xref: /openbsd-src/sys/kern/init_main.c (revision d1a3e9b9d934d1fd9ecfe775394b05c733355184)
1 /*	$OpenBSD: init_main.c,v 1.328 2025/01/01 07:44:54 jsg 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/errno.h>
44 #include <sys/kthread.h>
45 #include <sys/mount.h>
46 #include <sys/proc.h>
47 #include <sys/resourcevar.h>
48 #include <sys/signalvar.h>
49 #include <sys/systm.h>
50 #include <sys/clockintr.h>
51 #include <sys/namei.h>
52 #include <sys/vnode.h>
53 #include <sys/tty.h>
54 #include <sys/buf.h>
55 #include <sys/device.h>
56 #include <sys/socketvar.h>
57 #include <sys/lockf.h>
58 #include <sys/reboot.h>
59 #ifdef SYSVSHM
60 #include <sys/shm.h>
61 #endif
62 #ifdef SYSVSEM
63 #include <sys/sem.h>
64 #endif
65 #ifdef SYSVMSG
66 #include <sys/msg.h>
67 #endif
68 #include <sys/domain.h>
69 #include <sys/event.h>
70 #include <sys/msgbuf.h>
71 #include <sys/mbuf.h>
72 #include <sys/pipe.h>
73 #include <sys/witness.h>
74 #include <sys/smr.h>
75 #include <sys/evcount.h>
76 
77 #include <sys/syscallargs.h>
78 
79 #include <uvm/uvm_extern.h>
80 
81 #include <net/if.h>
82 #include <net/rtable.h>
83 
84 #if defined(CRYPTO)
85 #include <crypto/cryptodev.h>
86 #include <crypto/cryptosoft.h>
87 #endif
88 
89 #if defined(KUBSAN)
90 extern void kubsan_init(void);
91 #endif
92 
93 #if defined(NFSSERVER) || defined(NFSCLIENT)
94 extern void nfs_init(void);
95 #endif
96 
97 #include "stoeplitz.h"
98 #if NSTOEPLITZ > 0
99 extern void stoeplitz_init(void);
100 #endif
101 
102 #include "mpath.h"
103 #include "vscsi.h"
104 #include "softraid.h"
105 
106 const char	copyright[] =
107 "Copyright (c) 1982, 1986, 1989, 1991, 1993\n"
108 "\tThe Regents of the University of California.  All rights reserved.\n"
109 "Copyright (c) 1995-2025 OpenBSD. All rights reserved.  https://www.OpenBSD.org\n";
110 
111 /* Components of the first process -- never freed. */
112 struct	session session0;
113 struct	pgrp pgrp0;
114 struct	proc proc0;
115 struct	process process0;
116 struct	plimit limit0;
117 struct	vmspace vmspace0;
118 struct	sigacts sigacts0;
119 struct	process *initprocess;
120 struct	proc *reaperproc;
121 
122 extern	struct user *proc0paddr;
123 
124 struct	vnode *rootvp, *swapdev_vp;
125 int	boothowto;
126 int	db_active = 0;
127 int	ncpus =  1;
128 int	ncpusfound = 1;			/* number of cpus we find */
129 volatile int start_init_exec;		/* semaphore for start_init() */
130 
131 #if !defined(NO_PROPOLICE)
132 long	__guard_local __attribute__((section(".openbsd.randomdata")));
133 #endif
134 
135 /* XXX return int so gcc -Werror won't complain */
136 int	main(void *);
137 void	check_console(struct proc *);
138 void	start_init(void *);
139 void	db_ctf_init(void);
140 void	prof_init(void);
141 void	init_exec(void);
142 void	futex_init(void);
143 void	tslp_init(void);
144 void	taskq_init(void);
145 void	timeout_proc_init(void);
146 void	pool_gc_pages(void *);
147 void	percpu_init(void);
148 
149 #ifdef DIAGNOSTIC
150 int pdevinit_done = 0;
151 #endif
152 
153 /*
154  * System startup; initialize the world, create process 0, mount root
155  * filesystem, and fork to create init and pagedaemon.  Most of the
156  * hard work is done in the lower-level initialization routines including
157  * startup(), which does memory initialization and autoconfiguration.
