xref: /dflybsd-src/sys/kern/init_main.c (revision c0d274d062fd959993bf623f25f7cb6a8a676c4e)
1 /*
2  * Copyright (c) 1995 Terrence R. Lambert
3  * All rights reserved.
4  *
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	8.9 (Berkeley) 1/21/94
42  * $FreeBSD: src/sys/kern/init_main.c,v 1.134.2.8 2003/06/06 20:21:32 tegge Exp $
43  * $DragonFly: src/sys/kern/init_main.c,v 1.87 2008/06/07 11:37:23 mneumann Exp $
44  */
45 
46 #include "opt_init_path.h"
47 
48 #include <sys/param.h>
49 #include <sys/file.h>
50 #include <sys/filedesc.h>
51 #include <sys/kernel.h>
52 #include <sys/mount.h>
53 #include <sys/sysctl.h>
54 #include <sys/proc.h>
55 #include <sys/resourcevar.h>
56 #include <sys/signalvar.h>
57 #include <sys/systm.h>
58 #include <sys/vnode.h>
59 #include <sys/sysent.h>
60 #include <sys/reboot.h>
61 #include <sys/sysproto.h>
62 #include <sys/vmmeter.h>
63 #include <sys/unistd.h>
64 #include <sys/malloc.h>
65 #include <sys/machintr.h>
66 
67 #include <sys/refcount.h>
68 #include <sys/file2.h>
69 #include <sys/thread2.h>
70 #include <sys/sysref2.h>
71 #include <sys/spinlock2.h>
72 #include <sys/mplock2.h>
73 
74 #include <machine/cpu.h>
75 
76 #include <vm/vm.h>
77 #include <vm/vm_param.h>
78 #include <sys/lock.h>
79 #include <vm/pmap.h>
80 #include <vm/vm_map.h>
81 #include <vm/vm_extern.h>
82 #include <sys/user.h>
83 #include <sys/copyright.h>
84 
85 int vfs_mountroot_devfs(void);
86 
87 /* Components of the first process -- never freed. */
88 static struct session session0;
89 static struct pgrp pgrp0;
90 static struct sigacts sigacts0;
91 static struct filedesc filedesc0;
92 static struct plimit limit0;
93 static struct vmspace vmspace0;
94 struct proc *initproc;
95 struct proc proc0;
96 struct lwp lwp0;
97 struct thread thread0;
98 
99 int cmask = CMASK;
100 u_int cpu_mi_feature;
101 cpumask_t usched_global_cpumask;
102 extern	struct user *proc0paddr;
103 extern int fallback_elf_brand;
104 
105 int	boothowto = 0;		/* initialized so that it can be patched */
106 SYSCTL_INT(_debug, OID_AUTO, boothowto, CTLFLAG_RD, &boothowto, 0,
107     "Reboot flags, from console subsystem");
108 SYSCTL_ULONG(_kern, OID_AUTO, usched_global_cpumask, CTLFLAG_RW,
109     &usched_global_cpumask, 0, "global user scheduler cpumask");
110 
111 /*
112  * This ensures that there is at least one entry so that the sysinit_set
113  * symbol is not undefined.  A subsystem ID of SI_SPECIAL_DUMMY is never
114  * executed.
115  */
116 SYSINIT(placeholder, SI_SPECIAL_DUMMY, SI_ORDER_ANY, NULL, NULL)
117 
118 /*
119  * The sysinit table itself.  Items are checked off as the are run.
120  * If we want to register new sysinit types, add them to newsysinit.
121  */
122 SET_DECLARE(sysinit_set, struct sysinit);
123 struct sysinit **sysinit, **sysinit_end;
124 struct sysinit **newsysinit, **newsysinit_end;
125 
126 
127 /*
128  * Merge a new sysinit set into the current set, reallocating it if
129  * necessary.  This can only be called after malloc is running.
