blob: fc473d4b56fdf626ce5ac7681dcd86c4845c9af9 [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
Linus Torvalds1da177e2005-04-16 15:20:36 -070014#include <linux/types.h>
15#include <linux/module.h>
16#include <linux/proc_fs.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070017#include <linux/kernel.h>
18#include <linux/syscalls.h>
19#include <linux/string.h>
20#include <linux/ctype.h>
21#include <linux/delay.h>
22#include <linux/utsname.h>
23#include <linux/ioport.h>
24#include <linux/init.h>
25#include <linux/smp_lock.h>
26#include <linux/initrd.h>
27#include <linux/hdreg.h>
28#include <linux/bootmem.h>
29#include <linux/tty.h>
30#include <linux/gfp.h>
31#include <linux/percpu.h>
32#include <linux/kmod.h>
33#include <linux/kernel_stat.h>
34#include <linux/security.h>
35#include <linux/workqueue.h>
36#include <linux/profile.h>
37#include <linux/rcupdate.h>
38#include <linux/moduleparam.h>
39#include <linux/kallsyms.h>
40#include <linux/writeback.h>
41#include <linux/cpu.h>
42#include <linux/cpuset.h>
43#include <linux/efi.h>
44#include <linux/unistd.h>
45#include <linux/rmap.h>
46#include <linux/mempolicy.h>
47#include <linux/key.h>
Jan Beulich4552d5d2006-06-26 13:57:28 +020048#include <linux/unwind.h>
Adrian Bunkb6cd0b72006-06-27 02:53:54 -070049#include <linux/buffer_head.h>
Ingo Molnar9a11b49a2006-07-03 00:24:33 -070050#include <linux/debug_locks.h>
Ingo Molnarfbb9ce952006-07-03 00:24:50 -070051#include <linux/lockdep.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070052
53#include <asm/io.h>
54#include <asm/bugs.h>
55#include <asm/setup.h>
Andi Kleena9401992005-07-28 21:15:30 -070056#include <asm/sections.h>
Arjan van de Ven37b73c82006-01-06 00:12:01 -080057#include <asm/cacheflush.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070058
Linus Torvalds1da177e2005-04-16 15:20:36 -070059#ifdef CONFIG_X86_LOCAL_APIC
60#include <asm/smp.h>
61#endif
62
63/*
Coywolf Qi Hunt69c99ac2006-01-14 13:21:11 -080064 * This is one of the first .c files built. Error out early if we have compiler
65 * trouble.
66 *
67 * Versions of gcc older than that listed below may actually compile and link
68 * okay, but the end product can have subtle run time bugs. To avoid associated
69 * bogus bug reports, we flatly refuse to compile with a gcc that is known to be
70 * too old from the very beginning.
Linus Torvalds1da177e2005-04-16 15:20:36 -070071 */
Andrew Mortonfd285bb2006-01-08 01:04:07 -080072#if (__GNUC__ < 3) || (__GNUC__ == 3 && __GNUC_MINOR__ < 2)
Linus Torvalds1da177e2005-04-16 15:20:36 -070073#error Sorry, your GCC is too old. It builds incorrect kernels.
74#endif
75
76static int init(void *);
77
78extern void init_IRQ(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070079extern void fork_init(unsigned long);
80extern void mca_init(void);
81extern void sbus_init(void);
82extern void sysctl_init(void);
83extern void signals_init(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070084extern void pidhash_init(void);
85extern void pidmap_init(void);
86extern void prio_tree_init(void);
87extern void radix_tree_init(void);
88extern void free_initmem(void);
89extern void populate_rootfs(void);
90extern void driver_init(void);
91extern void prepare_namespace(void);
92#ifdef CONFIG_ACPI
93extern void acpi_early_init(void);
94#else
95static inline void acpi_early_init(void) { }
96#endif
Arjan van de Ven37b73c82006-01-06 00:12:01 -080097#ifndef CONFIG_DEBUG_RODATA
98static inline void mark_rodata_ro(void) { }
99#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100
101#ifdef CONFIG_TC
102extern void tc_init(void);
103#endif
104
105enum system_states system_state;
106EXPORT_SYMBOL(system_state);
107
108/*
109 * Boot command-line arguments
110 */
111#define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
112#define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
113
114extern void time_init(void);
115/* Default late time init is NULL. archs can override this later. */
116void (*late_time_init)(void);
117extern void softirq_init(void);
118
119/* Untouched command line (eg. for /proc) saved by arch-specific code. */
120char saved_command_line[COMMAND_LINE_SIZE];
121
122static char *execute_command;
Olof Johanssonffdfc402005-09-06 15:17:19 -0700123static char *ramdisk_execute_command;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124
125/* Setup configured maximum number of CPUs to activate */
126static unsigned int max_cpus = NR_CPUS;
127
128/*
129 * Setup routine for controlling SMP activation
130 *
131 * Command-line option of "nosmp" or "maxcpus=0" will disable SMP
132 * activation entirely (the MPS table probe still happens, though).
