xref: /openbsd-src/sys/kern/init_main.c (revision 4b70baf6e17fc8b27fc1f7fa7929335753fa94c3)
1 /*	$OpenBSD: init_main.c,v 1.284 2019/02/26 14:24:21 visa Exp $	*/
2 /*	$NetBSD: init_main.c,v 1.84.4.1 1996/06/02 09:08:06 mrg Exp $	*/
3 
4 /*
5  * Copyright (c) 1995 Christopher G. Demetriou.  All rights reserved.
6  * Copyright (c) 1982, 1986, 1989, 1991, 1992, 1993
7  *	The Regents of the University of California.  All rights reserved.
8  * (c) UNIX System Laboratories, Inc.
9  * All or some portions of this file are derived from material licensed
10  * to the University of California by American Telephone and Telegraph
11  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
12  * the permission of UNIX System Laboratories, Inc.
13  *
14  * Redistribution and use in source and binary forms, with or without
15  * modification, are permitted provided that the following conditions
16  * are met:
17  * 1. Redistributions of source code must retain the above copyright
18  *    notice, this list of conditions and the following disclaimer.
19  * 2. Redistributions in binary form must reproduce the above copyright
20  *    notice, this list of conditions and the following disclaimer in the
21  *    documentation and/or other materials provided with the distribution.
22  * 3. Neither the name of the University nor the names of its contributors
23  *    may be used to endorse or promote products derived from this software
24  *    without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  *
38  *	@(#)init_main.c	8.9 (Berkeley) 1/21/94
39  */
40 
41 #include <sys/param.h>
42 #include <sys/filedesc.h>
43 #include <sys/file.h>
44 #include <sys/errno.h>
45 #include <sys/exec.h>
46 #include <sys/kernel.h>
47 #include <sys/kthread.h>
48 #include <sys/mount.h>
49 #include <sys/proc.h>
50 #include <sys/resourcevar.h>
51 #include <sys/signalvar.h>
52 #include <sys/systm.h>
53 #include <sys/namei.h>
54 #include <sys/vnode.h>
55 #include <sys/tty.h>
56 #include <sys/conf.h>
57 #include <sys/buf.h>
58 #include <sys/device.h>
59 #include <sys/socketvar.h>
60 #include <sys/lockf.h>
61 #include <sys/protosw.h>
62 #include <sys/reboot.h>
63 #include <sys/user.h>
64 #ifdef SYSVSHM
65 #include <sys/shm.h>
66 #endif
67 #ifdef SYSVSEM
68 #include <sys/sem.h>
69 #endif
70 #ifdef SYSVMSG
71 #include <sys/msg.h>
72 #endif
73 #include <sys/domain.h>
74 #include <sys/msgbuf.h>
75 #include <sys/mbuf.h>
76 #include <sys/pipe.h>
77 #include <sys/task.h>
78 #include <sys/witness.h>
79 #include <sys/smr.h>
80 
81 #include <sys/syscall.h>
82 #include <sys/syscallargs.h>
83 
84 #include <uvm/uvm_extern.h>
85 
86 #include <dev/rndvar.h>
87 
88 #include <ufs/ufs/quota.h>
89 
90 #include <net/if.h>
91 #include <net/rtable.h>
92 #include <net/netisr.h>
93 
94 #if defined(CRYPTO)
95 #include <crypto/cryptodev.h>
96 #include <crypto/cryptosoft.h>
97 #endif
98 
99 #if defined(NFSSERVER) || defined(NFSCLIENT)
100 extern void nfs_init(void);
101 #endif
102 
103 #include "mpath.h"
104 #include "vscsi.h"
105 #include "softraid.h"
106 
107 const char	copyright[] =
108 "Copyright (c) 1982, 1986, 1989, 1991, 1993\n"
109 "\tThe Regents of the University of California.  All rights reserved.\n"
110 "Copyright (c) 1995-2019 OpenBSD. All rights reserved.  https://www.OpenBSD.org\n";
111 
112 /* Components of the first process -- never freed. */
113 struct	session session0;
114 struct	pgrp pgrp0;
115 struct	proc proc0;
116 struct	process process0;
117 struct	plimit limit0;
118 struct	vmspace vmspace0;
119 struct	sigacts sigacts0;
120 struct	process *initprocess;
121 struct	proc *reaperproc;
122 
123 extern	struct user *proc0paddr;
