blob: f715b9b897538cb04dc94fa900bd8c3f5d6e26e7 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/init/main.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 *
6 * GK 2/5/95 - Changed to support mounting root fs via NFS
7 * Added initrd & change_root: Werner Almesberger & Hans Lermen, Feb '96
8 * Moan early if gcc is old, avoiding bogus kernels - Paul Gortmaker, May '96
9 * Simplified starting of init: Michael A. Griffith <grif@acm.org>
10 */
11
12#define __KERNEL_SYSCALLS__
13
14#include <linux/config.h>
15#include <linux/types.h>
16#include <linux/module.h>
17#include <linux/proc_fs.h>
18#include <linux/devfs_fs_kernel.h>
19#include <linux/kernel.h>
20#include <linux/syscalls.h>
21#include <linux/string.h>
22#include <linux/ctype.h>
23#include <linux/delay.h>
24#include <linux/utsname.h>
25#include <linux/ioport.h>
26#include <linux/init.h>
27#include <linux/smp_lock.h>
28#include <linux/initrd.h>
29#include <linux/hdreg.h>
30#include <linux/bootmem.h>
31#include <linux/tty.h>
32#include <linux/gfp.h>
33#include <linux/percpu.h>
34#include <linux/kmod.h>
35#include <linux/kernel_stat.h>
36#include <linux/security.h>
37#include <linux/workqueue.h>
38#include <linux/profile.h>
39#include <linux/rcupdate.h>
40#include <linux/moduleparam.h>
41#include <linux/kallsyms.h>
42#include <linux/writeback.h>
43#include <linux/cpu.h>
44#include <linux/cpuset.h>
45#include <linux/efi.h>
46#include <linux/unistd.h>
47#include <linux/rmap.h>
48#include <linux/mempolicy.h>
49#include <linux/key.h>
50
51#include <asm/io.h>
52#include <asm/bugs.h>
53#include <asm/setup.h>
Andi Kleena9401992005-07-28 21:15:30 -070054#include <asm/sections.h>
Arjan van de Ven37b73c82006-01-06 00:12:01 -080055#include <asm/cacheflush.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070056
Linus Torvalds1da177e2005-04-16 15:20:36 -070057#ifdef CONFIG_X86_LOCAL_APIC
58#include <asm/smp.h>
59#endif
60
61/*
Coywolf Qi Hunt69c99ac2006-01-14 13:21:11 -080062 * This is one of the first .c files built. Error out early if we have compiler
63 * trouble.
64 *
65 * Versions of gcc older than that listed below may actually compile and link
66 * okay, but the end product can have subtle run time bugs. To avoid associated
67 * bogus bug reports, we flatly refuse to compile with a gcc that is known to be
68 * too old from the very beginning.
Linus Torvalds1da177e2005-04-16 15:20:36 -070069 */
Andrew Mortonfd285bb2006-01-08 01:04:07 -080070#if (__GNUC__ < 3) || (__GNUC__ == 3 && __GNUC_MINOR__ < 2)
Linus Torvalds1da177e2005-04-16 15:20:36 -070071#error Sorry, your GCC is too old. It builds incorrect kernels.
72#endif
73
74static int init(void *);
75
76extern void init_IRQ(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070077extern void fork_init(unsigned long);
78extern void mca_init(void);
79extern void sbus_init(void);
80extern void sysctl_init(void);
81extern void signals_init(void);
82extern void buffer_init(void);
83extern void pidhash_init(void);
84extern void pidmap_init(void);
85extern void prio_tree_init(void);
86extern void radix_tree_init(void);
87extern void free_initmem(void);
88extern void populate_rootfs(void);
89extern void driver_init(void);
90extern void prepare_namespace(void);
91#ifdef CONFIG_ACPI
92extern void acpi_early_init(void);
93#else
94static inline void acpi_early_init(void) { }
95#endif
Arjan van de Ven37b73c82006-01-06 00:12:01 -080096#ifndef CONFIG_DEBUG_RODATA
97static inline void mark_rodata_ro(void) { }
98#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -070099
100#ifdef CONFIG_TC
101extern void tc_init(void);
102#endif
103
104enum system_states system_state;
105EXPORT_SYMBOL(system_state);
106
107/*
108 * Boot command-line arguments
109 */
110#define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
111#define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
112
113extern void time_init(void);
114/* Default late time init is NULL. archs can override this later. */
115void (*late_time_init)(void);
116extern void softirq_init(void);
117
118/* Untouched command line (eg. for /proc) saved by arch-specific code. */
119char saved_command_line[COMMAND_LINE_SIZE];
120
121static char *execute_command;
Olof Johanssonffdfc402005-09-06 15:17:19 -0700122static char *ramdisk_execute_command;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123
124/* Setup configured maximum number of CPUs to activate */
125static unsigned int max_cpus = NR_CPUS;
126
127/*
128 * Setup routine for controlling SMP activation
129 *
130 * Command-line option of "nosmp" or "maxcpus=0" will disable SMP
131 * activation entirely (the MPS table probe still happens, though).
