1 /* $NetBSD: i386.c,v 1.13 2003/10/27 22:29:59 lukem 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 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the NetBSD 21 * Foundation, Inc. and its contributors. 22 * 4. Neither the name of The NetBSD Foundation nor the names of its 23 * contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39 #if HAVE_NBTOOL_CONFIG_H 40 #include "nbtool_config.h" 41 #endif 42 43 #include <sys/cdefs.h> 44 #if !defined(__lint) 45 __RCSID("$NetBSD: i386.c,v 1.13 2003/10/27 22:29:59 lukem Exp $"); 46 #endif /* !__lint */ 47 48 #include <sys/param.h> 49 50 #include <assert.h> 51 #include <err.h> 52 #include <md5.h> 53 #include <stddef.h> 54 #include <stdio.h> 55 #include <stdlib.h> 56 #include <string.h> 57 #include <unistd.h> 58 59 #include "installboot.h" 60 61 int 62 i386_setboot(ib_params *params) 63 { 64 int retval, i, bpbsize; 65 uint8_t *bootstrapbuf; 66 uint bootstrapsize; 67 ssize_t rv; 68 uint32_t magic; 69 struct x86_boot_params *bp; 70 struct mbr_sector mbr; 71 72 assert(params != NULL); 73 assert(params->fsfd != -1); 74 assert(params->filesystem != NULL); 75 assert(params->s1fd != -1); 76 assert(params->stage1 != NULL); 77 78 retval = 0; 79 bootstrapbuf = NULL; 80 81 /* 82 * There is only 8k of space in a UFSv1 partition (and ustarfs) 83 * so ensure we don't splat over anything important. 84 */ 85 if (params->s1stat.st_size > 8192) { 86 warnx("stage1 bootstrap `%s' is larger than 8192 bytes", 87 params->stage1); 88 goto done; 89 } 90 91 /* 92 * Read in the existing MBR. 93 */ 94 rv = pread(params->fsfd, &mbr, sizeof(mbr), MBR_BBSECTOR); 95 if (rv == -1) { 96 warn("Reading `%s'", params->filesystem); 97 goto done; 98 } else if (rv != sizeof(mbr)) { 99 warnx("Reading `%s': short read", params->filesystem); 100 goto done; 101 } 102 if (mbr.mbr_magic != le16toh(MBR_MAGIC)) { 103 if (params->flags & IB_VERBOSE) { 104 printf( 105 "Ignoring MBR with invalid magic in sector 0 of `%s'\n", 106 params->filesystem); 107 } 108 memset(&mbr, 0, sizeof(mbr)); 109 } 110 111 /* 112 * Allocate a buffer, with space to round up the input file 113 * to the next block size boundary, and with space for the boot 114 * block. 115 */ 116 bootstrapsize = roundup(params->s1stat.st_size, 512); 117 118 bootstrapbuf = malloc(bootstrapsize); 119 if (bootstrapbuf == NULL) { 120 warn("Allocating %u bytes", bootstrapsize); 121 goto done; 122 } 123 memset(bootstrapbuf, 0, bootstrapsize); 124 125 /* 126 * Read the file into the buffer. 127 */ 128 rv = pread(params->s1fd, bootstrapbuf, params->s1stat.st_size, 0); 129 if (rv == -1) { 130 warn("Reading `%s'", params->stage1); 131 goto done; 132 } else if (rv != params->s1stat.st_size) { 133 warnx("Reading `%s': short read", params->stage1); 134 goto done; 135 } 136 137 magic = *(uint32_t *)(bootstrapbuf + 512 * 2 + 4); 138 if (magic != htole32(X86_BOOT_MAGIC_1)) { 139 warnx("Invalid magic in stage1 boostrap %x != %x", 140 magic, htole32(X86_BOOT_MAGIC_1)); 141 goto done; 142 } 143 144 /* 145 * Determine size of BIOS Parameter Block (BPB) to copy from 146 * original MBR to the temporary buffer by examining the first 147 * few instruction in the new bootblock. Supported values: 148 * eb 3c 90 jmp ENDOF(mbr_bpbFAT16)+1, nop 149 * eb 58 90 jmp ENDOF(mbr_bpbFAT32)+1, nop 150 * (anything else) ; don't preserve 151 */ 152 bpbsize = 0; 153 if (bootstrapbuf[0] == 0xeb && bootstrapbuf[2] == 0x90 && 154 (bootstrapbuf[1] == 0x3c || bootstrapbuf[1] == 0x58)) 155 bpbsize = bootstrapbuf[1] + 2 - MBR_BPB_OFFSET; 156 157 /* 158 * Ensure bootxx hasn't got any code or date (i.e, non-zero bytes) in 159 * the partition table. 