1 /* $NetBSD: biosdisk.c,v 1.4 2021/05/17 19:31:38 mrg Exp $ */
2
3 /*
4 * Copyright (c) 1996, 1998
5 * Matthias Drochner. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 *
27 */
28
29 /*
30 * raw BIOS disk device for libsa.
31 * needs lowlevel parts from bios_disk.S and biosdisk_ll.c
32 * partly from netbsd:sys/arch/i386/boot/disk.c
33 * no bad144 handling!
34 *
35 * A lot of this must match sys/kern/subr_disk_mbr.c
36 */
37
38 /*
39 * Ported to boot 386BSD by Julian Elischer (julian@tfs.com) Sept 1992
40 *
41 * Mach Operating System
42 * Copyright (c) 1992, 1991 Carnegie Mellon University
43 * All Rights Reserved.
44 *
45 * Permission to use, copy, modify and distribute this software and its
46 * documentation is hereby granted, provided that both the copyright
47 * notice and this permission notice appear in all copies of the
48 * software, derivative works or modified versions, and any portions
49 * thereof, and that both notices appear in supporting documentation.
50 *
51 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
52 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
53 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
54 *
55 * Carnegie Mellon requests users of this software to return to
56 *
57 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
58 * School of Computer Science
59 * Carnegie Mellon University
60 * Pittsburgh PA 15213-3890
61 *
62 * any improvements or extensions that they make and grant Carnegie Mellon
63 * the rights to redistribute these changes.
64 */
65
66 #include <sys/types.h>
67 #include <sys/disklabel.h>
68
69 #include <lib/libkern/libkern.h>
70 #include <lib/libsa/stand.h>
71 #include <lib/libsa/saerrno.h>
72 #include <lib/libsa/loadfile.h>
73
74 #include <machine/disklabel.h>
75
76 #include "biosdisk.h"
77 #include "biosdisk_ll.h"
78
79 #include "bootinfo.h"
80
81 #define BUFSIZE (1 * BIOSDISK_SECSIZE)
82
83 struct biosdisk {
84 int dev;
85 int boff;
86 char buf[BUFSIZE];
87 };
88
89 static struct btinfo_bootdisk bi_disk;
90
91 #define RF_PROTECTED_SECTORS 64 /* XXX refer to <.../rf_optnames.h> */
92
93 static struct biosdisk *
alloc_biosdisk(int dev)94 alloc_biosdisk(int dev)
95 {
96 struct biosdisk *d;
97
98 d = (struct biosdisk *)ALLOC(sizeof(*d));
99 if (d == NULL)
100 return (NULL);
101
102 memset(d, 0, sizeof(*d));
103 d->dev = dev;
104
105 return (d);
106 }
107
108 static int
check_label(struct biosdisk * d,int sector)109 check_label(struct biosdisk *d, int sector)
110 {
111 struct disklabel *lp;
112
113 /* find partition in NetBSD disklabel */
114 if (readsects(d->dev, sector + LABELSECTOR, d->buf, 1)) {
115 #ifdef DISK_DEBUG
116 printf("Error reading disklabel\n");
117 #endif
118 return (EIO);
119 }
120
121 lp = (struct disklabel *)(d->buf + LABELOFFSET);
122 if (lp->d_magic != DISKMAGIC || dkcksum(lp)) {
123 #ifdef DISK_DEBUG
124 printf("warning: no disklabel\n");
125 #endif
126 return (-1);
127 }
128
129 d->boff = sector;
130 return (0);
131 }
132
133 static int
read_label(struct biosdisk * d)134 read_label(struct biosdisk *d)
135 {
136 struct mbr_sector *mbr_sect;
137 struct disklabel dflt_lbl;
138 struct mbr_partition mbr[MBR_PART_COUNT];
139 struct partition *p;
140 int sector, i;
141 int error;
142 int typ;
143 int ext_base, this_ext, next_ext;
144 #ifdef COMPAT_386BSD_MBRPART
145 int sector_386bsd = -1;
146 #endif
147
148 memset(&dflt_lbl, 0, sizeof dflt_lbl);
149 dflt_lbl.d_npartitions = 8;
150
151 d->boff = 0;
152
153 /*
154 * find NetBSD Partition in DOS partition table
155 * XXX check magic???
