Home | History | Annotate | Line # | Download | only in kern
kern_subr.c revision 1.27 
      1 /*	$NetBSD: kern_subr.c,v 1.27 1997/06/16 00:25:05 thorpej Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1997 Jason R. Thorpe.  All rights reserved.
      5  * Copyright (c) 1982, 1986, 1991, 1993
      6  *	The Regents of the University of California.  All rights reserved.
      7  * (c) UNIX System Laboratories, Inc.
      8  * All or some portions of this file are derived from material licensed
      9  * to the University of California by American Telephone and Telegraph
     10  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
     11  * the permission of UNIX System Laboratories, Inc.
     12  *
     13  * Copyright (c) 1992, 1993
     14  *	The Regents of the University of California.  All rights reserved.
     15  *
     16  * This software was developed by the Computer Systems Engineering group
     17  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
     18  * contributed to Berkeley.
     19  *
     20  * All advertising materials mentioning features or use of this software
     21  * must display the following acknowledgement:
     22  *	This product includes software developed by the University of
     23  *	California, Lawrence Berkeley Laboratory.
     24  *
     25  * Redistribution and use in source and binary forms, with or without
     26  * modification, are permitted provided that the following conditions
     27  * are met:
     28  * 1. Redistributions of source code must retain the above copyright
     29  *    notice, this list of conditions and the following disclaimer.
     30  * 2. Redistributions in binary form must reproduce the above copyright
     31  *    notice, this list of conditions and the following disclaimer in the
     32  *    documentation and/or other materials provided with the distribution.
     33  * 3. All advertising materials mentioning features or use of this software
     34  *    must display the following acknowledgement:
     35  *	This product includes software developed by the University of
     36  *	California, Berkeley and its contributors.
     37  * 4. Neither the name of the University nor the names of its contributors
     38  *    may be used to endorse or promote products derived from this software
     39  *    without specific prior written permission.
     40  *
     41  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     42  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     43  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     44  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     45  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     46  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     47  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     49  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     50  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     51  * SUCH DAMAGE.
     52  *
     53  *	@(#)kern_subr.c	8.3 (Berkeley) 1/21/94
     54  */
     55 
     56 #include <sys/param.h>
     57 #include <sys/systm.h>
     58 #include <sys/proc.h>
     59 #include <sys/malloc.h>
     60 #include <sys/mount.h>
     61 #include <sys/device.h>
     62 #include <sys/reboot.h>
     63 #include <sys/conf.h>
     64 #include <sys/disklabel.h>
     65 #include <sys/queue.h>
     66 
     67 #include <dev/cons.h>
     68 
     69 #include <net/if.h>
     70 
     71 /* XXX these should eventually move to subr_autoconf.c */
     72 static int findblkmajor __P((const char *, struct devnametobdevmaj *));
     73 static const char *findblkname __P((int, struct devnametobdevmaj *));
     74 static struct device *getdisk __P((char *, int, int,
     75 	struct devnametobdevmaj *, dev_t *, int));
     76 static struct device *parsedisk __P((char *, int, int,
     77 	struct devnametobdevmaj *, dev_t *));
     78 static int getstr __P((char *, int));
     79 
     80 int
     81 uiomove(buf, n, uio)
     82 	register void *buf;
     83 	register int n;
     84 	register struct uio *uio;
     85 {
     86 	register struct iovec *iov;
     87 	u_int cnt;
     88 	int error = 0;
     89 	char *cp = buf;
     90 
     91 #ifdef DIAGNOSTIC
     92 	if (uio->uio_rw != UIO_READ && uio->uio_rw != UIO_WRITE)
     93 		panic("uiomove: mode");
     94 	if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc)
     95 		panic("uiomove proc");
     96 #endif
     97 	while (n > 0 && uio->uio_resid) {
     98 		iov = uio->uio_iov;
     99 		cnt = iov->iov_len;
    100 		if (cnt == 0) {
    101 			uio->uio_iov++;
    102 			uio->uio_iovcnt--;
    103 			continue;
    104 		}
    105 		if (cnt > n)
    106 			cnt = n;
    107 		switch (uio->uio_segflg) {
    108 
    109 		case UIO_USERSPACE:
    110 			if (uio->uio_rw == UIO_READ)
    111 				error = copyout(cp, iov->iov_base, cnt);
    112 			else
    113 				error = copyin(iov->iov_base, cp, cnt);
    114 			if (error)
    115 				return (error);
    116 			break;
    117 
    118 		case UIO_SYSSPACE:
    119 			if (uio->uio_rw == UIO_READ)
    120 				bcopy(cp, iov->iov_base, cnt);
    121 			else
    122 				bcopy(iov->iov_base, cp, cnt);
    123 			break;
    124 		}
    125 		iov->iov_base += cnt;
    126 		iov->iov_len -= cnt;
    127 		uio->uio_resid -= cnt;
    128 		uio->uio_offset += cnt;
    129 		cp += cnt;
    130 		n -= cnt;
    131 	}
    132 	return (error);
    133 }
    134 
    135 /*
    136  * Give next character to user as result of read.
