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init_main.c revision 1.189
      1 /*	$NetBSD: init_main.c,v 1.189 2001/03/15 06:10:55 chs 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 #include "opt_syscall_debug.h"
     50 
     51 #include "rnd.h"
     52 
     53 #include <sys/param.h>
     54 #include <sys/acct.h>
     55 #include <sys/filedesc.h>
     56 #include <sys/file.h>
     57 #include <sys/errno.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/exec.h>
     74 #include <sys/socketvar.h>
     75 #include <sys/protosw.h>
     76 #include <sys/reboot.h>
     77 #include <sys/user.h>
     78 #include <sys/sysctl.h>
     79 #ifdef SYSVSHM
     80 #include <sys/shm.h>
     81 #endif
     82 #ifdef SYSVSEM
     83 #include <sys/sem.h>
     84 #endif
     85 #ifdef SYSVMSG
     86 #include <sys/msg.h>
     87 #endif
     88 #include <sys/domain.h>
     89 #include <sys/mbuf.h>
     90 #include <sys/namei.h>
     91 #if NRND > 0
     92 #include <sys/rnd.h>
     93 #endif
     94 
     95 #include <sys/syscall.h>
     96 #include <sys/syscallargs.h>
     97 
     98 #include <ufs/ufs/quota.h>
     99 
    100 #include <miscfs/genfs/genfs.h>
    101 #include <miscfs/syncfs/syncfs.h>
    102 
    103 #include <machine/cpu.h>
    104 
    105 #include <uvm/uvm.h>
    106 
    107 #include <net/if.h>
    108 #include <net/raw_cb.h>
    109 
    110 const char copyright[] = "\
    111 Copyright (c) 1996, 1997, 1998, 1999, 2000, 2001
    112     The NetBSD Foundation, Inc.  All rights reserved.
    113 Copyright (c) 1982, 1986, 1989, 1991, 1993
    114     The Regents of the University of California.  All rights reserved.
    115 
    116 ";
    117 
    118 /* Components of the first process -- never freed. */
    119 struct	session session0;
    120 struct	pgrp pgrp0;
    121 struct	proc proc0;
    122 struct	pcred cred0;
    123 struct	filedesc0 filedesc0;
    124 struct	cwdinfo cwdi0;
    125 struct	plimit limit0;
    126 struct	vmspace vmspace0;
    127 struct	sigacts sigacts0;
    128 #ifndef curproc
    129 struct	proc *curproc = &proc0;
    130 #endif
    131 struct	proc *initproc;
    132 
    133 int	cmask = CMASK;
    134 extern	struct user *proc0paddr;
    135 
    136 struct	vnode *rootvp, *swapdev_vp;
    137 int	boothowto;
    138 int	cold = 1;			/* still working on startup */
    139 struct	timeval boottime;
    140 
    141 __volatile int start_init_exec;		/* semaphore for start_init() */
    142 
    143 static void check_console(struct proc *p);
    144 static void start_init(void *);
    145 void main(void);
    146 
    147 extern const struct emul emul_netbsd;	/* defined in kern_exec.c */
    148 
    149 /*
    150  * System startup; initialize the world, create process 0, mount root
    151  * filesystem, and fork to create init and pagedaemon.  Most of the
    152  * hard work is done in the lower-level initialization routines including
    153  * startup(), which does memory initialization and autoconfiguration.
    154  */
    155 void
    156 main(void)
    157 {
    158 	struct proc *p;
    159 	struct pdevinit *pdev;
    160 	int i, s, error;
    161 	rlim_t lim;
    162 	extern struct pdevinit pdevinit[];
    163 	extern void schedcpu(void *);
    164 	extern void disk_init(void);
    165 #if defined(NFSSERVER) || defined(NFS)
    166 	extern void nfs_init(void);
    167 #endif
    168 #ifdef NVNODE_IMPLICIT
    169 	int usevnodes;
    170 #endif
    171 
    172 	/*
    173 	 * Initialize the current process pointer (curproc) before
    174 	 * any possible traps/probes to simplify trap processing.
