xref: /netbsd-src/sys/kern/kern_subr.c (revision 95d875fb90b1458e4f1de6950286ddcd6644bc61)
1 /*	$NetBSD: kern_subr.c,v 1.52 1999/06/26 08:25:25 augustss 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 *getdisk __P((char *, int, int, dev_t *, int));
113 static struct device *parsedisk __P((char *, int, int, dev_t *));
114 static int getstr __P((char *, int));
115 
116 int
117 uiomove(buf, n, uio)
118 	register void *buf;
119 	register int n;
120 	register struct uio *uio;
121 {
122 	register struct iovec *iov;
123 	u_int cnt;
124 	int error = 0;
125 	char *cp = buf;
126 
127 #ifdef DIAGNOSTIC
128 	if (uio->uio_rw != UIO_READ && uio->uio_rw != UIO_WRITE)
129 		panic("uiomove: mode");
130 	if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc)
131 		panic("uiomove proc");
132 #endif
133 	while (n > 0 && uio->uio_resid) {
134 		iov = uio->uio_iov;
135 		cnt = iov->iov_len;
136 		if (cnt == 0) {
137 			uio->uio_iov++;
138 			uio->uio_iovcnt--;
139 			continue;
140 		}
141 		if (cnt > n)
142 			cnt = n;
143 		switch (uio->uio_segflg) {
144 
145 		case UIO_USERSPACE:
146 			if (uio->uio_rw == UIO_READ)
147 				error = copyout(cp, iov->iov_base, cnt);
148 			else
149 				error = copyin(iov->iov_base, cp, cnt);
150 			if (error)
151 				return (error);
152 			break;
153 
154 		case UIO_SYSSPACE:
155 			if (uio->uio_rw == UIO_READ)
156 				error = kcopy(cp, iov->iov_base, cnt);
157 			else
158 				error = kcopy(iov->iov_base, cp, cnt);
159 			if (error)
160 				return(error);
161 			break;
162 		}
163 		iov->iov_base = (caddr_t)iov->iov_base + cnt;
164 		iov->iov_len -= cnt;
165 		uio->uio_resid -= cnt;
166 		uio->uio_offset += cnt;
167 		cp += cnt;
168 		n -= cnt;
169 	}
170 	return (error);
171 }
172 
173 /*
174  * Give next character to user as result of read.
175  */
176 int
177 ureadc(c, uio)
178 	register int c;
179 	register struct uio *uio;
180 {
181 	register struct iovec *iov;
182 
183 	if (uio->uio_resid <= 0)
184 		panic("ureadc: non-positive resid");
185 again:
186 	if (uio->uio_iovcnt <= 0)
187 		panic("ureadc: non-positive iovcnt");
188 	iov = uio->uio_iov;
189 	if (iov->iov_len <= 0) {
190 		uio->uio_iovcnt--;
191 		uio->uio_iov++;
192 		goto again;
193 	}
194 	switch (uio->uio_segflg) {
195 
196 	case UIO_USERSPACE:
197 		if (subyte(iov->iov_base, c) < 0)
198 			return (EFAULT);
199 		break;
200 
201 	case UIO_SYSSPACE:
202 		*(char *)iov->iov_base = c;
203 		break;
204 	}
205 	iov->iov_base = (caddr_t)iov->iov_base + 1;
206 	iov->iov_len--;
207 	uio->uio_resid--;
208 	uio->uio_offset++;
209 	return (0);
210 }
211 
212 /*
213  * General routine to allocate a hash table.
214  * Allocate enough memory to hold at least `elements' list-head pointers.
215  * Return a pointer to the allocated space and set *hashmask to a pattern
216  * suitable for masking a value to use as an index into the returned array.