132 *
133 * Command-line option of "maxcpus=<NUM>", where <NUM> is an integer
134 * greater than 0, limits the maximum number of CPUs activated in
135 * SMP mode to <NUM>.
136 */
137static int __init nosmp(char *str)
138{
139 max_cpus = 0;
140 return 1;
141}
142
143__setup("nosmp", nosmp);
144
145static int __init maxcpus(char *str)
146{
147 get_option(&str, &max_cpus);
148 return 1;
149}
150
151__setup("maxcpus=", maxcpus);
152
153static char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
154char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
155static const char *panic_later, *panic_param;
156
157extern struct obs_kernel_param __setup_start[], __setup_end[];
158
159static int __init obsolete_checksetup(char *line)
160{
161 struct obs_kernel_param *p;
162
163 p = __setup_start;
164 do {
165 int n = strlen(p->str);
166 if (!strncmp(line, p->str, n)) {
167 if (p->early) {
168 /* Already done in parse_early_param? (Needs
169 * exact match on param part) */
170 if (line[n] == '\0' || line[n] == '=')
171 return 1;
172 } else if (!p->setup_func) {
173 printk(KERN_WARNING "Parameter %s is obsolete,"
174 " ignored\n", p->str);
175 return 1;
176 } else if (p->setup_func(line + n))
177 return 1;
178 }
179 p++;
180 } while (p < __setup_end);
181 return 0;
182}
183
184/*
185 * This should be approx 2 Bo*oMips to start (note initial shift), and will
186 * still work even if initially too large, it will just take slightly longer
187 */
188unsigned long loops_per_jiffy = (1<<12);
189
190EXPORT_SYMBOL(loops_per_jiffy);
191
192static int __init debug_kernel(char *str)
193{
194 if (*str)
195 return 0;
196 console_loglevel = 10;
197 return 1;
198}
199
200static int __init quiet_kernel(char *str)
201{
202 if (*str)
203 return 0;
204 console_loglevel = 4;
205 return 1;
206}
207
208__setup("debug", debug_kernel);
209__setup("quiet", quiet_kernel);
210
211static int __init loglevel(char *str)
212{
213 get_option(&str, &console_loglevel);
214 return 1;
215}
216
217__setup("loglevel=", loglevel);
218
219/*
220 * Unknown boot options get handed to init, unless they look like
221 * failed parameters
222 */
223static int __init unknown_bootoption(char *param, char *val)
224{
225 /* Change NUL term back to "=", to make "param" the whole string. */
226 if (val) {
227 /* param=val or param="val"? */
228 if (val == param+strlen(param)+1)
229 val[-1] = '=';
230 else if (val == param+strlen(param)+2) {
231 val[-2] = '=';
232 memmove(val-1, val, strlen(val)+1);
233 val--;
234 } else
235 BUG();
236 }
237
238 /* Handle obsolete-style parameters */
239 if (obsolete_checksetup(param))
240 return 0;
241
242 /*
243 * Preemptive maintenance for "why didn't my mispelled command
244 * line work?"