    175 	 */
    176 	p = &proc0;
    177 	curproc = p;
    178 	p->p_cpu = curcpu();
    179 	/*
    180 	 * Attempt to find console and initialize
    181 	 * in case of early panic or other messages.
    182 	 */
    183 	consinit();
    184 	printf("%s", copyright);
    185 
    186 	KERNEL_LOCK_INIT();
    187 
    188 	uvm_init();
    189 
    190 	/* Do machine-dependent initialization. */
    191 	cpu_startup();
    192 
    193 	/* Initialize callouts. */
    194 	callout_startup();
    195 
    196 	/*
    197 	 * Initialize mbuf's.  Do this now because we might attempt to
    198 	 * allocate mbufs or mbuf clusters during autoconfiguration.
    199 	 */
    200 	mbinit();
    201 
    202 	/* Initialize sockets. */
    203 	soinit();
    204 
    205 	/*
    206 	 * The following 3 things must be done before autoconfiguration.
    207 	 */
    208 	disk_init();		/* initialize disk list */
    209 	tty_init();		/* initialize tty list */
    210 #if NRND > 0
    211 	rnd_init();		/* initialize RNG */
    212 #endif
    213 
    214 	/* Initialize the sysctl subsystem. */
    215 	sysctl_init();
    216 
    217 	/*
    218 	 * Initialize process and pgrp structures.
    219 	 */
    220 	procinit();
    221 
    222 	/*
    223 	 * Create process 0 (the swapper).
    224 	 */
    225 	s = proclist_lock_write();
    226 	LIST_INSERT_HEAD(&allproc, p, p_list);
    227 	LIST_INSERT_HEAD(PIDHASH(p->p_pid), p, p_hash);
    228 	proclist_unlock_write(s);
    229 
    230 	p->p_pgrp = &pgrp0;
    231 	LIST_INSERT_HEAD(PGRPHASH(0), &pgrp0, pg_hash);
    232 	LIST_INIT(&pgrp0.pg_members);
    233 	LIST_INSERT_HEAD(&pgrp0.pg_members, p, p_pglist);
    234 
    235 	pgrp0.pg_session = &session0;
    236 	session0.s_count = 1;
    237 	session0.s_sid = p->p_pid;
    238 	session0.s_leader = p;
    239 
    240 	/*
    241 	 * Set P_NOCLDWAIT so that kernel threads are reparented to
    242 	 * init(8) when they exit.  init(8) can easily wait them out
    243 	 * for us.
    244 	 */
    245 	p->p_flag = P_INMEM | P_SYSTEM | P_NOCLDWAIT;
    246 	p->p_stat = SONPROC;
    247 	p->p_nice = NZERO;
    248 	p->p_emul = &emul_netbsd;
    249 #ifdef __HAVE_SYSCALL_INTERN
    250 	(*p->p_emul->e_syscall_intern)(p);
    251 #endif
    252 	strncpy(p->p_comm, "swapper", MAXCOMLEN);
    253 
    254 	callout_init(&p->p_realit_ch);
    255 	callout_init(&p->p_tsleep_ch);
    256 
    257 	/* Create credentials. */
    258 	cred0.p_refcnt = 1;
    259 	p->p_cred = &cred0;
    260 	p->p_ucred = crget();
    261 	p->p_ucred->cr_ngroups = 1;	/* group 0 */
    262 
    263 	/* Create the file descriptor table. */
    264 	finit();
    265 	p->p_fd = &filedesc0.fd_fd;
    266 	fdinit1(&filedesc0);
    267 
    268 	/* Create the CWD info. */
    269 	p->p_cwdi = &cwdi0;
    270 	cwdi0.cwdi_cmask = cmask;
    271 	cwdi0.cwdi_refcnt = 1;
    272 
    273 	/* Create the limits structures. */
    274 	p->p_limit = &limit0;
    275 	for (i = 0; i < sizeof(p->p_rlimit)/sizeof(p->p_rlimit[0]); i++)
    276 		limit0.pl_rlimit[i].rlim_cur =
