Commit 554c7800 authored by Siddharth Aggarwal's avatar Siddharth Aggarwal

adding first time

parent cff2421e
/*-
* Copyright (c) 1999 Michael Smith
* All rights reserved.
* Copyright (c) 1999 Poul-Henning Kamp
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD: src/sys/kern/vfs_conf.c,v 1.49.2.4 2002/02/04 13:08:12 sobomax Exp $
*/
/*
* Locate and mount the root filesystem.
*
* The root filesystem is detailed in the kernel environment variable
* vfs.root.mountfrom, which is expected to be in the general format
*
* <vfsname>:[<path>]
* vfsname := the name of a VFS known to the kernel and capable
* of being mounted as root
* path := disk device name or other data used by the filesystem
* to locate its physical store
*
*/
#include "opt_rootdevname.h"
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/malloc.h>
#include <sys/reboot.h>
#include <sys/diskslice.h>
#include <sys/disklabel.h>
#include <sys/conf.h>
#include <sys/cons.h>
#include <paths.h>
#include "opt_ddb.h"
#ifdef DDB
#include <ddb/ddb.h>
#endif
MALLOC_DEFINE(M_MOUNT, "mount", "vfs mount structure");
#define ROOTNAME "root_device"
struct vnode *rootvnode;
/*
* The root specifiers we will try if RB_CDROM is specified.
*/
static char *cdrom_rootdevnames[] = {
"cd9660:cd0a",
"cd9660:acd0a",
"cd9660:wcd0a",
NULL
};
static void vfs_mountroot(void *junk);
static int vfs_mountroot_try(char *mountfrom);
static int vfs_mountroot_ask(void);
static void gets(char *cp);
/* legacy find-root code */
char *rootdevnames[2] = {NULL, NULL};
static int setrootbyname(char *name);
SYSINIT(mountroot, SI_SUB_MOUNT_ROOT, SI_ORDER_SECOND, vfs_mountroot, NULL);
/*
* Find and mount the root filesystem
*/
void (*shdinitp) (void);
static void
vfs_mountroot(void *junk)
{
int i;
/*
* The root filesystem information is compiled in, and we are
* booted with instructions to use it.
*/
#ifdef ROOTDEVNAME
if ((boothowto & RB_DFLTROOT) &&
!vfs_mountroot_try(ROOTDEVNAME))
return;
#endif
/*
* We are booted with instructions to prompt for the root filesystem,
* or to use the compiled-in default when it doesn't exist.
*/
if (boothowto & (RB_DFLTROOT | RB_ASKNAME)) {
if (!vfs_mountroot_ask())
return;
}
/*
* We've been given the generic "use CDROM as root" flag. This is
* necessary because one media may be used in many different
* devices, so we need to search for them.
*/
if (boothowto & RB_CDROM) {
for (i = 0; cdrom_rootdevnames[i] != NULL; i++) {
if (!vfs_mountroot_try(cdrom_rootdevnames[i]))
return;
}
}
(*shdinitp)();
/*
* Try to use the value read by the loader from /etc/fstab, or
* supplied via some other means. This is the preferred
* mechanism.
*/
if (!vfs_mountroot_try(getenv("vfs.root.mountfrom")))
return;
/*
* Try values that may have been computed by the machine-dependant
* legacy code.
*/
if (!vfs_mountroot_try(rootdevnames[0]))
return;
if (!vfs_mountroot_try(rootdevnames[1]))
return;
/*
* If we have a compiled-in default, and haven't already tried it, try
* it now.
*/
#ifdef ROOTDEVNAME
if (!(boothowto & RB_DFLTROOT))
if (!vfs_mountroot_try(ROOTDEVNAME))
return;
#endif
/*
* Everything so far has failed, prompt on the console if we haven't
* already tried that.
*/
if (!(boothowto & (RB_DFLTROOT | RB_ASKNAME)) && !vfs_mountroot_ask())
return;
panic("Root mount failed, startup aborted.");
}
/*
* Mount (mountfrom) as the root filesystem.
