xref: /freebsd/sys/kern/init_main.c (revision 6607310b740c499e273ae5bbf1f308ed91b61c05)
1 /*-
2  * Copyright (c) 1995 Terrence R. Lambert
3  * All rights reserved.
4  *
5  * Copyright (c) 1982, 1986, 1989, 1991, 1992, 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  * Redistribution and use in source and binary forms, with or without
14  * modification, are permitted provided that the following conditions
15  * are met:
16  * 1. Redistributions of source code must retain the above copyright
17  *    notice, this list of conditions and the following disclaimer.
18  * 2. Redistributions in binary form must reproduce the above copyright
19  *    notice, this list of conditions and the following disclaimer in the
20  *    documentation and/or other materials provided with the distribution.
21  * 3. All advertising materials mentioning features or use of this software
22  *    must display the following acknowledgement:
23  *	This product includes software developed by the University of
24  *	California, Berkeley and its contributors.
25  * 4. Neither the name of the University nor the names of its contributors
26  *    may be used to endorse or promote products derived from this software
27  *    without specific prior written permission.
28  *
29  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
30  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
31  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
32  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
33  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
34  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
35  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
36  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
37  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
38  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
39  * SUCH DAMAGE.
40  *
41  *	@(#)init_main.c	8.9 (Berkeley) 1/21/94
42  */
43 
44 #include <sys/cdefs.h>
45 __FBSDID("$FreeBSD$");
46 
47 #include "opt_ddb.h"
48 #include "opt_init_path.h"
49 #include "opt_mac.h"
50 
51 #include <sys/param.h>
52 #include <sys/kernel.h>
53 #include <sys/exec.h>
54 #include <sys/file.h>
55 #include <sys/filedesc.h>
56 #include <sys/ktr.h>
57 #include <sys/lock.h>
58 #include <sys/mount.h>
59 #include <sys/mutex.h>
60 #include <sys/syscallsubr.h>
61 #include <sys/sysctl.h>
62 #include <sys/proc.h>
63 #include <sys/resourcevar.h>
64 #include <sys/systm.h>
65 #include <sys/signalvar.h>
66 #include <sys/vnode.h>
67 #include <sys/sysent.h>
68 #include <sys/reboot.h>
69 #include <sys/sched.h>
70 #include <sys/sx.h>
71 #include <sys/sysproto.h>
72 #include <sys/vmmeter.h>
73 #include <sys/unistd.h>
74 #include <sys/malloc.h>
75 #include <sys/conf.h>
76 
77 #include <machine/cpu.h>
78 
79 #include <security/audit/audit.h>
80 #include <security/mac/mac_framework.h>
81 
82 #include <vm/vm.h>
83 #include <vm/vm_param.h>
84 #include <vm/pmap.h>
85 #include <vm/vm_map.h>
86 #include <sys/copyright.h>
87 
88 #include <ddb/ddb.h>
89 #include <ddb/db_sym.h>
90 
91 void mi_startup(void);				/* Should be elsewhere */
92 
93 /* Components of the first process -- never freed. */
94 static struct session session0;
95 static struct pgrp pgrp0;
96 struct	proc proc0;
97 struct	thread thread0 __aligned(16);
98 struct	vmspace vmspace0;
99 struct	proc *initproc;
100 
101 int	boothowto = 0;		/* initialized so that it can be patched */
102 SYSCTL_INT(_debug, OID_AUTO, boothowto, CTLFLAG_RD, &boothowto, 0, "");
103 int	bootverbose;
104 SYSCTL_INT(_debug, OID_AUTO, bootverbose, CTLFLAG_RW, &bootverbose, 0, "");
105 
106 /*
107  * This ensures that there is at least one entry so that the sysinit_set
108  * symbol is not undefined.  A sybsystem ID of SI_SUB_DUMMY is never
109  * executed.
110  */
111 SYSINIT(placeholder, SI_SUB_DUMMY, SI_ORDER_ANY, NULL, NULL)
112 
113 /*
114  * The sysinit table itself.  Items are checked off as the are run.
115  * If we want to register new sysinit types, add them to newsysinit.
