xref: /netbsd-src/sys/kern/kern_subr.c (revision e4d7c2e329d54c97e0c0bd3016bbe74f550c3d5e)
1 /*	$NetBSD: kern_subr.c,v 1.60 2000/03/01 03:51:29 enami Exp $	*/
2 
3 /*-
4  * Copyright (c) 1997, 1998, 1999 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
9  * NASA Ames Research Center, and by Luke Mewburn.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. All advertising materials mentioning features or use of this software
20  *    must display the following acknowledgement:
21  *	This product includes software developed by the NetBSD
22  *	Foundation, Inc. and its contributors.
23  * 4. Neither the name of The NetBSD Foundation nor the names of its
24  *    contributors may be used to endorse or promote products derived
25  *    from this software without specific prior written permission.
26  *
27  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
28  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
29  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
30  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
31  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
32  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
33  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
34  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
35  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
36  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
37  * POSSIBILITY OF SUCH DAMAGE.
38  */
39 
40 /*
41  * Copyright (c) 1982, 1986, 1991, 1993
42  *	The Regents of the University of California.  All rights reserved.
43  * (c) UNIX System Laboratories, Inc.
44  * All or some portions of this file are derived from material licensed
45  * to the University of California by American Telephone and Telegraph
46  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
47  * the permission of UNIX System Laboratories, Inc.
48  *
49  * Copyright (c) 1992, 1993
50  *	The Regents of the University of California.  All rights reserved.
51  *
52  * This software was developed by the Computer Systems Engineering group
53  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
54  * contributed to Berkeley.
55  *
56  * All advertising materials mentioning features or use of this software
57  * must display the following acknowledgement:
58  *	This product includes software developed by the University of
59  *	California, Lawrence Berkeley Laboratory.
60  *
61  * Redistribution and use in source and binary forms, with or without
62  * modification, are permitted provided that the following conditions
63  * are met:
64  * 1. Redistributions of source code must retain the above copyright
65  *    notice, this list of conditions and the following disclaimer.
66  * 2. Redistributions in binary form must reproduce the above copyright
67  *    notice, this list of conditions and the following disclaimer in the
68  *    documentation and/or other materials provided with the distribution.
69  * 3. All advertising materials mentioning features or use of this software
70  *    must display the following acknowledgement:
71  *	This product includes software developed by the University of
72  *	California, Berkeley and its contributors.
73  * 4. Neither the name of the University nor the names of its contributors
74  *    may be used to endorse or promote products derived from this software
75  *    without specific prior written permission.
76  *
77  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
78  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
79  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
80  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
81  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
82  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
83  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
84  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
85  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
86  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
87  * SUCH DAMAGE.
88  *
89  *	@(#)kern_subr.c	8.4 (Berkeley) 2/14/95
90  */
91 
92 #include "opt_md.h"
93 
94 #include <sys/param.h>
95 #include <sys/systm.h>
96 #include <sys/proc.h>
97 #include <sys/malloc.h>
98 #include <sys/mount.h>
99 #include <sys/device.h>
100 #include <sys/reboot.h>
101 #include <sys/conf.h>
102 #include <sys/disklabel.h>
103 #include <sys/queue.h>
104 
105 #include <dev/cons.h>
106 
107 #include <net/if.h>
108 
109 /* XXX these should eventually move to subr_autoconf.c */
110 static int findblkmajor __P((const char *));
111 static const char *findblkname __P((int));
112 static struct device *finddevice __P((const char *));
113 static struct device *getdisk __P((char *, int, int, dev_t *, int));
114 static struct device *parsedisk __P((char *, int, int, dev_t *));
115 static int getstr __P((char *, int));
116 
117 int
118 uiomove(buf, n, uio)
119 	register void *buf;
120 	register int n;
121 	register struct uio *uio;
122 {
123 	register struct iovec *iov;
124 	u_int cnt;
125 	int error = 0;
126 	char *cp = buf;
127 
128 #ifdef DIAGNOSTIC
129 	if (uio->uio_rw != UIO_READ && uio->uio_rw != UIO_WRITE)
130 		panic("uiomove: mode");
131 	if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc)
132 		panic("uiomove proc");
133 #endif
134 	while (n > 0 && uio->uio_resid) {
135 		iov = uio->uio_iov;
136 		cnt = iov->iov_len;
137 		if (cnt == 0) {
138 			uio->uio_iov++;
139 			uio->uio_iovcnt--;
140 			continue;
141 		}
142 		if (cnt > n)
143 			cnt = n;
144 		switch (uio->uio_segflg) {
145 
146 		case UIO_USERSPACE:
147 			if (uio->uio_rw == UIO_READ)
148 				error = copyout(cp, iov->iov_base, cnt);
149 			else
150 				error = copyin(iov->iov_base, cp, cnt);
151 			if (error)
152 				return (error);
153 			break;
154 
155 		case UIO_SYSSPACE:
156 			if (uio->uio_rw == UIO_READ)
157 				error = kcopy(cp, iov->iov_base, cnt);
158 			else
159 				error = kcopy(iov->iov_base, cp, cnt);
160 			if (error)
161 				return (error);
162 			break;
163 		}
164 		iov->iov_base = (caddr_t)iov->iov_base + cnt;
165 		iov->iov_len -= cnt;
166 		uio->uio_resid -= cnt;
167 		uio->uio_offset += cnt;
168 		cp += cnt;
169 		n -= cnt;
170 	}
171 	return (error);
172 }
173 
174 /*
175  * Give next character to user as result of read.
