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1.1 root 1: /*
2: * Ported to boot 386BSD by Julian Elischer ([email protected]) Sept 1992
3: *
4: * Mach Operating System
5: * Copyright (c) 1992, 1991 Carnegie Mellon University
6: * All Rights Reserved.
7: *
8: * Permission to use, copy, modify and distribute this software and its
9: * documentation is hereby granted, provided that both the copyright
10: * notice and this permission notice appear in all copies of the
11: * software, derivative works or modified versions, and any portions
12: * thereof, and that both notices appear in supporting documentation.
13: *
14: * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
15: * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
16: * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
17: *
18: * Carnegie Mellon requests users of this software to return to
19: *
20: * Software Distribution Coordinator or [email protected]
21: * School of Computer Science
22: * Carnegie Mellon University
23: * Pittsburgh PA 15213-3890
24: *
25: * any improvements or extensions that they make and grant Carnegie Mellon
26: * the rights to redistribute these changes.
27: */
28:
29: /*
30: * HISTORY
1.1.1.2 ! root 31: * disk.c,v
! 32: * Revision 1.3 1993/07/11 12:02:23 andrew
! 33: * Fixes from bde, including support for loading @ any MB boundary (e.g. a
! 34: * kernel linked for 0xfe100000 will load at the 1MB mark) and read-ahead
! 35: * buffering to speed booting from floppies. Also works with aha174x
! 36: * controllers in enhanced mode.
! 37: *
! 38: * Revision 1.2 1993/06/18 02:28:58 cgd
! 39: * make it *do* something when loading the kernel, a la sun twiddling-thing
! 40: *
! 41: * Revision 1.1 1993/03/21 18:08:36 cgd
1.1 root 42: * after 0.2.2 "stable" patches applied
43: *
44: * Revision 2.2 92/04/04 11:35:49 rpd
45: * Fabricated from 3.0 bootstrap and 2.5 boot disk.c:
46: * with support for scsi
47: * [92/03/30 mg32]
48: *
49: */
50:
51: /*
52: * 9/20/92
53: * Peng-Toh Sim. [email protected]
54: * Added bad144 support under 386bsd for wd's
55: * So, bad block remapping is done when loading the kernel.
56: */
57:
58: #include "boot.h"
59: #ifdef DO_BAD144
60: #include <sys/dkbad.h>
61: #endif DO_BAD144
62: #include <sys/disklabel.h>
63:
64: #define BIOS_DEV_FLOPPY 0x0
65: #define BIOS_DEV_WIN 0x80
66:
67: #define BPS 512
68: #define SPT(di) ((di)&0xff)
69: #define HEADS(di) ((((di)>>8)&0xff)+1)
70:
71: char *devs[] = {"wd", "hd", "fd", "wt", "sd", 0};
72:
73: #ifdef DO_BAD144
74: struct dkbad dkb;
75: int do_bad144;
76: int bsize;
77: #endif DO_BAD144
78:
79: int spt, spc;
80:
81: char *iodest;
82: struct fs *fs;
83: struct inode inode;
84: int dosdev, unit, part, maj, boff, poff, bnum, cnt;
85:
86: /*#define EMBEDDED_DISKLABEL 1*/
87: extern struct disklabel disklabel;
88: /*struct disklabel disklabel;*/
89:
90: devopen()
91: {
92: struct dos_partition *dptr;
93: struct disklabel *dl;
94: int dosdev = inode.i_dev;
95: int i, sector, di;
96:
97: di = get_diskinfo(dosdev);
98: spc = (spt = SPT(di)) * HEADS(di);
99: if (dosdev == 2)
100: {
101: boff = 0;
102: part = (spt == 15 ? 3 : 1);
103: }
104: else
105: {
106: #ifdef EMBEDDED_DISKLABEL
107: dl = &disklabel;
108: #else EMBEDDED_DISKLABEL
109: Bread(dosdev, 0);
110: dptr = (struct dos_partition *)(((char *)0)+DOSPARTOFF);
111: for (i = 0; i < NDOSPART; i++, dptr++)
112: if (dptr->dp_typ == DOSPTYP_386BSD)
113: break;
114: sector = dptr->dp_start + LABELSECTOR;
115: Bread(dosdev, sector++);
116: dl=((struct disklabel *)0);
117: disklabel = *dl; /* structure copy (maybe useful later)*/
118: #endif EMBEDDED_DISKLABEL
119: if (dl->d_magic != DISKMAGIC) {
120: printf("bad disklabel");
121: return 1;
122: }
123: if( (maj == 4) || (maj == 0) || (maj == 1))
124: {
125: if (dl->d_type == DTYPE_SCSI)
126: {
127: maj = 4; /* use scsi as boot dev */
128: }
129: else
130: {
131: maj = 0; /* must be ESDI/IDE */
132: }
133: }
134: boff = dl->d_partitions[part].p_offset;
135: #ifdef DO_BAD144