116  */
117 SET_DECLARE(sysinit_set, struct sysinit);
118 struct sysinit **sysinit, **sysinit_end;
119 struct sysinit **newsysinit, **newsysinit_end;
120 
121 /*
122  * Merge a new sysinit set into the current set, reallocating it if
123  * necessary.  This can only be called after malloc is running.
124  */
125 void
126 sysinit_add(struct sysinit **set, struct sysinit **set_end)
127 {
128 	struct sysinit **newset;
129 	struct sysinit **sipp;
130 	struct sysinit **xipp;
131 	int count;
132 
133 	count = set_end - set;
134 	if (newsysinit)
135 		count += newsysinit_end - newsysinit;
136 	else
137 		count += sysinit_end - sysinit;
138 	newset = malloc(count * sizeof(*sipp), M_TEMP, M_NOWAIT);
139 	if (newset == NULL)
140 		panic("cannot malloc for sysinit");
141 	xipp = newset;
142 	if (newsysinit)
143 		for (sipp = newsysinit; sipp < newsysinit_end; sipp++)
144 			*xipp++ = *sipp;
145 	else
146 		for (sipp = sysinit; sipp < sysinit_end; sipp++)
147 			*xipp++ = *sipp;
148 	for (sipp = set; sipp < set_end; sipp++)
149 		*xipp++ = *sipp;
150 	if (newsysinit)
151 		free(newsysinit, M_TEMP);
152 	newsysinit = newset;
153 	newsysinit_end = newset + count;
154 }
155 
156 /*
157  * System startup; initialize the world, create process 0, mount root
158  * filesystem, and fork to create init and pagedaemon.  Most of the
159  * hard work is done in the lower-level initialization routines including
160  * startup(), which does memory initialization and autoconfiguration.
161  *
162  * This allows simple addition of new kernel subsystems that require
163  * boot time initialization.  It also allows substitution of subsystem
164  * (for instance, a scheduler, kernel profiler, or VM system) by object
165  * module.  Finally, it allows for optional "kernel threads".
166  */
167 void
168 mi_startup(void)
169 {
170 
171 	register struct sysinit **sipp;		/* system initialization*/
172 	register struct sysinit **xipp;		/* interior loop of sort*/
173 	register struct sysinit *save;		/* bubble*/
174 
175 #if defined(VERBOSE_SYSINIT)
176 	int last;
177 	int verbose;
178 #endif
179 
180 	if (sysinit == NULL) {
181 		sysinit = SET_BEGIN(sysinit_set);
182 		sysinit_end = SET_LIMIT(sysinit_set);
183 	}
184 
185 restart:
186 	/*
187 	 * Perform a bubble sort of the system initialization objects by
188 	 * their subsystem (primary key) and order (secondary key).
189 	 */
190 	for (sipp = sysinit; sipp < sysinit_end; sipp++) {
191 		for (xipp = sipp + 1; xipp < sysinit_end; xipp++) {
192 			if ((*sipp)->subsystem < (*xipp)->subsystem ||
193 			     ((*sipp)->subsystem == (*xipp)->subsystem &&
194 			      (*sipp)->order <= (*xipp)->order))
195 				continue;	/* skip*/
196 			save = *sipp;
197 			*sipp = *xipp;
198 			*xipp = save;
199 		}
200 	}
201 
202 #if defined(VERBOSE_SYSINIT)
203 	last = SI_SUB_COPYRIGHT;
204 	verbose = 0;
205 #if !defined(DDB)
206 	printf("VERBOSE_SYSINIT: DDB not enabled, symbol lookups disabled.\n");
207 #endif
208 #endif
209 
210 	/*
211 	 * Traverse the (now) ordered list of system initialization tasks.
212 	 * Perform each task, and continue on to the next task.
213 	 *
214 	 * The last item on the list is expected to be the scheduler,
215 	 * which will not return.