158  */
159 /* XXX return int, so gcc -Werror won't complain */
160 int
161 main(void *framep)
162 {
163 	struct proc *p;
164 	struct process *pr;
165 	struct pdevinit *pdev;
166 	extern struct pdevinit pdevinit[];
167 	extern void disk_init(void);
168 
169 	/*
170 	 * Initialize the current process pointer (curproc) before
171 	 * any possible traps/probes to simplify trap processing.
172 	 */
173 	curproc = p = &proc0;
174 	p->p_cpu = curcpu();
175 
176 	/*
177 	 * Initialize timeouts.
178 	 */
179 	timeout_startup();
180 
181 	/*
182 	 * Attempt to find console and initialize
183 	 * in case of early panic or other messages.
184 	 */
185 	config_init();		/* init autoconfiguration data structures */
186 	consinit();
187 
188 	printf("%s\n", copyright);
189 
190 #ifdef KUBSAN
191 	/* Initialize kubsan. */
192 	kubsan_init();
193 #endif
194 
195 	WITNESS_INITIALIZE();
196 
197 	KERNEL_LOCK_INIT();
198 	SCHED_LOCK_INIT();
199 
200 	rw_obj_init();
201 	uvm_init();
202 	disk_init();		/* must come before autoconfiguration */
203 	tty_init();		/* initialise tty's */
204 	cpu_startup();
205 
206 	random_start(boothowto & RB_GOODRANDOM);	/* Start the flow */
207 
208 	/*
209 	 * Initialize mbuf's.  Do this now because we might attempt to
210 	 * allocate mbufs or mbuf clusters during autoconfiguration.
211 	 */
212 	mbinit();
213 
214 #if NSTOEPLITZ > 0
215 	stoeplitz_init();
216 #endif
217 
218 	/* Initialize sockets. */
219 	soinit();
220 
221 	/* Initialize SRP subsystem. */
222 	srp_startup();
223 
224 	/* Initialize SMR subsystem. */
225 	smr_startup();
226 
227 	/*
228 	 * Initialize process and pgrp structures.
229 	 */
230 	procinit();
231 
232 	/* Initialize file locking. */
233 	lf_init();
234 
235 	/*
236 	 * Initialize filedescriptors.
237 	 */
238 	filedesc_init();
239 
240 	/*
241 	 * Initialize pipes.
242 	 */
243 	pipe_init();
244 
245 	/*
246 	 * Initialize kqueues.
247 	 */
248 	kqueue_init();
249 
250 	/*
251 	 * Initialize futexes.
252 	 */
253 	futex_init();
254 	tslp_init();
255 
256 	/* Create credentials. */
257 	p->p_ucred = crget();
258 	p->p_ucred->cr_ngroups = 1;	/* group 0 */
259 
260 	/*
261 	 * Create process 0 (the swapper).