176  */
177 int
178 ureadc(c, uio)
179 	register int c;
180 	register struct uio *uio;
181 {
182 	register struct iovec *iov;
183 
184 	if (uio->uio_resid <= 0)
185 		panic("ureadc: non-positive resid");
186 again:
187 	if (uio->uio_iovcnt <= 0)
188 		panic("ureadc: non-positive iovcnt");
189 	iov = uio->uio_iov;
190 	if (iov->iov_len <= 0) {
191 		uio->uio_iovcnt--;
192 		uio->uio_iov++;
193 		goto again;
194 	}
195 	switch (uio->uio_segflg) {
196 
197 	case UIO_USERSPACE:
198 		if (subyte(iov->iov_base, c) < 0)
199 			return (EFAULT);
200 		break;
201 
202 	case UIO_SYSSPACE:
203 		*(char *)iov->iov_base = c;
204 		break;
205 	}
206 	iov->iov_base = (caddr_t)iov->iov_base + 1;
207 	iov->iov_len--;
208 	uio->uio_resid--;
209 	uio->uio_offset++;
210 	return (0);
211 }
212 
213 /*
214  * General routine to allocate a hash table.
215  * Allocate enough memory to hold at least `elements' list-head pointers.
216  * Return a pointer to the allocated space and set *hashmask to a pattern
217  * suitable for masking a value to use as an index into the returned array.
218  */
219 void *
220 hashinit(elements, type, flags, hashmask)
221 	int elements, type, flags;
222 	u_long *hashmask;
223 {
224 	long hashsize;
225 	LIST_HEAD(generic, generic) *hashtbl;
226 	int i;
227 
228 	if (elements <= 0)
229 		panic("hashinit: bad cnt");
230 	for (hashsize = 1; hashsize < elements; hashsize <<= 1)
231 		continue;
232 	hashtbl = malloc((u_long)hashsize * sizeof(*hashtbl), type, flags);
233 	for (i = 0; i < hashsize; i++)
234 		LIST_INIT(&hashtbl[i]);
235 	*hashmask = hashsize - 1;
236 	return (hashtbl);
237 }
238 
239 /*
240  * "Shutdown hook" types, functions, and variables.
241  */
242 
243 struct shutdownhook_desc {
244 	LIST_ENTRY(shutdownhook_desc) sfd_list;
245 	void	(*sfd_fn) __P((void *));
246 	void	*sfd_arg;
247 };
248 
249 LIST_HEAD(, shutdownhook_desc) shutdownhook_list;
250 
251 void *
252 shutdownhook_establish(fn, arg)
253 	void (*fn) __P((void *));
254 	void *arg;
255 {
256 	struct shutdownhook_desc *ndp;
257 
258 	ndp = (struct shutdownhook_desc *)
259 	    malloc(sizeof(*ndp), M_DEVBUF, M_NOWAIT);
260 	if (ndp == NULL)
261 		return (NULL);
262 
263 	ndp->sfd_fn = fn;
264 	ndp->sfd_arg = arg;
265 	LIST_INSERT_HEAD(&shutdownhook_list, ndp, sfd_list);
266 
267 	return (ndp);
268 }
269 
270 void
271 shutdownhook_disestablish(vhook)
272 	void *vhook;
273 {
274 #ifdef DIAGNOSTIC
275 	struct shutdownhook_desc *dp;
276 
277 	for (dp = shutdownhook_list.lh_first; dp != NULL;
278 	    dp = dp->sfd_list.le_next)
279                 if (dp == vhook)
280 			break;
281 	if (dp == NULL)
282 		panic("shutdownhook_disestablish: hook not established");
283 #endif
284 
285 	LIST_REMOVE((struct shutdownhook_desc *)vhook, sfd_list);
286 	free(vhook, M_DEVBUF);
287 }
288 
289 /*
290  * Run shutdown hooks.  Should be invoked immediately before the
291  * system is halted or rebooted, i.e. after file systems unmounted,
292  * after crash dump done, etc.