216 	 */
217 	for (sipp = sysinit; sipp < sysinit_end; sipp++) {
218 
219 		if ((*sipp)->subsystem == SI_SUB_DUMMY)
220 			continue;	/* skip dummy task(s)*/
221 
222 		if ((*sipp)->subsystem == SI_SUB_DONE)
223 			continue;
224 
225 #if defined(VERBOSE_SYSINIT)
226 		if ((*sipp)->subsystem > last) {
227 			verbose = 1;
228 			last = (*sipp)->subsystem;
229 			printf("subsystem %x\n", last);
230 		}
231 		if (verbose) {
232 #if defined(DDB)
233 			const char *name;
234 			c_db_sym_t sym;
235 			db_expr_t  offset;
236 
237 			sym = db_search_symbol((vm_offset_t)(*sipp)->func,
238 			    DB_STGY_PROC, &offset);
239 			db_symbol_values(sym, &name, NULL);
240 			if (name != NULL)
241 				printf("   %s(%p)... ", name, (*sipp)->udata);
242 			else
243 #endif
244 				printf("   %p(%p)... ", (*sipp)->func,
245 				    (*sipp)->udata);
246 		}
247 #endif
248 
249 		/* Call function */
250 		(*((*sipp)->func))((*sipp)->udata);
251 
252 #if defined(VERBOSE_SYSINIT)
253 		if (verbose)
254 			printf("done.\n");
255 #endif
256 
257 		/* Check off the one we're just done */
258 		(*sipp)->subsystem = SI_SUB_DONE;
259 
260 		/* Check if we've installed more sysinit items via KLD */
261 		if (newsysinit != NULL) {
262 			if (sysinit != SET_BEGIN(sysinit_set))
263 				free(sysinit, M_TEMP);
264 			sysinit = newsysinit;
265 			sysinit_end = newsysinit_end;
266 			newsysinit = NULL;
267 			newsysinit_end = NULL;
268 			goto restart;
269 		}
270 	}
271 
272 	panic("Shouldn't get here!");
273 	/* NOTREACHED*/
274 }
275 
276 
277 /*
278  ***************************************************************************
279  ****
280  **** The following SYSINIT's belong elsewhere, but have not yet
281  **** been moved.
282  ****
283  ***************************************************************************
284  */
285 static void
286 print_caddr_t(void *data __unused)
287 {
288 	printf("%s", (char *)data);
289 }
290 SYSINIT(announce, SI_SUB_COPYRIGHT, SI_ORDER_FIRST, print_caddr_t, copyright)
291 SYSINIT(trademark, SI_SUB_COPYRIGHT, SI_ORDER_SECOND, print_caddr_t, trademark)
292 SYSINIT(version, SI_SUB_COPYRIGHT, SI_ORDER_THIRD, print_caddr_t, version)
293 
294 #ifdef WITNESS
295 static char wit_warn[] =
296      "WARNING: WITNESS option enabled, expect reduced performance.\n";
297 SYSINIT(witwarn, SI_SUB_COPYRIGHT, SI_ORDER_THIRD + 1,
298    print_caddr_t, wit_warn)
299 SYSINIT(witwarn2, SI_SUB_RUN_SCHEDULER, SI_ORDER_THIRD + 1,
300    print_caddr_t, wit_warn)
301 #endif
302 
303 #ifdef DIAGNOSTIC
304 static char diag_warn[] =
305      "WARNING: DIAGNOSTIC option enabled, expect reduced performance.\n";
306 SYSINIT(diagwarn, SI_SUB_COPYRIGHT, SI_ORDER_THIRD + 2,
307     print_caddr_t, diag_warn)
308 SYSINIT(diagwarn2, SI_SUB_RUN_SCHEDULER, SI_ORDER_THIRD + 2,
309     print_caddr_t, diag_warn)
310 #endif
311 
312 static void
313 set_boot_verbose(void *data __unused)
314 {
315 
316 	if (boothowto & RB_VERBOSE)
317 		bootverbose++;
318 }
319 SYSINIT(boot_verbose, SI_SUB_TUNABLES, SI_ORDER_ANY, set_boot_verbose, NULL)
320 
321 struct sysentvec null_sysvec = {
322 	0,
323 	NULL,
324 	0,
325 	0,
326 	NULL,
327 	0,
328 	NULL,
329 	NULL,
330 	NULL,
331 	NULL,
332 	NULL,
333 	NULL,
334 	NULL,
335 	"null",
336 	NULL,
337 	NULL,
338 	0,
339 	PAGE_SIZE,
340 	VM_MIN_ADDRESS,
341 	VM_MAXUSER_ADDRESS,
342 	USRSTACK,
343 	PS_STRINGS,
344 	VM_PROT_ALL,
345 	NULL,
346 	NULL,
347 	NULL
348 };
349 
350 /*
351  ***************************************************************************
352  ****
353  **** The two following SYSINIT's are proc0 specific glue code.  I am not
354  **** convinced that they can not be safely combined, but their order of
355  **** operation has been maintained as the same as the original init_main.c
356  **** for right now.