    137  */
    138 int
    139 ureadc(c, uio)
    140 	register int c;
    141 	register struct uio *uio;
    142 {
    143 	register struct iovec *iov;
    144 
    145 	if (uio->uio_resid <= 0)
    146 		panic("ureadc: non-positive resid");
    147 again:
    148 	if (uio->uio_iovcnt <= 0)
    149 		panic("ureadc: non-positive iovcnt");
    150 	iov = uio->uio_iov;
    151 	if (iov->iov_len <= 0) {
    152 		uio->uio_iovcnt--;
    153 		uio->uio_iov++;
    154 		goto again;
    155 	}
    156 	switch (uio->uio_segflg) {
    157 
    158 	case UIO_USERSPACE:
    159 		if (subyte(iov->iov_base, c) < 0)
    160 			return (EFAULT);
    161 		break;
    162 
    163 	case UIO_SYSSPACE:
    164 		*iov->iov_base = c;
    165 		break;
    166 	}
    167 	iov->iov_base++;
    168 	iov->iov_len--;
    169 	uio->uio_resid--;
    170 	uio->uio_offset++;
    171 	return (0);
    172 }
    173 
    174 /*
    175  * General routine to allocate a hash table.
    176  */
    177 void *
    178 hashinit(elements, type, hashmask)
    179 	int elements, type;
    180 	u_long *hashmask;
    181 {
    182 	long hashsize;
    183 	LIST_HEAD(generic, generic) *hashtbl;
    184 	int i;
    185 
    186 	if (elements <= 0)
    187 		panic("hashinit: bad cnt");
    188 	for (hashsize = 1; hashsize <= elements; hashsize <<= 1)
    189 		continue;
    190 	hashsize >>= 1;
    191 	hashtbl = malloc((u_long)hashsize * sizeof(*hashtbl), type, M_WAITOK);
    192 	for (i = 0; i < hashsize; i++)
    193 		LIST_INIT(&hashtbl[i]);
    194 	*hashmask = hashsize - 1;
    195 	return (hashtbl);
    196 }
    197 
    198 /*
    199  * "Shutdown hook" types, functions, and variables.