293  *
294  * Each shutdown hook is removed from the list before it's run, so that
295  * it won't be run again.
296  */
297 void
298 doshutdownhooks()
299 {
300 	struct shutdownhook_desc *dp;
301 
302 	while ((dp = shutdownhook_list.lh_first) != NULL) {
303 		LIST_REMOVE(dp, sfd_list);
304 		(*dp->sfd_fn)(dp->sfd_arg);
305 #if 0
306 		/*
307 		 * Don't bother freeing the hook structure,, since we may
308 		 * be rebooting because of a memory corruption problem,
309 		 * and this might only make things worse.  It doesn't
310 		 * matter, anyway, since the system is just about to
311 		 * reboot.
312 		 */
313 		free(dp, M_DEVBUF);
314 #endif
315 	}
316 }
317 
318 /*
319  * "Power hook" types, functions, and variables.
320  */
321 
322 struct powerhook_desc {
323 	LIST_ENTRY(powerhook_desc) sfd_list;
324 	void	(*sfd_fn) __P((int, void *));
325 	void	*sfd_arg;
326 };
327 
328 LIST_HEAD(, powerhook_desc) powerhook_list;
329 
330 void *
331 powerhook_establish(fn, arg)
332 	void (*fn) __P((int, void *));
333 	void *arg;
334 {
335 	struct powerhook_desc *ndp;
336 
337 	ndp = (struct powerhook_desc *)
338 	    malloc(sizeof(*ndp), M_DEVBUF, M_NOWAIT);
339 	if (ndp == NULL)
340 		return (NULL);
341 
342 	ndp->sfd_fn = fn;
343 	ndp->sfd_arg = arg;
344 	LIST_INSERT_HEAD(&powerhook_list, ndp, sfd_list);
345 
346 	return (ndp);
347 }
348 
349 void
350 powerhook_disestablish(vhook)
351 	void *vhook;
352 {
353 #ifdef DIAGNOSTIC
354 	struct powerhook_desc *dp;
355 
356 	for (dp = powerhook_list.lh_first; dp != NULL;
357 	    dp = dp->sfd_list.le_next)
358                 if (dp == vhook)
359 			break;
360 	if (dp == NULL)
361 		panic("powerhook_disestablish: hook not established");
362 #endif
363 
364 	LIST_REMOVE((struct powerhook_desc *)vhook, sfd_list);
365 	free(vhook, M_DEVBUF);
366 }
367 
368 /*
369  * Run power hooks.
370  */
371 void
372 dopowerhooks(why)
373 	int why;
374 {
375 	struct powerhook_desc *dp;
376 
377 	for (dp = LIST_FIRST(&powerhook_list);
378 	     dp != NULL;
379 	     dp = LIST_NEXT(dp, sfd_list)) {
380 		(*dp->sfd_fn)(why, dp->sfd_arg);
381 	}
382 }
383 
384 /*
385  * "Mountroot hook" types, functions, and variables.
386  */
387 
388 struct mountroothook_desc {
389 	LIST_ENTRY(mountroothook_desc) mrd_list;
390 	struct	device *mrd_device;
391 	void 	(*mrd_func) __P((struct device *));
392 };
393 
394 LIST_HEAD(, mountroothook_desc) mountroothook_list;
395 
396 void *
397 mountroothook_establish(func, dev)
398 	void (*func) __P((struct device *));
399 	struct device *dev;
400 {
401 	struct mountroothook_desc *mrd;
402 
403 	mrd = (struct mountroothook_desc *)
404 	    malloc(sizeof(*mrd), M_DEVBUF, M_NOWAIT);
405 	if (mrd == NULL)
406 		return (NULL);
407 
408 	mrd->mrd_device = dev;
409 	mrd->mrd_func = func;
410 	LIST_INSERT_HEAD(&mountroothook_list, mrd, mrd_list);
411 
412 	return (mrd);
413 }
414 
415 void
416 mountroothook_disestablish(vhook)
417 	void *vhook;
418 {
419 #ifdef DIAGNOSTIC
420 	struct mountroothook_desc *mrd;
421 
422 	for (mrd = mountroothook_list.lh_first; mrd != NULL;
423 	    mrd = mrd->mrd_list.le_next)
424                 if (mrd == vhook)
425 			break;
426 	if (mrd == NULL)
427 		panic("mountroothook_disestablish: hook not established");
428 #endif
429 
430 	LIST_REMOVE((struct mountroothook_desc *)vhook, mrd_list);
431 	free(vhook, M_DEVBUF);
432 }
433 
434 void
435 mountroothook_destroy()
436 {
437 	struct mountroothook_desc *mrd;
438 
439 	while ((mrd = mountroothook_list.lh_first) != NULL) {
440 		LIST_REMOVE(mrd, mrd_list);
441 		free(mrd, M_DEVBUF);
442 	}
443 }
444 
445 void
446 domountroothook()
447 {
448 	struct mountroothook_desc *mrd;
449 
450 	for (mrd = mountroothook_list.lh_first; mrd != NULL;
451 	    mrd = mrd->mrd_list.le_next) {
452 		if (mrd->mrd_device == root_device) {
453 			(*mrd->mrd_func)(root_device);
454 			return;
455 		}
456 	}
457 }
458 
459 /*
460  * Exec hook code.