    277 		    limit0.pl_rlimit[i].rlim_max = RLIM_INFINITY;
    278 
    279 	limit0.pl_rlimit[RLIMIT_NOFILE].rlim_max = maxfiles;
    280 	limit0.pl_rlimit[RLIMIT_NOFILE].rlim_cur =
    281 	    maxfiles < NOFILE ? maxfiles : NOFILE;
    282 
    283 	limit0.pl_rlimit[RLIMIT_NPROC].rlim_max = maxproc;
    284 	limit0.pl_rlimit[RLIMIT_NPROC].rlim_cur =
    285 	    maxproc < MAXUPRC ? maxproc : MAXUPRC;
    286 
    287 	lim = ptoa(uvmexp.free);
    288 	limit0.pl_rlimit[RLIMIT_RSS].rlim_max = lim;
    289 	limit0.pl_rlimit[RLIMIT_MEMLOCK].rlim_max = lim;
    290 	limit0.pl_rlimit[RLIMIT_MEMLOCK].rlim_cur = lim / 3;
    291 	limit0.pl_corename = defcorename;
    292 	limit0.p_refcnt = 1;
    293 
    294 	/*
    295 	 * Initialize proc0's vmspace, which uses the kernel pmap.
    296 	 * All kernel processes (which never have user space mappings)
    297 	 * share proc0's vmspace, and thus, the kernel pmap.
    298 	 */
    299 	uvmspace_init(&vmspace0, pmap_kernel(), round_page(VM_MIN_ADDRESS),
    300 	    trunc_page(VM_MAX_ADDRESS), TRUE);
    301 	p->p_vmspace = &vmspace0;
    302 
    303 	p->p_addr = proc0paddr;				/* XXX */
    304 
    305 	/*
    306 	 * We continue to place resource usage info in the
    307 	 * user struct so they're pageable.
    308 	 */
    309 	p->p_stats = &p->p_addr->u_stats;
    310 
    311 	/*
    312 	 * Charge root for one process.
    313 	 */
    314 	(void)chgproccnt(0, 1);
    315 
    316 	rqinit();
    317 
    318 	/* Configure virtual memory system, set vm rlimits. */
    319 	uvm_init_limits(p);
    320 
    321 	/* Initialize the file systems. */
    322 #if defined(NFSSERVER) || defined(NFS)
    323 	nfs_init();			/* initialize server/shared data */
    324 #endif
    325 	vfsinit();
    326 
    327 	/* Configure the system hardware.  This will enable interrupts. */
    328 	configure();
    329 
    330 	ubc_init();		/* must be after autoconfig */
    331 
    332 	/* Lock the kernel on behalf of proc0. */
    333 	KERNEL_PROC_LOCK(p);
    334 
    335 #ifdef SYSVSHM
    336 	/* Initialize System V style shared memory. */
    337 	shminit();
    338 #endif
    339 
    340 #ifdef SYSVSEM
    341 	/* Initialize System V style semaphores. */
    342 	seminit();
    343 #endif
    344 
    345 #ifdef SYSVMSG
    346 	/* Initialize System V style message queues. */
    347 	msginit();
    348 #endif
    349 
    350 	/* Attach pseudo-devices. */
    351 	for (pdev = pdevinit; pdev->pdev_attach != NULL; pdev++)
    352 		(*pdev->pdev_attach)(pdev->pdev_count);
    353 
    354 	/*
    355 	 * Initialize protocols.  Block reception of incoming packets
    356 	 * until everything is ready.
    357 	 */
    358 	s = splimp();
    359 	ifinit();
    360 	domaininit();
    361 	splx(s);
    362 
    363 #ifdef GPROF
    364 	/* Initialize kernel profiling. */
    365 	kmstartup();
    366 #endif
    367 
    368 	/* Initialize system accouting. */
    369 	acct_init();
    370 
    371 	/*
    372 	 * Initialize signal-related data structures, and signal state
    373 	 * for proc0.