262 	 */
263 	pr = &process0;
264 	process_initialize(pr, p);
265 
266 	LIST_INSERT_HEAD(&allprocess, pr, ps_list);
267 	LIST_INSERT_HEAD(PIDHASH(0), pr, ps_hash);
268 	atomic_setbits_int(&pr->ps_flags, PS_SYSTEM);
269 
270 	/* Set the default routing table/domain. */
271 	process0.ps_rtableid = 0;
272 
273 	LIST_INSERT_HEAD(&allproc, p, p_list);
274 	pr->ps_pgrp = &pgrp0;
275 	LIST_INSERT_HEAD(TIDHASH(0), p, p_hash);
276 	LIST_INSERT_HEAD(PGRPHASH(0), &pgrp0, pg_hash);
277 	LIST_INIT(&pgrp0.pg_members);
278 	LIST_INSERT_HEAD(&pgrp0.pg_members, pr, ps_pglist);
279 
280 	pgrp0.pg_session = &session0;
281 	session0.s_count = 1;
282 	session0.s_leader = pr;
283 
284 	atomic_setbits_int(&p->p_flag, P_SYSTEM);
285 	p->p_stat = SONPROC;
286 	pr->ps_nice = NZERO;
287 	strlcpy(pr->ps_comm, "swapper", sizeof(pr->ps_comm));
288 
289 	/* Init timeouts. */
290 	timeout_set(&p->p_sleep_to, endtsleep, p);
291 
292 	/* Initialize signal state for process 0. */
293 	signal_init();
294 	siginit(&sigacts0);
295 	pr->ps_sigacts = &sigacts0;
296 
297 	/* Create the file descriptor table. */
298 	p->p_fd = pr->ps_fd = fdinit();
299 
300 	/* Create the limits structures. */
301 	lim_startup(&limit0);
302 	pr->ps_limit = &limit0;
303 
304 	/* Allocate a prototype map so we have something to fork. */
305 	uvmspace_init(&vmspace0, pmap_kernel(), round_page(VM_MIN_ADDRESS),
306 	    trunc_page(VM_MAX_ADDRESS), TRUE, TRUE);
307 	p->p_vmspace = pr->ps_vmspace = &vmspace0;
308 
309 	p->p_addr = proc0paddr;				/* XXX */
310 
311 	/*
312 	 * Charge root for one process.
313 	 */
314 	(void)chgproccnt(0, 1);
315 
316 	/* Initialize run queues */
317 	sched_init_runqueues();
318 	sleep_queue_init();
319 	clockqueue_init(&curcpu()->ci_queue);
320 	sched_init_cpu(curcpu());
321 	p->p_cpu->ci_randseed = (arc4random() & 0x7fffffff) + 1;
322 
323 	/* Initialize timeouts in process context. */
324 	timeout_proc_init();
325 
326 	/* Initialize task queues */
327 	taskq_init();
328 
329 	/* Initialize the interface/address trees */
330 	ifinit();
331 
332 	/* Lock the kernel on behalf of proc0. */
333 	KERNEL_LOCK();
334 
335 #if NMPATH > 0
336 	/* Attach mpath before hardware */
337 	config_rootfound("mpath", NULL);
338 #endif
339 
340 	/* Configure the devices */
341 	cpu_configure();
342 
343 	/* Configure virtual memory system, set vm rlimits. */
344 	uvm_init_limits(&limit0);
345 
346 	/* Per CPU memory allocation */
347 	percpu_init();
348 
349 	/* Initialize the file systems. */
350 #if defined(NFSSERVER) || defined(NFSCLIENT)
351 	nfs_init();			/* initialize server/shared data */
352 #endif
353 	vfsinit();
354 
355 	/* Start real time and statistics clocks. */
356 	initclocks();
357 
358 #ifdef SYSVSHM
359 	/* Initialize System V style shared memory. */
360 	shminit();
361 #endif
362 
363 #ifdef SYSVSEM
364 	/* Initialize System V style semaphores. */
365 	seminit();
366 #endif
367 
368 #ifdef SYSVMSG
369 	/* Initialize System V style message queues. */
370 	msginit();
371 #endif
372 
373 	/* Create default routing table before attaching lo0. */
374 	rtable_init();
375 
376 	/* Attach pseudo-devices. */
377 	for (pdev = pdevinit; pdev->pdev_attach != NULL; pdev++)
378 		if (pdev->pdev_count > 0)
379 			(*pdev->pdev_attach)(pdev->pdev_count);
380 #ifdef DIAGNOSTIC
381 	pdevinit_done = 1;
382 #endif
383 
384 #ifdef CRYPTO
385 	crypto_init();
386 	swcr_init();
387 #endif /* CRYPTO */
388 
389 	/*
390 	 * Initialize protocols.