461  */
462 
463 struct exechook_desc {
464 	LIST_ENTRY(exechook_desc) ehk_list;
465 	void	(*ehk_fn) __P((struct proc *, void *));
466 	void	*ehk_arg;
467 };
468 
469 LIST_HEAD(, exechook_desc) exechook_list;
470 
471 void *
472 exechook_establish(fn, arg)
473 	void (*fn) __P((struct proc *, void *));
474 	void *arg;
475 {
476 	struct exechook_desc *edp;
477 
478 	edp = (struct exechook_desc *)
479 	    malloc(sizeof(*edp), M_DEVBUF, M_NOWAIT);
480 	if (edp == NULL)
481 		return (NULL);
482 
483 	edp->ehk_fn = fn;
484 	edp->ehk_arg = arg;
485 	LIST_INSERT_HEAD(&exechook_list, edp, ehk_list);
486 
487 	return (edp);
488 }
489 
490 void
491 exechook_disestablish(vhook)
492 	void *vhook;
493 {
494 #ifdef DIAGNOSTIC
495 	struct exechook_desc *edp;
496 
497 	for (edp = exechook_list.lh_first; edp != NULL;
498 	    edp = edp->ehk_list.le_next)
499                 if (edp == vhook)
500 			break;
501 	if (edp == NULL)
502 		panic("exechook_disestablish: hook not established");
503 #endif
504 
505 	LIST_REMOVE((struct exechook_desc *)vhook, ehk_list);
506 	free(vhook, M_DEVBUF);
507 }
508 
509 /*
510  * Run exec hooks.
511  */
512 void
513 doexechooks(p)
514 	struct proc *p;
515 {
516 	struct exechook_desc *edp;
517 
518 	for (edp = LIST_FIRST(&exechook_list);
519 	     edp != NULL;
520 	     edp = LIST_NEXT(edp, ehk_list)) {
521 		(*edp->ehk_fn)(p, edp->ehk_arg);
522 	}
523 }
524 
525 /*
526  * Determine the root device and, if instructed to, the root file system.
527  */
528 
529 #include "md.h"
530 #if NMD == 0
531 #undef MEMORY_DISK_HOOKS
532 #endif
533 
534 #ifdef MEMORY_DISK_HOOKS
535 static struct device fakemdrootdev[NMD];
536 #endif
537 
538 #include "raid.h"
539 #if NRAID == 1
540 #define BOOT_FROM_RAID_HOOKS 1
541 #endif
542 
543 #ifdef BOOT_FROM_RAID_HOOKS
544 extern int numraid;
545 extern struct device *raidrootdev;
546 #endif
547 
548 void
549 setroot(bootdv, bootpartition)
550 	struct device *bootdv;
551 	int bootpartition;
552 {
553 	struct device *dv;
554 	int len;
555 #ifdef MEMORY_DISK_HOOKS
556 	int i;
557 #endif
558 	dev_t nrootdev;
559 	dev_t ndumpdev = NODEV;
560 	char buf[128];
561 	const char *rootdevname;
562 	const char *dumpdevname;
563 	struct device *rootdv = NULL;		/* XXX gcc -Wuninitialized */
564 	struct device *dumpdv = NULL;
565 	struct ifnet *ifp;
566 	const char *deffsname;
567 	struct vfsops *vops;
568 	extern int (*mountroot) __P((void));
569 
570 #ifdef MEMORY_DISK_HOOKS
571 	for (i = 0; i < NMD; i++) {
572 		fakemdrootdev[i].dv_class  = DV_DISK;
573 		fakemdrootdev[i].dv_cfdata = NULL;
574 		fakemdrootdev[i].dv_unit   = i;
575 		fakemdrootdev[i].dv_parent = NULL;
576 		sprintf(fakemdrootdev[i].dv_xname, "md%d", i);
577 	}
578 #endif /* MEMORY_DISK_HOOKS */
579 
580 #ifdef MEMORY_DISK_IS_ROOT
581 	bootdv = &fakemdrootdev[0];
582 	bootpartition = 0;
583 #endif
584 
585 	/*
586 	 * If NFS is specified as the file system, and we found
587 	 * a DV_DISK boot device (or no boot device at all), then
588 	 * find a reasonable network interface for "rootspec".
