1 /* $NetBSD: i386.c,v 1.18 2004/08/16 05:57:52 yamt 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 1.18 2004/08/16 05:57:52 yamt 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 u_int bootstrapsize; 67 ssize_t rv; 68 uint32_t magic; 69 struct x86_boot_params bp, *bpp; 70 int bplen; 71 struct mbr_sector mbr; 72 73 assert(params != NULL); 74 assert(params->fsfd != -1); 75 assert(params->filesystem != NULL); 76 assert(params->s1fd != -1); 77 assert(params->stage1 != NULL); 78 79 retval = 0; 80 bootstrapbuf = NULL; 81 82 /* 83 * There is only 8k of space in a UFSv1 partition (and ustarfs) 84 * so ensure we don't splat over anything important. 85 */ 86 if (params->s1stat.st_size > 8192) { 87 warnx("stage1 bootstrap `%s' is larger than 8192 bytes", 88 params->stage1); 89 goto done; 90 } 91 92 /* 93 * Read in the existing MBR. 94 */ 95 rv = pread(params->fsfd, &mbr, sizeof(mbr), MBR_BBSECTOR); 96 if (rv == -1) { 97 warn("Reading `%s'", params->filesystem); 98 goto done; 99 } else if (rv != sizeof(mbr)) { 100 warnx("Reading `%s': short read", params->filesystem); 101 goto done; 102 } 103 if (mbr.mbr_magic != le16toh(MBR_MAGIC)) { 104 if (params->flags & IB_VERBOSE) { 105 printf( 106 "Ignoring MBR with invalid magic in sector 0 of `%s'\n", 107 params->filesystem); 108 } 109 memset(&mbr, 0, sizeof(mbr)); 110 } 111 112 /* 113 * Allocate a buffer, with space to round up the input file 114 * to the next block size boundary, and with space for the boot 115 * block. 116 */ 117 bootstrapsize = roundup(params->s1stat.st_size, 512); 118 119 bootstrapbuf = malloc(bootstrapsize); 120 if (bootstrapbuf == NULL) { 121 warn("Allocating %u bytes", bootstrapsize); 122 goto done; 123 } 124 memset(bootstrapbuf, 0, bootstrapsize); 125 126 /* 127 * Read the file into the buffer. 128 */ 129 rv = pread(params->s1fd, bootstrapbuf, params->s1stat.st_size, 0); 130 if (rv == -1) { 131 warn("Reading `%s'", params->stage1); 132 goto done; 133 } else if (rv != params->s1stat.st_size) { 134 warnx("Reading `%s': short read", params->stage1); 135 goto done; 136 } 137 138 magic = *(uint32_t *)(bootstrapbuf + 512 * 2 + 4); 139 if (magic != htole32(X86_BOOT_MAGIC_1)) { 140 warnx("Invalid magic in stage1 boostrap %x != %x", 141 magic, htole32(X86_BOOT_MAGIC_1)); 142 goto done; 143 } 144 145 /* 146 * Determine size of BIOS Parameter Block (BPB) to copy from 147 * original MBR to the temporary buffer by examining the first 148 * few instruction in the new bootblock. Supported values: 149 * eb 3c 90 jmp ENDOF(mbr_bpbFAT16)+1, nop 150 * eb 58 90 jmp ENDOF(mbr_bpbFAT32)+1, nop 151 * (anything else) ; don't preserve 152 */ 153 bpbsize = 0; 154 if (bootstrapbuf[0] == 0xeb && bootstrapbuf[2] == 0x90 && 155 (bootstrapbuf[1] == 0x3c || bootstrapbuf[1] == 0x58)) 156 bpbsize = bootstrapbuf[1] + 2 - MBR_BPB_OFFSET; 157 158 /* 159 * Ensure bootxx hasn't got any code or data (i.e, non-zero bytes) in 160 * the partition table. 