391 	 */
392 	domaininit();
393 
394 	initconsbuf();
395 
396 #if defined(GPROF) || defined(DDBPROF)
397 	/* Initialize kernel profiling. */
398 	prof_init();
399 #endif
400 
401 	/* Enable per-CPU data. */
402 	mbcpuinit();
403 	kqueue_init_percpu();
404 	pmap_init_percpu();
405 	uvm_init_percpu();
406 	evcount_init_percpu();
407 
408 	/* init exec */
409 	init_exec();
410 
411 	/* Start the scheduler */
412 	scheduler_start();
413 
414 	/*
415 	 * Create process 1 (init(8)).  We do this now, as Unix has
416 	 * historically had init be process 1, and changing this would
417 	 * probably upset a lot of people.
418 	 *
419 	 * Note that process 1 won't immediately exec init(8), but will
420 	 * wait for us to inform it that the root file system has been
421 	 * mounted.
422 	 */
423 	{
424 		struct proc *initproc;
425 
426 		if (fork1(p, FORK_FORK, start_init, NULL, NULL, &initproc))
427 			panic("fork init");
428 		initprocess = initproc->p_p;
429 	}
430 
431 	/*
432 	 * Create any kernel threads whose creation was deferred because
433 	 * initprocess had not yet been created.
434 	 */
435 	kthread_run_deferred_queue();
436 
437 	/*
438 	 * Now that device driver threads have been created, wait for
439 	 * them to finish any deferred autoconfiguration.  Note we don't
440 	 * need to lock this semaphore, since we haven't booted any
441 	 * secondary processors, yet.
442 	 */
443 	while (config_pending)
444 		tsleep_nsec(&config_pending, PWAIT, "cfpend", INFSLP);
445 
446 	dostartuphooks();
447 
448 #if NVSCSI > 0
449 	config_rootfound("vscsi", NULL);
450 #endif
451 #if NSOFTRAID > 0
452 	config_rootfound("softraid", NULL);
453 #endif
454 
455 	/* Configure root/swap devices */
456 	diskconf();
457 
458 #ifdef DDB
459 	/* Make debug symbols available in ddb. */
460 	db_ctf_init();
461 #endif
462 
463 	if (mountroot == NULL || ((*mountroot)() != 0))
464 		panic("cannot mount root");
465 
466 	TAILQ_FIRST(&mountlist)->mnt_flag |= MNT_ROOTFS;
467 
468 	/* Get the vnode for '/'.  Set p->p_fd->fd_cdir to reference it. */
469 	if (VFS_ROOT(TAILQ_FIRST(&mountlist), &rootvnode))
470 		panic("cannot find root vnode");
471 	p->p_fd->fd_cdir = rootvnode;
472 	vref(p->p_fd->fd_cdir);
473 	VOP_UNLOCK(rootvnode);
474 	p->p_fd->fd_rdir = NULL;
475 
476 	/*
477 	 * Now that root is mounted, we can fixup initprocess's CWD
478 	 * info.  All other processes are kthreads, which merely
479 	 * share proc0's CWD info.
480 	 */
481 	initprocess->ps_fd->fd_cdir = rootvnode;
482 	vref(initprocess->ps_fd->fd_cdir);
483 	initprocess->ps_fd->fd_rdir = NULL;
484 
485 	/*
486 	 * Now can look at time, having had a chance to verify the time
487 	 * from the file system.