124 
125 struct	vnode *rootvp, *swapdev_vp;
126 int	boothowto;
127 int	db_active = 0;
128 int	ncpus =  1;
129 int	ncpusfound = 1;			/* number of cpus we find */
130 volatile int start_init_exec;		/* semaphore for start_init() */
131 
132 #if !defined(NO_PROPOLICE)
133 long	__guard_local __attribute__((section(".openbsd.randomdata")));
134 #endif
135 
136 /* XXX return int so gcc -Werror won't complain */
137 int	main(void *);
138 void	check_console(struct proc *);
139 void	start_init(void *);
140 void	crypto_init(void);
141 void	db_ctf_init(void);
142 void	prof_init(void);
143 void	init_exec(void);
144 void	kqueue_init(void);
145 void	futex_init(void);
146 void	taskq_init(void);
147 void	timeout_proc_init(void);
148 void	pool_gc_pages(void *);
149 void	percpu_init(void);
150 
151 extern char sigcode[], esigcode[], sigcoderet[];
152 #ifdef SYSCALL_DEBUG
153 extern char *syscallnames[];
154 #endif
155 
156 struct emul emul_native = {
157 	"native",
158 	NULL,
159 	SYS_syscall,
160 	SYS_MAXSYSCALL,
161 	sysent,
162 #ifdef SYSCALL_DEBUG
163 	syscallnames,
164 #else
165 	NULL,
166 #endif
167 	0,
168 	copyargs,
169 	setregs,
170 	NULL,		/* fixup */
171 	NULL,		/* coredump */
172 	sigcode,
173 	esigcode,
174 	sigcoderet
175 };
176 
177 #ifdef DIAGNOSTIC
178 int pdevinit_done = 0;
179 #endif
180 
181 /*
182  * System startup; initialize the world, create process 0, mount root
183  * filesystem, and fork to create init and pagedaemon.  Most of the
184  * hard work is done in the lower-level initialization routines including
185  * startup(), which does memory initialization and autoconfiguration.
186  */
187 /* XXX return int, so gcc -Werror won't complain */
188 int
189 main(void *framep)
190 {
191 	struct proc *p;
192 	struct process *pr;
193 	struct pdevinit *pdev;
194 	quad_t lim;
195 	int i;
196 	extern struct pdevinit pdevinit[];
197 	extern void disk_init(void);
198 
199 	/*
200 	 * Initialize the current process pointer (curproc) before
201 	 * any possible traps/probes to simplify trap processing.
202 	 */
203 	curproc = p = &proc0;
204 	p->p_cpu = curcpu();
205 
206 	/*
207 	 * Initialize timeouts.
208 	 */
209 	timeout_startup();
210 
211 	/*
212 	 * Attempt to find console and initialize
213 	 * in case of early panic or other messages.
214 	 */
215 	config_init();		/* init autoconfiguration data structures */
216 	consinit();
217 
218 	printf("%s\n", copyright);
219 
220 	WITNESS_INITIALIZE();
221 
222 	KERNEL_LOCK_INIT();
223 	SCHED_LOCK_INIT();
224 
225 	uvm_init();
226 	disk_init();		/* must come before autoconfiguration */
227 	tty_init();		/* initialise tty's */
228 	cpu_startup();
229 
230 	random_start();		/* Start the flow */
231 
232 	/*
233 	 * Initialize mbuf's.  Do this now because we might attempt to
234 	 * allocate mbufs or mbuf clusters during autoconfiguration.
235 	 */
236 	mbinit();
237 
238 	/* Initialize sockets. */
239 	soinit();
240 
241 	/* Initialize SRP subsystem. */
242 	srp_startup();
243 
244 	/* Initialize SMR subsystem. */
245 	smr_startup();
246 
247 	/*
248 	 * Initialize process and pgrp structures.
249 	 */
250 	procinit();
251 
252 	/* Initialize file locking. */
253 	lf_init();
254 
255 	/*
256 	 * Initialize filedescriptors.
257 	 */
258 	filedesc_init();
259 
260 	/*
261 	 * Initialize pipes.
262 	 */
263 	pipe_init();
264 
265 	/*
266 	 * Initialize kqueues.
267 	 */
268 	kqueue_init();
269 
270 	/*
271 	 * Initialize futexes.
272 	 */
273 	futex_init();
274 
275 	/* Create credentials. */
276 	p->p_ucred = crget();
277 	p->p_ucred->cr_ngroups = 1;	/* group 0 */
278 
279 	/*
280 	 * Create process 0 (the swapper).