160 */ 161 for (i = 0; i < sizeof(mbr.mbr_parts); i++) { 162 if (*(uint8_t *)(bootstrapbuf + MBR_PART_OFFSET + i) != 0) { 163 warnx( 164 "Partition table has non-zero byte at offset %d in `%s'", 165 MBR_PART_OFFSET + i, params->stage1); 166 goto done; 167 } 168 } 169 170 /* 171 * Copy the BPB and the partition table from the original MBR to the 172 * temporary buffer so that they're written back to the fs. 173 */ 174 if (bpbsize != 0) { 175 if (params->flags & IB_VERBOSE) 176 printf("Preserving %d (%#x) bytes of the BPB\n", 177 bpbsize, bpbsize); 178 memcpy(bootstrapbuf + MBR_BPB_OFFSET, &mbr.mbr_bpb, bpbsize); 179 } 180 memcpy(bootstrapbuf + MBR_PART_OFFSET, &mbr.mbr_parts, 181 sizeof(mbr.mbr_parts)); 182 183 /* 184 * Fill in any user-specified options. 185 */ 186 bp = (void *)(bootstrapbuf + 512 * 2 + 8); 187 if (le32toh(bp->bp_length) < sizeof *bp) { 188 warnx("Patch area in stage1 bootstrap is too small"); 189 goto done; 190 } 191 if (params->flags & IB_TIMEOUT) 192 bp->bp_timeout = htole32(params->timeout); 193 if (params->flags & IB_RESETVIDEO) 194 bp->bp_flags |= htole32(X86_BP_FLAGS_RESET_VIDEO); 195 if (params->flags & IB_CONSPEED) 196 bp->bp_conspeed = htole32(params->conspeed); 197 if (params->flags & IB_CONSOLE) { 198 static const char *names[] = { 199 "pc", "com0", "com1", "com2", "com3", 200 "com0kbd", "com1kbd", "com2kbd", "com3kbd", 201 NULL }; 202 for (i = 0; ; i++) { 203 if (names[i] == NULL) { 204 warnx("invalid console name, valid names are:"); 205 fprintf(stderr, "\t%s", names[0]); 206 for (i = 1; names[i] != NULL; i++) 207 fprintf(stderr, ", %s", names[i]); 208 fprintf(stderr, "\n"); 209 goto done; 210 } 211 if (strcmp(names[i], params->console) == 0) 212 break; 213 } 214 bp->bp_consdev = htole32(i); 215 } 216 if (params->flags & IB_PASSWORD) { 217 MD5_CTX md5ctx; 218 MD5Init(&md5ctx); 219 MD5Update(&md5ctx, params->password, strlen(params->password)); 220 MD5Final(bp->bp_password, &md5ctx); 221 bp->bp_flags |= htole32(X86_BP_FLAGS_PASSWORD); 222 } 223 224 if (params->flags & IB_NOWRITE) { 225 retval = 1; 226 goto done; 227 } 228 229 /* 230 * Write MBR code to sector zero. 231 */ 232 rv = pwrite(params->fsfd, bootstrapbuf, 512, 0); 233 if (rv == -1) { 234 warn("Writing `%s'", params->filesystem); 235 goto done; 236 } else if (rv != 512) { 237 warnx("Writing `%s': short write", params->filesystem); 238 goto done; 239 } 240 241 /* 242 * Skip disklabel in sector 1 and write bootxx to sectors 2..N. 243 */ 244 rv = pwrite(params->fsfd, bootstrapbuf + 512 * 2, 245 bootstrapsize - 512 * 2, 512 * 2); 246 if (rv == -1) { 247 warn("Writing `%s'", params->filesystem); 248 goto done; 249 } else if (rv != bootstrapsize - 512 * 2) { 250 warnx("Writing `%s': short write", params->filesystem); 251 goto done; 252 } 253 254 retval = 1; 255 256 done: 257 if (bootstrapbuf) 258 free(bootstrapbuf); 259 return retval; 260 } 261