    200  */
    201 
    202 struct shutdownhook_desc {
    203 	LIST_ENTRY(shutdownhook_desc) sfd_list;
    204 	void	(*sfd_fn) __P((void *));
    205 	void	*sfd_arg;
    206 };
    207 
    208 LIST_HEAD(, shutdownhook_desc) shutdownhook_list;
    209 
    210 void *
    211 shutdownhook_establish(fn, arg)
    212 	void (*fn) __P((void *));
    213 	void *arg;
    214 {
    215 	struct shutdownhook_desc *ndp;
    216 
    217 	ndp = (struct shutdownhook_desc *)
    218 	    malloc(sizeof (*ndp), M_DEVBUF, M_NOWAIT);
    219 	if (ndp == NULL)
    220 		return NULL;
    221 
    222 	ndp->sfd_fn = fn;
    223 	ndp->sfd_arg = arg;
    224 	LIST_INSERT_HEAD(&shutdownhook_list, ndp, sfd_list);
    225 
    226 	return (ndp);
    227 }
    228 
    229 void
    230 shutdownhook_disestablish(vhook)
    231 	void *vhook;
    232 {
    233 #ifdef DIAGNOSTIC
    234 	struct shutdownhook_desc *dp;
    235 
    236 	for (dp = shutdownhook_list.lh_first; dp != NULL;
    237 	    dp = dp->sfd_list.le_next)
    238                 if (dp == vhook)
    239 			break;
    240 	if (dp == NULL)
    241 		panic("shutdownhook_disestablish: hook not established");
    242 #endif
    243 
    244 	LIST_REMOVE((struct shutdownhook_desc *)vhook, sfd_list);
    245 	free(vhook, M_DEVBUF);
    246 }
    247 
    248 /*
    249  * Run shutdown hooks.  Should be invoked immediately before the
    250  * system is halted or rebooted, i.e. after file systems unmounted,
    251  * after crash dump done, etc.
    252  *
    253  * Each shutdown hook is removed from the list before it's run, so that
    254  * it won't be run again.
    255  */
    256 void
    257 doshutdownhooks()
    258 {
    259 	struct shutdownhook_desc *dp;
    260 
    261 	while ((dp = shutdownhook_list.lh_first) != NULL) {
    262 		LIST_REMOVE(dp, sfd_list);
    263 		(*dp->sfd_fn)(dp->sfd_arg);
    264 #if 0
    265 		/*
    266 		 * Don't bother freeing the hook structure,, since we may
    267 		 * be rebooting because of a memory corruption problem,
    268 		 * and this might only make things worse.  It doesn't
    269 		 * matter, anyway, since the system is just about to
    270 		 * reboot.
    271 		 */
    272 		free(dp, M_DEVBUF);
    273 #endif
    274 	}
    275 }
    276 
    277 /*
    278  * "Mountroot hook" types, functions, and variables.
    279  */
    280 
    281 struct mountroothook_desc {
    282 	LIST_ENTRY(mountroothook_desc) mrd_list;
    283 	struct	device *mrd_device;
    284 	void 	(*mrd_func) __P((struct device *));
    285 };
    286 
    287 LIST_HEAD(, mountroothook_desc) mountroothook_list;
    288 
    289 void *
    290 mountroothook_establish(func, dev)
    291 	void (*func) __P((struct device *));
    292 	struct device *dev;
    293 {
    294 	struct mountroothook_desc *mrd;
    295 
    296 	mrd = (struct mountroothook_desc *)
    297 	    malloc(sizeof(*mrd), M_DEVBUF, M_NOWAIT);
    298 	if (mrd == NULL)
    299 		return (NULL);
    300 
    301 	mrd->mrd_device = dev;
    302 	mrd->mrd_func = func;
    303 	LIST_INSERT_HEAD(&mountroothook_list, mrd, mrd_list);
    304 
    305 	return (mrd);
    306 }
    307 
    308 void
    309 mountroothook_disestablish(vhook)
    310 	void *vhook;
    311 {
    312 #ifdef DIAGNOSTIC
    313 	struct mountroothook_desc *mrd;
    314 
    315 	for (mrd = mountroothook_list.lh_first; mrd != NULL;
    316 	    mrd = mrd->mrd_list.le_next)
    317                 if (mrd == vhook)
    318 			break;
    319 	if (mrd == NULL)
    320 		panic("mountroothook_disestablish: hook not established");
    321 #endif
    322 
    323 	LIST_REMOVE((struct mountroothook_desc *)vhook, mrd_list);
    324 	free(vhook, M_DEVBUF);
    325 }
    326 
    327 void
    328 mountroothook_destroy()
    329 {
    330 	struct mountroothook_desc *mrd;
    331 
    332 	while ((mrd = mountroothook_list.lh_first) != NULL) {
    333 		LIST_REMOVE(mrd, mrd_list);
    334 		free(mrd, M_DEVBUF);
    335 	}
    336 }
    337 
    338 void
    339 domountroothook()
    340 {
    341 	struct mountroothook_desc *mrd;
    342 
    343 	for (mrd = mountroothook_list.lh_first; mrd != NULL;
    344 	    mrd = mrd->mrd_list.le_next) {
    345 		if (mrd->mrd_device == root_device) {
    346 			(*mrd->mrd_func)(root_device);
    347 			return;
    348 		}
    349 	}
    350 }
    351 
    352 /*
    353  * Determine the root device and, if instructed to, the root file system.