281 	 */
282 	pr = &process0;
283 	process_initialize(pr, p);
284 
285 	LIST_INSERT_HEAD(&allprocess, pr, ps_list);
286 	LIST_INSERT_HEAD(PIDHASH(0), pr, ps_hash);
287 	atomic_setbits_int(&pr->ps_flags, PS_SYSTEM);
288 
289 	/* Set the default routing table/domain. */
290 	process0.ps_rtableid = 0;
291 
292 	LIST_INSERT_HEAD(&allproc, p, p_list);
293 	pr->ps_pgrp = &pgrp0;
294 	LIST_INSERT_HEAD(TIDHASH(0), p, p_hash);
295 	LIST_INSERT_HEAD(PGRPHASH(0), &pgrp0, pg_hash);
296 	LIST_INIT(&pgrp0.pg_members);
297 	LIST_INSERT_HEAD(&pgrp0.pg_members, pr, ps_pglist);
298 
299 	pgrp0.pg_session = &session0;
300 	session0.s_count = 1;
301 	session0.s_leader = pr;
302 
303 	atomic_setbits_int(&p->p_flag, P_SYSTEM);
304 	p->p_stat = SONPROC;
305 	pr->ps_nice = NZERO;
306 	pr->ps_emul = &emul_native;
307 	strlcpy(pr->ps_comm, "swapper", sizeof(pr->ps_comm));
308 
309 	/* Init timeouts. */
310 	timeout_set(&p->p_sleep_to, endtsleep, p);
311 
312 	/* Initialize signal state for process 0. */
313 	signal_init();
314 	pr->ps_sigacts = &sigacts0;
315 	siginit(pr);
316 
317 	/* Create the file descriptor table. */
318 	p->p_fd = pr->ps_fd = fdinit();
319 
320 	/* Create the limits structures. */
321 	pr->ps_limit = &limit0;
322 	for (i = 0; i < nitems(p->p_rlimit); i++)
323 		limit0.pl_rlimit[i].rlim_cur =
324 		    limit0.pl_rlimit[i].rlim_max = RLIM_INFINITY;
325 	limit0.pl_rlimit[RLIMIT_NOFILE].rlim_cur = NOFILE;
326 	limit0.pl_rlimit[RLIMIT_NOFILE].rlim_max = MIN(NOFILE_MAX,
327 	    (maxfiles - NOFILE > NOFILE) ?  maxfiles - NOFILE : NOFILE);
328 	limit0.pl_rlimit[RLIMIT_NPROC].rlim_cur = MAXUPRC;
329 	lim = ptoa(uvmexp.free);
330 	limit0.pl_rlimit[RLIMIT_RSS].rlim_max = lim;
331 	limit0.pl_rlimit[RLIMIT_MEMLOCK].rlim_max = lim;
332 	limit0.pl_rlimit[RLIMIT_MEMLOCK].rlim_cur = lim / 3;
333 	limit0.p_refcnt = 1;
334 
335 	/* Allocate a prototype map so we have something to fork. */
336 	uvmspace_init(&vmspace0, pmap_kernel(), round_page(VM_MIN_ADDRESS),
337 	    trunc_page(VM_MAX_ADDRESS), TRUE, TRUE);
338 	p->p_vmspace = pr->ps_vmspace = &vmspace0;
339 
340 	p->p_addr = proc0paddr;				/* XXX */
341 
342 	/*
343 	 * Charge root for one process.
