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init_main.c revision 1.166
      1 /*	$NetBSD: init_main.c,v 1.166 2000/03/24 11:57:14 enami Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1995 Christopher G. Demetriou.  All rights reserved.
      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	8.16 (Berkeley) 5/14/95
     42  */
     43 
     44 #include "fs_nfs.h"
     45 #include "opt_nfsserver.h"
     46 #include "opt_sysv.h"
     47 #include "opt_maxuprc.h"
     48 #include "opt_multiprocessor.h"
     49 
     50 #include "rnd.h"
     51 
     52 #include <sys/param.h>
     53 #include <sys/acct.h>
     54 #include <sys/filedesc.h>
     55 #include <sys/file.h>
     56 #include <sys/errno.h>
     57 #include <sys/exec.h>
     58 #include <sys/callout.h>
     59 #include <sys/kernel.h>
     60 #include <sys/mount.h>
     61 #include <sys/map.h>
     62 #include <sys/proc.h>
     63 #include <sys/kthread.h>
     64 #include <sys/resourcevar.h>
     65 #include <sys/signalvar.h>
     66 #include <sys/systm.h>
     67 #include <sys/vnode.h>
     68 #include <sys/tty.h>
     69 #include <sys/conf.h>
     70 #include <sys/disklabel.h>
     71 #include <sys/buf.h>
     72 #include <sys/device.h>
     73 #include <sys/socketvar.h>
     74 #include <sys/protosw.h>
     75 #include <sys/reboot.h>
     76 #include <sys/user.h>
     77 #ifdef SYSVSHM
     78 #include <sys/shm.h>
     79 #endif
     80 #ifdef SYSVSEM
     81 #include <sys/sem.h>
     82 #endif
     83 #ifdef SYSVMSG
     84 #include <sys/msg.h>
     85 #endif
     86 #include <sys/domain.h>
     87 #include <sys/mbuf.h>
     88 #include <sys/namei.h>
     89 #if NRND > 0
     90 #include <sys/rnd.h>
     91 #endif
     92 
     93 #include <sys/syscall.h>
     94 #include <sys/syscallargs.h>
     95 
     96 #include <ufs/ufs/quota.h>
     97 
     98 #include <miscfs/genfs/genfs.h>
     99 #include <miscfs/syncfs/syncfs.h>
    100 
    101 #include <machine/cpu.h>
    102 
    103 #include <vm/vm.h>
    104 #include <vm/vm_pageout.h>
    105 
    106 #include <uvm/uvm.h>
    107 
    108 #include <net/if.h>
    109 #include <net/raw_cb.h>
    110 
    111 char	copyright[] = "\
    112 Copyright (c) 1996, 1997, 1998, 1999, 2000
    113     The NetBSD Foundation, Inc.  All rights reserved.
    114 Copyright (c) 1982, 1986, 1989, 1991, 1993
    115     The Regents of the University of California.  All rights reserved.
    116 
    117 ";
    118 
    119 /* Components of the first process -- never freed. */
    120 struct	session session0;
    121 struct	pgrp pgrp0;
    122 struct	proc proc0;
    123 struct	pcred cred0;
    124 struct	filedesc0 filedesc0;
    125 struct	cwdinfo cwdi0;
    126 struct	plimit limit0;
    127 struct	vmspace vmspace0;
    128 struct	sigacts sigacts0;
    129 #ifndef curproc
    130 struct	proc *curproc = &proc0;
    131 #endif
    132 struct	proc *initproc;
    133 
    134 int	cmask = CMASK;
    135 extern	struct user *proc0paddr;
    136 
    137 struct	vnode *rootvp, *swapdev_vp;
    138 int	boothowto;
    139 int	cold = 1;			/* still working on startup */
    140 struct	timeval boottime;
    141 struct	timeval runtime;
    142 
    143 __volatile int start_init_exec;		/* semaphore for start_init() */
    144 
    145 static void check_console __P((struct proc *p));
    146 static void start_init __P((void *));
    147 static void start_pagedaemon __P((void *));
    148 static void start_reaper __P((void *));
    149 void main __P((void));
    150 
    151 extern char sigcode[], esigcode[];
    152 #ifdef SYSCALL_DEBUG
    153 extern char *syscallnames[];
    154 #endif
    155 
    156 struct emul emul_netbsd = {
    157 	"netbsd",
    158 	NULL,
    159 	sendsig,
    160 	SYS_syscall,
    161 	SYS_MAXSYSCALL,
    162 	sysent,
    163 #ifdef SYSCALL_DEBUG
    164 	syscallnames,
    165 #else
    166 	NULL,
    167 #endif
    168 	0,
    169 	copyargs,
    170 	setregs,
    171 	sigcode,
    172 	esigcode,
    173 };
    174 
    175 /*
    176  * System startup; initialize the world, create process 0, mount root
    177  * filesystem, and fork to create init and pagedaemon.  Most of the
    178  * hard work is done in the lower-level initialization routines including
    179  * startup(), which does memory initialization and autoconfiguration.