    374 	 */
    375 	signal_init();
    376 	p->p_sigacts = &sigacts0;
    377 	siginit(p);
    378 
    379 	/* Kick off timeout driven events by calling first time. */
    380 	schedcpu(NULL);
    381 
    382 	/*
    383 	 * Create process 1 (init(8)).  We do this now, as Unix has
    384 	 * historically had init be process 1, and changing this would
    385 	 * probably upset a lot of people.
    386 	 *
    387 	 * Note that process 1 won't immediately exec init(8), but will
    388 	 * wait for us to inform it that the root file system has been
    389 	 * mounted.
    390 	 */
    391 	if (fork1(p, 0, SIGCHLD, NULL, 0, start_init, NULL, NULL, &initproc))
    392 		panic("fork init");
    393 
    394 	/*
    395 	 * Create any kernel threads who's creation was deferred because
    396 	 * initproc had not yet been created.
    397 	 */
    398 	kthread_run_deferred_queue();
    399 
    400 	/*
    401 	 * Now that device driver threads have been created, wait for
    402 	 * them to finish any deferred autoconfiguration.  Note we don't
    403 	 * need to lock this semaphore, since we haven't booted any
    404 	 * secondary processors, yet.
    405 	 */
    406 	while (config_pending)
    407 		(void) tsleep((void *)&config_pending, PWAIT, "cfpend", 0);
    408 
    409 	/*
    410 	 * Now that autoconfiguration has completed, we can determine
    411 	 * the root and dump devices.
    412 	 */
    413 	cpu_rootconf();
    414 	cpu_dumpconf();
    415 
    416 	/* Mount the root file system. */
    417 	do {
    418 		domountroothook();
    419 		if ((error = vfs_mountroot())) {
    420 			printf("cannot mount root, error = %d\n", error);
    421 			boothowto |= RB_ASKNAME;
    422 			setroot(root_device,
    423 			    (rootdev != NODEV) ? DISKPART(rootdev) : 0);
    424 		}
    425 	} while (error != 0);
    426 	mountroothook_destroy();
    427 
    428 	mountlist.cqh_first->mnt_flag |= MNT_ROOTFS;
    429 	mountlist.cqh_first->mnt_op->vfs_refcount++;
    430 
    431 	/*
    432 	 * Get the vnode for '/'.  Set filedesc0.fd_fd.fd_cdir to
    433 	 * reference it.
    434 	 */
    435 	if (VFS_ROOT(mountlist.cqh_first, &rootvnode))
    436 		panic("cannot find root vnode");
    437 	cwdi0.cwdi_cdir = rootvnode;
    438 	VREF(cwdi0.cwdi_cdir);
    439 	VOP_UNLOCK(rootvnode, 0);
    440 	cwdi0.cwdi_rdir = NULL;
    441 
    442 	/*
    443 	 * Now that root is mounted, we can fixup initproc's CWD
    444 	 * info.  All other processes are kthreads, which merely
    445 	 * share proc0's CWD info.
    446 	 */
    447 	initproc->p_cwdi->cwdi_cdir = rootvnode;
    448 	VREF(initproc->p_cwdi->cwdi_cdir);
    449 	initproc->p_cwdi->cwdi_rdir = NULL;
    450 
    451 	/*
    452 	 * Now can look at time, having had a chance to verify the time
    453 	 * from the file system.  Reset p->p_rtime as it may have been
    454 	 * munched in mi_switch() after the time got set.