    354  */
    355 
    356 #include "md.h"
    357 #if NMD == 0
    358 #undef MEMORY_DISK_HOOKS
    359 #endif
    360 
    361 #ifdef MEMORY_DISK_HOOKS
    362 static struct device fakemdrootdev = { DV_DISK, {}, NULL, 0, "md0", NULL };
    363 #endif
    364 
    365 void
    366 setroot(bootdv, bootpartition, nam2blk)
    367 	struct device *bootdv;
    368 	int bootpartition;
    369 	struct devnametobdevmaj *nam2blk;
    370 {
    371 	struct device *dv;
    372 	register int len, i;
    373 	dev_t nrootdev;
    374 	dev_t ndumpdev = NODEV;
    375 	char buf[128];
    376 	const char *rootdevname;
    377 	const char *dumpdevname;
    378 	struct device *rootdv = NULL;		/* XXX gcc -Wuninitialized */
    379 	struct device *dumpdv = NULL;
    380 	struct ifnet *ifp;
    381 	const char *deffsname;
    382 	struct vfsops *vops;
    383 	extern int (*mountroot) __P((void));
    384 	static struct devnametobdevmaj *last_nam2blk;
    385 
    386 	if (nam2blk == NULL) {
    387 		if (last_nam2blk == NULL)
    388 			panic("setroot: no name to bdev major map");
    389 		nam2blk = last_nam2blk;
    390 	}
    391 	last_nam2blk = nam2blk;
    392 
    393 #ifdef MEMORY_DISK_IS_ROOT
    394 	bootdv = &fakemdrootdev;
    395 	bootpartition = 0;
    396 #endif
    397 
    398 	/*
    399 	 * If NFS is specified as the file system, and we found
    400 	 * a DV_DISK boot device (or no boot device at all), then
    401 	 * find a reasonable network interface for "rootspec".
    402 	 */
    403 	vops = vfs_getopsbyname("nfs");
    404 	if (vops != NULL && vops->vfs_mountroot == mountroot &&
    405 	    rootspec == NULL &&
    406 	    (bootdv == NULL || bootdv->dv_class != DV_IFNET)) {
    407 		for (ifp = ifnet.tqh_first; ifp != NULL;
    408 		    ifp = ifp->if_list.tqe_next)
    409 			if ((ifp->if_flags &
    410 			     (IFF_LOOPBACK|IFF_POINTOPOINT)) == 0)
    411 				break;
    412 		if (ifp == NULL) {
    413 			/*
    414 			 * Can't find a suitable interface; ask the
    415 			 * user.
    416 			 */
    417 			boothowto |= RB_ASKNAME;
    418 		} else {
    419 			/*
    420 			 * Have a suitable interface; behave as if
    421 			 * the user specified this interface.
    422 			 */
    423 			rootspec = (const char *)ifp->if_xname;
    424 		}
    425 	}
    426 
    427 	/*
    428 	 * If wildcarded root and we the boot device wasn't determined,
    429 	 * ask the user.