357  ****
358  **** These probably belong in init_proc.c or kern_proc.c, since they
359  **** deal with proc0 (the fork template process).
360  ****
361  ***************************************************************************
362  */
363 /* ARGSUSED*/
364 static void
365 proc0_init(void *dummy __unused)
366 {
367 	struct proc *p;
368 	unsigned i;
369 	struct thread *td;
370 
371 	GIANT_REQUIRED;
372 	p = &proc0;
373 	td = &thread0;
374 
375 	/*
376 	 * Initialize magic number.
377 	 */
378 	p->p_magic = P_MAGIC;
379 
380 	/*
381 	 * Initialize thread and process structures.
382 	 */
383 	procinit();	/* set up proc zone */
384 	threadinit();	/* set up UMA zones */
385 
386 	/*
387 	 * Initialise scheduler resources.
388 	 * Add scheduler specific parts to proc, thread as needed.
389 	 */
390 	schedinit();	/* scheduler gets its house in order */
391 	/*
392 	 * Initialize sleep queue hash table
393 	 */
394 	sleepinit();
395 
396 	/*
397 	 * additional VM structures
398 	 */
399 	vm_init2();
400 
401 	/*
402 	 * Create process 0 (the swapper).
403 	 */
404 	LIST_INSERT_HEAD(&allproc, p, p_list);
405 	LIST_INSERT_HEAD(PIDHASH(0), p, p_hash);
406 	mtx_init(&pgrp0.pg_mtx, "process group", NULL, MTX_DEF | MTX_DUPOK);
407 	p->p_pgrp = &pgrp0;
408 	LIST_INSERT_HEAD(PGRPHASH(0), &pgrp0, pg_hash);
409 	LIST_INIT(&pgrp0.pg_members);
410 	LIST_INSERT_HEAD(&pgrp0.pg_members, p, p_pglist);
411 
412 	pgrp0.pg_session = &session0;
413 	mtx_init(&session0.s_mtx, "session", NULL, MTX_DEF);
414 	session0.s_count = 1;
415 	session0.s_leader = p;
416 
417 	p->p_sysent = &null_sysvec;
418 	p->p_flag = P_SYSTEM | P_INMEM;
419 	p->p_state = PRS_NORMAL;
420 	knlist_init(&p->p_klist, &p->p_mtx, NULL, NULL, NULL);
421 	STAILQ_INIT(&p->p_ktr);
422 	p->p_nice = NZERO;
423 	td->td_state = TDS_RUNNING;
424 	td->td_pri_class = PRI_TIMESHARE;
425 	td->td_user_pri = PUSER;
426 	td->td_base_user_pri = PUSER;
427 	td->td_priority = PVM;
428 	td->td_base_pri = PUSER;
429 	td->td_oncpu = 0;
430 	td->td_flags = TDF_INMEM|TDP_KTHREAD;
431 	p->p_peers = 0;
432 	p->p_leader = p;
433 
434 
435 	strncpy(p->p_comm, "kernel", sizeof (p->p_comm));
436 	strncpy(td->td_name, "swapper", sizeof (td->td_name));
437 
438 	callout_init(&p->p_itcallout, CALLOUT_MPSAFE);
439 	callout_init_mtx(&p->p_limco, &p->p_mtx, 0);
440 	callout_init(&td->td_slpcallout, CALLOUT_MPSAFE);
441 
442 	/* Create credentials. */
443 	p->p_ucred = crget();
444 	p->p_ucred->cr_ngroups = 1;	/* group 0 */
445 	p->p_ucred->cr_uidinfo = uifind(0);
446 	p->p_ucred->cr_ruidinfo = uifind(0);