344 	 */
345 	(void)chgproccnt(0, 1);
346 
347 	/* Initialize run queues */
348 	sched_init_runqueues();
349 	sleep_queue_init();
350 	sched_init_cpu(curcpu());
351 	p->p_cpu->ci_randseed = (arc4random() & 0x7fffffff) + 1;
352 
353 	/* Initialize timeouts in process context. */
354 	timeout_proc_init();
355 
356 	/* Initialize task queues */
357 	taskq_init();
358 
359 	/* Initialize the interface/address trees */
360 	ifinit();
361 
362 	/* Lock the kernel on behalf of proc0. */
363 	KERNEL_LOCK();
364 
365 #if NMPATH > 0
366 	/* Attach mpath before hardware */
367 	config_rootfound("mpath", NULL);
368 #endif
369 
370 	/* Configure the devices */
371 	cpu_configure();
372 
373 	/* Configure virtual memory system, set vm rlimits. */
374 	uvm_init_limits(p);
375 
376 	/* Per CPU memory allocation */
377 	percpu_init();
378 
379 	/* Initialize the file systems. */
380 #if defined(NFSSERVER) || defined(NFSCLIENT)
381 	nfs_init();			/* initialize server/shared data */
382 #endif
383 	vfsinit();
384 
385 	/* Start real time and statistics clocks. */
386 	initclocks();
387 
388 #ifdef SYSVSHM
389 	/* Initialize System V style shared memory. */
390 	shminit();
391 #endif
392 
393 #ifdef SYSVSEM
394 	/* Initialize System V style semaphores. */
395 	seminit();
396 #endif
397 
398 #ifdef SYSVMSG
399 	/* Initialize System V style message queues. */
400 	msginit();
401 #endif
402 
403 	/* Create default routing table before attaching lo0. */
404 	rtable_init();
405 
406 	/* Attach pseudo-devices. */
407 	for (pdev = pdevinit; pdev->pdev_attach != NULL; pdev++)
408 		if (pdev->pdev_count > 0)
409 			(*pdev->pdev_attach)(pdev->pdev_count);
410 #ifdef DIAGNOSTIC
411 	pdevinit_done = 1;
412 #endif
413 
414 #ifdef CRYPTO
415 	crypto_init();
416 	swcr_init();
417 #endif /* CRYPTO */
418 
419 	/*
420 	 * Initialize protocols.
421 	 */
422 	domaininit();
423 
424 	initconsbuf();
425 
426 #if defined(GPROF) || defined(DDBPROF)
427 	/* Initialize kernel profiling. */
428 	prof_init();
429 #endif
430 
431 	mbcpuinit();	/* enable per cpu mbuf data */
432 
433 	/* init exec and emul */
434 	init_exec();
435 
436 	/* Start the scheduler */
437 	scheduler_start();
438 
439 	/*
440 	 * Create process 1 (init(8)).  We do this now, as Unix has
441 	 * historically had init be process 1, and changing this would
442 	 * probably upset a lot of people.
443 	 *
444 	 * Note that process 1 won't immediately exec init(8), but will
445 	 * wait for us to inform it that the root file system has been
446 	 * mounted.
447 	 */
448 	{
449 		struct proc *initproc;
450 
451 		if (fork1(p, FORK_FORK, start_init, NULL, NULL, &initproc))
452 			panic("fork init");
453 		initprocess = initproc->p_p;
454 	}
455 
456 	randompid = 1;
457 
458 	/*
459 	 * Create any kernel threads whose creation was deferred because
460 	 * initprocess had not yet been created.
461 	 */
462 	kthread_run_deferred_queue();
463 
464 	/*
465 	 * Now that device driver threads have been created, wait for
466 	 * them to finish any deferred autoconfiguration.  Note we don't
467 	 * need to lock this semaphore, since we haven't booted any
468 	 * secondary processors, yet.
469 	 */
470 	while (config_pending)
471 		(void) tsleep((void *)&config_pending, PWAIT, "cfpend", 0);
472 
473 	dostartuphooks();
474 
475 #if NVSCSI > 0
476 	config_rootfound("vscsi", NULL);
477 #endif
478 #if NSOFTRAID > 0
479 	config_rootfound("softraid", NULL);
480 #endif
481 
482 	/* Configure root/swap devices */
483 	diskconf();
484 
485 #ifdef DDB
486 	/* Make debug symbols available in ddb. */
487 	db_ctf_init();
488 #endif
489 
490 	if (mountroot == NULL || ((*mountroot)() != 0))
491 		panic("cannot mount root");
492 
493 	TAILQ_FIRST(&mountlist)->mnt_flag |= MNT_ROOTFS;
494 
495 	/* Get the vnode for '/'.  Set p->p_fd->fd_cdir to reference it. */
496 	if (VFS_ROOT(TAILQ_FIRST(&mountlist), &rootvnode))
497 		panic("cannot find root vnode");
498 	p->p_fd->fd_cdir = rootvnode;
499 	vref(p->p_fd->fd_cdir);
500 	VOP_UNLOCK(rootvnode);
501 	p->p_fd->fd_rdir = NULL;
502 
503 	/*
504 	 * Now that root is mounted, we can fixup initprocess's CWD
505 	 * info.  All other processes are kthreads, which merely
506 	 * share proc0's CWD info.
507 	 */
508 	initprocess->ps_fd->fd_cdir = rootvnode;
509 	vref(initprocess->ps_fd->fd_cdir);
510 	initprocess->ps_fd->fd_rdir = NULL;
511 
512 	/*
513 	 * Now can look at time, having had a chance to verify the time
514 	 * from the file system.  Reset p->p_rtime as it may have been
515 	 * munched in mi_switch() after the time got set.