245 */
246 if (strchr(param, '.') && (!val || strchr(param, '.') < val)) {
247 printk(KERN_ERR "Unknown boot option `%s': ignoring\n", param);
248 return 0;
249 }
250
251 if (panic_later)
252 return 0;
253
254 if (val) {
255 /* Environment option */
256 unsigned int i;
257 for (i = 0; envp_init[i]; i++) {
258 if (i == MAX_INIT_ENVS) {
259 panic_later = "Too many boot env vars at `%s'";
260 panic_param = param;
261 }
262 if (!strncmp(param, envp_init[i], val - param))
263 break;
264 }
265 envp_init[i] = param;
266 } else {
267 /* Command line option */
268 unsigned int i;
269 for (i = 0; argv_init[i]; i++) {
270 if (i == MAX_INIT_ARGS) {
271 panic_later = "Too many boot init vars at `%s'";
272 panic_param = param;
273 }
274 }
275 argv_init[i] = param;
276 }
277 return 0;
278}
279
280static int __init init_setup(char *str)
281{
282 unsigned int i;
283
284 execute_command = str;
285 /*
286 * In case LILO is going to boot us with default command line,
287 * it prepends "auto" before the whole cmdline which makes
288 * the shell think it should execute a script with such name.
289 * So we ignore all arguments entered _before_ init=... [MJ]
290 */
291 for (i = 1; i < MAX_INIT_ARGS; i++)
292 argv_init[i] = NULL;
293 return 1;
294}
295__setup("init=", init_setup);
296
Olof Johanssonffdfc402005-09-06 15:17:19 -0700297static int __init rdinit_setup(char *str)
298{
299 unsigned int i;
300
301 ramdisk_execute_command = str;
302 /* See "auto" comment in init_setup */
303 for (i = 1; i < MAX_INIT_ARGS; i++)
304 argv_init[i] = NULL;
305 return 1;
306}
307__setup("rdinit=", rdinit_setup);
308
Linus Torvalds1da177e2005-04-16 15:20:36 -0700309#ifndef CONFIG_SMP
310
311#ifdef CONFIG_X86_LOCAL_APIC
312static void __init smp_init(void)
313{
314 APIC_init_uniprocessor();
315}
316#else
317#define smp_init() do { } while (0)
318#endif
319
320static inline void setup_per_cpu_areas(void) { }
321static inline void smp_prepare_cpus(unsigned int maxcpus) { }
322
323#else
324
325#ifdef __GENERIC_PER_CPU
Eric Dumazetb73b4592006-03-23 03:01:07 -0800326unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700327
328EXPORT_SYMBOL(__per_cpu_offset);
329
330static void __init setup_per_cpu_areas(void)
331{
332 unsigned long size, i;
333 char *ptr;
Eric Dumazet63872f82006-03-23 03:01:04 -0800334 unsigned long nr_possible_cpus = num_possible_cpus();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335
336 /* Copy section for each CPU (we discard the original) */
337 size = ALIGN(__per_cpu_end - __per_cpu_start, SMP_CACHE_BYTES);
338#ifdef CONFIG_MODULES
339 if (size < PERCPU_ENOUGH_ROOM)
340 size = PERCPU_ENOUGH_ROOM;
341#endif
Eric Dumazet63872f82006-03-23 03:01:04 -0800342 ptr = alloc_bootmem(size * nr_possible_cpus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700343
KAMEZAWA Hiroyuki0a945022006-03-28 01:56:37 -0800344 for_each_possible_cpu(i) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345 __per_cpu_offset[i] = ptr - __per_cpu_start;
346 memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start);
Eric Dumazet63872f82006-03-23 03:01:04 -0800347 ptr += size;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700348 }
349}
350#endif /* !__GENERIC_PER_CPU */
351
352/* Called by boot processor to activate the rest. */
353static void __init smp_init(void)
354{
355 unsigned int i;
356
357 /* FIXME: This should be done in userspace --RR */
358 for_each_present_cpu(i) {
359 if (num_online_cpus() >= max_cpus)
360 break;
361 if (!cpu_online(i))
362 cpu_up(i);
363 }
364
365 /* Any cleanup work */
366 printk(KERN_INFO "Brought up %ld CPUs\n", (long)num_online_cpus());
367 smp_cpus_done(max_cpus);
368#if 0
369 /* Get other processors into their bootup holding patterns. */
370
371 smp_commence();
372#endif
373}
374
375#endif
376
377/*
378 * We need to finalize in a non-__init function or else race conditions
379 * between the root thread and the init thread may cause start_kernel to
380 * be reaped by free_initmem before the root thread has proceeded to
381 * cpu_idle.