447 	p->p_ucred->cr_prison = NULL;	/* Don't jail it. */
448 #ifdef AUDIT
449 	audit_cred_kproc0(p->p_ucred);
450 #endif
451 #ifdef MAC
452 	mac_proc_create_swapper(p->p_ucred);
453 #endif
454 	td->td_ucred = crhold(p->p_ucred);
455 
456 	/* Create sigacts. */
457 	p->p_sigacts = sigacts_alloc();
458 
459 	/* Initialize signal state for process 0. */
460 	siginit(&proc0);
461 
462 	/* Create the file descriptor table. */
463 	p->p_fd = fdinit(NULL);
464 	p->p_fdtol = NULL;
465 
466 	/* Create the limits structures. */
467 	p->p_limit = lim_alloc();
468 	for (i = 0; i < RLIM_NLIMITS; i++)
469 		p->p_limit->pl_rlimit[i].rlim_cur =
470 		    p->p_limit->pl_rlimit[i].rlim_max = RLIM_INFINITY;
471 	p->p_limit->pl_rlimit[RLIMIT_NOFILE].rlim_cur =
472 	    p->p_limit->pl_rlimit[RLIMIT_NOFILE].rlim_max = maxfiles;
473 	p->p_limit->pl_rlimit[RLIMIT_NPROC].rlim_cur =
474 	    p->p_limit->pl_rlimit[RLIMIT_NPROC].rlim_max = maxproc;
475 	i = ptoa(cnt.v_free_count);
476 	p->p_limit->pl_rlimit[RLIMIT_RSS].rlim_max = i;
477 	p->p_limit->pl_rlimit[RLIMIT_MEMLOCK].rlim_max = i;
478 	p->p_limit->pl_rlimit[RLIMIT_MEMLOCK].rlim_cur = i / 3;
479 	p->p_cpulimit = RLIM_INFINITY;
480 
481 	p->p_stats = pstats_alloc();
482 
483 	/* Allocate a prototype map so we have something to fork. */
484 	pmap_pinit0(vmspace_pmap(&vmspace0));
485 	p->p_vmspace = &vmspace0;
486 	vmspace0.vm_refcnt = 1;
487 	vm_map_init(&vmspace0.vm_map, p->p_sysent->sv_minuser,
488 	    p->p_sysent->sv_maxuser);
489 	vmspace0.vm_map.pmap = vmspace_pmap(&vmspace0);
490 
491 	/*
492 	 * Charge root for one process.
493 	 */
494 	(void)chgproccnt(p->p_ucred->cr_ruidinfo, 1, 0);
495 }
496 SYSINIT(p0init, SI_SUB_INTRINSIC, SI_ORDER_FIRST, proc0_init, NULL)
497 
498 /* ARGSUSED*/
499 static void
500 proc0_post(void *dummy __unused)
501 {
502 	struct timespec ts;
503 	struct proc *p;
504 	struct rusage ru;
505 
506 	/*
507 	 * Now we can look at the time, having had a chance to verify the
508 	 * time from the filesystem.  Pretend that proc0 started now.
509 	 */
510 	sx_slock(&allproc_lock);
511 	FOREACH_PROC_IN_SYSTEM(p) {
512 		microuptime(&p->p_stats->p_start);
513 		PROC_SLOCK(p);
514 		rufetch(p, &ru);	/* Clears thread stats */
515 		PROC_SUNLOCK(p);
516 		p->p_rux.rux_runtime = 0;
517 		p->p_rux.rux_uticks = 0;
518 		p->p_rux.rux_sticks = 0;
519 		p->p_rux.rux_iticks = 0;
520 	}
521 	sx_sunlock(&allproc_lock);
522 	PCPU_SET(switchtime, cpu_ticks());
523 	PCPU_SET(switchticks, ticks);
524 
525 	/*
526 	 * Give the ``random'' number generator a thump.