    180  */
    181 void
    182 main()
    183 {
    184 	struct proc *p;
    185 	struct pdevinit *pdev;
    186 	int i, s, error;
    187 	extern struct pdevinit pdevinit[];
    188 	extern void roundrobin __P((void *));
    189 	extern void schedcpu __P((void *));
    190 	extern void disk_init __P((void));
    191 #if defined(NFSSERVER) || defined(NFS)
    192 	extern void nfs_init __P((void));
    193 #endif
    194 
    195 	/*
    196 	 * Initialize the current process pointer (curproc) before
    197 	 * any possible traps/probes to simplify trap processing.
    198 	 */
    199 	p = &proc0;
    200 	curproc = p;
    201 	/*
    202 	 * Attempt to find console and initialize
    203 	 * in case of early panic or other messages.
    204 	 */
    205 	consinit();
    206 	printf("%s", copyright);
    207 
    208 	uvm_init();
    209 
    210 	/* Do machine-dependent initialization. */
    211 	cpu_startup();
    212 
    213 	/* Initialize callouts. */
    214 	callout_startup();
    215 
    216 	/*
    217 	 * Initialize mbuf's.  Do this now because we might attempt to
    218 	 * allocate mbufs or mbuf clusters during autoconfiguration.
    219 	 */
    220 	mbinit();
    221 
    222 	/* Initialize sockets. */
    223 	soinit();
    224 
    225 	/*
    226 	 * The following 3 things must be done before autoconfiguration.
    227 	 */
    228 	disk_init();		/* initialize disk list */
    229 	tty_init();		/* initialize tty list */
    230 #if NRND > 0
    231 	rnd_init();		/* initialize RNG */
    232 #endif
    233 
    234 	/*
    235 	 * Initialize process and pgrp structures.
    236 	 */
    237 	procinit();
    238 
    239 	/*
    240 	 * Create process 0 (the swapper).
    241 	 */
    242 	s = proclist_lock_write();
    243 	LIST_INSERT_HEAD(&allproc, p, p_list);
    244 	proclist_unlock_write(s);
    245 
    246 	p->p_pgrp = &pgrp0;
    247 	LIST_INSERT_HEAD(PGRPHASH(0), &pgrp0, pg_hash);
    248 	LIST_INIT(&pgrp0.pg_members);
    249 	LIST_INSERT_HEAD(&pgrp0.pg_members, p, p_pglist);
    250 
    251 	pgrp0.pg_session = &session0;
    252 	session0.s_count = 1;
    253 	session0.s_sid = p->p_pid;
    254 	session0.s_leader = p;
    255 
    256 	/*
    257 	 * Set P_NOCLDWAIT so that kernel threads are reparented to
    258 	 * init(8) when they exit.  init(8) can easily wait them out
    259 	 * for us.
