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init_main.c revision 1.269
      1 /*	$NetBSD: init_main.c,v 1.269 2006/06/25 08:00:01 yamt Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1982, 1986, 1989, 1991, 1992, 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  * (c) UNIX System Laboratories, Inc.
      7  * All or some portions of this file are derived from material licensed
      8  * to the University of California by American Telephone and Telegraph
      9  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
     10  * the permission of UNIX System Laboratories, Inc.
     11  *
     12  * Redistribution and use in source and binary forms, with or without
     13  * modification, are permitted provided that the following conditions
     14  * are met:
     15  * 1. Redistributions of source code must retain the above copyright
     16  *    notice, this list of conditions and the following disclaimer.
     17  * 2. Redistributions in binary form must reproduce the above copyright
     18  *    notice, this list of conditions and the following disclaimer in the
     19  *    documentation and/or other materials provided with the distribution.
     20  * 3. Neither the name of the University nor the names of its contributors
     21  *    may be used to endorse or promote products derived from this software
     22  *    without specific prior written permission.
     23  *
     24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     34  * SUCH DAMAGE.
     35  *
     36  *	@(#)init_main.c	8.16 (Berkeley) 5/14/95
     37  */
     38 
     39 /*
     40  * Copyright (c) 1995 Christopher G. Demetriou.  All rights reserved.
     41  *
     42  * Redistribution and use in source and binary forms, with or without
     43  * modification, are permitted provided that the following conditions
     44  * are met:
     45  * 1. Redistributions of source code must retain the above copyright
     46  *    notice, this list of conditions and the following disclaimer.
     47  * 2. Redistributions in binary form must reproduce the above copyright
     48  *    notice, this list of conditions and the following disclaimer in the
     49  *    documentation and/or other materials provided with the distribution.
     50  * 3. All advertising materials mentioning features or use of this software
     51  *    must display the following acknowledgement:
     52  *	This product includes software developed by the University of
     53  *	California, Berkeley and its contributors.
     54  * 4. Neither the name of the University nor the names of its contributors
     55  *    may be used to endorse or promote products derived from this software
     56  *    without specific prior written permission.
     57  *
     58  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     59  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     60  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     61  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     62  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     63  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     64  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     65  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     66  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     67  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     68  * SUCH DAMAGE.
     69  *
     70  *	@(#)init_main.c	8.16 (Berkeley) 5/14/95
     71  */
     72 
     73 #include <sys/cdefs.h>
     74 __KERNEL_RCSID(0, "$NetBSD: init_main.c,v 1.269 2006/06/25 08:00:01 yamt Exp $");
     75 
     76 #include "opt_ipsec.h"
     77 #include "opt_kcont.h"
     78 #include "opt_multiprocessor.h"
     79 #include "opt_ntp.h"
     80 #include "opt_pipe.h"
     81 #include "opt_posix.h"
     82 #include "opt_syscall_debug.h"
     83 #include "opt_sysv.h"
     84 #include "opt_verified_exec.h"
     85 
     86 #include "rnd.h"
     87 
     88 #include <sys/param.h>
     89 #include <sys/acct.h>
     90 #include <sys/filedesc.h>
     91 #include <sys/file.h>
     92 #include <sys/errno.h>
     93 #include <sys/callout.h>
     94 #include <sys/kernel.h>
     95 #include <sys/kcont.h>
     96 #include <sys/kmem.h>