    430 	 */
    431 	if (rootspec == NULL && bootdv == NULL)
    432 		boothowto |= RB_ASKNAME;
    433 
    434  top:
    435 	if (boothowto & RB_ASKNAME) {
    436 		struct device *defdumpdv;
    437 
    438 		for (;;) {
    439 			printf("root device");
    440 			if (bootdv != NULL) {
    441 				printf(" (default %s", bootdv->dv_xname);
    442 				if (bootdv->dv_class == DV_DISK)
    443 					printf("%c", bootpartition + 'a');
    444 				printf(")");
    445 			}
    446 			printf(": ");
    447 			len = getstr(buf, sizeof(buf));
    448 			if (len == 0 && bootdv != NULL) {
    449 				strcpy(buf, bootdv->dv_xname);
    450 				len = strlen(buf);
    451 			}
    452 			if (len > 0 && buf[len - 1] == '*') {
    453 				buf[--len] = '\0';
    454 				dv = getdisk(buf, len, 1, nam2blk,
    455 				    &nrootdev, 0);
    456 				if (dv != NULL) {
    457 					rootdv = dv;
    458 					break;
    459 				}
    460 			}
    461 			dv = getdisk(buf, len, bootpartition, nam2blk,
    462 			    &nrootdev, 0);
    463 			if (dv != NULL) {
    464 				rootdv = dv;
    465 				break;
    466 			}
    467 		}
    468 
    469 		/*
    470 		 * Set up the default dump device.  If root is on
    471 		 * a network device, there is no default dump
    472 		 * device, since we don't support dumps to the
    473 		 * network.
    474 		 */
    475 		if (rootdv->dv_class == DV_IFNET)
    476 			defdumpdv = NULL;
    477 		else
    478 			defdumpdv = rootdv;
    479 
    480 		for (;;) {
    481 			printf("dump device");
    482 			if (defdumpdv != NULL) {
    483 				/*
    484 				 * Note, we know it's a disk if we get here.
    485 				 */
    486 				printf(" (default %sb)", defdumpdv->dv_xname);
    487 			}
    488 			printf(": ");
    489 			len = getstr(buf, sizeof(buf));
    490 			if (len == 0) {
    491 				if (defdumpdv != NULL) {
    492 					ndumpdev = MAKEDISKDEV(major(nrootdev),
    493 					    DISKUNIT(nrootdev), 1);
    494 				}
    495 				if (rootdv->dv_class == DV_IFNET)
    496 					dumpdv = NULL;
    497 				else
    498 					dumpdv = rootdv;
    499 				break;
    500 			}
    501 			if (len == 4 && strcmp(buf, "none") == 0) {
    502 				dumpspec = "none";
    503 				goto havedump;
    504 			}
    505 			dv = getdisk(buf, len, 1, nam2blk, &ndumpdev, 1);
    506 			if (dv) {
    507 				dumpdv = dv;
    508 				break;
    509 			}
    510 		}
    511 
    512  havedump:
    513 		rootdev = nrootdev;
    514 		dumpdev = ndumpdev;
    515 
    516 		for (i = 0; i < nvfssw; i++) {
    517 			if (vfssw[i] != NULL &&
    518 			    vfssw[i]->vfs_mountroot != NULL &&
    519 			    vfssw[i]->vfs_mountroot == mountroot)
    520 				break;
    521 		}
    522 		if (i >= nvfssw) {
    523 			mountroot = NULL;
    524 			deffsname = "generic";
    525 		} else
    526 			deffsname = vfssw[i]->vfs_name;
    527 		for (;;) {
    528 			printf("file system (default %s): ", deffsname);
    529 			len = getstr(buf, sizeof(buf));
    530 			if (len == 0)
    531 				break;
    532 			if (len == 4 && strcmp(buf, "halt") == 0)
    533 				cpu_reboot(RB_HALT, NULL);
    534 			else if (len == 7 && strcmp(buf, "generic") == 0) {
    535 				mountroot = NULL;
    536 				break;
    537 			}
    538 			vops = vfs_getopsbyname(buf);
    539 			if (vops == NULL || vops->vfs_mountroot == NULL) {
    540 				printf("use one of: generic");
    541 				for (i = 0; i < nvfssw; i++)
    542 					if (vfssw[i] != NULL &&
    543 					    vfssw[i]->vfs_mountroot != NULL)
    544 						printf(" %s",
    545 						    vfssw[i]->vfs_name);
    546 				printf(" halt\n");
    547 			} else {
    548 				mountroot = vops->vfs_mountroot;
    549 				break;
    550 			}
    551 		}
    552 
    553 	} else if (rootspec == NULL) {
    554 		int majdev;
    555 
    556 		/*
    557 		 * Wildcarded root; use the boot device.