    455 	 */
    456 	proclist_lock_read();
    457 	s = splsched();
    458 	for (p = LIST_FIRST(&allproc); p != NULL;
    459 	     p = LIST_NEXT(p, p_list)) {
    460 		p->p_stats->p_start = mono_time = boottime = time;
    461 		if (p->p_cpu != NULL)
    462 			p->p_cpu->ci_schedstate.spc_runtime = time;
    463 		p->p_rtime.tv_sec = p->p_rtime.tv_usec = 0;
    464 	}
    465 	splx(s);
    466 	proclist_unlock_read();
    467 
    468 	/* Create the pageout daemon kernel thread. */
    469 	uvm_swap_init();
    470 	if (kthread_create1(uvm_pageout, NULL, NULL, "pagedaemon"))
    471 		panic("fork pagedaemon");
    472 
    473 	/* Create the process reaper kernel thread. */
    474 	if (kthread_create1(reaper, NULL, NULL, "reaper"))
    475 		panic("fork reaper");
    476 
    477 	/* Create the filesystem syncer kernel thread. */
    478 	if (kthread_create1(sched_sync, NULL, NULL, "ioflush"))
    479 		panic("fork syncer");
    480 
    481 	/* Create the aiodone daemon kernel thread. */
    482 	if (kthread_create1(uvm_aiodone_daemon, NULL, NULL, "aiodoned"))
    483 		panic("fork aiodoned");
    484 
    485 #if defined(MULTIPROCESSOR)
    486 	/* Boot the secondary processors. */
    487 	cpu_boot_secondary_processors();
    488 #endif
    489 
    490 	/* Initialize exec structures */
    491 	exec_init(1);
    492 
    493 	/*
    494 	 * Okay, now we can let init(8) exec!  It's off to userland!
    495 	 */
    496 	start_init_exec = 1;
    497 	wakeup((void *)&start_init_exec);
    498 
    499 #ifdef NVNODE_IMPLICIT
    500 	/*
    501 	 * If maximum number of vnodes in namei vnode cache is not explicitly
    502 	 * defined in kernel config, adjust the number such as we use roughly
    503 	 * 0.5% of memory for vnode cache (but not less than NVNODE vnodes).
    504 	 */
    505 	usevnodes = (ptoa(physmem) / 200) / sizeof(struct vnode);
    506 	if (usevnodes > desiredvnodes)
    507 		desiredvnodes = usevnodes;
    508 #endif
    509 
    510 	/* The scheduler is an infinite loop. */
    511 	uvm_scheduler();
    512 	/* NOTREACHED */
    513 }
    514 
    515 static void
    516 check_console(struct proc *p)
    517 {
    518 	struct nameidata nd;
    519 	int error;
    520 
    521 	NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, "/dev/console", p);
    522 	error = namei(&nd);
    523 	if (error == 0)
    524 		vrele(nd.ni_vp);
    525 	else if (error == ENOENT)
    526 		printf("warning: no /dev/console\n");
    527 	else
    528 		printf("warning: lookup /dev/console: error %d\n", error);
    529 }
    530 
    531 /*
    532  * List of paths to try when searching for "init".
    533  */
    534 static const char *initpaths[] = {
    535 	"/sbin/init",
    536 	"/sbin/oinit",
    537 	"/sbin/init.bak",
    538 	NULL,
    539 };
    540 
    541 /*
    542  * Start the initial user process; try exec'ing each pathname in "initpaths".
    543  * The program is invoked with one argument containing the boot flags.
    544  */
    545 static void
    546 start_init(void *arg)
    547 {
    548 	struct proc *p = arg;
    549 	vaddr_t addr;
    550 	struct sys_execve_args /* {
    551 		syscallarg(const char *) path;
    552 		syscallarg(char * const *) argp;
    553 		syscallarg(char * const *) envp;
    554 	} */ args;
    555 	int options, i, error;
    556 	register_t retval[2];
    557 	char flags[4], *flagsp;
    558 	const char **pathp, *path, *slash;
    559 	char *ucp, **uap, *arg0, *arg1 = NULL;
    560 
    561 	/*
    562 	 * Now in process 1.
    563 	 */
    564 	strncpy(p->p_comm, "init", MAXCOMLEN);
    565 
    566 	/*
    567 	 * Wait for main() to tell us that it's safe to exec.