589 	 */
590 	vops = vfs_getopsbyname("nfs");
591 	if (vops != NULL && vops->vfs_mountroot == mountroot &&
592 	    rootspec == NULL &&
593 	    (bootdv == NULL || bootdv->dv_class != DV_IFNET)) {
594 		for (ifp = ifnet.tqh_first; ifp != NULL;
595 		    ifp = ifp->if_list.tqe_next)
596 			if ((ifp->if_flags &
597 			     (IFF_LOOPBACK|IFF_POINTOPOINT)) == 0)
598 				break;
599 		if (ifp == NULL) {
600 			/*
601 			 * Can't find a suitable interface; ask the
602 			 * user.
603 			 */
604 			boothowto |= RB_ASKNAME;
605 		} else {
606 			/*
607 			 * Have a suitable interface; behave as if
608 			 * the user specified this interface.
609 			 */
610 			rootspec = (const char *)ifp->if_xname;
611 		}
612 	}
613 
614 	/*
615 	 * If wildcarded root and we the boot device wasn't determined,
616 	 * ask the user.
617 	 */
618 	if (rootspec == NULL && bootdv == NULL)
619 		boothowto |= RB_ASKNAME;
620 
621  top:
622 	if (boothowto & RB_ASKNAME) {
623 		struct device *defdumpdv;
624 
625 		for (;;) {
626 			printf("root device");
627 			if (bootdv != NULL) {
628 				printf(" (default %s", bootdv->dv_xname);
629 				if (bootdv->dv_class == DV_DISK)
630 					printf("%c", bootpartition + 'a');
631 				printf(")");
632 			}
633 			printf(": ");
634 			len = getstr(buf, sizeof(buf));
635 			if (len == 0 && bootdv != NULL) {
636 				strcpy(buf, bootdv->dv_xname);
637 				len = strlen(buf);
638 			}
639 			if (len > 0 && buf[len - 1] == '*') {
640 				buf[--len] = '\0';
641 				dv = getdisk(buf, len, 1, &nrootdev, 0);
642 				if (dv != NULL) {
643 					rootdv = dv;
644 					break;
645 				}
646 			}
647 			dv = getdisk(buf, len, bootpartition, &nrootdev, 0);
648 			if (dv != NULL) {
649 				rootdv = dv;
650 				break;
651 			}
652 		}
653 
654 		/*
655 		 * Set up the default dump device.  If root is on
656 		 * a network device, there is no default dump
657 		 * device, since we don't support dumps to the
658 		 * network.
659 		 */
660 		if (rootdv->dv_class == DV_IFNET)
661 			defdumpdv = NULL;
662 		else
663 			defdumpdv = rootdv;
664 
665 		for (;;) {
666 			printf("dump device");
667 			if (defdumpdv != NULL) {
668 				/*
669 				 * Note, we know it's a disk if we get here.
670 				 */
671 				printf(" (default %sb)", defdumpdv->dv_xname);
672 			}
673 			printf(": ");
674 			len = getstr(buf, sizeof(buf));
675 			if (len == 0) {
676 				if (defdumpdv != NULL) {
677 					ndumpdev = MAKEDISKDEV(major(nrootdev),
678 					    DISKUNIT(nrootdev), 1);
679 				}
680 				dumpdv = defdumpdv;
681 				break;
682 			}
683 			if (len == 4 && strcmp(buf, "none") == 0) {
684 				dumpdv = NULL;
685 				break;
686 			}
687 			dv = getdisk(buf, len, 1, &ndumpdev, 1);
688 			if (dv != NULL) {
689 				dumpdv = dv;
690 				break;
691 			}
692 		}
693 
694 		rootdev = nrootdev;
695 		dumpdev = ndumpdev;
696 
697 		for (vops = LIST_FIRST(&vfs_list); vops != NULL;
698 		     vops = LIST_NEXT(vops, vfs_list)) {
699 			if (vops->vfs_mountroot != NULL &&
700 			    vops->vfs_mountroot == mountroot)
701 			break;
702 		}
703 
704 		if (vops == NULL) {
705 			mountroot = NULL;
706 			deffsname = "generic";
707 		} else
708 			deffsname = vops->vfs_name;
709 
710 		for (;;) {
711 			printf("file system (default %s): ", deffsname);
712 			len = getstr(buf, sizeof(buf));
713 			if (len == 0)
714 				break;
715 			if (len == 4 && strcmp(buf, "halt") == 0)
716 				cpu_reboot(RB_HALT, NULL);
717 			else if (len == 7 && strcmp(buf, "generic") == 0) {
718 				mountroot = NULL;
719 				break;
720 			}
721 			vops = vfs_getopsbyname(buf);
722 			if (vops == NULL || vops->vfs_mountroot == NULL) {
723 				printf("use one of: generic");
724 				for (vops = LIST_FIRST(&vfs_list);
725 				     vops != NULL;
726 				     vops = LIST_NEXT(vops, vfs_list)) {
727 					if (vops->vfs_mountroot != NULL)
728 						printf(" %s", vops->vfs_name);
729 				}
730 				printf(" halt\n");
731 			} else {
732 				mountroot = vops->vfs_mountroot;
733 				break;
734 			}
735 		}
736 
737 	} else if (rootspec == NULL) {
738 		int majdev;
739 
740 		/*
741 		 * Wildcarded root; use the boot device.