217  */
218 void *
219 hashinit(elements, type, flags, hashmask)
220 	int elements, type, flags;
221 	u_long *hashmask;
222 {
223 	long hashsize;
224 	LIST_HEAD(generic, generic) *hashtbl;
225 	int i;
226 
227 	if (elements <= 0)
228 		panic("hashinit: bad cnt");
229 	for (hashsize = 1; hashsize < elements; hashsize <<= 1)
230 		continue;
231 	hashtbl = malloc((u_long)hashsize * sizeof(*hashtbl), type, flags);
232 	for (i = 0; i < hashsize; i++)
233 		LIST_INIT(&hashtbl[i]);
234 	*hashmask = hashsize - 1;
235 	return (hashtbl);
236 }
237 
238 /*
239  * "Shutdown hook" types, functions, and variables.
240  */
241 
242 struct shutdownhook_desc {
243 	LIST_ENTRY(shutdownhook_desc) sfd_list;
244 	void	(*sfd_fn) __P((void *));
245 	void	*sfd_arg;
246 };
247 
248 LIST_HEAD(, shutdownhook_desc) shutdownhook_list;
249 
250 void *
251 shutdownhook_establish(fn, arg)
252 	void (*fn) __P((void *));
253 	void *arg;
254 {
255 	struct shutdownhook_desc *ndp;
256 
257 	ndp = (struct shutdownhook_desc *)
258 	    malloc(sizeof(*ndp), M_DEVBUF, M_NOWAIT);
259 	if (ndp == NULL)
260 		return NULL;
261 
262 	ndp->sfd_fn = fn;
263 	ndp->sfd_arg = arg;
264 	LIST_INSERT_HEAD(&shutdownhook_list, ndp, sfd_list);
265 
266 	return (ndp);
267 }
268 
269 void
270 shutdownhook_disestablish(vhook)
271 	void *vhook;
272 {
273 #ifdef DIAGNOSTIC
274 	struct shutdownhook_desc *dp;
275 
276 	for (dp = shutdownhook_list.lh_first; dp != NULL;
277 	    dp = dp->sfd_list.le_next)
278                 if (dp == vhook)
279 			break;
280 	if (dp == NULL)
281 		panic("shutdownhook_disestablish: hook not established");
282 #endif
283 
284 	LIST_REMOVE((struct shutdownhook_desc *)vhook, sfd_list);
285 	free(vhook, M_DEVBUF);
286 }
287 
288 /*
289  * Run shutdown hooks.  Should be invoked immediately before the
290  * system is halted or rebooted, i.e. after file systems unmounted,
291  * after crash dump done, etc.
292  *
293  * Each shutdown hook is removed from the list before it's run, so that
294  * it won't be run again.
295  */
296 void
297 doshutdownhooks()
298 {
299 	struct shutdownhook_desc *dp;
300 
301 	while ((dp = shutdownhook_list.lh_first) != NULL) {
302 		LIST_REMOVE(dp, sfd_list);
303 		(*dp->sfd_fn)(dp->sfd_arg);
304 #if 0
305 		/*
306 		 * Don't bother freeing the hook structure,, since we may
307 		 * be rebooting because of a memory corruption problem,
308 		 * and this might only make things worse.  It doesn't
309 		 * matter, anyway, since the system is just about to
310 		 * reboot.
311 		 */
312 		free(dp, M_DEVBUF);
313 #endif
314 	}
315 }
316 
317 /*
318  * "Power hook" types, functions, and variables.