     97 #include <sys/mount.h>
     98 #include <sys/proc.h>
     99 #include <sys/kthread.h>
    100 #include <sys/resourcevar.h>
    101 #include <sys/signalvar.h>
    102 #include <sys/systm.h>
    103 #include <sys/vnode.h>
    104 #include <sys/tty.h>
    105 #include <sys/conf.h>
    106 #include <sys/disklabel.h>
    107 #include <sys/buf.h>
    108 #include <sys/device.h>
    109 #include <sys/exec.h>
    110 #include <sys/socketvar.h>
    111 #include <sys/protosw.h>
    112 #include <sys/reboot.h>
    113 #include <sys/user.h>
    114 #include <sys/sysctl.h>
    115 #include <sys/event.h>
    116 #include <sys/mbuf.h>
    117 #ifdef FAST_IPSEC
    118 #include <netipsec/ipsec.h>
    119 #endif
    120 #ifdef SYSVSHM
    121 #include <sys/shm.h>
    122 #endif
    123 #ifdef SYSVSEM
    124 #include <sys/sem.h>
    125 #endif
    126 #ifdef SYSVMSG
    127 #include <sys/msg.h>
    128 #endif
    129 #ifdef P1003_1B_SEMAPHORE
    130 #include <sys/ksem.h>
    131 #endif
    132 #include <sys/domain.h>
    133 #include <sys/namei.h>
    134 #if NRND > 0
    135 #include <sys/rnd.h>
    136 #endif
    137 #ifndef PIPE_SOCKETPAIR
    138 #include <sys/pipe.h>
    139 #endif
    140 #ifdef LKM
    141 #include <sys/lkm.h>
    142 #endif
    143 #ifdef VERIFIED_EXEC
    144 #include <sys/verified_exec.h>
    145 #endif
    146 #include <sys/kauth.h>
    147 #include <net80211/ieee80211_netbsd.h>
    148 
    149 #include <sys/syscall.h>
    150 #include <sys/sa.h>
    151 #include <sys/syscallargs.h>
    152 
    153 #include <ufs/ufs/quota.h>
    154 
    155 #include <miscfs/genfs/genfs.h>
    156 #include <miscfs/syncfs/syncfs.h>
    157 
    158 #include <machine/cpu.h>
    159 
    160 #include <uvm/uvm.h>
    161 
    162 #include <dev/cons.h>
    163 
    164 #include <net/if.h>
    165 #include <net/raw_cb.h>
    166 
    167 extern struct proc proc0;
    168 extern struct lwp lwp0;
    169 extern struct cwdinfo cwdi0;
    170 
    171 #ifndef curlwp
    172 struct	lwp *curlwp = &lwp0;
    173 #endif
    174 struct	proc *initproc;
    175 
    176 struct	vnode *rootvp, *swapdev_vp;
    177 int	boothowto;
    178 int	cold = 1;			/* still working on startup */
    179 #ifndef __HAVE_TIMECOUNTER
    180 struct timeval boottime;
    181 #endif
    182 time_t	rootfstime;			/* recorded root fs time, if known */
    183 
    184 volatile int start_init_exec;		/* semaphore for start_init() */
    185 
    186 static void check_console(struct lwp *l);
    187 static void start_init(void *);
    188 void main(void);
    189 
    190 /*
    191  * System startup; initialize the world, create process 0, mount root
    192  * filesystem, and fork to create init and pagedaemon.  Most of the
    193  * hard work is done in the lower-level initialization routines including
    194  * startup(), which does memory initialization and autoconfiguration.
    195  */
    196 void
    197 main(void)
    198 {
    199 #ifdef __HAVE_TIMECOUNTER
    200 	struct timeval time;
    201 #endif
    202 	struct lwp *l;
    203 	struct proc *p;
    204 	struct pdevinit *pdev;
    205 	int s, error;
    206 	extern struct pdevinit pdevinit[];
    207 	extern void schedcpu(void *);
    208 #ifdef NVNODE_IMPLICIT
    209 	int usevnodes;
    210 #endif
    211 
    212 	/*
    213 	 * Initialize the current LWP pointer (curlwp) before
    214 	 * any possible traps/probes to simplify trap processing.
    215 	 */
    216 	l = &lwp0;
    217 	curlwp = l;
    218 	l->l_cpu = curcpu();
    219 	l->l_proc = &proc0;
    220 	l->l_lid = 1;
    221 
    222 	/*
    223 	 * Attempt to find console and initialize
    224 	 * in case of early panic or other messages.
    225 	 */
    226 	consinit();
    227 
    228 	KERNEL_LOCK_INIT();
    229 
    230 	uvm_init();
    231 
    232 	kmem_init();
    233 
    234 	/* Do machine-dependent initialization. */
    235 	cpu_startup();
    236 
    237 	/* Initialize callouts. */
    238 	callout_startup();
    239 
    240 	/* Initialize the buffer cache */
    241 	bufinit();
    242 
    243 	/*
    244 	 * Initialize mbuf's.  Do this now because we might attempt to
    245 	 * allocate mbufs or mbuf clusters during autoconfiguration.