516 	 */
517 	LIST_FOREACH(pr, &allprocess, ps_list) {
518 		getnanotime(&pr->ps_start);
519 		TAILQ_FOREACH(p, &pr->ps_threads, p_thr_link) {
520 			nanouptime(&p->p_cpu->ci_schedstate.spc_runtime);
521 			timespecclear(&p->p_rtime);
522 		}
523 	}
524 
525 	uvm_swap_init();
526 
527 	/* Create the pageout daemon kernel thread. */
528 	if (kthread_create(uvm_pageout, NULL, NULL, "pagedaemon"))
529 		panic("fork pagedaemon");
530 
531 	/* Create the reaper daemon kernel thread. */
532 	if (kthread_create(reaper, NULL, &reaperproc, "reaper"))
533 		panic("fork reaper");
534 
535 	/* Create the cleaner daemon kernel thread. */
536 	if (kthread_create(buf_daemon, NULL, &cleanerproc, "cleaner"))
537 		panic("fork cleaner");
538 
539 	/* Create the update daemon kernel thread. */
540 	if (kthread_create(syncer_thread, NULL, &syncerproc, "update"))
541 		panic("fork update");
542 
543 	/* Create the aiodone daemon kernel thread. */
544 	if (kthread_create(uvm_aiodone_daemon, NULL, NULL, "aiodoned"))
545 		panic("fork aiodoned");
546 
547 #if !defined(__hppa__)
548 	/* Create the page zeroing kernel thread. */
549 	if (kthread_create(uvm_pagezero_thread, NULL, NULL, "zerothread"))
550 		panic("fork zerothread");
551 #endif
552 
553 #if defined(MULTIPROCESSOR)
554 	/* Boot the secondary processors. */
555 	cpu_boot_secondary_processors();
556 #endif
557 
558 	config_process_deferred_mountroot();
559 
560 	/*
561 	 * Okay, now we can let init(8) exec!  It's off to userland!
562 	 */
563 	start_init_exec = 1;
564 	wakeup((void *)&start_init_exec);
565 
566 	/*
567 	 * Start the idle pool page garbage collector
568 	 */
569 #if !(defined(__m88k__) && defined(MULTIPROCESSOR))	/* XXX */
570 	pool_gc_pages(NULL);
571 #endif
572 
573 	start_periodic_resettodr();
574 
575         /*
576          * proc0: nothing to do, back to sleep
577          */
578         while (1)
579                 tsleep(&proc0, PVM, "scheduler", 0);
580 	/* NOTREACHED */
581 }
582 
583 /*
584  * List of paths to try when searching for "init".
585  */
586 static char *initpaths[] = {
587 	"/sbin/init",
588 	"/sbin/oinit",
589 	"/sbin/init.bak",
590 	NULL,
591 };
592 
593 void
594 check_console(struct proc *p)
595 {
596 	struct nameidata nd;
597 	int error;
598 
599 	NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, "/dev/console", p);
600 	error = namei(&nd);
601 	if (error) {
602 		if (error == ENOENT)
603 			printf("warning: /dev/console does not exist\n");
604 		else
605 			printf("warning: /dev/console error %d\n", error);
606 	} else
607 		vrele(nd.ni_vp);
608 }
609 
610 /*
611  * Start the initial user process; try exec'ing each pathname in "initpaths".
612  * The program is invoked with one argument containing the boot flags.
613  */
614 void
615 start_init(void *arg)
616 {
617 	struct proc *p = arg;
618 	vaddr_t addr;
619 	struct sys_execve_args /* {
620 		syscallarg(const char *) path;
621 		syscallarg(char *const *) argp;
622 		syscallarg(char *const *) envp;
623 	} */ args;
624 	int options, error;
625 	long i;
626 	register_t retval[2];
627 	char flags[4], *flagsp;
628 	char **pathp, *path, *ucp, **uap, *arg0, *arg1 = NULL;
629 
630 	/*
631 	 * Now in process 1.
632 	 */
633 
634 	/*
635 	 * Wait for main() to tell us that it's safe to exec.
636 	 */
637 	while (start_init_exec == 0)
638 		(void) tsleep((void *)&start_init_exec, PWAIT, "initexec", 0);
639 
640 	check_console(p);
641 
642 	/* process 0 ignores SIGCHLD, but we can't */
643 	p->p_p->ps_sigacts->ps_flags = 0;
644 
645 	/*
646 	 * Need just enough stack to hold the faked-up "execve()" arguments.