    558 		 */
    559 		rootdv = bootdv;
    560 
    561 		majdev = findblkmajor(bootdv->dv_xname, nam2blk);
    562 		if (majdev >= 0) {
    563 			/*
    564 			 * Root is on a disk.  `bootpartition' is root.
    565 			 */
    566 			rootdev = MAKEDISKDEV(majdev, bootdv->dv_unit,
    567 			    bootpartition);
    568 		}
    569 	} else {
    570 
    571 		/*
    572 		 * `root on <dev> ...'
    573 		 */
    574 
    575 		/*
    576 		 * If it's a network interface, we can bail out
    577 		 * early.
    578 		 */
    579 		for (dv = alldevs.tqh_first; dv != NULL;
    580 		    dv = dv->dv_list.tqe_next)
    581 			if (strcmp(dv->dv_xname, rootspec) == 0)
    582 				break;
    583 		if (dv != NULL && dv->dv_class == DV_IFNET) {
    584 			rootdv = dv;
    585 			goto haveroot;
    586 		}
    587 
    588 		rootdevname = findblkname(major(rootdev), nam2blk);
    589 		if (rootdevname == NULL) {
    590 			printf("unknown device major 0x%x\n", rootdev);
    591 			boothowto |= RB_ASKNAME;
    592 			goto top;
    593 		}
    594 		bzero(buf, sizeof(buf));
    595 		sprintf(buf, "%s%d", rootdevname, DISKUNIT(rootdev));
    596 
    597 		for (dv = alldevs.tqh_first; dv != NULL;
    598 		    dv = dv->dv_list.tqe_next) {
    599 			if (strcmp(buf, dv->dv_xname) == 0) {
    600 				rootdv = dv;
    601 				break;
    602 			}
    603 		}
    604 		if (rootdv == NULL) {
    605 			printf("device %s (0x%x) not configured\n",
    606 			    buf, rootdev);
    607 			boothowto |= RB_ASKNAME;
    608 			goto top;
    609 		}
    610 	}
    611 
    612  haveroot:
    613 
    614 	root_device = rootdv;
    615 
    616 	switch (rootdv->dv_class) {
    617 	case DV_IFNET:
    618 		/* Nothing. */
    619 		break;
    620 
    621 	case DV_DISK:
    622 		printf("root on %s%c", rootdv->dv_xname,
    623 		    DISKPART(rootdev) + 'a');
    624 		break;
    625 
    626 	default:
    627 		printf("can't determine root device\n");
    628 		boothowto |= RB_ASKNAME;
    629 		goto top;
    630 	}
    631 
    632 	/*
    633 	 * Now configure the dump device.
    634 	 */
    635 
    636 	if (dumpspec != NULL && strcmp(dumpspec, "none") == 0) {
    637 		/*
    638 		 * Operator doesn't want a dump device.
    639 		 */
    640 		goto nodumpdev;
    641 	}
    642 
    643 	/*
    644 	 * If we haven't figured out the dump device, do so, with
    645 	 * the following rules:
    646 	 *
    647 	 *	(a) We already know dumpdv in the RB_ASKNAME case.
    648 	 *
    649 	 *	(b) If dumpspec is set, try to use it.  If the device
    650 	 *	    is not available, punt.