133 *
134 * Command-line option of "maxcpus=<NUM>", where <NUM> is an integer
135 * greater than 0, limits the maximum number of CPUs activated in
136 * SMP mode to <NUM>.
137 */
138static int __init nosmp(char *str)
139{
140 max_cpus = 0;
141 return 1;
142}
143
144__setup("nosmp", nosmp);
145
146static int __init maxcpus(char *str)
147{
148 get_option(&str, &max_cpus);
149 return 1;
150}
151
152__setup("maxcpus=", maxcpus);
153
154static char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
155char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
156static const char *panic_later, *panic_param;
157
158extern struct obs_kernel_param __setup_start[], __setup_end[];
159
160static int __init obsolete_checksetup(char *line)
161{
162 struct obs_kernel_param *p;
163
164 p = __setup_start;
165 do {
166 int n = strlen(p->str);
167 if (!strncmp(line, p->str, n)) {
168 if (p->early) {
169 /* Already done in parse_early_param? (Needs
170 * exact match on param part) */
171 if (line[n] == '\0' || line[n] == '=')
172 return 1;
173 } else if (!p->setup_func) {
174 printk(KERN_WARNING "Parameter %s is obsolete,"
175 " ignored\n", p->str);
176 return 1;
177 } else if (p->setup_func(line + n))
178 return 1;
179 }
180 p++;
181 } while (p < __setup_end);
182 return 0;
183}
184
185/*
186 * This should be approx 2 Bo*oMips to start (note initial shift), and will
187 * still work even if initially too large, it will just take slightly longer
188 */
189unsigned long loops_per_jiffy = (1<<12);
190
191EXPORT_SYMBOL(loops_per_jiffy);
192
193static int __init debug_kernel(char *str)
194{
195 if (*str)
196 return 0;
197 console_loglevel = 10;
198 return 1;
199}
200
201static int __init quiet_kernel(char *str)
202{
203 if (*str)
204 return 0;
205 console_loglevel = 4;
206 return 1;
207}
208
209__setup("debug", debug_kernel);
210__setup("quiet", quiet_kernel);
211
212static int __init loglevel(char *str)
213{
214 get_option(&str, &console_loglevel);
215 return 1;
216}
217
218__setup("loglevel=", loglevel);
219
220/*
221 * Unknown boot options get handed to init, unless they look like
222 * failed parameters
223 */
224static int __init unknown_bootoption(char *param, char *val)
225{
226 /* Change NUL term back to "=", to make "param" the whole string. */
227 if (val) {
228 /* param=val or param="val"? */
229 if (val == param+strlen(param)+1)
230 val[-1] = '=';
231 else if (val == param+strlen(param)+2) {
232 val[-2] = '=';
233 memmove(val-1, val, strlen(val)+1);
234 val--;
235 } else
236 BUG();
237 }
238
239 /* Handle obsolete-style parameters */
240 if (obsolete_checksetup(param))
241 return 0;
242
243 /*
244 * Preemptive maintenance for "why didn't my mispelled command
245 * line work?"
246 */
247 if (strchr(param, '.') && (!val || strchr(param, '.') < val)) {
248 printk(KERN_ERR "Unknown boot option `%s': ignoring\n", param);
249 return 0;
250 }
251
252 if (panic_later)
253 return 0;
254
255 if (val) {
256 /* Environment option */
257 unsigned int i;
258 for (i = 0; envp_init[i]; i++) {
259 if (i == MAX_INIT_ENVS) {
260 panic_later = "Too many boot env vars at `%s'";
261 panic_param = param;
262 }
263 if (!strncmp(param, envp_init[i], val - param))
264 break;
265 }
266 envp_init[i] = param;
267 } else {
268 /* Command line option */
269 unsigned int i;
270 for (i = 0; argv_init[i]; i++) {
271 if (i == MAX_INIT_ARGS) {
272 panic_later = "Too many boot init vars at `%s'";
273 panic_param = param;
274 }
275 }
276 argv_init[i] = param;
277 }
278 return 0;
279}
280
281static int __init init_setup(char *str)
282{
283 unsigned int i;
284
285 execute_command = str;
286 /*
287 * In case LILO is going to boot us with default command line,
288 * it prepends "auto" before the whole cmdline which makes
289 * the shell think it should execute a script with such name.