    246 	 */
    247 	mbinit();
    248 
    249 	/* Initialize sockets. */
    250 	soinit();
    251 
    252 #ifdef KCONT
    253 	/* Initialize kcont. */
    254         kcont_init();
    255 #endif
    256 
    257 	/*
    258 	 * The following things must be done before autoconfiguration.
    259 	 */
    260 	evcnt_init();		/* initialize event counters */
    261 #if NRND > 0
    262 	rnd_init();		/* initialize RNG */
    263 #endif
    264 	/* Initialize the sysctl subsystem. */
    265 	sysctl_init();
    266 
    267 	/* Initialize process and pgrp structures. */
    268 	procinit();
    269 
    270 	/* Initialize signal-related data structures. */
    271 	signal_init();
    272 
    273 	/* Create process 0 (the swapper). */
    274 	proc0_init();
    275 
    276 	/*
    277 	 * Charge root for one process.
    278 	 */
    279 	(void)chgproccnt(0, 1);
    280 
    281 	rqinit();
    282 
    283 	/* Initialize the file systems. */
    284 #ifdef NVNODE_IMPLICIT
    285 	/*
    286 	 * If maximum number of vnodes in namei vnode cache is not explicitly
    287 	 * defined in kernel config, adjust the number such as we use roughly
    288 	 * 1.0% of memory for vnode cache (but not less than NVNODE vnodes).
    289 	 */
    290 	usevnodes = (ptoa((unsigned)physmem) / 100) / sizeof(struct vnode);
    291 	if (usevnodes > desiredvnodes)
    292 		desiredvnodes = usevnodes;
    293 #endif
    294 	vfsinit();
    295 
    296 
    297 #ifdef __HAVE_TIMECOUNTER
    298 	inittimecounter();
    299 #ifdef NTP
    300 	ntp_init();
    301 #endif
    302 #endif /* __HAVE_TIMECOUNTER */
    303 
    304 	/* Configure the system hardware.  This will enable interrupts. */
    305 	configure();
    306 
    307 	ubc_init();		/* must be after autoconfig */
    308 
    309 	/* Lock the kernel on behalf of proc0. */
    310 	KERNEL_PROC_LOCK(l);
    311 
    312 #ifdef SYSVSHM
    313 	/* Initialize System V style shared memory. */
    314 	shminit();
    315 #endif
    316 
    317 #ifdef SYSVSEM
    318 	/* Initialize System V style semaphores. */
    319 	seminit();
    320 #endif
    321 
    322 #ifdef SYSVMSG
    323 	/* Initialize System V style message queues. */
    324 	msginit();
    325 #endif
    326 
    327 #ifdef P1003_1B_SEMAPHORE
    328 	/* Initialize posix semaphores */
    329 	ksem_init();
    330 #endif
    331 
    332 	/* Initialize kauth. */
    333 	kauth_init();
    334 
    335 #ifdef VERIFIED_EXEC
    336 	  /*
    337 	   * Initialise the fingerprint operations vectors before
    338 	   * fingerprints can be loaded.
    339 	   */
    340 	veriexec_init_fp_ops();
    341 #endif
    342 
    343 	/* Attach pseudo-devices. */
    344 	for (pdev = pdevinit; pdev->pdev_attach != NULL; pdev++)
    345 		(*pdev->pdev_attach)(pdev->pdev_count);
    346 
    347 #ifdef	FAST_IPSEC
    348 	/* Attach network crypto subsystem */
    349 	ipsec_attach();
    350 #endif
    351 
    352 	/*
    353 	 * Initialize protocols.  Block reception of incoming packets
    354 	 * until everything is ready.
    355 	 */
    356 	s = splnet();
    357 	ifinit();
    358 	domaininit();
    359 	if_attachdomain();
    360 	splx(s);
    361 
    362 #ifdef GPROF
    363 	/* Initialize kernel profiling. */
    364 	kmstartup();
    365 #endif
    366 
    367 	/* Initialize system accouting. */
    368 	acct_init();
    369 
    370 	/* Kick off timeout driven events by calling first time. */
    371 	schedcpu(NULL);
    372 
    373 	/*
    374 	 * Create process 1 (init(8)).  We do this now, as Unix has
    375 	 * historically had init be process 1, and changing this would
    376 	 * probably upset a lot of people.