742 		 */
743 		rootdv = bootdv;
744 
745 		majdev = findblkmajor(bootdv->dv_xname);
746 		if (majdev >= 0) {
747 			/*
748 			 * Root is on a disk.  `bootpartition' is root.
749 			 */
750 			rootdev = MAKEDISKDEV(majdev, bootdv->dv_unit,
751 			    bootpartition);
752 		}
753 	} else {
754 
755 		/*
756 		 * `root on <dev> ...'
757 		 */
758 
759 		/*
760 		 * If it's a network interface, we can bail out
761 		 * early.
762 		 */
763 		dv = finddevice(rootspec);
764 		if (dv != NULL && dv->dv_class == DV_IFNET) {
765 			rootdv = dv;
766 			goto haveroot;
767 		}
768 
769 		rootdevname = findblkname(major(rootdev));
770 		if (rootdevname == NULL) {
771 			printf("unknown device major 0x%x\n", rootdev);
772 			boothowto |= RB_ASKNAME;
773 			goto top;
774 		}
775 		memset(buf, 0, sizeof(buf));
776 		sprintf(buf, "%s%d", rootdevname, DISKUNIT(rootdev));
777 
778 		rootdv = finddevice(buf);
779 		if (rootdv == NULL) {
780 			printf("device %s (0x%x) not configured\n",
781 			    buf, rootdev);
782 			boothowto |= RB_ASKNAME;
783 			goto top;
784 		}
785 	}
786 
787  haveroot:
788 
789 	root_device = rootdv;
790 
791 	switch (rootdv->dv_class) {
792 	case DV_IFNET:
793 		printf("root on %s", rootdv->dv_xname);
794 		break;
795 
796 	case DV_DISK:
797 		printf("root on %s%c", rootdv->dv_xname,
798 		    DISKPART(rootdev) + 'a');
799 		break;
800 
801 	default:
802 		printf("can't determine root device\n");
803 		boothowto |= RB_ASKNAME;
804 		goto top;
805 	}
806 
807 	/*
808 	 * Now configure the dump device.
809 	 *
810 	 * If we haven't figured out the dump device, do so, with
811 	 * the following rules:
812 	 *
813 	 *	(a) We already know dumpdv in the RB_ASKNAME case.
814 	 *
815 	 *	(b) If dumpspec is set, try to use it.  If the device
816 	 *	    is not available, punt.
817 	 *
818 	 *	(c) If dumpspec is not set, the dump device is
819 	 *	    wildcarded or unspecified.  If the root device
820 	 *	    is DV_IFNET, punt.  Otherwise, use partition b
821 	 *	    of the root device.
822 	 */
823 
824 	if (boothowto & RB_ASKNAME) {		/* (a) */
825 		if (dumpdv == NULL)
826 			goto nodumpdev;
827 	} else if (dumpspec != NULL) {		/* (b) */
828 		if (strcmp(dumpspec, "none") == 0 || dumpdev == NODEV) {
829 			/*
830 			 * Operator doesn't want a dump device.
831 			 * Or looks like they tried to pick a network
832 			 * device.  Oops.
833 			 */
834 			goto nodumpdev;
835 		}
836 
837 		dumpdevname = findblkname(major(dumpdev));
838 		if (dumpdevname == NULL)
839 			goto nodumpdev;
840 		memset(buf, 0, sizeof(buf));
841 		sprintf(buf, "%s%d", dumpdevname, DISKUNIT(dumpdev));
842 
843 		dumpdv = finddevice(buf);
844 		if (dumpdv == NULL) {
845 			/*
846 			 * Device not configured.