319  */
320 
321 struct powerhook_desc {
322 	LIST_ENTRY(powerhook_desc) sfd_list;
323 	void	(*sfd_fn) __P((int, void *));
324 	void	*sfd_arg;
325 };
326 
327 LIST_HEAD(, powerhook_desc) powerhook_list;
328 
329 void *
330 powerhook_establish(fn, arg)
331 	void (*fn) __P((int, void *));
332 	void *arg;
333 {
334 	struct powerhook_desc *ndp;
335 
336 	ndp = (struct powerhook_desc *)
337 	    malloc(sizeof(*ndp), M_DEVBUF, M_NOWAIT);
338 	if (ndp == NULL)
339 		return NULL;
340 
341 	ndp->sfd_fn = fn;
342 	ndp->sfd_arg = arg;
343 	LIST_INSERT_HEAD(&powerhook_list, ndp, sfd_list);
344 
345 	return (ndp);
346 }
347 
348 void
349 powerhook_disestablish(vhook)
350 	void *vhook;
351 {
352 #ifdef DIAGNOSTIC
353 	struct powerhook_desc *dp;
354 
355 	for (dp = powerhook_list.lh_first; dp != NULL;
356 	    dp = dp->sfd_list.le_next)
357                 if (dp == vhook)
358 			break;
359 	if (dp == NULL)
360 		panic("powerhook_disestablish: hook not established");
361 #endif
362 
363 	LIST_REMOVE((struct powerhook_desc *)vhook, sfd_list);
364 	free(vhook, M_DEVBUF);
365 }
366 
367 /*
368  * Run power hooks.
369  */
370 void
371 dopowerhooks(why)
372 	int why;
373 {
374 	struct powerhook_desc *dp;
375 
376 	for (dp = LIST_FIRST(&powerhook_list);
377 	     dp != NULL;
378 	     dp = LIST_NEXT(dp, sfd_list)) {
379 		(*dp->sfd_fn)(why, dp->sfd_arg);
380 	}
381 }
382 
383 /*
384  * "Mountroot hook" types, functions, and variables.
385  */
386 
387 struct mountroothook_desc {
388 	LIST_ENTRY(mountroothook_desc) mrd_list;
389 	struct	device *mrd_device;
390 	void 	(*mrd_func) __P((struct device *));
391 };
392 
393 LIST_HEAD(, mountroothook_desc) mountroothook_list;
394 
395 void *
396 mountroothook_establish(func, dev)
397 	void (*func) __P((struct device *));
398 	struct device *dev;
399 {
400 	struct mountroothook_desc *mrd;
401 
402 	mrd = (struct mountroothook_desc *)
403 	    malloc(sizeof(*mrd), M_DEVBUF, M_NOWAIT);
404 	if (mrd == NULL)
405 		return (NULL);
406 
407 	mrd->mrd_device = dev;
408 	mrd->mrd_func = func;
409 	LIST_INSERT_HEAD(&mountroothook_list, mrd, mrd_list);
410 
411 	return (mrd);
412 }
413 
414 void
415 mountroothook_disestablish(vhook)
416 	void *vhook;
417 {
418 #ifdef DIAGNOSTIC
419 	struct mountroothook_desc *mrd;
420 
421 	for (mrd = mountroothook_list.lh_first; mrd != NULL;
422 	    mrd = mrd->mrd_list.le_next)
423                 if (mrd == vhook)
424 			break;
425 	if (mrd == NULL)
426 		panic("mountroothook_disestablish: hook not established");
427 #endif
428 
429 	LIST_REMOVE((struct mountroothook_desc *)vhook, mrd_list);
430 	free(vhook, M_DEVBUF);
431 }
432 
433 void
434 mountroothook_destroy()
435 {
436 	struct mountroothook_desc *mrd;
437 
438 	while ((mrd = mountroothook_list.lh_first) != NULL) {
439 		LIST_REMOVE(mrd, mrd_list);
440 		free(mrd, M_DEVBUF);
441 	}
442 }
443 
444 void
445 domountroothook()
446 {
447 	struct mountroothook_desc *mrd;
448 
449 	for (mrd = mountroothook_list.lh_first; mrd != NULL;
450 	    mrd = mrd->mrd_list.le_next) {
451 		if (mrd->mrd_device == root_device) {
452 			(*mrd->mrd_func)(root_device);
453 			return;
454 		}
455 	}
456 }
457 
458 /*
459  * Determine the root device and, if instructed to, the root file system.