130  */
131 void
132 sysinit_add(struct sysinit **set, struct sysinit **set_end)
133 {
134 	struct sysinit **newset;
135 	struct sysinit **sipp;
136 	struct sysinit **xipp;
137 	int count;
138 
139 	count = set_end - set;
140 	if (newsysinit)
141 		count += newsysinit_end - newsysinit;
142 	else
143 		count += sysinit_end - sysinit;
144 	newset = kmalloc(count * sizeof(*sipp), M_TEMP, M_WAITOK);
145 	xipp = newset;
146 	if (newsysinit) {
147 		for (sipp = newsysinit; sipp < newsysinit_end; sipp++)
148 			*xipp++ = *sipp;
149 	} else {
150 		for (sipp = sysinit; sipp < sysinit_end; sipp++)
151 			*xipp++ = *sipp;
152 	}
153 	for (sipp = set; sipp < set_end; sipp++)
154 		*xipp++ = *sipp;
155 	if (newsysinit)
156 		kfree(newsysinit, M_TEMP);
157 	newsysinit = newset;
158 	newsysinit_end = newset + count;
159 }
160 
161 /*
162  * Callbacks from machine-dependant startup code (e.g. init386) to set
163  * up low level entities related to cpu #0's globaldata.
164  *
165  * Called from very low level boot code.
166  */
167 void
168 mi_proc0init(struct globaldata *gd, struct user *proc0paddr)
169 {
170 	lwkt_init_thread(&thread0, proc0paddr, LWKT_THREAD_STACK, 0, gd);
171 	lwkt_set_comm(&thread0, "thread0");
172 	RB_INIT(&proc0.p_lwp_tree);
173 	spin_init(&proc0.p_spin);
174 	lwkt_token_init(&proc0.p_token, "iproc");
175 	proc0.p_lasttid = 0;	/* +1 = next TID */
176 	lwp_rb_tree_RB_INSERT(&proc0.p_lwp_tree, &lwp0);
177 	lwp0.lwp_thread = &thread0;
178 	lwp0.lwp_proc = &proc0;
179 	proc0.p_usched = usched_init();
180 	lwp0.lwp_cpumask = (cpumask_t)-1;
181 	varsymset_init(&proc0.p_varsymset, NULL);
182 	thread0.td_flags |= TDF_RUNNING;
183 	thread0.td_proc = &proc0;
184 	thread0.td_lwp = &lwp0;
185 	thread0.td_switch = cpu_lwkt_switch;
186 	lwkt_schedule_self(curthread);
187 }
188 
189 /*
190  * System startup; initialize the world, create process 0, mount root
191  * filesystem, and fork to create init and pagedaemon.  Most of the
192  * hard work is done in the lower-level initialization routines including
193  * startup(), which does memory initialization and autoconfiguration.
194  *
195  * This allows simple addition of new kernel subsystems that require
196  * boot time initialization.  It also allows substitution of subsystem
197  * (for instance, a scheduler, kernel profiler, or VM system) by object
198  * module.  Finally, it allows for optional "kernel threads".
199  */
200 void
201 mi_startup(void)
202 {
203 	struct sysinit *sip;		/* system initialization*/
204 	struct sysinit **sipp;		/* system initialization*/
205 	struct sysinit **xipp;		/* interior loop of sort*/
206 	struct sysinit *save;		/* bubble*/
207 
208 	if (sysinit == NULL) {
209 		sysinit = SET_BEGIN(sysinit_set);
210 #if defined(__amd64__) && defined(_KERNEL_VIRTUAL)
211 		/*
212 		 * XXX For whatever reason, on 64-bit vkernels
213 		 * the value of sysinit obtained from the
214 		 * linker set is wrong.
215 		 */
216 		if ((long)sysinit % 8 != 0) {
217 			kprintf("Fixing sysinit value...\n");
218 			sysinit = (long)sysinit + 4;
219 		}
220 #endif
221 		sysinit_end = SET_LIMIT(sysinit_set);
222 	}
223 #if defined(__amd64__) && defined(_KERNEL_VIRTUAL)
224 	KKASSERT((long)sysinit % 8 == 0);
225 #endif
226 
227 restart:
228 	/*
229 	 * Perform a bubble sort of the system initialization objects by
230 	 * their subsystem (primary key) and order (secondary key).
231 	 */
232 	for (sipp = sysinit; sipp < sysinit_end; sipp++) {
233 		for (xipp = sipp + 1; xipp < sysinit_end; xipp++) {
234 			if ((*sipp)->subsystem < (*xipp)->subsystem ||
235 			     ((*sipp)->subsystem == (*xipp)->subsystem &&
236 			      (*sipp)->order <= (*xipp)->order))
237 				continue;	/* skip*/
238 			save = *sipp;
239 			*sipp = *xipp;
240 			*xipp = save;
241 		}
242 	}
243 
244 	/*
245 	 * Traverse the (now) ordered list of system initialization tasks.
246 	 * Perform each task, and continue on to the next task.