    651 	 *
    652 	 *	(c) If dumpspec is not set, the dump device is
    653 	 *	    wildcarded or unspecified.  If the root device
    654 	 *	    is DV_IFNET, punt.  Otherwise, use partition b
    655 	 *	    of the root device.
    656 	 */
    657 
    658 	if (boothowto & RB_ASKNAME) {
    659 		if (dumpdv == NULL) {
    660 			/*
    661 			 * Just return; dumpdev is already set to NODEV
    662 			 * and we don't want to print a newline in this
    663 			 * case.
    664 			 */
    665 			return;
    666 		}
    667 		goto out;
    668 	}
    669 
    670 	if (dumpspec != NULL) {
    671 		if (dumpdev == NODEV) {
    672 			/*
    673 			 * Looks like they tried to pick a network
    674 			 * device.  Oops.
    675 			 */
    676 			goto nodumpdev;
    677 		}
    678 
    679 		dumpdevname = findblkname(major(dumpdev), nam2blk);
    680 		if (dumpdevname == NULL)
    681 			goto nodumpdev;
    682 		bzero(buf, sizeof(buf));
    683 		sprintf(buf, "%s%d", dumpdevname, DISKUNIT(dumpdev));
    684 
    685 		for (dv = alldevs.tqh_first; dv != NULL;
    686 		    dv = dv->dv_list.tqe_next) {
    687 			if (strcmp(buf, dv->dv_xname) == 0) {
    688 				dumpdv = dv;
    689 				break;
    690 			}
    691 		}
    692 		if (dv == NULL) {
    693 			/*
    694 			 * Device not configured.
    695 			 */
    696 			goto nodumpdev;
    697 		}
    698 	} else if (rootdv->dv_class == DV_IFNET)
    699 		goto nodumpdev;
    700 	else {
    701 		dumpdv = rootdv;
    702 		dumpdev = MAKEDISKDEV(major(rootdev), dumpdv->dv_unit, 1);
    703 	}
    704 
    705  out:
    706 	printf(" dumps on %s%c\n", dumpdv->dv_xname, DISKPART(dumpdev) + 'a');
    707 	return;
    708 
    709  nodumpdev:
    710 	dumpdev = NODEV;
    711 	printf("\n");
    712 }
    713 
    714 static int
    715 findblkmajor(name, nam2blk)
    716 	const char *name;
    717 	struct devnametobdevmaj *nam2blk;
    718 {
    719 	int i;
    720 
    721 	if (nam2blk == NULL)
    722 		return (-1);
    723 
    724 	for (i = 0; nam2blk[i].d_name != NULL; i++)
    725 		if (strncmp(name, nam2blk[i].d_name,
    726 		    strlen(nam2blk[i].d_name)) == 0)
    727 			return (nam2blk[i].d_maj);
    728 	return (-1);
    729 }
    730 
    731 const char *
    732 findblkname(maj, nam2blk)
    733 	int maj;
    734 	struct devnametobdevmaj *nam2blk;
    735 {
    736 	int i;
    737 
    738 	if (nam2blk == NULL)
    739 		return (NULL);
    740 
    741 	for (i = 0; nam2blk[i].d_name != NULL; i++)
    742 		if (nam2blk[i].d_maj == maj)
    743 			return (nam2blk[i].d_name);
    744 	return (NULL);
    745 }
    746 
    747 static struct device *
    748 getdisk(str, len, defpart, nam2blk, devp, isdump)
    749 	char *str;
    750 	int len, defpart;
    751 	struct devnametobdevmaj *nam2blk;
    752 	dev_t *devp;
    753 	int isdump;
    754 {
    755 	struct device *dv;
    756 
    757 	if ((dv = parsedisk(str, len, defpart, nam2blk, devp)) == NULL) {
    758 		printf("use one of:");
    759 #ifdef MEMORY_DISK_HOOKS
    760 		if (isdump == 0)
    761 			printf(" %s[a-%c]", fakemdrootdev.dv_xname,