647 	 */
648 #ifdef MACHINE_STACK_GROWS_UP
649 	addr = USRSTACK;
650 #else
651 	addr = USRSTACK - PAGE_SIZE;
652 #endif
653 	p->p_vmspace->vm_maxsaddr = (caddr_t)addr;
654 	p->p_vmspace->vm_minsaddr = (caddr_t)(addr + PAGE_SIZE);
655 	if (uvm_map(&p->p_vmspace->vm_map, &addr, PAGE_SIZE,
656 	    NULL, UVM_UNKNOWN_OFFSET, 0,
657 	    UVM_MAPFLAG(PROT_READ | PROT_WRITE, PROT_MASK, MAP_INHERIT_COPY,
658 	    MADV_NORMAL, UVM_FLAG_FIXED|UVM_FLAG_OVERLAY|UVM_FLAG_COPYONW|UVM_FLAG_STACK)))
659 		panic("init: couldn't allocate argument space");
660 
661 	for (pathp = &initpaths[0]; (path = *pathp) != NULL; pathp++) {
662 #ifdef MACHINE_STACK_GROWS_UP
663 		ucp = (char *)addr;
664 #else
665 		ucp = (char *)(addr + PAGE_SIZE);
666 #endif
667 		/*
668 		 * Construct the boot flag argument.
669 		 */
670 		flagsp = flags;
671 		*flagsp++ = '-';
672 		options = 0;
673 
674 		if (boothowto & RB_SINGLE) {
675 			*flagsp++ = 's';
676 			options = 1;
677 		}
678 #ifdef notyet
679 		if (boothowto & RB_FASTBOOT) {
680 			*flagsp++ = 'f';
681 			options = 1;
682 		}
683 #endif
684 
685 		/*
686 		 * Move out the flags (arg 1), if necessary.
687 		 */
688 		if (options != 0) {
689 			*flagsp++ = '\0';
690 			i = flagsp - flags;
691 #ifdef DEBUG
692 			printf("init: copying out flags `%s' %ld\n", flags, i);
693 #endif
694 #ifdef MACHINE_STACK_GROWS_UP
695 			arg1 = ucp;
696 			(void)copyout((caddr_t)flags, (caddr_t)ucp, i);
697 			ucp += i;
698 #else
699 			(void)copyout((caddr_t)flags, (caddr_t)(ucp -= i), i);
700 			arg1 = ucp;
701 #endif
702 		}
703 
704 		/*
705 		 * Move out the file name (also arg 0).
706 		 */
707 		i = strlen(path) + 1;
708 #ifdef DEBUG
709 		printf("init: copying out path `%s' %ld\n", path, i);
710 #endif
711 #ifdef MACHINE_STACK_GROWS_UP
712 		arg0 = ucp;
713 		(void)copyout((caddr_t)path, (caddr_t)ucp, i);
714 		ucp += i;
715 		ucp = (caddr_t)ALIGN((u_long)ucp);
716 		uap = (char **)ucp + 3;
717 #else
718 		(void)copyout((caddr_t)path, (caddr_t)(ucp -= i), i);
719 		arg0 = ucp;
720 		uap = (char **)((u_long)ucp & ~ALIGNBYTES);
721 #endif
722 
723 		/*
724 		 * Move out the arg pointers.
725 		 */
726 		i = 0;
727 		copyout(&i, (caddr_t)--uap, sizeof(register_t)); /* terminator */
728 		if (options != 0)
729 			copyout(&arg1, (caddr_t)--uap, sizeof(register_t));
730 		copyout(&arg0, (caddr_t)--uap, sizeof(register_t));
731 
732 		/*
733 		 * Point at the arguments.
734 		 */
735 		SCARG(&args, path) = arg0;
736 		SCARG(&args, argp) = uap;
737 		SCARG(&args, envp) = NULL;
738 
739 		/*
740 		 * Now try to exec the program.  If can't for any reason
741 		 * other than it doesn't exist, complain.
742 		 */
743 		if ((error = sys_execve(p, &args, retval)) == 0) {
744 			KERNEL_UNLOCK();
745 			return;
746 		}
747 		if (error != ENOENT)
748 			printf("exec %s: error %d\n", path, error);
749 	}
750 	printf("init: not found\n");
751 	panic("no init");
752 }
753