fd", "wt", "sd", 0};
	44
	45	#ifdef DO_BAD144
	46	struct dkbad dkb;
	47	int do_bad144;
	48	int bsize;
	49	#endif DO_BAD144
	50
	51	int spt, spc;
	52
	53	char *iodest;
	54	struct fs *fs;
	55	struct inode inode;
	56	int dosdev, unit, part, maj, boff, poff, bnum, cnt;
	57
	58	/#define EMBEDDED_DISKLABEL 1/
	59	extern struct disklabel disklabel;
	60	/struct disklabel disklabel;/
	61
	62	devopen()
	63	{
	64	struct dos_partition *dptr;
	65	struct disklabel *dl;
	66	int dosdev = inode.i_dev;
	67	int i, sector, di;
	68
	69	di = get_diskinfo(dosdev);
	70	spc = (spt = SPT(di)) * HEADS(di);
	71	if (dosdev == 2)
	72	{
	73	boff = 0;
	74	part = (spt == 15 ? 3 : 1);
	75	}
	76	else
	77	{
	78	#ifdef EMBEDDED_DISKLABEL
	79	dl = &disklabel;
	80	#else EMBEDDED_DISKLABEL
	81	Bread(dosdev, 0);
	82	dptr = (struct dos_partition )(((char )0)+DOSPARTOFF);
	83	for (i = 0; i < NDOSPART; i++, dptr++)
	84	if (dptr->dp_typ == DOSPTYP_386BSD)
	85	break;
	86	sector = dptr->dp_start + LABELSECTOR;
	87	Bread(dosdev, sector++);
	88	dl=((struct disklabel *)0);
	89	disklabel = dl; / structure copy (maybe useful later)*/
	90	#endif EMBEDDED_DISKLABEL
	91	if (dl->d_magic != DISKMAGIC) {
92	printf("bad disklabel");
93	return 1;
94	}
95	if( (maj == 4) \|\| (maj == 0) \|\| (maj == 1))
96	{
97	if (dl->d_type == DTYPE_SCSI)
98	{
99	maj = 4; /* use scsi as boot dev */
100	}
101	else
102	{
103	maj = 0; /* must be ESDI/IDE */
104	}
105	}
106	boff = dl->d_partitions[part].p_offset;
107	#ifdef DO_BAD144
108	bsize = dl->d_partitions[part].p_size;
109	do_bad144 = 0;
110	if (dl->d_flags & D_BADSECT) {
111	/* this disk uses bad144 */
112	int i;
113	int dkbbnum;
114	struct dkbad *dkbptr;
115
116	/* find the first readable bad144 sector */
117	/* some of this code is copied from ufs/disk_subr.c */
118	/* read a bad sector table */
119	dkbbnum = dl->d_secperunit - dl->d_nsectors;
120	if (dl->d_secsize > DEV_BSIZE)
121	dkbbnum *= dl->d_secsize / DEV_BSIZE;
122	else
123	dkbbnum /= DEV_BSIZE / dl->d_secsize;
124	i = 0;
125	do_bad144 = 0;
126	do {
127	/* XXX: what if the "DOS sector" < 512 bytes ??? */
128	Bread(dosdev, dkbbnum + i);
129	dkbptr = (struct dkbad *) 0;
130	/* XXX why is this not in <sys/dkbad.h> ??? */
131	#define DKBAD_MAGIC 0x4321
132	if (dkbptr->bt_mbz == 0 &&
133	dkbptr->bt_flag == DKBAD_MAGIC) {
134	dkb = dkbptr; / structure copy */
135	do_bad144 = 1;
136	break;
137	}
138	i += 2;
139	} while (i < 10 && i < dl->d_nsectors);
140	if (!do_bad144)
141	printf("Bad badsect table\n");
142	else
143	printf("Using bad144 bad sector at %d\n", dkbbnum+i);
144	}
145	#endif DO_BAD144
146	}
147	return 0;
148	}
149
150	devread()
151	{
152	int offset, sector = bnum;
153	int dosdev = inode.i_dev;
154	for (offset = 0; offset < cnt; offset += BPS)
155	{
156	Bread(dosdev, badsect(dosdev, sector++));
157	bcopy(0, iodest+offset, BPS);
158	}
159	}
160
78ed81a3	161	#define I_ADDR ((void ) 0) / XXX where all reads go */
	162
	163	/* Read ahead buffer large enough for one track on a 1440K floppy. For
	164	* reading from floppies, the bootstrap has to be loaded on a 64K boundary
	165	* to ensure that this buffer doesn't cross a 64K DMA boundary.
	166	*/
	167	#define RA_SECTORS 18
	168	static char ra_buf[RA_SECTORS * BPS];
	169	static int ra_end;
	170	static int ra_first;
	171
15637ed4 RG	172	Bread(dosdev,sector)
	173	int dosdev,sector;
	174	{
78ed81a3	175	if (sector < ra_first \|\| sector >= ra_end)
15637ed4	176	{
78ed81a3	177	int cyl, head, sec, nsec;
	178
	179	cyl = sector/spc;
	180	head = (sector % spc) / spt;
	181	sec = sector % spt;
	182	nsec = spt - sec;
	183	if (nsec > RA_SECTORS)
	184	nsec = RA_SECTORS;
	185	twiddle();
	186	if (biosread(dosdev, cyl, head, sec, nsec, ra_buf) != 0)
	187	{
	188	nsec = 1;
	189	twiddle();
	190	while (biosread(dosdev, cyl, head, sec, nsec, ra_buf) != 0) {
	191	printf("Error: C:%d H:%d S:%d\n", cyl, head, sec);
	192	twiddle();
	193	}
	194	}
	195	ra_first = sector;
	196	ra_end = sector + nsec;
15637ed4	197	}
78ed81a3	198	bcopy(ra_buf + (sector - ra_first) * BPS, I_ADDR, BPS);
15637ed4 RG	199	}
	200
	201	badsect(dosdev, sector)
	202	int dosdev, sector;
	203	{
	204	int i;
	205	#ifdef DO_BAD144
	206	if (do_bad144) {
	207	u_short cyl;
	208	u_short head;
	209	u_short sec;
	210	int newsec;
	211	struct disklabel *dl = &disklabel;
	212
	213	/* XXX */
	214	/* from wd.c */
	215	/* bt_cyl = cylinder number in sorted order */
	216	/* bt_trksec is actually (head << 8) + sec */
	217
	218	/* only remap sectors in the partition */
	219	if (sector < boff \|\| sector >= boff + bsize) {
	220	goto no_remap;
	221	}
	222
	223	cyl = sector / dl->d_secpercyl;
	224	head = (sector % dl->d_secpercyl) / dl->d_nsectors;
	225	sec = sector % dl->d_nsectors;
	226	sec = (head<<8) + sec;
	227
	228	/* now, look in the table for a possible bad sector */
	229	for (i=0; i<126; i++) {
	230	if (dkb.bt_bad[i].bt_cyl == cyl) {
	231	/* found same cylinder */
	232	if (dkb.bt_bad[i].bt_trksec == sec) {
	233	/* FOUND! */
	234	break;
	235	}
	236	} else if (dkb.bt_bad[i].bt_cyl > cyl) {
	237	i = 126;
	238	break;
	239	}
	240	}
	241	if (i == 126) {
	242	/* didn't find bad sector */
	243	goto no_remap;
	244	}
	245	/* otherwise find replacement sector */
	246	newsec = dl->d_secperunit - dl->d_nsectors - i -1;
	247	return newsec;
	248	}
	249	#endif DO_BAD144
	250	no_remap:
	251	return sector;
	252	}