382 *
383 * gcc-3.4 accidentally inlines this function, so use noinline.
384 */
385
386static void noinline rest_init(void)
387 __releases(kernel_lock)
388{
389 kernel_thread(init, NULL, CLONE_FS | CLONE_SIGHAND);
390 numa_default_policy();
391 unlock_kernel();
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200392
393 /*
394 * The boot idle thread must execute schedule()
395 * at least one to get things moving:
396 */
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800397 preempt_enable_no_resched();
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200398 schedule();
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800399 preempt_disable();
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200400
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800401 /* Call into cpu_idle with preempt disabled */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402 cpu_idle();
403}
404
405/* Check for early params. */
406static int __init do_early_param(char *param, char *val)
407{
408 struct obs_kernel_param *p;
409
410 for (p = __setup_start; p < __setup_end; p++) {
411 if (p->early && strcmp(param, p->str) == 0) {
412 if (p->setup_func(val) != 0)
413 printk(KERN_WARNING
414 "Malformed early option '%s'\n", param);
415 }
416 }
417 /* We accept everything at this stage. */
418 return 0;
419}
420
421/* Arch code calls this early on, or if not, just before other parsing. */
422void __init parse_early_param(void)
423{
424 static __initdata int done = 0;
425 static __initdata char tmp_cmdline[COMMAND_LINE_SIZE];
426
427 if (done)
428 return;
429
430 /* All fall through to do_early_param. */
431 strlcpy(tmp_cmdline, saved_command_line, COMMAND_LINE_SIZE);
432 parse_args("early options", tmp_cmdline, NULL, 0, do_early_param);
433 done = 1;
434}
435
436/*
437 * Activate the first processor.
438 */
439
Stas Sergeev44fd2292006-03-23 02:59:44 -0800440static void __init boot_cpu_init(void)
441{
442 int cpu = smp_processor_id();
443 /* Mark the boot cpu "present", "online" etc for SMP and UP case */
444 cpu_set(cpu, cpu_online_map);
445 cpu_set(cpu, cpu_present_map);
446 cpu_set(cpu, cpu_possible_map);
447}
448
Linus Torvalds1da177e2005-04-16 15:20:36 -0700449asmlinkage void __init start_kernel(void)
450{
451 char * command_line;
452 extern struct kernel_param __start___param[], __stop___param[];
453/*
454 * Interrupts are still disabled. Do necessary setups, then
455 * enable them
456 */
457 lock_kernel();
Stas Sergeev44fd2292006-03-23 02:59:44 -0800458 boot_cpu_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700459 page_address_init();
460 printk(KERN_NOTICE);
461 printk(linux_banner);
462 setup_arch(&command_line);
463 setup_per_cpu_areas();
Stas Sergeev44fd2292006-03-23 02:59:44 -0800464 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465
466 /*
467 * Set up the scheduler prior starting any interrupts (such as the
468 * timer interrupt). Full topology setup happens at smp_init()
469 * time - but meanwhile we still have a functioning scheduler.
470 */
471 sched_init();
472 /*
473 * Disable preemption - early bootup scheduling is extremely
474 * fragile until we cpu_idle() for the first time.
475 */
476 preempt_disable();
477 build_all_zonelists();
478 page_alloc_init();
479 printk(KERN_NOTICE "Kernel command line: %s\n", saved_command_line);
480 parse_early_param();
481 parse_args("Booting kernel", command_line, __start___param,
482 __stop___param - __start___param,
483 &unknown_bootoption);
484 sort_main_extable();
485 trap_init();
486 rcu_init();
487 init_IRQ();
488 pidhash_init();
489 init_timers();
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800490 hrtimers_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700491 softirq_init();
492 time_init();
493
494 /*
495 * HACK ALERT! This is early. We're enabling the console before
496 * we've done PCI setups etc, and console_init() must be aware of
497 * this. But we do want output early, in case something goes wrong.