460  */
461 
462 #include "md.h"
463 #if NMD == 0
464 #undef MEMORY_DISK_HOOKS
465 #endif
466 
467 #ifdef MEMORY_DISK_HOOKS
468 static struct device fakemdrootdev[NMD];
469 #endif
470 
471 void
472 setroot(bootdv, bootpartition)
473 	struct device *bootdv;
474 	int bootpartition;
475 {
476 	struct device *dv;
477 	int len, print_newline = 0;
478 #ifdef MEMORY_DISK_HOOKS
479 	int i;
480 #endif
481 	dev_t nrootdev;
482 	dev_t ndumpdev = NODEV;
483 	char buf[128];
484 	const char *rootdevname;
485 	const char *dumpdevname;
486 	struct device *rootdv = NULL;		/* XXX gcc -Wuninitialized */
487 	struct device *dumpdv = NULL;
488 	struct ifnet *ifp;
489 	const char *deffsname;
490 	struct vfsops *vops;
491 	extern int (*mountroot) __P((void));
492 
493 #ifdef MEMORY_DISK_HOOKS
494 	for (i = 0; i < NMD; i++) {
495 		fakemdrootdev[i].dv_class  = DV_DISK;
496 		fakemdrootdev[i].dv_cfdata = NULL;
497 		fakemdrootdev[i].dv_unit   = i;
498 		fakemdrootdev[i].dv_parent = NULL;
499 		sprintf(fakemdrootdev[i].dv_xname, "md%d", i);
500 	}
501 #endif /* MEMORY_DISK_HOOKS */
502 
503 #ifdef MEMORY_DISK_IS_ROOT
504 	bootdv = &fakemdrootdev[0];
505 	bootpartition = 0;
506 #endif
507 
508 	/*
509 	 * If NFS is specified as the file system, and we found
510 	 * a DV_DISK boot device (or no boot device at all), then
511 	 * find a reasonable network interface for "rootspec".
512 	 */
513 	vops = vfs_getopsbyname("nfs");
514 	if (vops != NULL && vops->vfs_mountroot == mountroot &&
515 	    rootspec == NULL &&
516 	    (bootdv == NULL || bootdv->dv_class != DV_IFNET)) {
517 		for (ifp = ifnet.tqh_first; ifp != NULL;
518 		    ifp = ifp->if_list.tqe_next)
519 			if ((ifp->if_flags &
520 			     (IFF_LOOPBACK|IFF_POINTOPOINT)) == 0)
521 				break;
522 		if (ifp == NULL) {
523 			/*
524 			 * Can't find a suitable interface; ask the
525 			 * user.
526 			 */
527 			boothowto |= RB_ASKNAME;
528 		} else {
529 			/*
530 			 * Have a suitable interface; behave as if
531 			 * the user specified this interface.
532 			 */
533 			rootspec = (const char *)ifp->if_xname;
534 		}
535 	}
536 
537 	/*
538 	 * If wildcarded root and we the boot device wasn't determined,
539 	 * ask the user.
540 	 */
541 	if (rootspec == NULL && bootdv == NULL)
542 		boothowto |= RB_ASKNAME;
543 
544  top:
545 	if (boothowto & RB_ASKNAME) {
546 		struct device *defdumpdv;
547 
548 		for (;;) {
549 			printf("root device");
550 			if (bootdv != NULL) {
551 				printf(" (default %s", bootdv->dv_xname);
552 				if (bootdv->dv_class == DV_DISK)
553 					printf("%c", bootpartition + 'a');
554 				printf(")");
555 			}
556 			printf(": ");
557 			len = getstr(buf, sizeof(buf));
558 			if (len == 0 && bootdv != NULL) {
559 				strcpy(buf, bootdv->dv_xname);
560 				len = strlen(buf);
561 			}
562 			if (len > 0 && buf[len - 1] == '*') {
563 				buf[--len] = '\0';
564 				dv = getdisk(buf, len, 1, &nrootdev, 0);
565 				if (dv != NULL) {
566 					rootdv = dv;
567 					break;
568 				}
569 			}
570 			dv = getdisk(buf, len, bootpartition, &nrootdev, 0);
571 			if (dv != NULL) {
572 				rootdv = dv;
573 				break;
574 			}
575 		}
576 
577 		/*
578 		 * Set up the default dump device.  If root is on
579 		 * a network device, there is no default dump
580 		 * device, since we don't support dumps to the
581 		 * network.
