1 /*- 2 * Copyright (c) 1999 Michael Smith 3 * All rights reserved. 4 * Copyright (c) 1999 Poul-Henning Kamp 5 * 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 AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 * 28 * $FreeBSD$ 29 */ 30 31 /* 32 * Locate and mount the root filesystem. 33 * 34 * The root filesystem is detailed in the kernel environment variable 35 * vfs.root.mountfrom, which is expected to be in the general format 36 * 37 * <vfsname>:[<path>] 38 * vfsname := the name of a VFS known to the kernel and capable 39 * of being mounted as root 40 * path := disk device name or other data used by the filesystem 41 * to locate its physical store 42 * 43 */ 44 45 #include <sys/param.h> 46 #include <sys/kernel.h> 47 #include <sys/systm.h> 48 #include <sys/proc.h> 49 #include <sys/vnode.h> 50 #include <sys/mount.h> 51 #include <sys/malloc.h> 52 #include <sys/reboot.h> 53 #include <sys/diskslice.h> 54 #include <sys/disklabel.h> 55 #include <sys/conf.h> 56 #include <sys/cons.h> 57 58 MALLOC_DEFINE(M_MOUNT, "mount", "vfs mount structure"); 59 60 #define ROOTNAME "root_device" 61 62 struct vnode *rootvnode; 63 64 /* 65 * The root specifiers we will try if RB_CDROM is specified. 66 */ 67 static char *cdrom_rootdevnames[] = { 68 "cd9660:cd0a", 69 "cd9660:acd0a", 70 "cd9660:wcd0a", 71 NULL 72 }; 73 74 static void vfs_mountroot(void *junk); 75 static int vfs_mountroot_try(char *mountfrom); 76 static int vfs_mountroot_ask(void); 77 static void gets(char *cp); 78 79 /* legacy find-root code */ 80 char *rootdevnames[2] = {NULL, NULL}; 81 static int setrootbyname(char *name); 82 83 SYSINIT(mountroot, SI_SUB_MOUNT_ROOT, SI_ORDER_SECOND, vfs_mountroot, NULL); 84 85 /* 86 * Find and mount the root filesystem 87 */ 88 static void 89 vfs_mountroot(void *junk) 90 { 91 int i; 92 93 /* 94 * The root filesystem information is compiled in, and we are 95 * booted with instructions to use it. 96 */ 97 #ifdef ROOTDEVNAME 98 if ((boothowto & RB_DFLTROOT) && 99 !vfs_mountroot_try(ROOTDEVNAME)) 100 return; 101 #endif 102 /* 103 * We are booted with instructions to prompt for the root filesystem, 104 * or to use the compiled-in default when it doesn't exist. 105 */ 106 if (boothowto & (RB_DFLTROOT | RB_ASKNAME)) { 107 if (!vfs_mountroot_ask()) 108 return; 109 } 110 111 /* 112 * We've been given the generic "use CDROM as root" flag. This is 113 * necessary because one media may be used in many different 114 * devices, so we need to search for them. 115 */ 116 if (boothowto & RB_CDROM) { 117 for (i = 0; cdrom_rootdevnames[i] != NULL; i++) { 118 if (!vfs_mountroot_try(cdrom_rootdevnames[i])) 119 return; 120 } 121 } 122 123 /* 124 * Try to use the value read by the loader from /etc/fstab, or 125 * supplied via some other means. This is the preferred 126 * mechanism. 127 */ 128 if (!vfs_mountroot_try(getenv("vfs.root.mountfrom"))) 129 return; 130 131 /* 132 * Try values that may have been computed by the machine-dependant 133 * legacy code. 134 */ 135 if (!vfs_mountroot_try(rootdevnames[0])) 136 return; 137 if (!vfs_mountroot_try(rootdevnames[1])) 138 return; 139 140 /* 141 * If we have a compiled-in default, and haven't already tried it, try 142 * it now. 143 */ 144 #ifdef ROOTDEVNAME 145 if (!(boothowto & RB_DFLTROOT)) 146 if (!vfs_mountroot_try(ROOTDEVNAME)) 147 return; 148 #endif 149 150 /* 151 * Everything so far has failed, prompt on the console if we haven't 152 * already tried that. 153 */ 154 if (!(boothowto & (RB_DFLTROOT | RB_ASKNAME)) && !vfs_mountroot_ask()) 155 return; 156 panic("Root mount failed, startup aborted."); 157 } 158 159 /* 160 * Mount (mountfrom) as the root filesystem. 