290 * So we ignore all arguments entered _before_ init=... [MJ]
291 */
292 for (i = 1; i < MAX_INIT_ARGS; i++)
293 argv_init[i] = NULL;
294 return 1;
295}
296__setup("init=", init_setup);
297
Olof Johanssonffdfc402005-09-06 15:17:19 -0700298static int __init rdinit_setup(char *str)
299{
300 unsigned int i;
301
302 ramdisk_execute_command = str;
303 /* See "auto" comment in init_setup */
304 for (i = 1; i < MAX_INIT_ARGS; i++)
305 argv_init[i] = NULL;
306 return 1;
307}
308__setup("rdinit=", rdinit_setup);
309
Linus Torvalds1da177e2005-04-16 15:20:36 -0700310#ifndef CONFIG_SMP
311
312#ifdef CONFIG_X86_LOCAL_APIC
313static void __init smp_init(void)
314{
315 APIC_init_uniprocessor();
316}
317#else
318#define smp_init() do { } while (0)
319#endif
320
321static inline void setup_per_cpu_areas(void) { }
322static inline void smp_prepare_cpus(unsigned int maxcpus) { }
323
324#else
325
326#ifdef __GENERIC_PER_CPU
Eric Dumazetb73b4592006-03-23 03:01:07 -0800327unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700328
329EXPORT_SYMBOL(__per_cpu_offset);
330
331static void __init setup_per_cpu_areas(void)
332{
333 unsigned long size, i;
334 char *ptr;
Eric Dumazet63872f82006-03-23 03:01:04 -0800335 unsigned long nr_possible_cpus = num_possible_cpus();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336
337 /* Copy section for each CPU (we discard the original) */
338 size = ALIGN(__per_cpu_end - __per_cpu_start, SMP_CACHE_BYTES);
339#ifdef CONFIG_MODULES
340 if (size < PERCPU_ENOUGH_ROOM)
341 size = PERCPU_ENOUGH_ROOM;
342#endif
Eric Dumazet63872f82006-03-23 03:01:04 -0800343 ptr = alloc_bootmem(size * nr_possible_cpus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700344
KAMEZAWA Hiroyuki0a945022006-03-28 01:56:37 -0800345 for_each_possible_cpu(i) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346 __per_cpu_offset[i] = ptr - __per_cpu_start;
347 memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start);
Eric Dumazet63872f82006-03-23 03:01:04 -0800348 ptr += size;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700349 }
350}
351#endif /* !__GENERIC_PER_CPU */
352
353/* Called by boot processor to activate the rest. */
354static void __init smp_init(void)
355{
356 unsigned int i;
357
358 /* FIXME: This should be done in userspace --RR */
359 for_each_present_cpu(i) {
360 if (num_online_cpus() >= max_cpus)
361 break;
362 if (!cpu_online(i))
363 cpu_up(i);
364 }
365
366 /* Any cleanup work */
367 printk(KERN_INFO "Brought up %ld CPUs\n", (long)num_online_cpus());
368 smp_cpus_done(max_cpus);
369#if 0
370 /* Get other processors into their bootup holding patterns. */
371
372 smp_commence();
373#endif
374}
375
376#endif
377
378/*
379 * We need to finalize in a non-__init function or else race conditions
380 * between the root thread and the init thread may cause start_kernel to
381 * be reaped by free_initmem before the root thread has proceeded to
382 * cpu_idle.
383 *
384 * gcc-3.4 accidentally inlines this function, so use noinline.