    568 	 */
    569 	while (start_init_exec == 0)
    570 		(void) tsleep((void *)&start_init_exec, PWAIT, "initexec", 0);
    571 
    572 	/*
    573 	 * This is not the right way to do this.  We really should
    574 	 * hand-craft a descriptor onto /dev/console to hand to init,
    575 	 * but that's a _lot_ more work, and the benefit from this easy
    576 	 * hack makes up for the "good is the enemy of the best" effect.
    577 	 */
    578 	check_console(p);
    579 
    580 	/*
    581 	 * Need just enough stack to hold the faked-up "execve()" arguments.
    582 	 */
    583 	addr = USRSTACK - PAGE_SIZE;
    584 	if (uvm_map(&p->p_vmspace->vm_map, &addr, PAGE_SIZE,
    585                     NULL, UVM_UNKNOWN_OFFSET, 0,
    586                     UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_COPY,
    587 		    UVM_ADV_NORMAL,
    588                     UVM_FLAG_FIXED|UVM_FLAG_OVERLAY|UVM_FLAG_COPYONW)) != 0)
    589 		panic("init: couldn't allocate argument space");
    590 	p->p_vmspace->vm_maxsaddr = (caddr_t)addr;
    591 
    592 	for (pathp = &initpaths[0]; (path = *pathp) != NULL; pathp++) {
    593 		ucp = (char *)(addr + PAGE_SIZE);
    594 
    595 		/*
    596 		 * Construct the boot flag argument.
    597 		 */
    598 		flagsp = flags;
    599 		*flagsp++ = '-';
    600 		options = 0;
    601 
    602 		if (boothowto & RB_SINGLE) {
    603 			*flagsp++ = 's';
    604 			options = 1;
    605 		}
    606 #ifdef notyet
    607 		if (boothowto & RB_FASTBOOT) {
    608 			*flagsp++ = 'f';
    609 			options = 1;
    610 		}
    611 #endif
    612 
    613 		/*
    614 		 * Move out the flags (arg 1), if necessary.
    615 		 */
    616 		if (options != 0) {
    617 			*flagsp++ = '\0';
    618 			i = flagsp - flags;
    619 #ifdef DEBUG
    620 			printf("init: copying out flags `%s' %d\n", flags, i);
    621 #endif
    622 			(void)copyout((caddr_t)flags, (caddr_t)(ucp -= i), i);
    623 			arg1 = ucp;
    624 		}
    625 
    626 		/*
    627 		 * Move out the file name (also arg 0).
    628 		 */
    629 		i = strlen(path) + 1;
    630 #ifdef DEBUG
    631 		printf("init: copying out path `%s' %d\n", path, i);
    632 #endif
    633 		(void)copyout((caddr_t)path, (caddr_t)(ucp -= i), i);
    634 		arg0 = ucp;
    635 
    636 		/*
    637 		 * Move out the arg pointers.
    638 		 */
    639 		uap = (char **)((long)ucp & ~ALIGNBYTES);
    640 		(void)suword((caddr_t)--uap, 0);	/* terminator */
    641 		if (options != 0)
    642 			(void)suword((caddr_t)--uap, (long)arg1);
    643 		slash = strrchr(path, '/');
    644 		if (slash)
    645 			(void)suword((caddr_t)--uap,
    646 			    (long)arg0 + (slash + 1 - path));
    647 		else
    648 			(void)suword((caddr_t)--uap, (long)arg0);
    649 
    650 		/*
    651 		 * Point at the arguments.
    652 		 */
    653 		SCARG(&args, path) = arg0;
    654 		SCARG(&args, argp) = uap;
    655 		SCARG(&args, envp) = NULL;
    656 
    657 		/*
    658 		 * Now try to exec the program.  If can't for any reason
    659 		 * other than it doesn't exist, complain.
    660 		 */
    661 		error = sys_execve(p, &args, retval);
    662 		if (error == 0 || error == EJUSTRETURN) {
    663 			KERNEL_PROC_UNLOCK(p);
    664 			return;
    665 		}
    666 		if (error != ENOENT)
    667 			printf("exec %s: error %d\n", path, error);
    668 	}
    669 	printf("init: not found\n");
    670 	panic("no init");
    671 }
    672