    377 	 *
    378 	 * Note that process 1 won't immediately exec init(8), but will
    379 	 * wait for us to inform it that the root file system has been
    380 	 * mounted.
    381 	 */
    382 	if (fork1(l, 0, SIGCHLD, NULL, 0, start_init, NULL, NULL, &initproc))
    383 		panic("fork init");
    384 
    385 	/*
    386 	 * Create any kernel threads who's creation was deferred because
    387 	 * initproc had not yet been created.
    388 	 */
    389 	kthread_run_deferred_queue();
    390 
    391 	/*
    392 	 * Now that device driver threads have been created, wait for
    393 	 * them to finish any deferred autoconfiguration.  Note we don't
    394 	 * need to lock this semaphore, since we haven't booted any
    395 	 * secondary processors, yet.
    396 	 */
    397 	while (config_pending)
    398 		(void) tsleep(&config_pending, PWAIT, "cfpend", 0);
    399 
    400 	/*
    401 	 * Finalize configuration now that all real devices have been
    402 	 * found.  This needs to be done before the root device is
    403 	 * selected, since finalization may create the root device.
    404 	 */
    405 	config_finalize();
    406 
    407 	/*
    408 	 * Now that autoconfiguration has completed, we can determine
    409 	 * the root and dump devices.
    410 	 */
    411 	cpu_rootconf();
    412 	cpu_dumpconf();
    413 
    414 	/* Mount the root file system. */
    415 	do {
    416 		domountroothook();
    417 		if ((error = vfs_mountroot())) {
    418 			printf("cannot mount root, error = %d\n", error);
    419 			boothowto |= RB_ASKNAME;
    420 			setroot(root_device,
    421 			    (rootdev != NODEV) ? DISKPART(rootdev) : 0);
    422 		}
    423 	} while (error != 0);
    424 	mountroothook_destroy();
    425 
    426 	/*
    427 	 * Initialise the time-of-day clock, passing the time recorded
    428 	 * in the root filesystem (if any) for use by systems that
    429 	 * don't have a non-volatile time-of-day device.
    430 	 */
    431 	inittodr(rootfstime);
    432 
    433 	CIRCLEQ_FIRST(&mountlist)->mnt_flag |= MNT_ROOTFS;
    434 	CIRCLEQ_FIRST(&mountlist)->mnt_op->vfs_refcount++;
    435 
    436 	/*
    437 	 * Get the vnode for '/'.  Set filedesc0.fd_fd.fd_cdir to
    438 	 * reference it.
    439 	 */
    440 	error = VFS_ROOT(CIRCLEQ_FIRST(&mountlist), &rootvnode);
    441 	if (error)
    442 		panic("cannot find root vnode, error=%d", error);
    443 	cwdi0.cwdi_cdir = rootvnode;
    444 	VREF(cwdi0.cwdi_cdir);
    445 	VOP_UNLOCK(rootvnode, 0);
    446 	cwdi0.cwdi_rdir = NULL;
    447 
    448 	/*
    449 	 * Now that root is mounted, we can fixup initproc's CWD
    450 	 * info.  All other processes are kthreads, which merely
    451 	 * share proc0's CWD info.
    452 	 */
    453 	initproc->p_cwdi->cwdi_cdir = rootvnode;
    454 	VREF(initproc->p_cwdi->cwdi_cdir);
    455 	initproc->p_cwdi->cwdi_rdir = NULL;
    456 
    457 	/*
    458 	 * Now can look at time, having had a chance to verify the time
    459 	 * from the file system.  Reset p->p_rtime as it may have been
    460 	 * munched in mi_switch() after the time got set.