156 */
157 ext_base = 0;
158 next_ext = 0;
159 for (;;) {
160 this_ext = ext_base + next_ext;
161 next_ext = 0;
162 mbr_sect = (struct mbr_sector *)d->buf;
163 memcpy(&mbr, mbr_sect->mbr_parts, sizeof(mbr));
164 if (readsects(d->dev, this_ext, d->buf, 1)) {
165 #ifdef DISK_DEBUG
166 printf("error reading MBR sector %d\n", this_ext);
167 #endif
168 return (EIO);
169 }
170 memcpy(&mbr, mbr_sect->mbr_parts, sizeof(mbr));
171 /* Look for NetBSD partition ID */
172 for (i = 0; i < MBR_PART_COUNT; i++) {
173 typ = mbr[i].mbrp_type;
174 if (typ == 0)
175 continue;
176 sector = this_ext + mbr[i].mbrp_start;
177 if (typ == MBR_PTYPE_NETBSD) {
178 error = check_label(d, sector);
179 if (error >= 0)
180 return error;
181 }
182 if (MBR_IS_EXTENDED(typ)) {
183 next_ext = mbr[i].mbrp_start;
184 continue;
185 }
186 #ifdef COMPAT_386BSD_MBRPART
187 if (this_ext == 0 && typ == MBR_PTYPE_386BSD)
188 sector_386bsd = sector;
189 #endif
190 if (this_ext != 0) {
191 if (dflt_lbl.d_npartitions >= MAXPARTITIONS)
192 continue;
193 p = &dflt_lbl.d_partitions[dflt_lbl.d_npartitions++];
194 } else
195 p = &dflt_lbl.d_partitions[i];
196 p->p_offset = sector;
197 p->p_size = mbr[i].mbrp_size;
198 p->p_fstype = xlat_mbr_fstype(typ);
199 }
200 if (next_ext == 0)
201 break;
202 if (ext_base == 0) {
203 ext_base = next_ext;
204 next_ext = 0;
205 }
206 }
207
208 sector = 0;
209 #ifdef COMPAT_386BSD_MBRPART
210 if (sector_386bsd != -1) {
211 printf("old BSD partition ID!\n");
212 sector = sector_386bsd;
213 }
214 #endif
215
216 /*
217 * One of two things:
218 * 1. no MBR
219 * 2. no NetBSD partition in MBR
220 *
221 * We simply default to "start of disk" in this case and
222 * press on.
223 */
224 error = check_label(d, sector);
225 if (error >= 0)
226 return (error);
227
228 /*
229 * Nothing at start of disk, return info from mbr partitions.
230 */
231 /* XXX fill it to make checksum match kernel one */
232 dflt_lbl.d_checksum = dkcksum(&dflt_lbl);
233 memcpy(d->buf, &dflt_lbl, sizeof(dflt_lbl));
234 return (-1);
235 }
236
237
238 /*
239 * Determine likely partition for possible sector number of dos
240 * partition.
241 */
242 u_int
biosdisk_findptn(int biosdev,u_int sector)243 biosdisk_findptn(int biosdev, u_int sector)
244 {
245 struct biosdisk *d;
246 u_int partition = 0;
247 struct disklabel *lp;
248
249 /* Look for netbsd partition that is the dos boot one */
250 d = alloc_biosdisk(biosdev);
251 if (d == NULL)
252 return (0);
253
254 if (read_label(d) == 0) {
255 lp = (struct disklabel *)(d->buf + LABELOFFSET);
256 for (partition = lp->d_npartitions; --partition;){
257 if (lp->d_partitions[partition].p_fstype == FS_UNUSED)
258 continue;
259 if (lp->d_partitions[partition].p_offset == sector)
260 break;
261 }
262 }
263
264 DEALLOC(d, sizeof(*d));
265 return (partition);
266 }
267
268 int
biosdisk_open(struct open_file * f,...)269 biosdisk_open(struct open_file *f, ...)