    260 	 */
    261 	p->p_flag = P_INMEM | P_SYSTEM | P_NOCLDWAIT;
    262 	p->p_stat = SRUN;
    263 	p->p_nice = NZERO;
    264 	p->p_emul = &emul_netbsd;
    265 	strncpy(p->p_comm, "swapper", MAXCOMLEN);
    266 
    267 	callout_init(&p->p_realit_ch);
    268 	callout_init(&p->p_tsleep_ch);
    269 
    270 	/* Create credentials. */
    271 	cred0.p_refcnt = 1;
    272 	p->p_cred = &cred0;
    273 	p->p_ucred = crget();
    274 	p->p_ucred->cr_ngroups = 1;	/* group 0 */
    275 
    276 	/* Create the file descriptor table. */
    277 	finit();
    278 	p->p_fd = &filedesc0.fd_fd;
    279 	fdinit1(&filedesc0);
    280 
    281 	/* Create the CWD info. */
    282 	p->p_cwdi = &cwdi0;
    283 	cwdi0.cwdi_cmask = cmask;
    284 	cwdi0.cwdi_refcnt = 1;
    285 
    286 	/* Create the limits structures. */
    287 	p->p_limit = &limit0;
    288 	for (i = 0; i < sizeof(p->p_rlimit)/sizeof(p->p_rlimit[0]); i++)
    289 		limit0.pl_rlimit[i].rlim_cur =
    290 		    limit0.pl_rlimit[i].rlim_max = RLIM_INFINITY;
    291 
    292 	limit0.pl_rlimit[RLIMIT_NOFILE].rlim_max = maxfiles;
    293 	limit0.pl_rlimit[RLIMIT_NOFILE].rlim_cur =
    294 	    maxfiles < NOFILE ? maxfiles : NOFILE;
    295 
    296 	limit0.pl_rlimit[RLIMIT_NPROC].rlim_max = maxproc;
    297 	limit0.pl_rlimit[RLIMIT_NPROC].rlim_cur =
    298 	    maxproc < MAXUPRC ? maxproc : MAXUPRC;
    299 
    300 	i = ptoa(uvmexp.free);
    301 	limit0.pl_rlimit[RLIMIT_RSS].rlim_max = i;
    302 	limit0.pl_rlimit[RLIMIT_MEMLOCK].rlim_max = i;
    303 	limit0.pl_rlimit[RLIMIT_MEMLOCK].rlim_cur = i / 3;
    304 	limit0.pl_corename = defcorename;
    305 	limit0.p_refcnt = 1;
    306 
    307 	/*
    308 	 * Initialize proc0's vmspace, which uses the kernel pmap.
    309 	 * All kernel processes (which never have user space mappings)
    310 	 * share proc0's vmspace, and thus, the kernel pmap.
    311 	 */
    312 	uvmspace_init(&vmspace0, pmap_kernel(), round_page(VM_MIN_ADDRESS),
    313 	    trunc_page(VM_MAX_ADDRESS), TRUE);
    314 	p->p_vmspace = &vmspace0;
    315 
    316 	p->p_addr = proc0paddr;				/* XXX */
    317 
    318 	/*
    319 	 * We continue to place resource usage info in the
    320 	 * user struct so they're pageable.
    321 	 */
    322 	p->p_stats = &p->p_addr->u_stats;
    323 
    324 	/*
    325 	 * Charge root for one process.
    326 	 */
    327 	(void)chgproccnt(0, 1);
    328 
    329 	rqinit();
    330 
    331 	/* Configure virtual memory system, set vm rlimits. */
    332 	uvm_init_limits(p);
    333 
    334 	/* Initialize the file systems. */
    335 #if defined(NFSSERVER) || defined(NFS)
    336 	nfs_init();			/* initialize server/shared data */
    337 #endif
    338 	vfsinit();
    339 
    340 	/* Configure the system hardware.  This will enable interrupts. */
    341 	configure();
    342 
    343 #ifdef SYSVSHM
    344 	/* Initialize System V style shared memory. */
    345 	shminit();
    346 #endif
    347 
    348 #ifdef SYSVSEM
    349 	/* Initialize System V style semaphores. */
    350 	seminit();
    351 #endif
    352 
    353 #ifdef SYSVMSG
    354 	/* Initialize System V style message queues. */
    355 	msginit();
    356 #endif
    357 
    358 	/* Attach pseudo-devices. */
    359 	for (pdev = pdevinit; pdev->pdev_attach != NULL; pdev++)
    360 		(*pdev->pdev_attach)(pdev->pdev_count);
    361 
    362 	/*
    363 	 * Initialize protocols.  Block reception of incoming packets
    364 	 * until everything is ready.