*/
static int
vfs_mountroot_try(char *mountfrom)
{
struct mount *mp;
char *vfsname, *path;
int error;
char patt[32];
int s;
vfsname = NULL;
path = NULL;
mp = NULL;
error = EINVAL;
if (mountfrom == NULL)
return(error); /* don't complain */
s = splcam(); /* Overkill, but annoying without it */
printf("Mounting root from %s\n", mountfrom);
splx(s);
/* parse vfs name and path */
vfsname = malloc(MFSNAMELEN, M_MOUNT, M_WAITOK);
path = malloc(MNAMELEN, M_MOUNT, M_WAITOK);
vfsname[0] = path[0] = 0;
sprintf(patt, "%%%d[a-z0-9]:%%%ds", MFSNAMELEN, MNAMELEN);
if (sscanf(mountfrom, patt, vfsname, path) < 1)
goto done;
/* allocate a root mount */
error = vfs_rootmountalloc(vfsname, path[0] != 0 ? path : ROOTNAME,
&mp);
if (error != 0) {
printf("Can't allocate root mount for filesystem '%s': %d\n",
vfsname, error);
goto done;
}
mp->mnt_flag |= MNT_ROOTFS;
/* do our best to set rootdev */
if ((path[0] != 0) && setrootbyname(path))
printf("setrootbyname failed\n");
/* If the root device is a type "memory disk", mount RW */
if (rootdev != NODEV && devsw(rootdev) &&
(devsw(rootdev)->d_flags & D_MEMDISK))
mp->mnt_flag &= ~MNT_RDONLY;
error = VFS_MOUNT(mp, NULL, NULL, NULL, curproc);
done:
if (vfsname != NULL)
free(vfsname, M_MOUNT);
if (path != NULL)
free(path, M_MOUNT);
if (error != 0) {
if (mp != NULL) {
vfs_unbusy(mp, curproc);
free(mp, M_MOUNT);
}
printf("Root mount failed: %d\n", error);
} else {
/* register with list of mounted filesystems */
simple_lock(&mountlist_slock);
TAILQ_INSERT_HEAD(&mountlist, mp, mnt_list);
simple_unlock(&mountlist_slock);
/* sanity check system clock against root filesystem timestamp */
inittodr(mp->mnt_time);
vfs_unbusy(mp, curproc);
}
return(error);
}
/*
* Spin prompting on the console for a suitable root filesystem
*/
static int
vfs_mountroot_ask(void)
{
char name[128];
int i;
dev_t dev;
for(;;) {
printf("\nManual root filesystem specification:\n");
printf(" <fstype>:<device> Mount <device> using filesystem <fstype>\n");
printf(" eg. ufs:%sda0s1a\n", _PATH_DEV);
printf(" ? List valid disk boot devices\n");
printf(" <empty line> Abort manual input\n");
printf("\nmountroot> ");
gets(name);
if (name[0] == 0)
return(1);
if (name[0] == '?') {
printf("Possibly valid devices for 'ufs' root:\n");
for (i = 0; i < NUMCDEVSW; i++) {
dev = makedev(i, 0);
if (devsw(dev) != NULL)
printf(" \"%s\"", devsw(dev)->d_name);
}
printf("\n");
continue;
}
if (!vfs_mountroot_try(name))
return(0);
}
}
static void
gets(char *cp)
{
char *lp;
int c;
lp = cp;
for (;;) {
printf("%c", c = cngetc() & 0177);
switch (c) {
case -1:
case '\n':
case '\r':
*lp++ = '\0';
return;
case '\b':
case '\177':
if (lp > cp) {
printf(" \b");
lp--;
}
continue;
case '#':
lp--;
if (lp < cp)
lp = cp;
continue;
case '@':
case 'u' & 037:
lp = cp;
printf("%c", '\n');
continue;
default:
*lp++ = c;
}
}
}
/*
* Convert a given name to the dev_t of the disk-like device
* it refers to.
*/
dev_t
getdiskbyname(char *name) {
char *cp;
int cd, unit, slice, part;
dev_t dev;
slice = 0;
part = 0;
cp = rindex(name, '/');
if (cp != NULL) {
name = cp + 1;
}
cp = name;
while (cp != '\0' && (*cp < '0' || *cp > '9'))
cp++;
if (cp == name) {
printf("missing device name\n");
return (NODEV);
}
if (*cp == '\0') {
printf("missing unit number\n");
return (NODEV);
}
unit = *cp - '0';
*cp++ = '\0';
for (cd = 0; cd < NUMCDEVSW; cd++) {
dev = makedev(cd, 0);
if (devsw(dev) != NULL &&
strcmp(devsw(dev)->d_name, name) == 0)
goto gotit;
}
printf("no such device '%s'\n", name);
return (NODEV);
gotit:
while (*cp >= '0' && *cp <= '9')
unit = 10 * unit + *cp++ - '0';
if (*cp == 's' && cp[1] >= '0' && cp[1] <= '9') {
slice = cp[1] - '0' + 1;
cp += 2;
}
if (*cp >= 'a' && *cp <= 'h') {
part = *cp - 'a';
cp++;
}
if (*cp != '\0') {
printf("junk after name\n");
return (NODEV);
}
return (makedev(cd, dkmakeminor(unit, slice, part)));
}
/*
* Set rootdev to match (name), given that we expect it to
* refer to a disk-like device.
*/
static int
setrootbyname(char *name)
{
dev_t diskdev;
diskdev = getdiskbyname(name);
if (diskdev != NODEV) {
rootdev = diskdev;
return (0);
}
return (1);
}
#ifdef DDB
DB_SHOW_COMMAND(disk, db_getdiskbyname)
{
dev_t dev;
if (modif[0] == '\0') {
db_error("usage: show disk/devicename");
return;
}
dev = getdiskbyname(modif);
if (dev != NODEV)
db_printf("dev_t = %p\n", dev);
else
db_printf("No disk device matched.\n");
}
#endif
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