847 			 */
848 			goto nodumpdev;
849 		}
850 	} else {				/* (c) */
851 		if (rootdv->dv_class == DV_IFNET)
852 			goto nodumpdev;
853 		else {
854 			dumpdv = rootdv;
855 			dumpdev = MAKEDISKDEV(major(rootdev),
856 			    dumpdv->dv_unit, 1);
857 		}
858 	}
859 
860 	printf(" dumps on %s%c\n", dumpdv->dv_xname, DISKPART(dumpdev) + 'a');
861 	return;
862 
863  nodumpdev:
864 	dumpdev = NODEV;
865 	printf("\n");
866 }
867 
868 static int
869 findblkmajor(name)
870 	const char *name;
871 {
872 	int i;
873 
874 	for (i = 0; dev_name2blk[i].d_name != NULL; i++)
875 		if (strncmp(name, dev_name2blk[i].d_name,
876 		    strlen(dev_name2blk[i].d_name)) == 0)
877 			return (dev_name2blk[i].d_maj);
878 	return (-1);
879 }
880 
881 const char *
882 findblkname(maj)
883 	int maj;
884 {
885 	int i;
886 
887 	for (i = 0; dev_name2blk[i].d_name != NULL; i++)
888 		if (dev_name2blk[i].d_maj == maj)
889 			return (dev_name2blk[i].d_name);
890 	return (NULL);
891 }
892 
893 static struct device *
894 finddevice(name)
895 	const char *name;
896 {
897 	struct device *dv;
898 #ifdef BOOT_FROM_RAID_HOOKS
899 	int j;
900 
901 	for (j = 0; j < numraid; j++) {
902 		if (strcmp(name, raidrootdev[j].dv_xname) == 0) {
903 			dv = &raidrootdev[j];
904 			return (dv);
905 		}
906 	}
907 #endif;
908 
909 	for (dv = TAILQ_FIRST(&alldevs); dv != NULL;
910 	    dv = TAILQ_NEXT(dv, dv_list))
911 		if (strcmp(dv->dv_xname, name) == 0)
912 			break;
913 	return (dv);
914 }
915 
916 static struct device *
917 getdisk(str, len, defpart, devp, isdump)
918 	char *str;
919 	int len, defpart;
920 	dev_t *devp;
921 	int isdump;
922 {
923 	struct device	*dv;
924 #ifdef MEMORY_DISK_HOOKS
925 	int		i;
926 #endif
927 #ifdef BOOT_FROM_RAID_HOOKS
928 	int 		j;
929 #endif
930 
931 	if ((dv = parsedisk(str, len, defpart, devp)) == NULL) {
932 		printf("use one of:");
933 #ifdef MEMORY_DISK_HOOKS
934 		if (isdump == 0)
935 			for (i = 0; i < NMD; i++)
936 				printf(" %s[a-%c]", fakemdrootdev[i].dv_xname,
937 				    'a' + MAXPARTITIONS - 1);
938 #endif
939 #ifdef BOOT_FROM_RAID_HOOKS
940 		if (isdump == 0)
941 			for (j = 0; j < numraid; j++)
942 				printf(" %s[a-%c]", raidrootdev[j].dv_xname,
943 				    'a' + MAXPARTITIONS - 1);
944 #endif
945 		for (dv = alldevs.tqh_first; dv != NULL;
946 		    dv = dv->dv_list.tqe_next) {
947 			if (dv->dv_class == DV_DISK)
948 				printf(" %s[a-%c]", dv->dv_xname,
949 				    'a' + MAXPARTITIONS - 1);
950 			if (isdump == 0 && dv->dv_class == DV_IFNET)
951 				printf(" %s", dv->dv_xname);
952 		}
953 		if (isdump)
954 			printf(" none");
955 		printf(" halt\n");
956 	}
957 	return (dv);
958 }
959 
960 static struct device *
961 parsedisk(str, len, defpart, devp)
962 	char *str;
963 	int len, defpart;
964 	dev_t *devp;
965 {
966 	struct device *dv;
967 	char *cp, c;
968 	int majdev, part;
969 #ifdef MEMORY_DISK_HOOKS
970 	int i;
971 #endif
972 	if (len == 0)
973 		return (NULL);
974 
975 	if (len == 4 && strcmp(str, "halt") == 0)
976 		cpu_reboot(RB_HALT, NULL);
977 
978 	cp = str + len - 1;
979 	c = *cp;
980 	if (c >= 'a' && c <= ('a' + MAXPARTITIONS - 1)) {
981 		part = c - 'a';
982 		*cp = '\0';
983 	} else
984 		part = defpart;
985 
986 #ifdef MEMORY_DISK_HOOKS
987 	for (i = 0; i < NMD; i++)
988 		if (strcmp(str, fakemdrootdev[i].dv_xname) == 0) {
989 			dv = &fakemdrootdev[i];
990 			goto gotdisk;
991 		}
992 #endif
993 
994 	dv = finddevice(str);
995 	if (dv != NULL) {
996 		if (dv->dv_class == DV_DISK) {
997 #ifdef MEMORY_DISK_HOOKS
998  gotdisk:
999 #endif
1000 			majdev = findblkmajor(dv->dv_xname);
1001 			if (majdev < 0)
1002 				panic("parsedisk");
1003 			*devp = MAKEDISKDEV(majdev, dv->dv_unit, part);
1004 		}
1005 
1006 		if (dv->dv_class == DV_IFNET)
1007 			*devp = NODEV;
1008 	}
1009 
1010 	*cp = c;
1011 	return (dv);
1012 }
1013 
1014 /*
1015  * XXX shouldn't this be a common function?
