1 /* $OpenBSD: landisk_installboot.c,v 1.12 2022/12/28 21:30:16 jmc Exp $ */ 2 3 /* 4 * Copyright (c) 2013 Joel Sing <jsing@openbsd.org> 5 * 6 * Permission to use, copy, modify, and distribute this software for any 7 * purpose with or without fee is hereby granted, provided that the above 8 * copyright notice and this permission notice appear in all copies. 9 * 10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 17 */ 18 19 #include <sys/param.h> /* DEV_BSIZE */ 20 #include <sys/disklabel.h> 21 #include <sys/dkio.h> 22 #include <sys/ioctl.h> 23 #include <sys/stat.h> 24 25 #include <ufs/ffs/fs.h> 26 27 #include <err.h> 28 #include <fcntl.h> 29 #include <stdio.h> 30 #include <stdlib.h> 31 #include <string.h> 32 #include <unistd.h> 33 34 #include "installboot.h" 35 36 void md_bootstrap(int, char *, char *); 37 38 char *bootldr; 39 40 void 41 md_init(void) 42 { 43 stages = 2; 44 stage1 = "/usr/mdec/xxboot"; 45 stage2 = "/usr/mdec/boot"; 46 47 bootldr = "/boot"; 48 } 49 50 void 51 md_loadboot(void) 52 { 53 } 54 55 void 56 md_prepareboot(int devfd, char *dev) 57 { 58 } 59 60 void 61 md_installboot(int devfd, char *dev) 62 { 63 /* XXX - is this necessary? */ 64 sync(); 65 66 bootldr = fileprefix(root, bootldr); 67 if (bootldr == NULL) 68 exit(1); 69 if (!nowrite) 70 if (filecopy(stage2, bootldr) == -1) 71 exit(1); 72 73 /* 74 * Write bootblock into the beginning of the OpenBSD partition or 75 * at the beginning of the disk. 76 */ 77 md_bootstrap(devfd, dev, stage1); 78 } 79 80 void 81 md_bootstrap(int devfd, char *dev, char *bootfile) 82 { 83 struct disklabel dl; 84 struct disklabel *lp; 85 struct partition *pp; 86 char *boot, *p, part; 87 size_t bootsize; 88 size_t bootsec; 89 struct stat sb; 90 daddr_t bootpos = 0; 91 int fd, i; 92 93 /* 94 * Install bootstrap code onto the given disk, preserving the 95 * existing disklabel. 96 */ 97 98 /* Read disklabel from disk. */ 99 if (ioctl(devfd, DIOCGDINFO, &dl) == -1) 100 err(1, "disklabel"); 101 if (dl.d_secsize == 0) { 102 warnx("disklabel has sector size of 0, assuming %d", DEV_BSIZE); 103 dl.d_secsize = DEV_BSIZE; 104 } 105 106 /* Read bootstrap file. */ 107 if (verbose) 108 fprintf(stderr, "reading bootstrap from %s\n", bootfile); 109 fd = open(bootfile, O_RDONLY); 110 if (fd == -1) 111 err(1, "open %s", bootfile); 112 if (fstat(fd, &sb) == -1) 113 err(1, "fstat %s", bootfile); 114 bootsec = howmany((ssize_t)sb.st_size, dl.d_secsize); 115 bootsize = bootsec * dl.d_secsize; 116 if (verbose) 117 fprintf(stderr, "bootstrap is %zu bytes " 118 "(%zu sectors @ %u bytes = %zu bytes)\n", 119 (ssize_t)sb.st_size, bootsec, dl.d_secsize, bootsize); 120 boot = calloc(1, bootsize); 121 if (boot == NULL) 122 err(1, "calloc"); 123 if (read(fd, boot, bootsize) != (ssize_t)sb.st_size) 124 err(1, "read"); 125 close(fd); 126 127 /* 128 * The landisk bootstrap can work when put either at the start of the 129 * disk, or at the start of an OpenBSD MBR partition, invoked from 130 * /usr/mdec/mbr. 131 * Check for a partition table in order to decide where to put the 132 * first-level bootstrap code. 133 */ 134 135 if (dl.d_secsize >= sizeof(struct dos_mbr)) { 136 uint8_t *secbuf; 137 struct dos_mbr *mbr; 138 139 secbuf = malloc(dl.d_secsize); 140 if (secbuf == NULL) 141 err(1, "malloc"); 142 143 /* Read MBR. */ 144 if (pread(devfd, secbuf, dl.d_secsize, 0) != dl.d_secsize) 145 err(4, "can't read mbr"); 146 mbr = (struct dos_mbr *)secbuf; 147 /* safe check because landisk is little endian */ 148 if (mbr->dmbr_sign == DOSMBR_SIGNATURE) { 149 for (i = 0; i < NDOSPART; i++) { 150 if (mbr->dmbr_parts[i].dp_typ == 151 DOSPTYP_OPENBSD) { 152 bootpos = mbr->dmbr_parts[i].dp_start; 153 break; 154 } 155 } 156 } 157 158 free(secbuf); 159 } 160 161 if (bootpos == 0) { 162 /* 163 * Installing at the start of the disk. 164 * Check that the bootstrap will fit - partitions must not 165 * overlap, or if they do, the partition type must be either 166 * FS_BOOT or FS_UNUSED. The 'c' partition will always overlap 167 * and is ignored. 168 */ 169 if (verbose) 170 fprintf(stderr, 171 "ensuring used partitions do not overlap " 172 "with bootstrap sectors 0-%zu\n", bootsec); 173 for (i = 0; i < dl.d_npartitions; i++) { 174 part = 'a' + i; 175 pp = &dl.d_partitions[i]; 176 if (i == RAW_PART) 177 continue; 178 if (DL_GETPSIZE(pp) == 0) 179 continue; 180 if (bootpos + (u_int64_t)bootsec <= DL_GETPOFFSET(pp)) 181 continue; 182 switch (pp->p_fstype) { 183 case FS_BOOT: 184 break; 185 case FS_UNUSED: 186 warnx("bootstrap overlaps " 187 "with unused partition %c", part); 188 break; 189 default: 190 errx(1, "bootstrap overlaps with partition %c", 191 part); 192 } 193 } 194 } else { 195 /* 196 * Installing at the start of the OpenBSD partition. 197 * We only need to ensure the bootstrap code fits in the 198 * BBSIZE reserved area at the beginning of the file 199 * system. 200 */ 201 if (bootsize > BBSIZE) 202 errx(1, "bootstrap is too large"); 203 } 204 205 /* 206 * Make sure the bootstrap has left space for the disklabel. 207 * N.B.: LABELSECTOR *is* a DEV_BSIZE quantity! 208 */ 209 lp = (struct disklabel *)(boot + (LABELSECTOR * DEV_BSIZE) + 210 LABELOFFSET); 211 for (i = 0, p = (char *)lp; i < (int)sizeof(*lp); i++) 212 if (p[i] != 0) 213 errx(1, "bootstrap has data in disklabel area"); 214 215 /* Patch the disklabel into the bootstrap code. */ 216 memcpy(lp, &dl, sizeof(dl)); 217 218 /* Write the bootstrap out to the disk. */ 219 bootpos *= dl.d_secsize; 220 if (verbose) 221 fprintf(stderr, "%s bootstrap to disk at offset %llx\n", 222 (nowrite ? "would write" : "writing"), bootpos); 223 if (nowrite) 224 return; 225 if (pwrite(devfd, boot, bootsize, bootpos) != (ssize_t)bootsize) 226 err(1, "pwrite"); 227 } 228