247 	 *
248 	 * The last item on the list is expected to be the scheduler,
249 	 * which will not return.
250 	 */
251 	for (sipp = sysinit; sipp < sysinit_end; sipp++) {
252 		sip = *sipp;
253 		if (sip->subsystem == SI_SPECIAL_DUMMY)
254 			continue;	/* skip dummy task(s)*/
255 
256 		if (sip->subsystem == SI_SPECIAL_DONE)
257 			continue;
258 
259 		/* Call function */
260 		(*(sip->func))(sip->udata);
261 
262 		/* Check off the one we're just done */
263 		sip->subsystem = SI_SPECIAL_DONE;
264 
265 		/* Check if we've installed more sysinit items via KLD */
266 		if (newsysinit != NULL) {
267 			if (sysinit != SET_BEGIN(sysinit_set))
268 				kfree(sysinit, M_TEMP);
269 			sysinit = newsysinit;
270 			sysinit_end = newsysinit_end;
271 			newsysinit = NULL;
272 			newsysinit_end = NULL;
273 			goto restart;
274 		}
275 	}
276 
277 	panic("Shouldn't get here!");
278 	/* NOTREACHED*/
279 }
280 
281 
282 /*
283  ***************************************************************************
284  ****
285  **** The following SYSINIT's belong elsewhere, but have not yet
286  **** been moved.
287  ****
288  ***************************************************************************
289  */
290 static void
291 print_caddr_t(void *data __unused)
292 {
293 	kprintf("%s", (char *)data);
294 }
295 SYSINIT(announce, SI_BOOT1_COPYRIGHT, SI_ORDER_FIRST, print_caddr_t, copyright)
296 
297 /*
298  * Leave the critical section that protected us from spurious interrupts
299  * so device probes work.
300  */
301 static void
302 leavecrit(void *dummy __unused)
303 {
304 	MachIntrABI.stabilize();
305 	cpu_enable_intr();
306 	MachIntrABI.cleanup();
307 	crit_exit();
308 	KKASSERT(!IN_CRITICAL_SECT(curthread));
309 
310 	if (bootverbose)
311 		kprintf("Leaving critical section, allowing interrupts\n");
312 }
313 SYSINIT(leavecrit, SI_BOOT2_LEAVE_CRIT, SI_ORDER_ANY, leavecrit, NULL)
314 
315 /*
316  * This is called after the threading system is up and running,
317  * including the softclock, clock interrupts, and SMP.
318  */
319 static void
320 tsleepworks(void *dummy __unused)
321 {
322 	tsleep_now_works = 1;
323 }
324 SYSINIT(tsleepworks, SI_BOOT2_FINISH_SMP, SI_ORDER_SECOND, tsleepworks, NULL)
325 
326 /*
327  * This is called after devices have configured.  Tell the kernel we are
328  * no longer in cold boot.
329  */
330 static void
331 endofcoldboot(void *dummy __unused)
332 {
333 	cold = 0;
334 }
335 SYSINIT(endofcoldboot, SI_SUB_ISWARM, SI_ORDER_ANY, endofcoldboot, NULL)
336 
337 /*
338  ***************************************************************************
339  ****
340  **** The two following SYSINT's are proc0 specific glue code.  I am not
341  **** convinced that they can not be safely combined, but their order of
342  **** operation has been maintained as the same as the original init_main.c
343  **** for right now.
344  ****
345  **** These probably belong in init_proc.c or kern_proc.c, since they
346  **** deal with proc0 (the fork template process).
347  ****
348  ***************************************************************************
349  */
350 /* ARGSUSED*/
351 static void
352 proc0_init(void *dummy __unused)
353 {
354 	struct proc *p;
355 	struct lwp *lp;
356 
357 	p = &proc0;
358 	lp = &lwp0;
359 
360 	/*
361 	 * Initialize process and pgrp structures.
362 	 */
363 	procinit();
364 
365 	/*
366 	 * additional VM structures
367 	 */
368 	vm_init2();
369 
370 	/*
371 	 * Create process 0 (the swapper).