1016  */
1017 static int
1018 getstr(cp, size)
1019 	char *cp;
1020 	int size;
1021 {
1022 	char *lp;
1023 	int c, len;
1024 
1025 	cnpollc(1);
1026 
1027 	lp = cp;
1028 	len = 0;
1029 	for (;;) {
1030 		c = cngetc();
1031 		switch (c) {
1032 		case '\n':
1033 		case '\r':
1034 			printf("\n");
1035 			*lp++ = '\0';
1036 			cnpollc(0);
1037 			return (len);
1038 		case '\b':
1039 		case '\177':
1040 		case '#':
1041 			if (len) {
1042 				--len;
1043 				--lp;
1044 				printf("\b \b");
1045 			}
1046 			continue;
1047 		case '@':
1048 		case 'u'&037:
1049 			len = 0;
1050 			lp = cp;
1051 			printf("\n");
1052 			continue;
1053 		default:
1054 			if (len + 1 >= size || c < ' ') {
1055 				printf("\007");
1056 				continue;
1057 			}
1058 			printf("%c", c);
1059 			++len;
1060 			*lp++ = c;
1061 		}
1062 	}
1063 }
1064 
1065 /*
1066  * snprintf() `bytes' into `buf', reformatting it so that the number,
1067  * plus a possible `x' + suffix extension) fits into len bytes (including
1068  * the terminating NUL).
1069  * Returns the number of bytes stored in buf, or -1 if there was a problem.
1070  * E.g, given a len of 9 and a suffix of `B':
1071  *	bytes		result
1072  *	-----		------
1073  *	99999		`99999 B'
1074  *	100000		`97 KB'
1075  *	66715648	`65152 KB'
1076  *	252215296	`240 MB'
1077  */
1078 int
1079 humanize_number(buf, len, bytes, suffix, divisor)
1080 	char		*buf;
1081 	size_t		 len;
1082 	u_int64_t	 bytes;
1083 	const char	*suffix;
1084 	int 		divisor;
1085 {
1086 		/* prefixes are: (none), Kilo, Mega, Giga, Tera, Peta, Exa */
1087 	static const char prefixes[] = " KMGTPE";
1088 
1089 	int		i, r;
1090 	u_int64_t	max;
1091 	size_t		suffixlen;
1092 
1093 	if (buf == NULL || suffix == NULL)
1094 		return (-1);
1095 	if (len > 0)
1096 		buf[0] = '\0';
1097 	suffixlen = strlen(suffix);
1098 			/* check if enough room for `x y' + suffix + `\0' */
1099 	if (len < 4 + suffixlen)
1100 		return (-1);
1101 
1102 	max = 1;
1103 	for (i = 0; i < len - suffixlen - 3; i++)
1104 		max *= 10;
1105 	for (i = 0; bytes >= max && i < sizeof(prefixes); i++)
1106 		bytes /= divisor;
1107 
1108 	r = snprintf(buf, len, "%qu%s%c%s", (unsigned long long)bytes,
1109 	    i == 0 ? "" : " ", prefixes[i], suffix);
1110 
1111 	return (r);
1112 }
1113 
1114 int
1115 format_bytes(buf, len, bytes)
1116 	char		*buf;
1117 	size_t		 len;
1118 	u_int64_t	 bytes;
1119 {
1120 	int	rv;
1121 	size_t	nlen;
1122 
1123 	rv = humanize_number(buf, len, bytes, "B", 1024);
1124 	if (rv != -1) {
1125 			/* nuke the trailing ` B' if it exists */
1126 		nlen = strlen(buf) - 2;
1127 		if (strcmp(&buf[nlen], " B") == 0)
1128 			buf[nlen] = '\0';
1129 	}
1130 	return (rv);
1131 }
1132