582 		 */
583 		if (rootdv->dv_class == DV_IFNET)
584 			defdumpdv = NULL;
585 		else
586 			defdumpdv = rootdv;
587 
588 		for (;;) {
589 			printf("dump device");
590 			if (defdumpdv != NULL) {
591 				/*
592 				 * Note, we know it's a disk if we get here.
593 				 */
594 				printf(" (default %sb)", defdumpdv->dv_xname);
595 			}
596 			printf(": ");
597 			len = getstr(buf, sizeof(buf));
598 			if (len == 0) {
599 				if (defdumpdv != NULL) {
600 					ndumpdev = MAKEDISKDEV(major(nrootdev),
601 					    DISKUNIT(nrootdev), 1);
602 				}
603 				if (rootdv->dv_class == DV_IFNET)
604 					dumpdv = NULL;
605 				else
606 					dumpdv = rootdv;
607 				break;
608 			}
609 			if (len == 4 && strcmp(buf, "none") == 0) {
610 				dumpspec = "none";
611 				goto havedump;
612 			}
613 			dv = getdisk(buf, len, 1, &ndumpdev, 1);
614 			if (dv) {
615 				dumpdv = dv;
616 				break;
617 			}
618 		}
619 
620  havedump:
621 		rootdev = nrootdev;
622 		dumpdev = ndumpdev;
623 
624 		for (vops = LIST_FIRST(&vfs_list); vops != NULL;
625 		     vops = LIST_NEXT(vops, vfs_list)) {
626 			if (vops->vfs_mountroot != NULL &&
627 			    vops->vfs_mountroot == mountroot)
628 			break;
629 		}
630 
631 		if (vops == NULL) {
632 			mountroot = NULL;
633 			deffsname = "generic";
634 		} else
635 			deffsname = vops->vfs_name;
636 
637 		for (;;) {
638 			printf("file system (default %s): ", deffsname);
639 			len = getstr(buf, sizeof(buf));
640 			if (len == 0)
641 				break;
642 			if (len == 4 && strcmp(buf, "halt") == 0)
643 				cpu_reboot(RB_HALT, NULL);
644 			else if (len == 7 && strcmp(buf, "generic") == 0) {
645 				mountroot = NULL;
646 				break;
647 			}
648 			vops = vfs_getopsbyname(buf);
649 			if (vops == NULL || vops->vfs_mountroot == NULL) {
650 				printf("use one of: generic");
651 				for (vops = LIST_FIRST(&vfs_list);
652 				     vops != NULL;
653 				     vops = LIST_NEXT(vops, vfs_list)) {
654 					if (vops->vfs_mountroot != NULL)
655 						printf(" %s", vops->vfs_name);
656 				}
657 				printf(" halt\n");
658 			} else {
659 				mountroot = vops->vfs_mountroot;
660 				break;
661 			}
662 		}
663 
664 	} else if (rootspec == NULL) {
665 		int majdev;
666 
667 		/*
668 		 * Wildcarded root; use the boot device.
669 		 */
670 		rootdv = bootdv;
671 
672 		majdev = findblkmajor(bootdv->dv_xname);
673 		if (majdev >= 0) {
674 			/*
675 			 * Root is on a disk.  `bootpartition' is root.
676 			 */
677 			rootdev = MAKEDISKDEV(majdev, bootdv->dv_unit,
678 			    bootpartition);
679 		}
680 	} else {
681 
682 		/*
683 		 * `root on <dev> ...'
684 		 */
685 
686 		/*
687 		 * If it's a network interface, we can bail out
688 		 * early.