372 	 */
373 	LIST_INSERT_HEAD(&allproc, p, p_list);
374 	LIST_INSERT_HEAD(PGRPHASH(0), &pgrp0, pg_hash);
375 	LIST_INIT(&pgrp0.pg_members);
376 	lwkt_token_init(&pgrp0.pg_token, "pgrp0");
377 	refcount_init(&pgrp0.pg_refs, 1);
378 	lockinit(&pgrp0.pg_lock, "pgwt0", 0, 0);
379 	LIST_INSERT_HEAD(&pgrp0.pg_members, p, p_pglist);
380 
381 	pgrp0.pg_session = &session0;
382 	session0.s_count = 1;
383 	session0.s_leader = p;
384 
385 	pgref(&pgrp0);
386 	p->p_pgrp = &pgrp0;
387 
388 	p->p_sysent = &aout_sysvec;
389 
390 	p->p_flag = P_SYSTEM;
391 	p->p_stat = SACTIVE;
392 	lp->lwp_stat = LSRUN;
393 	p->p_nice = NZERO;
394 	p->p_rtprio.type = RTP_PRIO_NORMAL;
395 	p->p_rtprio.prio = 0;
396 	lp->lwp_rtprio = p->p_rtprio;
397 
398 	p->p_peers = 0;
399 	p->p_leader = p;
400 
401 	bcopy("swapper", p->p_comm, sizeof ("swapper"));
402 	bcopy("swapper", thread0.td_comm, sizeof ("swapper"));
403 
404 	/* Create credentials. */
405 	p->p_ucred = crget();
406 	p->p_ucred->cr_ruidinfo = uifind(0);
407 	p->p_ucred->cr_ngroups = 1;	/* group 0 */
408 	p->p_ucred->cr_uidinfo = uifind(0);
409 	thread0.td_ucred = crhold(p->p_ucred);	/* bootstrap fork1() */
410 
411 	/* Don't jail it */
412 	p->p_ucred->cr_prison = NULL;
413 
414 	/* Create sigacts. */
415 	p->p_sigacts = &sigacts0;
416 	refcount_init(&p->p_sigacts->ps_refcnt, 1);
417 
418 	/* Initialize signal state for process 0. */
419 	siginit(p);
420 
421 	/* Create the file descriptor table. */
422 	fdinit_bootstrap(p, &filedesc0, cmask);
423 
424 	/* Create the limits structures. */
425 	plimit_init0(&limit0);
426 	p->p_limit = &limit0;
427 
428 	/* Allocate a prototype map so we have something to fork. */
429 	pmap_pinit0(vmspace_pmap(&vmspace0));
430 	p->p_vmspace = &vmspace0;
431 	lp->lwp_vmspace = p->p_vmspace;
432 	sysref_init(&vmspace0.vm_sysref, &vmspace_sysref_class);
433 	vm_map_init(&vmspace0.vm_map,
434 		    round_page(VM_MIN_USER_ADDRESS),
435 		    trunc_page(VM_MAX_USER_ADDRESS),
436 		    vmspace_pmap(&vmspace0));
437 	sysref_activate(&vmspace0.vm_sysref);
438 
439 	kqueue_init(&lwp0.lwp_kqueue, &filedesc0);
440 
441 	/*
442 	 * Charge root for one process.
443 	 */
444 	(void)chgproccnt(p->p_ucred->cr_uidinfo, 1, 0);
445 	vm_init_limits(p);
446 }
447 SYSINIT(p0init, SI_BOOT2_PROC0, SI_ORDER_FIRST, proc0_init, NULL)
448 
449 static int proc0_post_callback(struct proc *p, void *data __unused);
450 
451 /* ARGSUSED*/
452 static void
453 proc0_post(void *dummy __unused)
454 {
455 	struct timespec ts;
456 
457 	/*
458 	 * Now we can look at the time, having had a chance to verify the
459 	 * time from the file system.  Pretend that proc0 started now.
460 	 */
461 	allproc_scan(proc0_post_callback, NULL);
462 
463 	/*
464 	 * Give the ``random'' number generator a thump.
465 	 * XXX: Does read_random() contain enough bits to be used here ?
466 	 */
467 	nanotime(&ts);
468 	skrandom(ts.tv_sec ^ ts.tv_nsec);
469 }
470 
471 static int
472 proc0_post_callback(struct proc *p, void *data __unused)
473 {
474 	microtime(&p->p_start);
475 	return(0);
476 }
477 
478 SYSINIT(p0post, SI_SUB_PROC0_POST, SI_ORDER_FIRST, proc0_post, NULL)
479 
480 /*
481  ***************************************************************************
482  ****
483  **** The following SYSINIT's and glue code should be moved to the
484  **** respective files on a per subsystem basis.