    461 	 */
    462 	proclist_lock_read();
    463 	s = splsched();
    464 #ifdef __HAVE_TIMECOUNTER
    465 	getmicrotime(&time);
    466 #else
    467 	mono_time = time;
    468 #endif
    469 	boottime = time;
    470 	LIST_FOREACH(p, &allproc, p_list) {
    471 		KASSERT((p->p_flag & P_MARKER) == 0);
    472 		p->p_stats->p_start = time;
    473 		LIST_FOREACH(l, &p->p_lwps, l_sibling) {
    474 			if (l->l_cpu != NULL)
    475 				l->l_cpu->ci_schedstate.spc_runtime = time;
    476 		}
    477 		p->p_rtime.tv_sec = p->p_rtime.tv_usec = 0;
    478 	}
    479 	splx(s);
    480 	proclist_unlock_read();
    481 
    482 	/* Create the pageout daemon kernel thread. */
    483 	uvm_swap_init();
    484 	if (kthread_create1(uvm_pageout, NULL, NULL, "pagedaemon"))
    485 		panic("fork pagedaemon");
    486 
    487 	/* Create the filesystem syncer kernel thread. */
    488 	if (kthread_create1(sched_sync, NULL, NULL, "ioflush"))
    489 		panic("fork syncer");
    490 
    491 	/* Create the aiodone daemon kernel thread. */
    492 	if (kthread_create1(uvm_aiodone_daemon, NULL, &uvm.aiodoned_proc,
    493 	    "aiodoned"))
    494 		panic("fork aiodoned");
    495 
    496 #if defined(MULTIPROCESSOR)
    497 	/* Boot the secondary processors. */
    498 	cpu_boot_secondary_processors();
    499 #endif
    500 
    501 	/* Initialize exec structures */
    502 	exec_init(1);
    503 
    504 	/*
    505 	 * Okay, now we can let init(8) exec!  It's off to userland!
    506 	 */
    507 	start_init_exec = 1;
    508 	wakeup(&start_init_exec);
    509 
    510 	/* The scheduler is an infinite loop. */
    511 	uvm_scheduler();
    512 	/* NOTREACHED */
    513 }
    514 
    515 void
    516 setrootfstime(time_t t)
    517 {
    518 	rootfstime = t;
    519 }
    520 
    521 static void
    522 check_console(struct lwp *l)
    523 {
    524 	struct nameidata nd;
    525 	int error;
    526 
    527 	NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, "/dev/console", l);
    528 	error = namei(&nd);
    529 	if (error == 0)
    530 		vrele(nd.ni_vp);
    531 	else if (error == ENOENT)
    532 		printf("warning: no /dev/console\n");
    533 	else
    534 		printf("warning: lookup /dev/console: error %d\n", error);
    535 }
    536 
    537 /*
    538  * List of paths to try when searching for "init".
    539  */
    540 static const char *initpaths[] = {
    541 	"/sbin/init",
    542 	"/sbin/oinit",
    543 	"/sbin/init.bak",
    544 	NULL,
    545 };
    546 
    547 /*
    548  * Start the initial user process; try exec'ing each pathname in "initpaths".
    549  * The program is invoked with one argument containing the boot flags.
    550  */
    551 static void
    552 start_init(void *arg)
    553 {
    554 	struct lwp *l = arg;
    555 	struct proc *p = l->l_proc;
    556 	vaddr_t addr;
    557 	struct sys_execve_args /* {
    558 		syscallarg(const char *) path;
    559 		syscallarg(char * const *) argp;
    560 		syscallarg(char * const *) envp;
    561 	} */ args;
    562 	int options, i, error;
    563 	register_t retval[2];
    564 	char flags[4], *flagsp;
    565 	const char *path, *slash;
    566 	char *ucp, **uap, *arg0, *arg1 = NULL;
    567 	char ipath[129];
    568 	int ipx, len;
    569 
    570 	/*
    571 	 * Now in process 1.
    572 	 */
    573 	strncpy(p->p_comm, "init", MAXCOMLEN);
    574 
    575 	/*
    576 	 * Wait for main() to tell us that it's safe to exec.
    577 	 */
    578 	while (start_init_exec == 0)
    579 		(void) tsleep(&start_init_exec, PWAIT, "initexec", 0);
    580 
    581 	/*
    582 	 * This is not the right way to do this.  We really should
    583 	 * hand-craft a descriptor onto /dev/console to hand to init,
    584 	 * but that's a _lot_ more work, and the benefit from this easy
    585 	 * hack makes up for the "good is the enemy of the best" effect.
    586 	 */
    587 	check_console(l);
    588 
    589 	/*
    590 	 * Need just enough stack to hold the faked-up "execve()" arguments.