    365 	 */
    366 	s = splimp();
    367 	ifinit();
    368 	domaininit();
    369 	splx(s);
    370 
    371 #ifdef GPROF
    372 	/* Initialize kernel profiling. */
    373 	kmstartup();
    374 #endif
    375 
    376 	/* Initialize system accouting. */
    377 	acct_init();
    378 
    379 	/*
    380 	 * Initialize signal-related data structures, and signal state
    381 	 * for proc0.
    382 	 */
    383 	signal_init();
    384 	p->p_sigacts = &sigacts0;
    385 	siginit(p);
    386 
    387 	/* Kick off timeout driven events by calling first time. */
    388 	roundrobin(NULL);
    389 	schedcpu(NULL);
    390 
    391 	/*
    392 	 * Create process 1 (init(8)).  We do this now, as Unix has
    393 	 * historically had init be process 1, and changing this would
    394 	 * probably upset a lot of people.
    395 	 *
    396 	 * Note that process 1 won't immediately exec init(8), but will
    397 	 * wait for us to inform it that the root file system has been
    398 	 * mounted.
    399 	 */
    400 	if (fork1(p, 0, SIGCHLD, NULL, 0, NULL, &initproc))
    401 		panic("fork init");
    402 	cpu_set_kpc(initproc, start_init, initproc);
    403 
    404 	/*
    405 	 * Create any kernel threads who's creation was deferred because
    406 	 * initproc had not yet been created.
    407 	 */
    408 	kthread_run_deferred_queue();
    409 
    410 	/*
    411 	 * Now that device driver threads have been created, wait for
    412 	 * them to finish any deferred autoconfiguration.  Note we don't
    413 	 * need to lock this semaphore, since we haven't booted any
    414 	 * secondary processors, yet.
    415 	 */
    416 	while (config_pending)
    417 		(void) tsleep((void *)&config_pending, PWAIT, "cfpend", 0);
    418 
    419 	/*
    420 	 * Now that autoconfiguration has completed, we can determine
    421 	 * the root and dump devices.
    422 	 */
    423 	cpu_rootconf();
    424 	cpu_dumpconf();
    425 
    426 	/* Mount the root file system. */
    427 	do {
    428 		domountroothook();
    429 		if ((error = vfs_mountroot())) {
    430 			printf("cannot mount root, error = %d\n", error);
    431 			boothowto |= RB_ASKNAME;
    432 			setroot(root_device,
    433 			    (rootdev != NODEV) ? DISKPART(rootdev) : 0);
    434 		}
    435 	} while (error != 0);
    436 	mountroothook_destroy();
    437 
    438 	mountlist.cqh_first->mnt_flag |= MNT_ROOTFS;
    439 	mountlist.cqh_first->mnt_op->vfs_refcount++;
    440 
    441 	/*
    442 	 * Get the vnode for '/'.  Set filedesc0.fd_fd.fd_cdir to
    443 	 * reference it.
    444 	 */
    445 	if (VFS_ROOT(mountlist.cqh_first, &rootvnode))
    446 		panic("cannot find root vnode");
    447 	cwdi0.cwdi_cdir = rootvnode;
    448 	VREF(cwdi0.cwdi_cdir);
    449 	VOP_UNLOCK(rootvnode, 0);
    450 	cwdi0.cwdi_rdir = NULL;
    451 
    452 	/*
    453 	 * Now that root is mounted, we can fixup initproc's CWD
    454 	 * info.  All other processes are kthreads, which merely
    455 	 * share proc0's CWD info.
    456 	 */
    457 	initproc->p_cwdi->cwdi_cdir = rootvnode;
    458 	VREF(initproc->p_cwdi->cwdi_cdir);
    459 	initproc->p_cwdi->cwdi_rdir = NULL;
    460 
    461 	/*
    462 	 * Now can look at time, having had a chance to verify the time
    463 	 * from the file system.  Reset p->p_rtime as it may have been
    464 	 * munched in mi_switch() after the time got set.