    762 			    'a' + MAXPARTITIONS - 1);
    763 #endif
    764 		for (dv = alldevs.tqh_first; dv != NULL;
    765 		    dv = dv->dv_list.tqe_next) {
    766 			if (dv->dv_class == DV_DISK)
    767 				printf(" %s[a-%c]", dv->dv_xname,
    768 				    'a' + MAXPARTITIONS - 1);
    769 			if (isdump == 0 && dv->dv_class == DV_IFNET)
    770 				printf(" %s", dv->dv_xname);
    771 		}
    772 		if (isdump)
    773 			printf(" none");
    774 		printf(" halt\n");
    775 	}
    776 	return (dv);
    777 }
    778 
    779 static struct device *
    780 parsedisk(str, len, defpart, nam2blk, devp)
    781 	char *str;
    782 	int len, defpart;
    783 	struct devnametobdevmaj *nam2blk;
    784 	dev_t *devp;
    785 {
    786 	struct device *dv;
    787 	char *cp, c;
    788 	int majdev, part;
    789 
    790 	if (len == 0)
    791 		return (NULL);
    792 
    793 	if (len == 4 && strcmp(str, "halt") == 0)
    794 		cpu_reboot(RB_HALT, NULL);
    795 
    796 	cp = str + len - 1;
    797 	c = *cp;
    798 	if (c >= 'a' && c <= ('a' + MAXPARTITIONS - 1)) {
    799 		part = c - 'a';
    800 		*cp = '\0';
    801 	} else
    802 		part = defpart;
    803 
    804 #ifdef MEMORY_DISK_HOOKS
    805 	if (strcmp(str, fakemdrootdev.dv_xname) == 0) {
    806 		dv = &fakemdrootdev;
    807 		goto gotdisk;
    808 	}
    809 #endif
    810 
    811 	for (dv = alldevs.tqh_first; dv != NULL; dv = dv->dv_list.tqe_next) {
    812 		if (dv->dv_class == DV_DISK &&
    813 		    strcmp(str, dv->dv_xname) == 0) {
    814 #ifdef MEMORY_DISK_HOOKS
    815  gotdisk:
    816 #endif
    817 			majdev = findblkmajor(dv->dv_xname, nam2blk);
    818 			if (majdev < 0)
    819 				panic("parsedisk");
    820 			*devp = MAKEDISKDEV(majdev, dv->dv_unit, part);
    821 			break;
    822 		}
    823 
    824 		if (dv->dv_class == DV_IFNET &&
    825 		    strcmp(str, dv->dv_xname) == 0) {
    826 			*devp = NODEV;
    827 			break;
    828 		}
    829 	}
    830 
    831 	*cp = c;
    832 	return (dv);
    833 }
    834 
    835 /*
    836  * XXX shouldn't this be a common function?
    837  */
    838 static int
    839 getstr(cp, size)
    840 	char *cp;
    841 	int size;
    842 {
    843 	char *lp;
    844 	int c, len;
    845 
    846 	cnpollc(1);
    847 
    848 	lp = cp;
    849 	len = 0;
    850 	for (;;) {
    851 		c = cngetc();
    852 		switch (c) {
    853 		case '\n':
    854 		case '\r':
    855 			printf("\n");
    856 			*lp++ = '\0';
    857 			cnpollc(0);
    858 			return (len);
    859 		case '\b':
    860 		case '\177':
    861 		case '#':
    862 			if (len) {
    863 				--len;
    864 				--lp;
    865 				printf("\b \b");
    866 			}
    867 			continue;
    868 		case '@':
    869 		case 'u'&037:
    870 			len = 0;
    871 			lp = cp;
    872 			printf("\n");
    873 			continue;
    874 		default:
    875 			if (len + 1 >= size || c < ' ') {
    876 				printf("\007");
    877 				continue;
    878 			}
    879 			printf("%c", c);
    880 			++len;
    881 			*lp++ = c;
    882 		}
    883 	}
    884 }
    885