    591 	 */
    592 	addr = (vaddr_t)STACK_ALLOC(USRSTACK, PAGE_SIZE);
    593 	if (uvm_map(&p->p_vmspace->vm_map, &addr, PAGE_SIZE,
    594                     NULL, UVM_UNKNOWN_OFFSET, 0,
    595                     UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_COPY,
    596 		    UVM_ADV_NORMAL,
    597                     UVM_FLAG_FIXED|UVM_FLAG_OVERLAY|UVM_FLAG_COPYONW)) != 0)
    598 		panic("init: couldn't allocate argument space");
    599 	p->p_vmspace->vm_maxsaddr = (caddr_t)STACK_MAX(addr, PAGE_SIZE);
    600 
    601 	ipx = 0;
    602 	while (1) {
    603 		if (boothowto & RB_ASKNAME) {
    604 			printf("init path");
    605 			if (initpaths[ipx])
    606 				printf(" (default %s)", initpaths[ipx]);
    607 			printf(": ");
    608 			len = cngetsn(ipath, sizeof(ipath)-1);
    609 			if (len == 0) {
    610 				if (initpaths[ipx])
    611 					path = initpaths[ipx++];
    612 				else
    613 					continue;
    614 			} else {
    615 				ipath[len] = '\0';
    616 				path = ipath;
    617 			}
    618 		} else {
    619 			if ((path = initpaths[ipx++]) == NULL)
    620 				break;
    621 		}
    622 
    623 		ucp = (char *)USRSTACK;
    624 
    625 		/*
    626 		 * Construct the boot flag argument.
    627 		 */
    628 		flagsp = flags;
    629 		*flagsp++ = '-';
    630 		options = 0;
    631 
    632 		if (boothowto & RB_SINGLE) {
    633 			*flagsp++ = 's';
    634 			options = 1;
    635 		}
    636 #ifdef notyet
    637 		if (boothowto & RB_FASTBOOT) {
    638 			*flagsp++ = 'f';
    639 			options = 1;
    640 		}
    641 #endif
    642 
    643 		/*
    644 		 * Move out the flags (arg 1), if necessary.
    645 		 */
    646 		if (options != 0) {
    647 			*flagsp++ = '\0';
    648 			i = flagsp - flags;
    649 #ifdef DEBUG
    650 			printf("init: copying out flags `%s' %d\n", flags, i);
    651 #endif
    652 			arg1 = STACK_ALLOC(ucp, i);
    653 			ucp = STACK_MAX(arg1, i);
    654 			(void)copyout((caddr_t)flags, arg1, i);
    655 		}
    656 
    657 		/*
    658 		 * Move out the file name (also arg 0).
    659 		 */
    660 		i = strlen(path) + 1;
    661 #ifdef DEBUG
    662 		printf("init: copying out path `%s' %d\n", path, i);
    663 #else
    664 		if (boothowto & RB_ASKNAME || path != initpaths[0])
    665 			printf("init: trying %s\n", path);
    666 #endif
    667 		arg0 = STACK_ALLOC(ucp, i);
    668 		ucp = STACK_MAX(arg0, i);
    669 		(void)copyout(path, arg0, i);
    670 
    671 		/*
    672 		 * Move out the arg pointers.
    673 		 */
    674 		ucp = (caddr_t)STACK_ALIGN(ucp, ALIGNBYTES);
    675 		uap = (char **)STACK_ALLOC(ucp, sizeof(char *) * 3);
    676 		SCARG(&args, path) = arg0;
    677 		SCARG(&args, argp) = uap;
    678 		SCARG(&args, envp) = NULL;
    679 		slash = strrchr(path, '/');
    680 		if (slash)
    681 			(void)suword((caddr_t)uap++,
    682 			    (long)arg0 + (slash + 1 - path));
    683 		else
    684 			(void)suword((caddr_t)uap++, (long)arg0);
    685 		if (options != 0)
    686 			(void)suword((caddr_t)uap++, (long)arg1);
    687 		(void)suword((caddr_t)uap++, 0);	/* terminator */
    688 
    689 		/*
    690 		 * Now try to exec the program.  If can't for any reason
    691 		 * other than it doesn't exist, complain.
    692 		 */
    693 		error = sys_execve(l, &args, retval);
    694 		if (error == 0 || error == EJUSTRETURN) {
    695 			KERNEL_PROC_UNLOCK(l);
    696 			return;
    697 		}
    698 		printf("exec %s: error %d\n", path, error);
    699 	}
    700 	printf("init: not found\n");
    701 	panic("no init");
    702 }
    703