385 */
386
387static void noinline rest_init(void)
388 __releases(kernel_lock)
389{
390 kernel_thread(init, NULL, CLONE_FS | CLONE_SIGHAND);
391 numa_default_policy();
392 unlock_kernel();
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200393
394 /*
395 * The boot idle thread must execute schedule()
396 * at least one to get things moving:
397 */
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800398 preempt_enable_no_resched();
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200399 schedule();
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800400 preempt_disable();
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200401
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800402 /* Call into cpu_idle with preempt disabled */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700403 cpu_idle();
404}
405
406/* Check for early params. */
407static int __init do_early_param(char *param, char *val)
408{
409 struct obs_kernel_param *p;
410
411 for (p = __setup_start; p < __setup_end; p++) {
412 if (p->early && strcmp(param, p->str) == 0) {
413 if (p->setup_func(val) != 0)
414 printk(KERN_WARNING
415 "Malformed early option '%s'\n", param);
416 }
417 }
418 /* We accept everything at this stage. */
419 return 0;
420}
421
422/* Arch code calls this early on, or if not, just before other parsing. */
423void __init parse_early_param(void)
424{
425 static __initdata int done = 0;
426 static __initdata char tmp_cmdline[COMMAND_LINE_SIZE];
427
428 if (done)
429 return;
430
431 /* All fall through to do_early_param. */
432 strlcpy(tmp_cmdline, saved_command_line, COMMAND_LINE_SIZE);
433 parse_args("early options", tmp_cmdline, NULL, 0, do_early_param);
434 done = 1;
435}
436
437/*
438 * Activate the first processor.
439 */
440
Stas Sergeev44fd2292006-03-23 02:59:44 -0800441static void __init boot_cpu_init(void)
442{
443 int cpu = smp_processor_id();
444 /* Mark the boot cpu "present", "online" etc for SMP and UP case */
445 cpu_set(cpu, cpu_online_map);
446 cpu_set(cpu, cpu_present_map);
447 cpu_set(cpu, cpu_possible_map);
448}
449
Andrew Morton033ab7f2006-06-30 01:55:50 -0700450void __init __attribute__((weak)) smp_setup_processor_id(void)
451{
452}
453
Linus Torvalds1da177e2005-04-16 15:20:36 -0700454asmlinkage void __init start_kernel(void)
455{
456 char * command_line;
457 extern struct kernel_param __start___param[], __stop___param[];
Andrew Morton033ab7f2006-06-30 01:55:50 -0700458
459 smp_setup_processor_id();
460
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700461 /*
462 * Need to run as early as possible, to initialize the
463 * lockdep hash:
464 */
465 lockdep_init();
466
467 local_irq_disable();
468 early_boot_irqs_off();
469
Linus Torvalds1da177e2005-04-16 15:20:36 -0700470/*
471 * Interrupts are still disabled. Do necessary setups, then
472 * enable them
473 */
474 lock_kernel();
Stas Sergeev44fd2292006-03-23 02:59:44 -0800475 boot_cpu_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700476 page_address_init();
477 printk(KERN_NOTICE);
478 printk(linux_banner);
479 setup_arch(&command_line);
480 setup_per_cpu_areas();
Stas Sergeev44fd2292006-03-23 02:59:44 -0800481 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700482
483 /*
484 * Set up the scheduler prior starting any interrupts (such as the
485 * timer interrupt). Full topology setup happens at smp_init()
486 * time - but meanwhile we still have a functioning scheduler.
487 */
488 sched_init();
489 /*
490 * Disable preemption - early bootup scheduling is extremely
491 * fragile until we cpu_idle() for the first time.
492 */
493 preempt_disable();
494 build_all_zonelists();
495 page_alloc_init();
496 printk(KERN_NOTICE "Kernel command line: %s\n", saved_command_line);
497 parse_early_param();
498 parse_args("Booting kernel", command_line, __start___param,
499 __stop___param - __start___param,
500 &unknown_bootoption);
501 sort_main_extable();
Jan Beulich4552d5d2006-06-26 13:57:28 +0200502 unwind_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700503 trap_init();
504 rcu_init();
505 init_IRQ();
506 pidhash_init();
507 init_timers();
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800508 hrtimers_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700509 softirq_init();
john stultzad596172006-06-26 00:25:06 -0700510 timekeeping_init();
john stultz88fecaa2006-07-03 00:24:04 -0700511 time_init();
Heiko Carstens93e02812006-07-03 00:24:24 -0700512 profile_init();
513 if (!irqs_disabled())
514 printk("start_kernel(): bug: interrupts were enabled early\n");
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700515 early_boot_irqs_on();
Heiko Carstens93e02812006-07-03 00:24:24 -0700516 local_irq_enable();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700517
518 /*
519 * HACK ALERT! This is early. We're enabling the console before
520 * we've done PCI setups etc, and console_init() must be aware of
521 * this. But we do want output early, in case something goes wrong.