498 */
499 console_init();
500 if (panic_later)
501 panic(panic_later, panic_param);
502 profile_init();
503 local_irq_enable();
504#ifdef CONFIG_BLK_DEV_INITRD
505 if (initrd_start && !initrd_below_start_ok &&
506 initrd_start < min_low_pfn << PAGE_SHIFT) {
507 printk(KERN_CRIT "initrd overwritten (0x%08lx < 0x%08lx) - "
508 "disabling it.\n",initrd_start,min_low_pfn << PAGE_SHIFT);
509 initrd_start = 0;
510 }
511#endif
512 vfs_caches_init_early();
Paul Jacksonc417f022006-01-08 01:02:01 -0800513 cpuset_init_early();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700514 mem_init();
515 kmem_cache_init();
Christoph Lametere7c8d5c2005-06-21 17:14:47 -0700516 setup_per_cpu_pageset();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700517 numa_policy_init();
518 if (late_time_init)
519 late_time_init();
520 calibrate_delay();
521 pidmap_init();
522 pgtable_cache_init();
523 prio_tree_init();
524 anon_vma_init();
525#ifdef CONFIG_X86
526 if (efi_enabled)
527 efi_enter_virtual_mode();
528#endif
529 fork_init(num_physpages);
530 proc_caches_init();
531 buffer_init();
532 unnamed_dev_init();
533 key_init();
534 security_init();
535 vfs_caches_init(num_physpages);
536 radix_tree_init();
537 signals_init();
538 /* rootfs populating might need page-writeback */
539 page_writeback_init();
540#ifdef CONFIG_PROC_FS
541 proc_root_init();
542#endif
543 cpuset_init();
544
545 check_bugs();
546
547 acpi_early_init(); /* before LAPIC and SMP init */
548
549 /* Do the rest non-__init'ed, we're now alive */
550 rest_init();
551}
552
553static int __initdata initcall_debug;
554
555static int __init initcall_debug_setup(char *str)
556{
557 initcall_debug = 1;
558 return 1;
559}
560__setup("initcall_debug", initcall_debug_setup);
561
562struct task_struct *child_reaper = &init_task;
563
564extern initcall_t __initcall_start[], __initcall_end[];
565
566static void __init do_initcalls(void)
567{
568 initcall_t *call;
569 int count = preempt_count();
570
571 for (call = __initcall_start; call < __initcall_end; call++) {
Andrew Mortonc1cda482006-03-25 03:07:15 -0800572 char *msg = NULL;
573 char msgbuf[40];
574 int result;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700575
576 if (initcall_debug) {
Andrew Mortonc1cda482006-03-25 03:07:15 -0800577 printk("Calling initcall 0x%p", *call);
578 print_fn_descriptor_symbol(": %s()",
579 (unsigned long) *call);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700580 printk("\n");
581 }
582
Andrew Mortonc1cda482006-03-25 03:07:15 -0800583 result = (*call)();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700584
Andrew Mortonf3a19cb2006-05-01 12:15:52 -0700585 if (result && result != -ENODEV && initcall_debug) {
Andrew Mortonc1cda482006-03-25 03:07:15 -0800586 sprintf(msgbuf, "error code %d", result);
587 msg = msgbuf;
588 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700589 if (preempt_count() != count) {
590 msg = "preemption imbalance";
591 preempt_count() = count;
592 }
593 if (irqs_disabled()) {
594 msg = "disabled interrupts";
595 local_irq_enable();
596 }
597 if (msg) {
Andrew Mortonc1cda482006-03-25 03:07:15 -0800598 printk(KERN_WARNING "initcall at 0x%p", *call);
599 print_fn_descriptor_symbol(": %s()",
600 (unsigned long) *call);
601 printk(": returned with %s\n", msg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700602 }
603 }
604
605 /* Make sure there is no pending stuff from the initcall sequence */
606 flush_scheduled_work();
607}
608
609/*
610 * Ok, the machine is now initialized. None of the devices
611 * have been touched yet, but the CPU subsystem is up and
612 * running, and memory and process management works.