527 	 */
528 	nanotime(&ts);
529 	srandom(ts.tv_sec ^ ts.tv_nsec);
530 }
531 SYSINIT(p0post, SI_SUB_INTRINSIC_POST, SI_ORDER_FIRST, proc0_post, NULL)
532 
533 /*
534  ***************************************************************************
535  ****
536  **** The following SYSINIT's and glue code should be moved to the
537  **** respective files on a per subsystem basis.
538  ****
539  ***************************************************************************
540  */
541 
542 
543 /*
544  ***************************************************************************
545  ****
546  **** The following code probably belongs in another file, like
547  **** kern/init_init.c.
548  ****
549  ***************************************************************************
550  */
551 
552 /*
553  * List of paths to try when searching for "init".
554  */
555 static char init_path[MAXPATHLEN] =
556 #ifdef	INIT_PATH
557     __XSTRING(INIT_PATH);
558 #else
559     "/sbin/init:/sbin/oinit:/sbin/init.bak:/rescue/init:/stand/sysinstall";
560 #endif
561 SYSCTL_STRING(_kern, OID_AUTO, init_path, CTLFLAG_RD, init_path, 0,
562 	"Path used to search the init process");
563 
564 /*
565  * Shutdown timeout of init(8).
566  * Unused within kernel, but used to control init(8), hence do not remove.
567  */
568 #ifndef INIT_SHUTDOWN_TIMEOUT
569 #define INIT_SHUTDOWN_TIMEOUT 120
570 #endif
571 static int init_shutdown_timeout = INIT_SHUTDOWN_TIMEOUT;
572 SYSCTL_INT(_kern, OID_AUTO, init_shutdown_timeout,
573 	CTLFLAG_RW, &init_shutdown_timeout, 0, "");
574 
575 /*
576  * Start the initial user process; try exec'ing each pathname in init_path.
577  * The program is invoked with one argument containing the boot flags.
578  */
579 static void
580 start_init(void *dummy)
581 {
582 	vm_offset_t addr;
583 	struct execve_args args;
584 	int options, error;
585 	char *var, *path, *next, *s;
586 	char *ucp, **uap, *arg0, *arg1;
587 	struct thread *td;
588 	struct proc *p;
589 
590 	mtx_lock(&Giant);
591 
592 	GIANT_REQUIRED;
593 
594 	td = curthread;
595 	p = td->td_proc;
596 
597 	vfs_mountroot();
598 
599 	/*
600 	 * Need just enough stack to hold the faked-up "execve()" arguments.
601 	 */
602 	addr = p->p_sysent->sv_usrstack - PAGE_SIZE;
603 	if (vm_map_find(&p->p_vmspace->vm_map, NULL, 0, &addr, PAGE_SIZE,
604 			FALSE, VM_PROT_ALL, VM_PROT_ALL, 0) != 0)
605 		panic("init: couldn't allocate argument space");
606 	p->p_vmspace->vm_maxsaddr = (caddr_t)addr;
607 	p->p_vmspace->vm_ssize = 1;
608 
609 	if ((var = getenv("init_path")) != NULL) {
610 		strlcpy(init_path, var, sizeof(init_path));
611 		freeenv(var);
612 	}
613 
614 	for (path = init_path; *path != '\0'; path = next) {
615 		while (*path == ':')
616 			path++;
617 		if (*path == '\0')
618 			break;
619 		for (next = path; *next != '\0' && *next != ':'; next++)
620 			/* nothing */ ;
621 		if (bootverbose)
622 			printf("start_init: trying %.*s\n", (int)(next - path),
623 			    path);
624 
625 		/*
626 		 * Move out the boot flag argument.