689 		 */
690 		for (dv = alldevs.tqh_first; dv != NULL;
691 		    dv = dv->dv_list.tqe_next)
692 			if (strcmp(dv->dv_xname, rootspec) == 0)
693 				break;
694 		if (dv != NULL && dv->dv_class == DV_IFNET) {
695 			rootdv = dv;
696 			goto haveroot;
697 		}
698 
699 		rootdevname = findblkname(major(rootdev));
700 		if (rootdevname == NULL) {
701 			printf("unknown device major 0x%x\n", rootdev);
702 			boothowto |= RB_ASKNAME;
703 			goto top;
704 		}
705 		memset(buf, 0, sizeof(buf));
706 		sprintf(buf, "%s%d", rootdevname, DISKUNIT(rootdev));
707 
708 		for (dv = alldevs.tqh_first; dv != NULL;
709 		    dv = dv->dv_list.tqe_next) {
710 			if (strcmp(buf, dv->dv_xname) == 0) {
711 				rootdv = dv;
712 				break;
713 			}
714 		}
715 		if (rootdv == NULL) {
716 			printf("device %s (0x%x) not configured\n",
717 			    buf, rootdev);
718 			boothowto |= RB_ASKNAME;
719 			goto top;
720 		}
721 	}
722 
723  haveroot:
724 
725 	root_device = rootdv;
726 
727 	switch (rootdv->dv_class) {
728 	case DV_IFNET:
729 		/* Nothing. */
730 		break;
731 
732 	case DV_DISK:
733 		printf("root on %s%c", rootdv->dv_xname,
734 		    DISKPART(rootdev) + 'a');
735 		print_newline = 1;
736 		break;
737 
738 	default:
739 		printf("can't determine root device\n");
740 		boothowto |= RB_ASKNAME;
741 		goto top;
742 	}
743 
744 	/*
745 	 * Now configure the dump device.
746 	 */
747 
748 	if (dumpspec != NULL && strcmp(dumpspec, "none") == 0) {
749 		/*
750 		 * Operator doesn't want a dump device.
751 		 */
752 		goto nodumpdev;
753 	}
754 
755 	/*
756 	 * If we haven't figured out the dump device, do so, with
757 	 * the following rules:
758 	 *
759 	 *	(a) We already know dumpdv in the RB_ASKNAME case.
760 	 *
761 	 *	(b) If dumpspec is set, try to use it.  If the device
762 	 *	    is not available, punt.
763 	 *
764 	 *	(c) If dumpspec is not set, the dump device is
765 	 *	    wildcarded or unspecified.  If the root device
766 	 *	    is DV_IFNET, punt.  Otherwise, use partition b
767 	 *	    of the root device.
768 	 */
769 
770 	if (boothowto & RB_ASKNAME) {
771 		if (dumpdv == NULL) {
772 			/*
773 			 * Just return; dumpdev is already set to NODEV
774 			 * and we don't want to print a newline in this
775 			 * case.
776 			 */
777 			return;
778 		}
779 		goto out;
780 	}
781 
782 	if (dumpspec != NULL) {
783 		if (dumpdev == NODEV) {
784 			/*
785 			 * Looks like they tried to pick a network
786 			 * device.  Oops.
787 			 */
788 			goto nodumpdev;
789 		}
790 
791 		dumpdevname = findblkname(major(dumpdev));
792 		if (dumpdevname == NULL)
793 			goto nodumpdev;
794 		memset(buf, 0, sizeof(buf));
795 		sprintf(buf, "%s%d", dumpdevname, DISKUNIT(dumpdev));
796 
797 		for (dv = alldevs.tqh_first; dv != NULL;
798 		    dv = dv->dv_list.tqe_next) {
799 			if (strcmp(buf, dv->dv_xname) == 0) {
800 				dumpdv = dv;
801 				break;
802 			}
803 		}
804 		if (dv == NULL) {
805 			/*
806 			 * Device not configured.