136: bsize = dl->d_partitions[part].p_size;
137: do_bad144 = 0;
138: if (dl->d_flags & D_BADSECT) {
139: /* this disk uses bad144 */
140: int i;
141: int dkbbnum;
142: struct dkbad *dkbptr;
143:
144: /* find the first readable bad144 sector */
145: /* some of this code is copied from ufs/disk_subr.c */
146: /* read a bad sector table */
147: dkbbnum = dl->d_secperunit - dl->d_nsectors;
148: if (dl->d_secsize > DEV_BSIZE)
149: dkbbnum *= dl->d_secsize / DEV_BSIZE;
150: else
151: dkbbnum /= DEV_BSIZE / dl->d_secsize;
152: i = 0;
153: do_bad144 = 0;
154: do {
155: /* XXX: what if the "DOS sector" < 512 bytes ??? */
156: Bread(dosdev, dkbbnum + i);
157: dkbptr = (struct dkbad *) 0;
158: /* XXX why is this not in <sys/dkbad.h> ??? */
159: #define DKBAD_MAGIC 0x4321
160: if (dkbptr->bt_mbz == 0 &&
161: dkbptr->bt_flag == DKBAD_MAGIC) {
162: dkb = *dkbptr; /* structure copy */
163: do_bad144 = 1;
164: break;
165: }
166: i += 2;
167: } while (i < 10 && i < dl->d_nsectors);
168: if (!do_bad144)
169: printf("Bad badsect table\n");
170: else
171: printf("Using bad144 bad sector at %d\n", dkbbnum+i);
172: }
173: #endif DO_BAD144
174: }
175: return 0;
176: }
177:
178: devread()
179: {
180: int offset, sector = bnum;
181: int dosdev = inode.i_dev;
182: for (offset = 0; offset < cnt; offset += BPS)
183: {
184: Bread(dosdev, badsect(dosdev, sector++));
185: bcopy(0, iodest+offset, BPS);
186: }
187: }
188:
1.1.1.2 ! root 189: #define I_ADDR ((void *) 0) /* XXX where all reads go */
! 190:
! 191: /* Read ahead buffer large enough for one track on a 1440K floppy. For
! 192: * reading from floppies, the bootstrap has to be loaded on a 64K boundary
! 193: * to ensure that this buffer doesn't cross a 64K DMA boundary.
! 194: */
! 195: #define RA_SECTORS 18
! 196: static char ra_buf[RA_SECTORS * BPS];
! 197: static int ra_end;
! 198: static int ra_first;
! 199:
1.1 root 200: Bread(dosdev,sector)
201: int dosdev,sector;
202: {
1.1.1.2 ! root 203: if (sector < ra_first || sector >= ra_end)
1.1 root 204: {
1.1.1.2 ! root 205: int cyl, head, sec, nsec;
! 206:
! 207: cyl = sector/spc;
! 208: head = (sector % spc) / spt;
! 209: sec = sector % spt;
! 210: nsec = spt - sec;
! 211: if (nsec > RA_SECTORS)
! 212: nsec = RA_SECTORS;
! 213: twiddle();
! 214: if (biosread(dosdev, cyl, head, sec, nsec, ra_buf) != 0)
! 215: {
! 216: nsec = 1;
! 217: twiddle();
! 218: while (biosread(dosdev, cyl, head, sec, nsec, ra_buf) != 0) {
! 219: printf("Error: C:%d H:%d S:%d\n", cyl, head, sec);
! 220: twiddle();
! 221: }
! 222: }
! 223: ra_first = sector;
! 224: ra_end = sector + nsec;
1.1 root 225: }
1.1.1.2 ! root 226: bcopy(ra_buf + (sector - ra_first) * BPS, I_ADDR, BPS);
1.1 root 227: }
228:
229: badsect(dosdev, sector)
230: int dosdev, sector;
231: {
232: int i;
233: #ifdef DO_BAD144
234: if (do_bad144) {
235: u_short cyl;
236: u_short head;
237: u_short sec;
238: int newsec;
239: struct disklabel *dl = &disklabel;
240:
241: /* XXX */
242: /* from wd.c */
243: /* bt_cyl = cylinder number in sorted order */
244: /* bt_trksec is actually (head << 8) + sec */
245:
246: /* only remap sectors in the partition */
247: if (sector < boff || sector >= boff + bsize) {
248: goto no_remap;
249: }
250:
251: cyl = sector / dl->d_secpercyl;
252: head = (sector % dl->d_secpercyl) / dl->d_nsectors;
253: sec = sector % dl->d_nsectors;
254: sec = (head<<8) + sec;
255:
256: /* now, look in the table for a possible bad sector */
257: for (i=0; i<126; i++) {
258: if (dkb.bt_bad[i].bt_cyl == cyl) {
259: /* found same cylinder */
260: if (dkb.bt_bad[i].bt_trksec == sec) {
261: /* FOUND! */
262: break;
263: }
264: } else if (dkb.bt_bad[i].bt_cyl > cyl) {
265: i = 126;
266: break;
267: }
268: }
269: if (i == 126) {
270: /* didn't find bad sector */
271: goto no_remap;
272: }
273: /* otherwise find replacement sector */
274: newsec = dl->d_secperunit - dl->d_nsectors - i -1;
275: return newsec;
276: }
277: #endif DO_BAD144
278: no_remap:
279: return sector;
280: }
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