488 	 */
489 	LIST_FOREACH(pr, &allprocess, ps_list) {
490 		nanouptime(&pr->ps_start);
491 	}
492 	nanouptime(&curcpu()->ci_schedstate.spc_runtime);
493 
494 	uvm_swap_init();
495 
496 	/* Create the pageout daemon kernel thread. */
497 	if (kthread_create(uvm_pageout, NULL, NULL, "pagedaemon"))
498 		panic("fork pagedaemon");
499 
500 	/* Create the reaper daemon kernel thread. */
501 	if (kthread_create(reaper, NULL, &reaperproc, "reaper"))
502 		panic("fork reaper");
503 
504 	/* Create the cleaner daemon kernel thread. */
505 	if (kthread_create(buf_daemon, NULL, &cleanerproc, "cleaner"))
506 		panic("fork cleaner");
507 
508 	/* Create the update daemon kernel thread. */
509 	if (kthread_create(syncer_thread, NULL, &syncerproc, "update"))
510 		panic("fork update");
511 
512 	/* Create the aiodone daemon kernel thread. */
513 	if (kthread_create(uvm_aiodone_daemon, NULL, NULL, "aiodoned"))
514 		panic("fork aiodoned");
515 
516 #if !defined(__hppa__)
517 	/* Create the page zeroing kernel thread. */
518 	if (kthread_create(uvm_pagezero_thread, NULL, NULL, "zerothread"))
519 		panic("fork zerothread");
520 #endif
521 
522 #if defined(MULTIPROCESSOR)
523 	/* Boot the secondary processors. */
524 	cpu_boot_secondary_processors();
525 #endif
526 
527 	/* Now that all CPUs partake in scheduling, start SMR thread. */
528 	smr_startup_thread();
529 
530 	config_process_deferred_mountroot();
531 
532 	/*
533 	 * Okay, now we can let init(8) exec!  It's off to userland!
534 	 */
535 	start_init_exec = 1;
536 	wakeup((void *)&start_init_exec);
537 
538 	/*
539 	 * Start the idle pool page garbage collector
540 	 */
541 #if defined(MULTIPROCESSOR)
542 	pool_gc_pages(NULL);
543 #endif
544 
545 	start_periodic_resettodr();
546 
547         /*
548          * proc0: nothing to do, back to sleep
549          */
550         while (1)
551                 tsleep_nsec(&proc0, PVM, "scheduler", INFSLP);
552 	/* NOTREACHED */
553 }
554 
555 /*
556  * List of paths to try when searching for "init".
557  */
558 static char *initpaths[] = {
559 	"/sbin/init",
560 	"/sbin/oinit",
561 	"/sbin/init.bak",
562 	NULL,
563 };
564 
565 void
566 check_console(struct proc *p)
567 {
568 	struct nameidata nd;
569 	int error;
570 
571 	NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, "/dev/console", p);
572 	error = namei(&nd);
573 	if (error) {
574 		if (error == ENOENT)
575 			printf("warning: /dev/console does not exist\n");
576 		else
577 			printf("warning: /dev/console error %d\n", error);
578 	} else
579 		vrele(nd.ni_vp);
580 }
581 
582 /*
583  * Start the initial user process; try exec'ing each pathname in "initpaths".
584  * The program is invoked with one argument containing the boot flags.
585  */
586 void
587 start_init(void *arg)
588 {
589 	struct proc *p = arg;
590 	vaddr_t addr;
591 	struct sys_execve_args /* {
592 		syscallarg(const char *) path;
593 		syscallarg(char *const *) argp;
594 		syscallarg(char *const *) envp;
595 	} */ args;
596 	int options, error;
597 	long i;
598 	register_t retval[2];
599 	char flags[4], *flagsp;
600 	char **pathp, *path, *ucp, **uap, *arg0, *arg1 = NULL;
601 
602 	/*
603 	 * Now in process 1.
604 	 */
605 
606 	/*
607 	 * Wait for main() to tell us that it's safe to exec.
608 	 */
609 	while (start_init_exec == 0)
610 		tsleep_nsec(&start_init_exec, PWAIT, "initexec", INFSLP);
611 
612 	check_console(p);
613 
614 	/* process 0 ignores SIGCHLD, but we can't */
615 	p->p_p->ps_sigacts->ps_sigflags = 0;
616 
617 	/*
618 	 * Need just enough stack to hold the faked-up "execve()" arguments.