161 */ 162 static int 163 vfs_mountroot_try(char *mountfrom) 164 { 165 struct mount *mp; 166 char *vfsname, *path; 167 int error; 168 char patt[32]; 169 int s; 170 171 vfsname = NULL; 172 path = NULL; 173 mp = NULL; 174 error = EINVAL; 175 176 if (mountfrom == NULL) 177 return(error); /* don't complain */ 178 179 s = splcam(); /* Overkill, but annoying without it */ 180 printf("Mounting root from %s\n", mountfrom); 181 splx(s); 182 183 /* parse vfs name and path */ 184 vfsname = malloc(MFSNAMELEN, M_MOUNT, M_WAITOK); 185 path = malloc(MNAMELEN, M_MOUNT, M_WAITOK); 186 vfsname[0] = path[0] = 0; 187 sprintf(patt, "%%%d[a-z0-9]:%%%ds", MFSNAMELEN, MNAMELEN); 188 if (sscanf(mountfrom, patt, vfsname, path) < 1) 189 goto done; 190 191 /* allocate a root mount */ 192 error = vfs_rootmountalloc(vfsname, path[0] != 0 ? path : ROOTNAME, 193 &mp); 194 if (error != 0) { 195 printf("Can't allocate root mount for filesystem '%s': %d\n", 196 vfsname, error); 197 goto done; 198 } 199 mp->mnt_flag |= MNT_ROOTFS; 200 201 /* do our best to set rootdev */ 202 if ((path[0] != 0) && setrootbyname(path)) 203 printf("setrootbyname failed\n"); 204 205 /* If the root device is a type "memory disk", mount RW */ 206 if (rootdev != NODEV && devsw(rootdev) && 207 (devsw(rootdev)->d_flags & D_MEMDISK)) 208 mp->mnt_flag &= ~MNT_RDONLY; 209 210 error = VFS_MOUNT(mp, NULL, NULL, NULL, curproc); 211 212 done: 213 if (vfsname != NULL) 214 free(vfsname, M_MOUNT); 215 if (path != NULL) 216 free(path, M_MOUNT); 217 if (error != 0) { 218 if (mp != NULL) { 219 vfs_unbusy(mp, curproc); 220 free(mp, M_MOUNT); 221 } 222 printf("Root mount failed: %d\n", error); 223 } else { 224 225 /* register with list of mounted filesystems */ 226 simple_lock(&mountlist_slock); 227 TAILQ_INSERT_HEAD(&mountlist, mp, mnt_list); 228 simple_unlock(&mountlist_slock); 229 230 /* sanity check system clock against root filesystem timestamp */ 231 inittodr(mp->mnt_time); 232 vfs_unbusy(mp, curproc); 233 } 234 return(error); 235 } 236 237 /* 238 * Spin prompting on the console for a suitable root filesystem 239 */ 240 static int 241 vfs_mountroot_ask(void) 242 { 243 char name[128]; 244 int i; 245 dev_t dev; 246 247 for(;;) { 248 printf("\nManual root filesystem specification:\n"); 249 printf(" <fstype>:<device> Mount <device> using filesystem <fstype>\n"); 250 printf(" eg. ufs:/dev/da0s1a\n"); 251 printf(" ? List valid disk boot devices\n"); 252 printf(" <empty line> Abort manual input\n"); 253 printf("\nmountroot> "); 254 gets(name); 255 if (name[0] == 0) 256 return(1); 257 if (name[0] == '?') { 258 printf("Possibly valid devices for 'ufs' root:\n"); 259 for (i = 0; i < NUMCDEVSW; i++) { 260 dev = makedev(i, 0); 261 if (devsw(dev) != NULL) 262 printf(" \"%s\"", devsw(dev)->d_name); 263 } 264 printf("\n"); 265 continue; 266 } 267 if (!vfs_mountroot_try(name)) 268 return(0); 269 } 270 } 271 272 static void 273 gets(char *cp) 274 { 275 char *lp; 276 int c; 277 278 lp = cp; 279 for (;;) { 280 printf("%c", c = cngetc() & 0177); 281 switch (c) { 282 case -1: 283 case '\n': 284 case '\r': 285 *lp++ = '\0'; 286 return; 287 case '\b': 288 case '\177': 289 if (lp > cp) { 290 printf(" \b"); 291 lp--; 292 } 293 continue; 294 case '#': 295 lp--; 296 if (lp < cp) 297 lp = cp; 298 continue; 299 case '@': 300 case 'u' & 037: 301 lp = cp; 302 printf("%c", '\n'); 303 continue; 304 default: 305 *lp++ = c; 306 } 307 } 308 } 309 310 /* 311 * Set rootdev to match (name), given that we expect it to 312 * refer to a disk-like device. 313 */ 314 static int 315 setrootbyname(char *name) 316 { 317 char *cp; 318 int cd, unit, slice, part; 319 dev_t dev; 320 321 slice = 0; 322 part = 0; 323 cp = rindex(name, '/'); 324 if (cp != NULL) { 325 name = cp + 1; 326 } 327 cp = name; 328 while (cp != '\0' && (*cp < '0' || *cp > '9')) 329 cp++; 330 if (cp == name) { 331 printf("missing device name\n"); 332 return(1); 333 } 334 if (*cp == '\0') { 335 printf("missing unit number\n"); 336 return(1); 337 } 338 unit = *cp - '0'; 339 *cp++ = '\0'; 340 for (cd = 0; cd < NUMCDEVSW; cd++) { 341 dev = makedev(cd, 0); 342 if (devsw(dev) != NULL && 343 strcmp(devsw(dev)->d_name, name) == 0) 344 goto gotit; 345 } 346 printf("no such device '%s'\n", name); 347 return (2); 348 gotit: 349 while (*cp >= '0' && *cp <= '9') 350 unit += 10 * unit + *cp++ - '0'; 351 if (*cp == 's' && cp[1] >= '0' && cp[1] <= '9') { 352 slice = cp[1] - '0' + 1; 353 cp += 2; 354 } 355 if (*cp >= 'a' && *cp <= 'h') { 356 part = *cp - 'a'; 357 cp++; 358 } 359 if (*cp != '\0') { 360 printf("junk after name\n"); 361 return (1); 362 } 363 rootdev = makedev(cd, dkmakeminor(unit, slice, part)); 364 return 0; 365 } 366 367