613 *
614 * Now we can finally start doing some real work..
615 */
616static void __init do_basic_setup(void)
617{
618 /* drivers will send hotplug events */
619 init_workqueues();
620 usermodehelper_init();
621 driver_init();
622
623#ifdef CONFIG_SYSCTL
624 sysctl_init();
625#endif
626
Linus Torvalds1da177e2005-04-16 15:20:36 -0700627 do_initcalls();
628}
629
630static void do_pre_smp_initcalls(void)
631{
632 extern int spawn_ksoftirqd(void);
633#ifdef CONFIG_SMP
634 extern int migration_init(void);
635
636 migration_init();
637#endif
638 spawn_ksoftirqd();
Ingo Molnar8446f1d2005-09-06 15:16:27 -0700639 spawn_softlockup_task();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700640}
641
642static void run_init_process(char *init_filename)
643{
644 argv_init[0] = init_filename;
645 execve(init_filename, argv_init, envp_init);
646}
647
Linus Torvalds1da177e2005-04-16 15:20:36 -0700648static int init(void * unused)
649{
650 lock_kernel();
651 /*
652 * init can run on any cpu.
653 */
654 set_cpus_allowed(current, CPU_MASK_ALL);
655 /*
656 * Tell the world that we're going to be the grim
657 * reaper of innocent orphaned children.
658 *
659 * We don't want people to have to make incorrect
660 * assumptions about where in the task array this
661 * can be found.
662 */
663 child_reaper = current;
664
Linus Torvalds1da177e2005-04-16 15:20:36 -0700665 smp_prepare_cpus(max_cpus);
666
667 do_pre_smp_initcalls();
668
Linus Torvalds1da177e2005-04-16 15:20:36 -0700669 smp_init();
670 sched_init_smp();
671
672 cpuset_init_smp();
673
674 /*
675 * Do this before initcalls, because some drivers want to access
676 * firmware files.
677 */
678 populate_rootfs();
679
680 do_basic_setup();
681
682 /*
683 * check if there is an early userspace init. If yes, let it do all
684 * the work
685 */
Olof Johanssonffdfc402005-09-06 15:17:19 -0700686
687 if (!ramdisk_execute_command)
688 ramdisk_execute_command = "/init";
689
690 if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
691 ramdisk_execute_command = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700692 prepare_namespace();
Olof Johanssonffdfc402005-09-06 15:17:19 -0700693 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700694
695 /*
696 * Ok, we have completed the initial bootup, and
697 * we're essentially up and running. Get rid of the
698 * initmem segments and start the user-mode stuff..
699 */
700 free_initmem();
701 unlock_kernel();
Arjan van de Ven37b73c82006-01-06 00:12:01 -0800702 mark_rodata_ro();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700703 system_state = SYSTEM_RUNNING;
704 numa_default_policy();
705
706 if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
707 printk(KERN_WARNING "Warning: unable to open an initial console.\n");
708
709 (void) sys_dup(0);
710 (void) sys_dup(0);
Olof Johanssonffdfc402005-09-06 15:17:19 -0700711
712 if (ramdisk_execute_command) {
713 run_init_process(ramdisk_execute_command);
714 printk(KERN_WARNING "Failed to execute %s\n",
715 ramdisk_execute_command);
716 }
717
Linus Torvalds1da177e2005-04-16 15:20:36 -0700718 /*
719 * We try each of these until one succeeds.
720 *
721 * The Bourne shell can be used instead of init if we are
722 * trying to recover a really broken machine.
723 */
Avery, Brianc1d7ef72005-09-06 15:16:56 -0700724 if (execute_command) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700725 run_init_process(execute_command);
Avery, Brianc1d7ef72005-09-06 15:16:56 -0700726 printk(KERN_WARNING "Failed to execute %s. Attempting "
727 "defaults...\n", execute_command);
728 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700729 run_init_process("/sbin/init");
730 run_init_process("/etc/init");
731 run_init_process("/bin/init");
732 run_init_process("/bin/sh");
733
734 panic("No init found. Try passing init= option to kernel.");
735}