485  ****
486  ***************************************************************************
487  */
488 
489 
490 /*
491  ***************************************************************************
492  ****
493  **** The following code probably belongs in another file, like
494  **** kern/init_init.c.
495  ****
496  ***************************************************************************
497  */
498 
499 /*
500  * List of paths to try when searching for "init".
501  */
502 static char init_path[MAXPATHLEN] =
503 #ifdef	INIT_PATH
504     __XSTRING(INIT_PATH);
505 #else
506     "/sbin/init:/sbin/oinit:/sbin/init.bak";
507 #endif
508 SYSCTL_STRING(_kern, OID_AUTO, init_path, CTLFLAG_RD, init_path, 0, "");
509 
510 /*
511  * Start the initial user process; try exec'ing each pathname in init_path.
512  * The program is invoked with one argument containing the boot flags.
513  */
514 static void
515 start_init(void *dummy, struct trapframe *frame)
516 {
517 	vm_offset_t addr;
518 	struct execve_args args;
519 	int options, error;
520 	char *var, *path, *next, *s;
521 	char *ucp, **uap, *arg0, *arg1;
522 	struct proc *p;
523 	struct lwp *lp;
524 	struct mount *mp;
525 	struct vnode *vp;
526 	char *env;
527 
528         /*
529 	 * This is passed in by the bootloader
530          */
531 	env = kgetenv("kernelname");
532 	if (env != NULL)
533 		strlcpy(kernelname, env, sizeof(kernelname));
534 
535 	/*
536 	 * The MP lock is not held on entry.  We release it before
537 	 * returning to userland.
538 	 */
539 	get_mplock();
540 	p = curproc;
541 
542 	lp = ONLY_LWP_IN_PROC(p);
543 
544 	/* Get the vnode for '/'.  Set p->p_fd->fd_cdir to reference it. */
545 	mp = mountlist_boot_getfirst();
546 	if (VFS_ROOT(mp, &vp))
547 		panic("cannot find root vnode");
548 	if (mp->mnt_ncmountpt.ncp == NULL) {
549 		cache_allocroot(&mp->mnt_ncmountpt, mp, vp);
550 		cache_unlock(&mp->mnt_ncmountpt);	/* leave ref intact */
551 	}
552 	p->p_fd->fd_cdir = vp;
553 	vref(p->p_fd->fd_cdir);
554 	p->p_fd->fd_rdir = vp;
555 	vref(p->p_fd->fd_rdir);
556 	vfs_cache_setroot(vp, cache_hold(&mp->mnt_ncmountpt));
557 	vn_unlock(vp);			/* leave ref intact */
558 	cache_copy(&mp->mnt_ncmountpt, &p->p_fd->fd_ncdir);
559 	cache_copy(&mp->mnt_ncmountpt, &p->p_fd->fd_nrdir);
560 
561 	kprintf("Mounting devfs\n");
562 	vfs_mountroot_devfs();
563 
564 	/*
565 	 * Need just enough stack to hold the faked-up "execve()" arguments.
566 	 */
567 	addr = trunc_page(USRSTACK - PAGE_SIZE);
568 	error = vm_map_find(&p->p_vmspace->vm_map, NULL, 0, &addr,
569 			    PAGE_SIZE, PAGE_SIZE,
570 			    FALSE, VM_MAPTYPE_NORMAL,
571 			    VM_PROT_ALL, VM_PROT_ALL,
572 			    0);
573 	if (error)
574 		panic("init: couldn't allocate argument space");
575 	p->p_vmspace->vm_maxsaddr = (caddr_t)addr;
576 	p->p_vmspace->vm_ssize = 1;
577 
578 	if ((var = kgetenv("init_path")) != NULL) {
579 		strncpy(init_path, var, sizeof init_path);
580 		init_path[sizeof init_path - 1] = 0;
581 	}
582 	if ((var = kgetenv("kern.fallback_elf_brand")) != NULL)
583 		fallback_elf_brand = strtol(var, NULL, 0);
584 
585 	for (path = init_path; *path != '\0'; path = next) {
586 		while (*path == ':')
587 			path++;
588 		if (*path == '\0')
589 			break;
590 		for (next = path; *next != '\0' && *next != ':'; next++)
591 			/* nothing */ ;
592 		if (bootverbose)
593 			kprintf("start_init: trying %.*s\n", (int)(next - path),
594 			    path);
595 
596 		/*
597 		 * Move out the boot flag argument.
