2 * Mach Operating System
3 * Copyright (c) 1992, 1991 Carnegie Mellon University
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.
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.
16 * Carnegie Mellon requests users of this software to return to
18 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
19 * School of Computer Science
20 * Carnegie Mellon University
21 * Pittsburgh PA 15213-3890
23 * any improvements or extensions that they make and grant Carnegie Mellon
24 * the rights to redistribute these changes.
26 * from: Mach, Revision 2.2 92/04/04 11:35:49 rpd
27 * $FreeBSD: src/sys/i386/boot/biosboot/disk.c,v 1.28 1999/12/08 09:32:48 phk Exp $
32 * If there is no 386BSD partition, initialize the label sector with
33 * LABELSECTOR instead of with garbage.
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.
41 #include <sys/disklabel.h>
42 #include <sys/diskslice.h>
44 #define BIOS_DEV_FLOPPY 0x0
45 #define BIOS_DEV_WIN 0x80
48 #define SPT(di) ((di)&0xff)
49 #define HEADS(di) ((((di)>>8)&0xff)+1)
57 int dosdev, unit, slice, part, maj, boff;
59 /*#define EMBEDDED_DISKLABEL 1*/
61 /* Read ahead buffer large enough for one track on a 1440K floppy. For
62 * reading from floppies, the bootstrap has to be loaded on a 64K boundary
63 * to ensure that this buffer doesn't cross a 64K DMA boundary.
66 static char ra_buf[RA_SECTORS * BPS];
71 static char *Bread(int dosdev, int sector);
76 struct dos_partition *dptr;
79 int i, sector = 0, di, dosdev_copy;
82 di = get_diskinfo(dosdev_copy);
85 /* Hack for 2.88MB floppy drives. */
86 if (!(dosdev_copy & 0x80) && spt == 36)
89 spc = spt * HEADS(di);
93 #ifdef EMBEDDED_DISKLABEL
95 #else EMBEDDED_DISKLABEL
96 p = Bread(dosdev_copy, 0);
97 dptr = (struct dos_partition *)(p+DOSPARTOFF);
98 slice = WHOLE_DISK_SLICE;
99 for (i = 0; i < NDOSPART; i++, dptr++)
100 if (dptr->dp_typ == DOSPTYP_386BSD) {
101 slice = BASE_SLICE + i;
102 sector = dptr->dp_start;
105 p = Bread(dosdev_copy, sector + LABELSECTOR);
106 dl=((struct disklabel *)p);
107 disklabel = *dl; /* structure copy (maybe useful later)*/
108 #endif EMBEDDED_DISKLABEL
109 if (dl->d_magic != DISKMAGIC) {
110 printf("bad disklabel\n");
113 if( (maj == 4) || (maj == 0) || (maj == 1))
115 if (dl->d_type == DTYPE_SCSI)
117 maj = 4; /* use scsi as boot dev */
121 maj = 0; /* must be ESDI/IDE */
124 /* This little trick is for OnTrack DiskManager disks */
125 boff = dl->d_partitions[part].p_offset -
126 dl->d_partitions[2].p_offset + sector;
128 bsize = dl->d_partitions[part].p_size;
130 printf("empty partition\n");
141 * Be aware that cnt is rounded up to N*BPS
144 devread(char *iodest, int sector, int cnt)
150 for (offset = 0; offset < cnt; offset += BPS)
152 dosdev_copy = dosdev;
153 p = Bread(dosdev_copy, sector++);
154 bcopy(p, iodest+offset, BPS);
160 Bread(int dosdev, int sector)
162 if (dosdev != ra_dev || sector < ra_first || sector >= ra_end)
164 int cyl, head, sec, nsec;
168 printf("Error: C:%d > 1023 (BIOS limit)\n", cyl);
169 for(;;); /* loop forever */
171 head = (sector % spc) / spt;
174 if (nsec > RA_SECTORS)
177 if (biosread(dosdev, cyl, head, sec, nsec, ra_buf) != 0)
181 while (biosread(dosdev, cyl, head, sec, nsec, ra_buf) != 0) {
182 printf("Error: D:0x%x C:%d H:%d S:%d\n",
183 dosdev, cyl, head, sec);
189 ra_end = sector + nsec;
191 return (ra_buf + (sector - ra_first) * BPS);