522 */
523 console_init();
524 if (panic_later)
525 panic(panic_later, panic_param);
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700526
527 lockdep_info();
528
Ingo Molnar9a11b49a2006-07-03 00:24:33 -0700529 /*
530 * Need to run this when irqs are enabled, because it wants
531 * to self-test [hard/soft]-irqs on/off lock inversion bugs
532 * too:
533 */
534 locking_selftest();
535
Linus Torvalds1da177e2005-04-16 15:20:36 -0700536#ifdef CONFIG_BLK_DEV_INITRD
537 if (initrd_start && !initrd_below_start_ok &&
538 initrd_start < min_low_pfn << PAGE_SHIFT) {
539 printk(KERN_CRIT "initrd overwritten (0x%08lx < 0x%08lx) - "
540 "disabling it.\n",initrd_start,min_low_pfn << PAGE_SHIFT);
541 initrd_start = 0;
542 }
543#endif
544 vfs_caches_init_early();
Paul Jacksonc417f022006-01-08 01:02:01 -0800545 cpuset_init_early();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700546 mem_init();
547 kmem_cache_init();
Christoph Lametere7c8d5c2005-06-21 17:14:47 -0700548 setup_per_cpu_pageset();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700549 numa_policy_init();
550 if (late_time_init)
551 late_time_init();
552 calibrate_delay();
553 pidmap_init();
554 pgtable_cache_init();
555 prio_tree_init();
556 anon_vma_init();
557#ifdef CONFIG_X86
558 if (efi_enabled)
559 efi_enter_virtual_mode();
560#endif
561 fork_init(num_physpages);
562 proc_caches_init();
563 buffer_init();
564 unnamed_dev_init();
565 key_init();
566 security_init();
567 vfs_caches_init(num_physpages);
568 radix_tree_init();
569 signals_init();
570 /* rootfs populating might need page-writeback */
571 page_writeback_init();
572#ifdef CONFIG_PROC_FS
573 proc_root_init();
574#endif
575 cpuset_init();
576
577 check_bugs();
578
579 acpi_early_init(); /* before LAPIC and SMP init */
580
581 /* Do the rest non-__init'ed, we're now alive */
582 rest_init();
583}
584
585static int __initdata initcall_debug;
586
587static int __init initcall_debug_setup(char *str)
588{
589 initcall_debug = 1;
590 return 1;
591}
592__setup("initcall_debug", initcall_debug_setup);
593
594struct task_struct *child_reaper = &init_task;
595
596extern initcall_t __initcall_start[], __initcall_end[];
597
598static void __init do_initcalls(void)
599{
600 initcall_t *call;
601 int count = preempt_count();
602
603 for (call = __initcall_start; call < __initcall_end; call++) {
Andrew Mortonc1cda482006-03-25 03:07:15 -0800604 char *msg = NULL;
605 char msgbuf[40];
606 int result;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700607
608 if (initcall_debug) {
Andrew Mortonc1cda482006-03-25 03:07:15 -0800609 printk("Calling initcall 0x%p", *call);
610 print_fn_descriptor_symbol(": %s()",
611 (unsigned long) *call);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700612 printk("\n");
613 }
614
Andrew Mortonc1cda482006-03-25 03:07:15 -0800615 result = (*call)();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700616
Andrew Mortonf3a19cb2006-05-01 12:15:52 -0700617 if (result && result != -ENODEV && initcall_debug) {
Andrew Mortonc1cda482006-03-25 03:07:15 -0800618 sprintf(msgbuf, "error code %d", result);
619 msg = msgbuf;
620 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700621 if (preempt_count() != count) {
622 msg = "preemption imbalance";
623 preempt_count() = count;
624 }
625 if (irqs_disabled()) {
626 msg = "disabled interrupts";
627 local_irq_enable();
628 }
629 if (msg) {
Andrew Mortonc1cda482006-03-25 03:07:15 -0800630 printk(KERN_WARNING "initcall at 0x%p", *call);
631 print_fn_descriptor_symbol(": %s()",
632 (unsigned long) *call);
633 printk(": returned with %s\n", msg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700634 }
635 }
636
637 /* Make sure there is no pending stuff from the initcall sequence */
638 flush_scheduled_work();
639}
640
641/*
642 * Ok, the machine is now initialized. None of the devices
643 * have been touched yet, but the CPU subsystem is up and
644 * running, and memory and process management works.