619 	 */
620 #ifdef MACHINE_STACK_GROWS_UP
621 	addr = USRSTACK;
622 #else
623 	addr = USRSTACK - PAGE_SIZE;
624 #endif
625 	p->p_vmspace->vm_maxsaddr = (caddr_t)addr;
626 	p->p_vmspace->vm_minsaddr = (caddr_t)(addr + PAGE_SIZE);
627 	if (uvm_map(&p->p_vmspace->vm_map, &addr, PAGE_SIZE,
628 	    NULL, UVM_UNKNOWN_OFFSET, 0,
629 	    UVM_MAPFLAG(PROT_READ | PROT_WRITE, PROT_MASK, MAP_INHERIT_COPY,
630 	    MADV_NORMAL,
631 	    UVM_FLAG_FIXED|UVM_FLAG_OVERLAY|UVM_FLAG_COPYONW|UVM_FLAG_STACK)))
632 		panic("init: couldn't allocate argument space");
633 
634 	for (pathp = &initpaths[0]; (path = *pathp) != NULL; pathp++) {
635 #ifdef MACHINE_STACK_GROWS_UP
636 		ucp = (char *)addr;
637 #else
638 		ucp = (char *)(addr + PAGE_SIZE);
639 #endif
640 		/*
641 		 * Construct the boot flag argument.
642 		 */
643 		flagsp = flags;
644 		*flagsp++ = '-';
645 		options = 0;
646 
647 		if (boothowto & RB_SINGLE) {
648 			*flagsp++ = 's';
649 			options = 1;
650 		}
651 #ifdef notyet
652 		if (boothowto & RB_FASTBOOT) {
653 			*flagsp++ = 'f';
654 			options = 1;
655 		}
656 #endif
657 
658 		/*
659 		 * Move out the flags (arg 1), if necessary.
660 		 */
661 		if (options != 0) {
662 			*flagsp++ = '\0';
663 			i = flagsp - flags;
664 #ifdef DEBUG
665 			printf("init: copying out flags `%s' %ld\n", flags, i);
666 #endif
667 #ifdef MACHINE_STACK_GROWS_UP
668 			arg1 = ucp;
669 			(void)copyout((caddr_t)flags, (caddr_t)ucp, i);
670 			ucp += i;
671 #else
672 			(void)copyout((caddr_t)flags, (caddr_t)(ucp -= i), i);
673 			arg1 = ucp;
674 #endif
675 		}
676 
677 		/*
678 		 * Move out the file name (also arg 0).
679 		 */
680 		i = strlen(path) + 1;
681 #ifdef DEBUG
682 		printf("init: copying out path `%s' %ld\n", path, i);
683 #endif
684 #ifdef MACHINE_STACK_GROWS_UP
685 		arg0 = ucp;
686 		(void)copyout((caddr_t)path, (caddr_t)ucp, i);
687 		ucp += i;
688 		ucp = (caddr_t)ALIGN((u_long)ucp);
689 		uap = (char **)ucp + 3;
690 #else
691 		(void)copyout((caddr_t)path, (caddr_t)(ucp -= i), i);
692 		arg0 = ucp;
693 		uap = (char **)((u_long)ucp & ~ALIGNBYTES);
694 #endif
695 
696 		/*
697 		 * Move out the arg pointers.
698 		 */
699 		i = 0;
700 		copyout(&i, (caddr_t)--uap, sizeof(register_t)); /* terminator */
701 		if (options != 0)
702 			copyout(&arg1, (caddr_t)--uap, sizeof(register_t));
703 		copyout(&arg0, (caddr_t)--uap, sizeof(register_t));
704 
705 		/*
706 		 * Point at the arguments.
707 		 */
708 		SCARG(&args, path) = arg0;
709 		SCARG(&args, argp) = uap;
710 		SCARG(&args, envp) = NULL;
711 
712 		/*
713 		 * Now try to exec the program.  If can't for any reason
714 		 * other than it doesn't exist, complain.
715 		 */
716 		if ((error = sys_execve(p, &args, retval)) == EJUSTRETURN) {
717 			KERNEL_UNLOCK();
718 			return;
719 		}
720 		if (error != ENOENT)
721 			printf("exec %s: error %d\n", path, error);
722 	}
723 	printf("init: not found\n");
724 	panic("no init");
725 }
726