627 		 */
628 		options = 0;
629 		ucp = (char *)p->p_sysent->sv_usrstack;
630 		(void)subyte(--ucp, 0);		/* trailing zero */
631 		if (boothowto & RB_SINGLE) {
632 			(void)subyte(--ucp, 's');
633 			options = 1;
634 		}
635 #ifdef notyet
636                 if (boothowto & RB_FASTBOOT) {
637 			(void)subyte(--ucp, 'f');
638 			options = 1;
639 		}
640 #endif
641 
642 #ifdef BOOTCDROM
643 		(void)subyte(--ucp, 'C');
644 		options = 1;
645 #endif
646 
647 		if (options == 0)
648 			(void)subyte(--ucp, '-');
649 		(void)subyte(--ucp, '-');		/* leading hyphen */
650 		arg1 = ucp;
651 
652 		/*
653 		 * Move out the file name (also arg 0).
654 		 */
655 		(void)subyte(--ucp, 0);
656 		for (s = next - 1; s >= path; s--)
657 			(void)subyte(--ucp, *s);
658 		arg0 = ucp;
659 
660 		/*
661 		 * Move out the arg pointers.
662 		 */
663 		uap = (char **)((intptr_t)ucp & ~(sizeof(intptr_t)-1));
664 		(void)suword((caddr_t)--uap, (long)0);	/* terminator */
665 		(void)suword((caddr_t)--uap, (long)(intptr_t)arg1);
666 		(void)suword((caddr_t)--uap, (long)(intptr_t)arg0);
667 
668 		/*
669 		 * Point at the arguments.
670 		 */
671 		args.fname = arg0;
672 		args.argv = uap;
673 		args.envv = NULL;
674 
675 		/*
676 		 * Now try to exec the program.  If can't for any reason
677 		 * other than it doesn't exist, complain.
678 		 *
679 		 * Otherwise, return via fork_trampoline() all the way
680 		 * to user mode as init!
681 		 */
682 		if ((error = execve(td, &args)) == 0) {
683 			mtx_unlock(&Giant);
684 			return;
685 		}
686 		if (error != ENOENT)
687 			printf("exec %.*s: error %d\n", (int)(next - path),
688 			    path, error);
689 	}
690 	printf("init: not found in path %s\n", init_path);
691 	panic("no init");
692 }
693 
694 /*
695  * Like kproc_create(), but runs in it's own address space.
696  * We do this early to reserve pid 1.
697  *
698  * Note special case - do not make it runnable yet.  Other work
699  * in progress will change this more.
700  */
701 static void
702 create_init(const void *udata __unused)
703 {
704 	struct ucred *newcred, *oldcred;
705 	int error;
706 
707 	error = fork1(&thread0, RFFDG | RFPROC | RFSTOPPED, 0, &initproc);
708 	if (error)
709 		panic("cannot fork init: %d\n", error);
710 	KASSERT(initproc->p_pid == 1, ("create_init: initproc->p_pid != 1"));
711 	/* divorce init's credentials from the kernel's */
712 	newcred = crget();
713 	PROC_LOCK(initproc);
714 	initproc->p_flag |= P_SYSTEM | P_INMEM;
715 	oldcred = initproc->p_ucred;
716 	crcopy(newcred, oldcred);
717 #ifdef MAC
718 	mac_proc_create_init(newcred);
719 #endif
720 #ifdef AUDIT
721 	audit_cred_proc1(newcred);
722 #endif
723 	initproc->p_ucred = newcred;
724 	PROC_UNLOCK(initproc);
725 	crfree(oldcred);
726 	cred_update_thread(FIRST_THREAD_IN_PROC(initproc));
727 	cpu_set_fork_handler(FIRST_THREAD_IN_PROC(initproc), start_init, NULL);
728 }
729 SYSINIT(init, SI_SUB_CREATE_INIT, SI_ORDER_FIRST, create_init, NULL)
730 
731 /*
732  * Make it runnable now.
733  */
734 static void
735 kick_init(const void *udata __unused)
736 {
737 	struct thread *td;
738 
739 	td = FIRST_THREAD_IN_PROC(initproc);
740 	thread_lock(td);
741 	TD_SET_CAN_RUN(td);
742 	sched_add(td, SRQ_BORING);
743 	thread_unlock(td);
744 }
745 SYSINIT(kickinit, SI_SUB_KTHREAD_INIT, SI_ORDER_FIRST, kick_init, NULL)
746