807 			 */
808 			goto nodumpdev;
809 		}
810 	} else if (rootdv->dv_class == DV_IFNET)
811 		goto nodumpdev;
812 	else {
813 		dumpdv = rootdv;
814 		dumpdev = MAKEDISKDEV(major(rootdev), dumpdv->dv_unit, 1);
815 	}
816 
817  out:
818 	printf(" dumps on %s%c\n", dumpdv->dv_xname, DISKPART(dumpdev) + 'a');
819 	return;
820 
821  nodumpdev:
822 	dumpdev = NODEV;
823 	if (print_newline)
824 		printf("\n");
825 }
826 
827 static int
828 findblkmajor(name)
829 	const char *name;
830 {
831 	int i;
832 
833 	for (i = 0; dev_name2blk[i].d_name != NULL; i++)
834 		if (strncmp(name, dev_name2blk[i].d_name,
835 		    strlen(dev_name2blk[i].d_name)) == 0)
836 			return (dev_name2blk[i].d_maj);
837 	return (-1);
838 }
839 
840 const char *
841 findblkname(maj)
842 	int maj;
843 {
844 	int i;
845 
846 	for (i = 0; dev_name2blk[i].d_name != NULL; i++)
847 		if (dev_name2blk[i].d_maj == maj)
848 			return (dev_name2blk[i].d_name);
849 	return (NULL);
850 }
851 
852 static struct device *
853 getdisk(str, len, defpart, devp, isdump)
854 	char *str;
855 	int len, defpart;
856 	dev_t *devp;
857 	int isdump;
858 {
859 	struct device	*dv;
860 #ifdef MEMORY_DISK_HOOKS
861 	int		i;
862 #endif
863 
864 	if ((dv = parsedisk(str, len, defpart, devp)) == NULL) {
865 		printf("use one of:");
866 #ifdef MEMORY_DISK_HOOKS
867 		if (isdump == 0)
868 			for (i = 0; i < NMD; i++)
869 				printf(" %s[a-%c]", fakemdrootdev[i].dv_xname,
870 				    'a' + MAXPARTITIONS - 1);
871 #endif
872 		for (dv = alldevs.tqh_first; dv != NULL;
873 		    dv = dv->dv_list.tqe_next) {
874 			if (dv->dv_class == DV_DISK)
875 				printf(" %s[a-%c]", dv->dv_xname,
876 				    'a' + MAXPARTITIONS - 1);
877 			if (isdump == 0 && dv->dv_class == DV_IFNET)
878 				printf(" %s", dv->dv_xname);
879 		}
880 		if (isdump)
881 			printf(" none");
882 		printf(" halt\n");
883 	}
884 	return (dv);
885 }
886 
887 static struct device *
888 parsedisk(str, len, defpart, devp)
889 	char *str;
890 	int len, defpart;
891 	dev_t *devp;
892 {
893 	struct device *dv;
894 	char *cp, c;
895 	int majdev, part;
896 #ifdef MEMORY_DISK_HOOKS
897 	int i;
898 #endif
899 
900 	if (len == 0)
901 		return (NULL);
902 
903 	if (len == 4 && strcmp(str, "halt") == 0)
904 		cpu_reboot(RB_HALT, NULL);
905 
906 	cp = str + len - 1;
907 	c = *cp;
908 	if (c >= 'a' && c <= ('a' + MAXPARTITIONS - 1)) {
909 		part = c - 'a';
910 		*cp = '\0';
911 	} else
912 		part = defpart;
913 
914 #ifdef MEMORY_DISK_HOOKS
915 	for (i = 0; i < NMD; i++)
916 		if (strcmp(str, fakemdrootdev[i].dv_xname) == 0) {
917 			dv = &fakemdrootdev[i];
918 			goto gotdisk;
919 		}
920 #endif
921 
922 	for (dv = alldevs.tqh_first; dv != NULL; dv = dv->dv_list.tqe_next) {
923 		if (dv->dv_class == DV_DISK &&
924 		    strcmp(str, dv->dv_xname) == 0) {
925 #ifdef MEMORY_DISK_HOOKS
926  gotdisk:
927 #endif
928 			majdev = findblkmajor(dv->dv_xname);
929 			if (majdev < 0)
930 				panic("parsedisk");
931 			*devp = MAKEDISKDEV(majdev, dv->dv_unit, part);
932 			break;
933 		}
934 
935 		if (dv->dv_class == DV_IFNET &&
936 		    strcmp(str, dv->dv_xname) == 0) {
937 			*devp = NODEV;
938 			break;
939 		}
940 	}
941 
942 	*cp = c;
943 	return (dv);
944 }
945 
946 /*
947  * XXX shouldn't this be a common function?