    465 	 */
    466 	proclist_lock_read();
    467 	s = splclock();		/* so we can read time */
    468 	for (p = LIST_FIRST(&allproc); p != NULL;
    469 	     p = LIST_NEXT(p, p_list)) {
    470 		p->p_stats->p_start = runtime = mono_time = boottime = time;
    471 		p->p_rtime.tv_sec = p->p_rtime.tv_usec = 0;
    472 	}
    473 	splx(s);
    474 	proclist_unlock_read();
    475 
    476 	/* Create the pageout daemon kernel thread. */
    477 	uvm_swap_init();
    478 	if (kthread_create1(start_pagedaemon, NULL, NULL, "pagedaemon"))
    479 		panic("fork pagedaemon");
    480 
    481 	/* Create the process reaper kernel thread. */
    482 	if (kthread_create1(start_reaper, NULL, NULL, "reaper"))
    483 		panic("fork reaper");
    484 
    485 	/* Create the filesystem syncer kernel thread. */
    486 	if (kthread_create1(sched_sync, NULL, NULL, "ioflush"))
    487 		panic("fork syncer");
    488 
    489 #if defined(MULTIPROCESSOR)
    490 	/* Boot the secondary processors. */
    491 	cpu_boot_secondary_processors();
    492 #endif
    493 
    494 	/*
    495 	 * Okay, now we can let init(8) exec!  It's off to userland!
    496 	 */
    497 	start_init_exec = 1;
    498 	wakeup((void *)&start_init_exec);
    499 
    500 	/* The scheduler is an infinite loop. */
    501 	uvm_scheduler();
    502 	/* NOTREACHED */
    503 }
    504 
    505 static void
    506 check_console(p)
    507 	struct proc *p;
    508 {
    509 	struct nameidata nd;
    510 	int error;
    511 
    512 	NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, "/dev/console", p);
    513 	error = namei(&nd);
    514 	if (error == 0)
    515 		vrele(nd.ni_vp);
    516 	else if (error == ENOENT)
    517 		printf("warning: no /dev/console\n");
    518 	else
    519 		printf("warning: lookup /dev/console: error %d\n", error);
    520 }
    521 
    522 /*
    523  * List of paths to try when searching for "init".
    524  */
    525 static char *initpaths[] = {
    526 	"/sbin/init",
    527 	"/sbin/oinit",
    528 	"/sbin/init.bak",
    529 	NULL,
    530 };
    531 
    532 /*
    533  * Start the initial user process; try exec'ing each pathname in "initpaths".
    534  * The program is invoked with one argument containing the boot flags.
    535  */
    536 static void
    537 start_init(arg)
    538 	void *arg;
    539 {
    540 	struct proc *p = arg;
    541 	vaddr_t addr;
    542 	struct sys_execve_args /* {
    543 		syscallarg(const char *) path;
    544 		syscallarg(char * const *) argp;
    545 		syscallarg(char * const *) envp;
    546 	} */ args;
    547 	int options, i, error;
    548 	register_t retval[2];
    549 	char flags[4], *flagsp;
    550 	char **pathp, *path, *slash, *ucp, **uap, *arg0, *arg1 = NULL;
    551 
    552 	/*
    553 	 * Now in process 1.
    554 	 */
    555 	strncpy(p->p_comm, "init", MAXCOMLEN);
    556 
    557 	/*
    558 	 * Wait for main() to tell us that it's safe to exec.
    559 	 */
    560 	while (start_init_exec == 0)
    561 		(void) tsleep((void *)&start_init_exec, PWAIT, "initexec", 0);
    562 
    563 	/*
    564 	 * This is not the right way to do this.  We really should
    565 	 * hand-craft a descriptor onto /dev/console to hand to init,
    566 	 * but that's a _lot_ more work, and the benefit from this easy
    567 	 * hack makes up for the "good is the enemy of the best" effect.
    568 	 */
    569 	check_console(p);
    570 
    571 	/*
    572 	 * Need just enough stack to hold the faked-up "execve()" arguments.