270 {
271 va_list ap;
272 struct biosdisk *d;
273 struct disklabel *lp;
274 int dev;
275 int partition;
276 int error = 0;
277
278 va_start(ap, f);
279 dev = va_arg(ap, int);
280 d = alloc_biosdisk(dev);
281 if (d == NULL) {
282 error = ENXIO;
283 goto out;
284 }
285
286 partition = va_arg(ap, int);
287 bi_disk.biosdev = d->dev;
288 bi_disk.partition = partition;
289 bi_disk.labelsector = -1;
290
291 if (partition == RAW_PART)
292 goto nolabel;
293 error = read_label(d);
294 if (error == -1) {
295 error = 0;
296 goto nolabel;
297 }
298 if (error)
299 goto out;
300
301 lp = (struct disklabel *)(d->buf + LABELOFFSET);
302 if (partition >= lp->d_npartitions ||
303 lp->d_partitions[partition].p_fstype == FS_UNUSED) {
304 #ifdef DISK_DEBUG
305 printf("illegal partition\n");
306 #endif
307 error = EPART;
308 goto out;
309 }
310 bi_disk.labelsector = d->boff + LABELSECTOR;
311 bi_disk.label.type = lp->d_type;
312 memcpy(bi_disk.label.packname, lp->d_packname, 16);
313 bi_disk.label.checksum = lp->d_checksum;
314
315 d->boff = lp->d_partitions[partition].p_offset;
316 if (lp->d_partitions[partition].p_fstype == FS_RAID) {
317 d->boff += RF_PROTECTED_SECTORS;
318 }
319 nolabel:
320
321 #ifdef DISK_DEBUG
322 printf("partition @%d\n", d->boff);
323 #endif
324
325 BI_ADD(&bi_disk, BTINFO_BOOTDISK, sizeof(bi_disk));
326
327 f->f_devdata = d;
328 out:
329 va_end(ap);
330 if (error)
331 DEALLOC(d, sizeof(struct biosdisk));
332 return (error);
333 }
334
335 int
biosdisk_close(struct open_file * f)336 biosdisk_close(struct open_file *f)
337 {
338 struct biosdisk *d = f->f_devdata;
339
340 DEALLOC(d, sizeof(struct biosdisk));
341 f->f_devdata = NULL;
342
343 return (0);
344 }
345
346 int
biosdisk_ioctl(struct open_file * f,u_long cmd,void * arg)347 biosdisk_ioctl(struct open_file *f, u_long cmd, void *arg)
348 {
349
350 return (EIO);
351 }
352
353 int
biosdisk_strategy(void * devdata,int flag,daddr_t dblk,size_t size,void * buf,size_t * rsize)354 biosdisk_strategy(void *devdata, int flag, daddr_t dblk, size_t size, void *buf, size_t *rsize)
355 {
356 struct biosdisk *d;
357 int blks;
358 int frag;
359
360 if (flag != F_READ)
361 return EROFS;
362
363 d = (struct biosdisk *)devdata;
364
365 dblk += d->boff;
366
367 blks = size / BIOSDISK_SECSIZE;
368 if (blks && readsects(d->dev, dblk, buf, blks)) {
369 if (rsize)
370 *rsize = 0;
371 return (EIO);
372 }
373
374 /* do we really need this? */
375 frag = size % BIOSDISK_SECSIZE;
376 if (frag) {
377 if (readsects(d->dev, dblk + blks, d->buf, 1)) {
378 if (rsize)
379 *rsize = blks * BIOSDISK_SECSIZE;
380 return (EIO);
381 }
382 memcpy(buf + blks * BIOSDISK_SECSIZE, d->buf, frag);
383 }
384
385 if (rsize)
386 *rsize = size;
387 return (0);
388 }
389