948  */
949 static int
950 getstr(cp, size)
951 	char *cp;
952 	int size;
953 {
954 	char *lp;
955 	int c, len;
956 
957 	cnpollc(1);
958 
959 	lp = cp;
960 	len = 0;
961 	for (;;) {
962 		c = cngetc();
963 		switch (c) {
964 		case '\n':
965 		case '\r':
966 			printf("\n");
967 			*lp++ = '\0';
968 			cnpollc(0);
969 			return (len);
970 		case '\b':
971 		case '\177':
972 		case '#':
973 			if (len) {
974 				--len;
975 				--lp;
976 				printf("\b \b");
977 			}
978 			continue;
979 		case '@':
980 		case 'u'&037:
981 			len = 0;
982 			lp = cp;
983 			printf("\n");
984 			continue;
985 		default:
986 			if (len + 1 >= size || c < ' ') {
987 				printf("\007");
988 				continue;
989 			}
990 			printf("%c", c);
991 			++len;
992 			*lp++ = c;
993 		}
994 	}
995 }
996 
997 /*
998  * snprintf() `bytes' into `buf', reformatting it so that the number,
999  * plus a possible `x' + suffix extension) fits into len bytes (including
1000  * the terminating NUL).
1001  * Returns the number of bytes stored in buf, or -1 * if there was a problem.
1002  * E.g, given a len of 9 and a suffix of `B':
1003  *	bytes		result
1004  *	-----		------
1005  *	99999		`99999 B'
1006  *	100000		`97 KB'
1007  *	66715648	`65152 KB'
1008  *	252215296	`240 MB'
1009  */
1010 int
1011 humanize_number(buf, len, bytes, suffix)
1012 	char		*buf;
1013 	size_t		 len;
1014 	u_int64_t	 bytes;
1015 	const char	*suffix;
1016 {
1017 		/* prefixes are: (none), Kilo, Mega, Giga, Tera, Peta, Exa */
1018 	static const char prefixes[] = " KMGTPE";
1019 
1020 	int		i, r;
1021 	u_int64_t	max;
1022 	size_t		suffixlen;
1023 
1024 	if (buf == NULL || suffix == NULL)
1025 		return (-1);
1026 	if (len > 0)
1027 		buf[0] = '\0';
1028 	suffixlen = strlen(suffix);
1029 			/* check if enough room for `x y' + suffix + `\0' */
1030 	if (len < 4 + suffixlen)
1031 		return (-1);
1032 
1033 	max = 1;
1034 	for (i = 0; i < len - suffixlen - 3; i++)
1035 		max *= 10;
1036 	for (i = 0; bytes >= max && i < sizeof(prefixes); i++)
1037 		bytes /= 1024;
1038 
1039 	r = snprintf(buf, len, "%qu%s%c%s", (unsigned long long)bytes,
1040 	    i == 0 ? "" : " ", prefixes[i], suffix);
1041 
1042 	return (r);
1043 }
1044 
1045 int
1046 format_bytes(buf, len, bytes)
1047 	char		*buf;
1048 	size_t		 len;
1049 	u_int64_t	 bytes;
1050 {
1051 	int	rv;
1052 	size_t	nlen;
1053 
1054 	rv = humanize_number(buf, len, bytes, "B");
1055 	if (rv != -1) {
1056 			/* nuke the trailing ` B' if it exists */
1057 		nlen = strlen(buf) - 2;
1058 		if (strcmp(&buf[nlen], " B") == 0)
1059 			buf[nlen] = '\0';
1060 	}
1061 	return (rv);
1062 }
1063