    573 	 */
    574 	addr = USRSTACK - PAGE_SIZE;
    575 	if (uvm_map(&p->p_vmspace->vm_map, &addr, PAGE_SIZE,
    576                     NULL, UVM_UNKNOWN_OFFSET,
    577                     UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_COPY,
    578 		    UVM_ADV_NORMAL,
    579                     UVM_FLAG_FIXED|UVM_FLAG_OVERLAY|UVM_FLAG_COPYONW))
    580 		!= KERN_SUCCESS)
    581 		panic("init: couldn't allocate argument space");
    582 	p->p_vmspace->vm_maxsaddr = (caddr_t)addr;
    583 
    584 	for (pathp = &initpaths[0]; (path = *pathp) != NULL; pathp++) {
    585 		ucp = (char *)(addr + PAGE_SIZE);
    586 
    587 		/*
    588 		 * Construct the boot flag argument.
    589 		 */
    590 		flagsp = flags;
    591 		*flagsp++ = '-';
    592 		options = 0;
    593 
    594 		if (boothowto & RB_SINGLE) {
    595 			*flagsp++ = 's';
    596 			options = 1;
    597 		}
    598 #ifdef notyet
    599 		if (boothowto & RB_FASTBOOT) {
    600 			*flagsp++ = 'f';
    601 			options = 1;
    602 		}
    603 #endif
    604 
    605 		/*
    606 		 * Move out the flags (arg 1), if necessary.
    607 		 */
    608 		if (options != 0) {
    609 			*flagsp++ = '\0';
    610 			i = flagsp - flags;
    611 #ifdef DEBUG
    612 			printf("init: copying out flags `%s' %d\n", flags, i);
    613 #endif
    614 			(void)copyout((caddr_t)flags, (caddr_t)(ucp -= i), i);
    615 			arg1 = ucp;
    616 		}
    617 
    618 		/*
    619 		 * Move out the file name (also arg 0).
    620 		 */
    621 		i = strlen(path) + 1;
    622 #ifdef DEBUG
    623 		printf("init: copying out path `%s' %d\n", path, i);
    624 #endif
    625 		(void)copyout((caddr_t)path, (caddr_t)(ucp -= i), i);
    626 		arg0 = ucp;
    627 
    628 		/*
    629 		 * Move out the arg pointers.
    630 		 */
    631 		uap = (char **)((long)ucp & ~ALIGNBYTES);
    632 		(void)suword((caddr_t)--uap, 0);	/* terminator */
    633 		if (options != 0)
    634 			(void)suword((caddr_t)--uap, (long)arg1);
    635 		slash = strrchr(path, '/');
    636 		if (slash)
    637 			(void)suword((caddr_t)--uap,
    638 			    (long)arg0 + (slash + 1 - path));
    639 		else
    640 			(void)suword((caddr_t)--uap, (long)arg0);
    641 
    642 		/*
    643 		 * Point at the arguments.
    644 		 */
    645 		SCARG(&args, path) = arg0;
    646 		SCARG(&args, argp) = uap;
    647 		SCARG(&args, envp) = NULL;
    648 
    649 		/*
    650 		 * Now try to exec the program.  If can't for any reason
    651 		 * other than it doesn't exist, complain.
    652 		 */
    653 		error = sys_execve(p, &args, retval);
    654 		if (error == 0 || error == EJUSTRETURN)
    655 			return;
    656 		if (error != ENOENT)
    657 			printf("exec %s: error %d\n", path, error);
    658 	}
    659 	printf("init: not found\n");
    660 	panic("no init");
    661 }
    662 
    663 /* ARGSUSED */
    664 static void
    665 start_pagedaemon(arg)
    666 	void *arg;
    667 {
    668 
    669 	uvm_pageout();
    670 	/* NOTREACHED */
    671 }
    672 
    673 /* ARGSUSED */
    674 static void
    675 start_reaper(arg)
    676 	void *arg;
    677 {
    678 
    679 	reaper();
    680 	/* NOTREACHED */
    681 }
    682