161 */ 162 for (i = 0; i < sizeof(mbr.mbr_parts); i++) { 163 if (*(uint8_t *)(bootstrapbuf + MBR_PART_OFFSET + i) != 0) { 164 warnx( 165 "Partition table has non-zero byte at offset %d in `%s'", 166 MBR_PART_OFFSET + i, params->stage1); 167 goto done; 168 } 169 } 170 171 /* 172 * Copy the BPB and the partition table from the original MBR to the 173 * temporary buffer so that they're written back to the fs. 174 */ 175 if (bpbsize != 0) { 176 if (params->flags & IB_VERBOSE) 177 printf("Preserving %d (%#x) bytes of the BPB\n", 178 bpbsize, bpbsize); 179 memcpy(bootstrapbuf + MBR_BPB_OFFSET, &mbr.mbr_bpb, bpbsize); 180 } 181 memcpy(bootstrapbuf + MBR_PART_OFFSET, &mbr.mbr_parts, 182 sizeof(mbr.mbr_parts)); 183 184 /* 185 * Fill in any user-specified options into the 186 * struct x86_boot_params 187 * that's 8 bytes in from the start of the third sector. 188 * See sys/arch/i386/stand/bootxx/bootxx.S for more information. 189 */ 190 bpp = (void *)(bootstrapbuf + 512 * 2 + 8); 191 bplen = le32toh(bpp->bp_length); 192 if (bplen > sizeof bp) 193 /* Ignore pad space in bootxx */ 194 bplen = sizeof bp; 195 /* Take (and update) local copy so we handle size mismatches */ 196 memset(&bp, 0, sizeof bp); 197 memcpy(&bp, bpp, bplen); 198 if (params->flags & IB_TIMEOUT) 199 bp.bp_timeout = htole32(params->timeout); 200 if (params->flags & IB_RESETVIDEO) 201 bp.bp_flags |= htole32(X86_BP_FLAGS_RESET_VIDEO); 202 if (params->flags & IB_CONSPEED) 203 bp.bp_conspeed = htole32(params->conspeed); 204 if (params->flags & IB_CONSADDR) 205 bp.bp_consaddr = htole32(params->consaddr); 206 if (params->flags & IB_CONSOLE) { 207 static const char *names[] = { 208 "pc", "com0", "com1", "com2", "com3", 209 "com0kbd", "com1kbd", "com2kbd", "com3kbd", 210 NULL }; 211 for (i = 0; ; i++) { 212 if (names[i] == NULL) { 213 warnx("invalid console name, valid names are:"); 214 fprintf(stderr, "\t%s", names[0]); 215 for (i = 1; names[i] != NULL; i++) 216 fprintf(stderr, ", %s", names[i]); 217 fprintf(stderr, "\n"); 218 goto done; 219 } 220 if (strcmp(names[i], params->console) == 0) 221 break; 222 } 223 bp.bp_consdev = htole32(i); 224 } 225 if (params->flags & IB_PASSWORD) { 226 MD5_CTX md5ctx; 227 MD5Init(&md5ctx); 228 MD5Update(&md5ctx, params->password, strlen(params->password)); 229 MD5Final(bp.bp_password, &md5ctx); 230 bp.bp_flags |= htole32(X86_BP_FLAGS_PASSWORD); 231 } 232 if (params->flags & IB_KEYMAP) 233 strlcpy(bp.bp_keymap, params->keymap, sizeof bp.bp_keymap); 234 /* Check we aren't trying to set anything we can't save */ 235 if (bplen < sizeof bp && memcmp((char *)&bp + bplen, 236 (char *)&bp + bplen + 1, 237 sizeof bp - bplen - 1) != 0) { 238 warnx("Patch area in stage1 bootstrap is too small"); 239 goto done; 240 } 241 memcpy(bpp, &bp, bplen); 242 243 if (params->flags & IB_NOWRITE) { 244 retval = 1; 245 goto done; 246 } 247 248 /* 249 * Write MBR code to sector zero. 250 */ 251 rv = pwrite(params->fsfd, bootstrapbuf, 512, 0); 252 if (rv == -1) { 253 warn("Writing `%s'", params->filesystem); 254 goto done; 255 } else if (rv != 512) { 256 warnx("Writing `%s': short write", params->filesystem); 257 goto done; 258 } 259 260 /* 261 * Skip disklabel in sector 1 and write bootxx to sectors 2..N. 262 */ 263 rv = pwrite(params->fsfd, bootstrapbuf + 512 * 2, 264 bootstrapsize - 512 * 2, 512 * 2); 265 if (rv == -1) { 266 warn("Writing `%s'", params->filesystem); 267 goto done; 268 } else if (rv != bootstrapsize - 512 * 2) { 269 warnx("Writing `%s': short write", params->filesystem); 270 goto done; 271 } 272 273 retval = 1; 274 275 done: 276 if (bootstrapbuf) 277 free(bootstrapbuf); 278 return retval; 279 } 280