645 *
646 * Now we can finally start doing some real work..
647 */
648static void __init do_basic_setup(void)
649{
650 /* drivers will send hotplug events */
651 init_workqueues();
652 usermodehelper_init();
653 driver_init();
654
655#ifdef CONFIG_SYSCTL
656 sysctl_init();
657#endif
658
Linus Torvalds1da177e2005-04-16 15:20:36 -0700659 do_initcalls();
660}
661
662static void do_pre_smp_initcalls(void)
663{
664 extern int spawn_ksoftirqd(void);
665#ifdef CONFIG_SMP
666 extern int migration_init(void);
667
668 migration_init();
669#endif
670 spawn_ksoftirqd();
Ingo Molnar8446f1d2005-09-06 15:16:27 -0700671 spawn_softlockup_task();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700672}
673
674static void run_init_process(char *init_filename)
675{
676 argv_init[0] = init_filename;
677 execve(init_filename, argv_init, envp_init);
678}
679
Linus Torvalds1da177e2005-04-16 15:20:36 -0700680static int init(void * unused)
681{
682 lock_kernel();
683 /*
684 * init can run on any cpu.
685 */
686 set_cpus_allowed(current, CPU_MASK_ALL);
687 /*
688 * Tell the world that we're going to be the grim
689 * reaper of innocent orphaned children.
690 *
691 * We don't want people to have to make incorrect
692 * assumptions about where in the task array this
693 * can be found.
694 */
695 child_reaper = current;
696
Linus Torvalds1da177e2005-04-16 15:20:36 -0700697 smp_prepare_cpus(max_cpus);
698
699 do_pre_smp_initcalls();
700
Linus Torvalds1da177e2005-04-16 15:20:36 -0700701 smp_init();
702 sched_init_smp();
703
704 cpuset_init_smp();
705
706 /*
707 * Do this before initcalls, because some drivers want to access
708 * firmware files.
709 */
710 populate_rootfs();
711
712 do_basic_setup();
713
714 /*
715 * check if there is an early userspace init. If yes, let it do all
716 * the work
717 */
Olof Johanssonffdfc402005-09-06 15:17:19 -0700718
719 if (!ramdisk_execute_command)
720 ramdisk_execute_command = "/init";
721
722 if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
723 ramdisk_execute_command = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700724 prepare_namespace();
Olof Johanssonffdfc402005-09-06 15:17:19 -0700725 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700726
727 /*
728 * Ok, we have completed the initial bootup, and
729 * we're essentially up and running. Get rid of the
730 * initmem segments and start the user-mode stuff..
731 */
732 free_initmem();
733 unlock_kernel();
Arjan van de Ven37b73c82006-01-06 00:12:01 -0800734 mark_rodata_ro();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700735 system_state = SYSTEM_RUNNING;
736 numa_default_policy();
737
738 if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
739 printk(KERN_WARNING "Warning: unable to open an initial console.\n");
740
741 (void) sys_dup(0);
742 (void) sys_dup(0);
Olof Johanssonffdfc402005-09-06 15:17:19 -0700743
744 if (ramdisk_execute_command) {
745 run_init_process(ramdisk_execute_command);
746 printk(KERN_WARNING "Failed to execute %s\n",
747 ramdisk_execute_command);
748 }
749
Linus Torvalds1da177e2005-04-16 15:20:36 -0700750 /*
751 * We try each of these until one succeeds.
752 *
753 * The Bourne shell can be used instead of init if we are
754 * trying to recover a really broken machine.
755 */
Avery, Brianc1d7ef72005-09-06 15:16:56 -0700756 if (execute_command) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700757 run_init_process(execute_command);
Avery, Brianc1d7ef72005-09-06 15:16:56 -0700758 printk(KERN_WARNING "Failed to execute %s. Attempting "
759 "defaults...\n", execute_command);
760 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700761 run_init_process("/sbin/init");
762 run_init_process("/etc/init");
763 run_init_process("/bin/init");
764 run_init_process("/bin/sh");
765
766 panic("No init found. Try passing init= option to kernel.");
767}