1 /* $NetBSD: landisk.c,v 1.9 2024/05/11 06:50:23 andvar Exp $ */
2
3 /*-
4 * Copyright (c) 2003 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by David Laight.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 #if HAVE_NBTOOL_CONFIG_H
33 #include "nbtool_config.h"
34 #endif
35
36 #include <sys/cdefs.h>
37 #if !defined(__lint)
38 __RCSID("$NetBSD: landisk.c,v 1.9 2024/05/11 06:50:23 andvar Exp $");
39 #endif /* !__lint */
40
41 #include <sys/param.h>
42
43 #include <assert.h>
44 #include <err.h>
45 #include <md5.h>
46 #include <stddef.h>
47 #include <stdio.h>
48 #include <stdlib.h>
49 #include <string.h>
50 #include <unistd.h>
51
52 #include "installboot.h"
53
54 static int landisk_setboot(ib_params *);
55
56 struct ib_mach ib_mach_landisk = {
57 .name = "landisk",
58 .setboot = landisk_setboot,
59 .clearboot = no_clearboot,
60 .editboot = no_editboot,
61 .valid_flags = IB_TIMEOUT,
62 };
63
64 static int
landisk_setboot(ib_params * params)65 landisk_setboot(ib_params *params)
66 {
67 struct mbr_sector mbr;
68 struct landisk_boot_params bp, *bpp;
69 uint8_t *bootstrapbuf;
70 ssize_t rv;
71 uint32_t magic;
72 size_t bootstrapsize;
73 int retval, i;
74 uint32_t bplen;
75
76 assert(params != NULL);
77 assert(params->fsfd != -1);
78 assert(params->filesystem != NULL);
79 assert(params->s1fd != -1);
80 assert(params->stage1 != NULL);
81
82 retval = 0;
83 bootstrapbuf = NULL;
84
85 /*
86 * There is only 8k of space in a FFSv1 partition (and ustarfs)
87 * so ensure we don't splat over anything important.
88 */
89 if (params->s1stat.st_size > 8192) {
90 warnx("stage1 bootstrap `%s' is larger than 8192 bytes",
91 params->stage1);
92 goto done;
93 }
94
95 /*
96 * Read in the existing MBR.
97 */
98 rv = pread(params->fsfd, &mbr, sizeof(mbr), MBR_BBSECTOR);
99 if (rv == -1) {
100 warn("Reading `%s'", params->filesystem);
101 goto done;
102 } else if (rv != sizeof(mbr)) {
103 warnx("Reading `%s': short read", params->filesystem);
104 goto done;
105 }
106 if (mbr.mbr_magic != le16toh(MBR_MAGIC)) {
107 const char *p = (const char *)&mbr;
108 const char *e = p + sizeof(mbr);
109 while (p < e && !*p)
110 p++;
111 if (p != e) {
112 if (params->flags & IB_VERBOSE) {
113 printf(
114 "Ignoring MBR with invalid magic in sector 0 of `%s'\n",
115 params->filesystem);
116 }
117 memset(&mbr, 0, sizeof(mbr));
118 }
119 }
120
121 /*
122 * Allocate a buffer, with space to round up the input file
123 * to the next block size boundary, and with space for the boot
124 * block.
125 */
126 bootstrapsize = roundup(params->s1stat.st_size, 512);
127
128 bootstrapbuf = malloc(bootstrapsize);
129 if (bootstrapbuf == NULL) {
130 warn("Allocating %zu bytes", bootstrapsize);
131 goto done;
132 }
133 memset(bootstrapbuf, 0, bootstrapsize);
134
135 /*
136 * Read the file into the buffer.
