2 * Copyright (c) 1999 Michael Smith
4 * Copyright (c) 1999 Poul-Henning Kamp
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
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.
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
32 * Locate and mount the root filesystem.
34 * The root filesystem is detailed in the kernel environment variable
35 * vfs.root.mountfrom, which is expected to be in the general format
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
45 #include <sys/param.h>
46 #include <sys/kernel.h>
47 #include <sys/systm.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>
58 MALLOC_DEFINE(M_MOUNT, "mount", "vfs mount structure");
60 #define ROOTNAME "root_device"
62 struct vnode *rootvnode;
65 * The root specifiers we will try if RB_CDROM is specified.
67 static char *cdrom_rootdevnames[] = {
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);
79 /* legacy find-root code */
80 char *rootdevnames[2] = {NULL, NULL};
81 static int setrootbyname(char *name);
83 SYSINIT(mountroot, SI_SUB_MOUNT_ROOT, SI_ORDER_SECOND, vfs_mountroot, NULL);
86 * Find and mount the root filesystem
89 vfs_mountroot(void *junk)
94 * The root filesystem information is compiled in, and we are
95 * booted with instructions to use it.
98 if ((boothowto & RB_DFLTROOT) &&
99 !vfs_mountroot_try(ROOTDEVNAME))
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.
106 if (boothowto & (RB_DFLTROOT | RB_ASKNAME)) {
107 if (!vfs_mountroot_ask())
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.
116 if (boothowto & RB_CDROM) {
117 for (i = 0; cdrom_rootdevnames[i] != NULL; i++) {
118 if (!vfs_mountroot_try(cdrom_rootdevnames[i]))
124 * Try to use the value read by the loader from /etc/fstab, or
125 * supplied via some other means. This is the preferred
128 if (!vfs_mountroot_try(getenv("vfs.root.mountfrom")))
132 * Try values that may have been computed by the machine-dependant
135 if (!vfs_mountroot_try(rootdevnames[0]))
137 if (!vfs_mountroot_try(rootdevnames[1]))
141 * If we have a compiled-in default, and haven't already tried it, try
145 if (!(boothowto & RB_DFLTROOT))
146 if (!vfs_mountroot_try(ROOTDEVNAME))
151 * Everything so far has failed, prompt on the console if we haven't
152 * already tried that.
154 if (!(boothowto & (RB_DFLTROOT | RB_ASKNAME)) && !vfs_mountroot_ask())
156 panic("Root mount failed, startup aborted.");
160 * Mount (mountfrom) as the root filesystem.
163 vfs_mountroot_try(char *mountfrom)
166 char *vfsname, *path;
175 if (mountfrom == NULL)
176 return(error); /* don't complain */
178 printf("Mounting root from %s\n", mountfrom);
180 /* parse vfs name and path */
181 vfsname = malloc(MFSNAMELEN, M_MOUNT, M_WAITOK);
182 path = malloc(MNAMELEN, M_MOUNT, M_WAITOK);
183 vfsname[0] = path[0] = 0;
184 sprintf(patt, "%%%d[a-z0-9]:%%%ds", MFSNAMELEN, MNAMELEN);
185 if (sscanf(mountfrom, patt, vfsname, path) < 1)
188 /* allocate a root mount */
189 if ((error = vfs_rootmountalloc(vfsname, ROOTNAME, &mp))) {
190 printf("Can't allocate root mount for filesystem '%s': %d\n",
194 mp->mnt_flag |= MNT_ROOTFS;
196 /* do our best to set rootdev */
197 if ((path[0] != 0) && setrootbyname(path))
198 printf("setrootbyname failed\n");
200 strcpy(mp->mnt_stat.f_mntfromname, path);
201 error = VFS_MOUNT(mp, NULL, NULL, NULL, curproc);
205 free(vfsname, M_MOUNT);
211 printf("Root mount failed: %d\n", error);
214 /* register with list of mounted filesystems */
215 simple_lock(&mountlist_slock);
216 TAILQ_INSERT_HEAD(&mountlist, mp, mnt_list);
217 simple_unlock(&mountlist_slock);
219 /* sanity check system clock against root filesystem timestamp */
220 inittodr(mp->mnt_time);
223 vfs_unbusy(mp, curproc);
228 * Spin prompting on the console for a suitable root filesystem
231 vfs_mountroot_ask(void)
238 printf("\nManual root filesystem specification:\n");
239 printf(" <fstype>:<device> Mount <device> using filesystem <fstype>\n");
240 printf(" eg. ufs:/dev/da0s1a\n");
241 printf(" ? List valid disk boot devices\n");
242 printf(" <empty line> Abort manual input\n");
247 if (name[0] == '?') {
248 printf("Possibly valid devices for 'ufs' root:\n");
249 for (i = 0; i < NUMCDEVSW; i++) {
250 dev = makebdev(i, 0);
251 if (devsw(dev) != NULL)
252 printf(" \"%s\"", devsw(dev)->d_name);
257 if (!vfs_mountroot_try(name))
270 printf("%c", c = cngetc() & 0177);
301 * Set rootdev to match (name), given that we expect it to
302 * refer to a disk-like device.
305 setrootbyname(char *name)
308 int bd, unit, slice, part;
313 cp = rindex(name, '/');
320 while (cp != '\0' && (*cp < '0' || *cp > '9'))
323 printf("missing device name\n");
327 printf("missing unit number\n");
332 for (bd = 0; bd < NUMCDEVSW; bd++) {
333 dev = makebdev(bd, 0);
334 if (devsw(dev) != NULL &&
335 strcmp(devsw(dev)->d_name, name) == 0)
338 printf("no such device '%s'\n", name);
341 while (*cp >= '0' && *cp <= '9')
342 unit += 10 * unit + *cp++ - '0';
343 if (*cp == 's' && cp[1] >= '0' && cp[1] <= '9') {
344 slice = cp[1] - '0' + 1;
347 if (*cp >= 'a' && *cp <= 'h') {
352 printf("junk after name\n");
355 rootdev = makebdev(bd, dkmakeminor(unit, slice, part));