598 		 */
599 		options = 0;
600 		ucp = (char *)USRSTACK;
601 		(void)subyte(--ucp, 0);		/* trailing zero */
602 		if (boothowto & RB_SINGLE) {
603 			(void)subyte(--ucp, 's');
604 			options = 1;
605 		}
606 #ifdef notyet
607                 if (boothowto & RB_FASTBOOT) {
608 			(void)subyte(--ucp, 'f');
609 			options = 1;
610 		}
611 #endif
612 
613 #ifdef BOOTCDROM
614 		(void)subyte(--ucp, 'C');
615 		options = 1;
616 #endif
617 		if (options == 0)
618 			(void)subyte(--ucp, '-');
619 		(void)subyte(--ucp, '-');		/* leading hyphen */
620 		arg1 = ucp;
621 
622 		/*
623 		 * Move out the file name (also arg 0).
624 		 */
625 		(void)subyte(--ucp, 0);
626 		for (s = next - 1; s >= path; s--)
627 			(void)subyte(--ucp, *s);
628 		arg0 = ucp;
629 
630 		/*
631 		 * Move out the arg pointers.
632 		 */
633 		uap = (char **)((intptr_t)ucp & ~(sizeof(intptr_t)-1));
634 		(void)suword((caddr_t)--uap, (long)0);	/* terminator */
635 		(void)suword((caddr_t)--uap, (long)(intptr_t)arg1);
636 		(void)suword((caddr_t)--uap, (long)(intptr_t)arg0);
637 
638 		/*
639 		 * Point at the arguments.
640 		 */
641 		args.fname = arg0;
642 		args.argv = uap;
643 		args.envv = NULL;
644 
645 		/*
646 		 * Now try to exec the program.  If can't for any reason
647 		 * other than it doesn't exist, complain.
648 		 *
649 		 * Otherwise, return via fork_trampoline() all the way
650 		 * to user mode as init!
651 		 *
652 		 * WARNING!  We may have been moved to another cpu after
653 		 * acquiring the current user process designation.  The
654 		 * MP lock will migrate with us though so we still have to
655 		 * release it.
656 		 */
657 		if ((error = sys_execve(&args)) == 0) {
658 			rel_mplock();
659 			lp->lwp_proc->p_usched->acquire_curproc(lp);
660 			return;
661 		}
662 		if (error != ENOENT)
663 			kprintf("exec %.*s: error %d\n", (int)(next - path),
664 			    path, error);
665 	}
666 	kprintf("init: not found in path %s\n", init_path);
667 	panic("no init");
668 }
669 
670 /*
671  * Like kthread_create(), but runs in it's own address space.
672  * We do this early to reserve pid 1.
673  *
674  * Note special case - do not make it runnable yet.  Other work
675  * in progress will change this more.
676  */
677 static void
678 create_init(const void *udata __unused)
679 {
680 	int error;
681 	struct lwp *lp;
682 
683 	crit_enter();
684 	error = fork1(&lwp0, RFFDG | RFPROC, &initproc);
685 	if (error)
686 		panic("cannot fork init: %d", error);
687 	initproc->p_flag |= P_SYSTEM;
688 	lp = ONLY_LWP_IN_PROC(initproc);
689 	cpu_set_fork_handler(lp, start_init, NULL);
690 	crit_exit();
691 }
692 SYSINIT(init, SI_SUB_CREATE_INIT, SI_ORDER_FIRST, create_init, NULL)
693 
694 /*
695  * Make it runnable now.
696  */
697 static void
698 kick_init(const void *udata __unused)
699 {
700 	start_forked_proc(&lwp0, initproc);
701 }
702 SYSINIT(kickinit, SI_SUB_KTHREAD_INIT, SI_ORDER_FIRST, kick_init, NULL)
703 
704 /*
705  * Machine independant globaldata initialization
706  *
707  * WARNING!  Called from early boot, 'mycpu' may not work yet.
708  */
709 void
710 mi_gdinit(struct globaldata *gd, int cpuid)
711 {
712 	TAILQ_INIT(&gd->gd_systimerq);
713 	gd->gd_sysid_alloc = cpuid;	/* prime low bits for cpu lookup */
714 	gd->gd_cpuid = cpuid;
715 	gd->gd_cpumask = CPUMASK(cpuid);
716 	lwkt_gdinit(gd);
717 	vm_map_entry_reserve_cpu_init(gd);
718 	sleep_gdinit(gd);
719 	usched_global_cpumask |= CPUMASK(cpuid);
720 }
721 
722