137 */
138 rv = pread(params->s1fd, bootstrapbuf, params->s1stat.st_size, 0);
139 if (rv == -1) {
140 warn("Reading `%s'", params->stage1);
141 goto done;
142 } else if (rv != params->s1stat.st_size) {
143 warnx("Reading `%s': short read", params->stage1);
144 goto done;
145 }
146
147 magic = *(uint32_t *)(bootstrapbuf + 512 * 2 + 4);
148 if (magic != htole32(LANDISK_BOOT_MAGIC_1)) {
149 warnx("Invalid magic in stage1 bootstrap %x != %x",
150 magic, htole32(LANDISK_BOOT_MAGIC_1));
151 goto done;
152 }
153
154 /*
155 * Determine size of BIOS Parameter Block (BPB) to copy from
156 * original MBR to the temporary buffer by examining the first
157 * few instruction in the new bootblock. Supported values:
158 * 2b a0 11 jmp ENDOF(mbr_bpbFAT32)+1, nop
159 * (anything else) ; don't preserve
160 */
161 #if 0
162 int bpbsize;
163 if (bootstrapbuf[1] == 0xa0 && bootstrapbuf[2] == 0x11 &&
164 (bootstrapbuf[0] == 0x2b /*|| bootstrapbuf[0] == 0x1d*/)) {
165 bpbsize = bootstrapbuf[0] + 2 - MBR_BPB_OFFSET;
166 }
167 #endif
168
169 /*
170 * Ensure bootxx hasn't got any code or data (i.e, non-zero bytes) in
171 * the partition table.
172 */
173 for (i = 0; i < (int)sizeof(mbr.mbr_parts); i++) {
174 if (*(uint8_t *)(bootstrapbuf + MBR_PART_OFFSET + i) != 0) {
175 warnx(
176 "Partition table has non-zero byte at offset %d in `%s'",
177 MBR_PART_OFFSET + i, params->stage1);
178 goto done;
179 }
180 }
181
182 #if 0
183 /*
184 * Copy the BPB and the partition table from the original MBR to the
185 * temporary buffer so that they're written back to the fs.
186 */
187 if (bpbsize != 0) {
188 if (params->flags & IB_VERBOSE)
189 printf("Preserving %d (%#x) bytes of the BPB\n",
190 bpbsize, bpbsize);
191 (void)memcpy(bootstrapbuf + MBR_BPB_OFFSET, &mbr.mbr_bpb,
192 bpbsize);
193 }
194 #endif
195 memcpy(bootstrapbuf + MBR_PART_OFFSET, &mbr.mbr_parts,
196 sizeof(mbr.mbr_parts));
197
198 /*
199 * Fill in any user-specified options into the
200 * struct landisk_boot_params
201 * that's 8 bytes in from the start of the third sector.
202 * See sys/arch/landisk/stand/bootxx/bootxx.S for more information.
203 */
204 bpp = (void *)(bootstrapbuf + 512 * 2 + 8);
205 bplen = le32toh(bpp->bp_length);
206 if (bplen > sizeof bp)
207 /* Ignore pad space in bootxx */
208 bplen = sizeof bp;
209 /* Take (and update) local copy so we handle size mismatches */
210 memset(&bp, 0, sizeof bp);
211 memcpy(&bp, bpp, bplen);
212 if (params->flags & IB_TIMEOUT)
213 bp.bp_timeout = htole32(params->timeout);
214 /* Check we aren't trying to set anything we can't save */
215 if (bplen < sizeof bp && memcmp((char *)&bp + bplen,
216 (char *)&bp + bplen + 1,
217 sizeof bp - bplen - 1) != 0) {
218 warnx("Patch area in stage1 bootstrap is too small");
219 goto done;
220 }
221 memcpy(bpp, &bp, bplen);
222
223 if (params->flags & IB_NOWRITE) {
224 retval = 1;
225 goto done;
226 }
227
228 /*
229 * Write MBR code to sector zero.
230 */
231 rv = pwrite(params->fsfd, bootstrapbuf, 512, 0);
232 if (rv == -1) {
233 warn("Writing `%s'", params->filesystem);
234 goto done;
235 } else if (rv != 512) {
236 warnx("Writing `%s': short write", params->filesystem);
237 goto done;
238 }
239
240 /*
241 * Skip disklabel in sector 1 and write bootxx to sectors 2..N.
242 */
243 rv = pwrite(params->fsfd, bootstrapbuf + 512 * 2,
244 bootstrapsize - 512 * 2, 512 * 2);
245 if (rv == -1) {
246 warn("Writing `%s'", params->filesystem);
247 goto done;
248 } else if ((size_t)rv != bootstrapsize - 512 * 2) {
249 warnx("Writing `%s': short write", params->filesystem);
250 goto done;
251 }
252
253 retval = 1;
254
255 done:
256 if (bootstrapbuf)
257 free(bootstrapbuf);
258 return retval;
259 }
260