blob: 0766e69712b2a86efa74caf3c5bd487bbbcd3753 [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>
Shailabh Nagarc7572492006-07-14 00:24:40 -070044#include <linux/taskstats_kern.h>
Shailabh Nagarca74e922006-07-14 00:24:36 -070045#include <linux/delayacct.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070046#include <linux/unistd.h>
47#include <linux/rmap.h>
48#include <linux/mempolicy.h>
49#include <linux/key.h>
Jan Beulich4552d5d2006-06-26 13:57:28 +020050#include <linux/unwind.h>
Adrian Bunkb6cd0b72006-06-27 02:53:54 -070051#include <linux/buffer_head.h>
Ingo Molnar9a11b49a2006-07-03 00:24:33 -070052#include <linux/debug_locks.h>
Ingo Molnarfbb9ce952006-07-03 00:24:50 -070053#include <linux/lockdep.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070054
55#include <asm/io.h>
56#include <asm/bugs.h>
57#include <asm/setup.h>
Andi Kleena9401992005-07-28 21:15:30 -070058#include <asm/sections.h>
Arjan van de Ven37b73c82006-01-06 00:12:01 -080059#include <asm/cacheflush.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070060
Linus Torvalds1da177e2005-04-16 15:20:36 -070061#ifdef CONFIG_X86_LOCAL_APIC
62#include <asm/smp.h>
63#endif
64
65/*
Coywolf Qi Hunt69c99ac2006-01-14 13:21:11 -080066 * This is one of the first .c files built. Error out early if we have compiler
67 * trouble.
68 *
69 * Versions of gcc older than that listed below may actually compile and link
70 * okay, but the end product can have subtle run time bugs. To avoid associated
71 * bogus bug reports, we flatly refuse to compile with a gcc that is known to be
72 * too old from the very beginning.
Linus Torvalds1da177e2005-04-16 15:20:36 -070073 */
Andrew Mortonfd285bb2006-01-08 01:04:07 -080074#if (__GNUC__ < 3) || (__GNUC__ == 3 && __GNUC_MINOR__ < 2)
Linus Torvalds1da177e2005-04-16 15:20:36 -070075#error Sorry, your GCC is too old. It builds incorrect kernels.
76#endif
77
78static int init(void *);
79
80extern void init_IRQ(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070081extern void fork_init(unsigned long);
82extern void mca_init(void);
83extern void sbus_init(void);
84extern void sysctl_init(void);
85extern void signals_init(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070086extern void pidhash_init(void);
87extern void pidmap_init(void);
88extern void prio_tree_init(void);
89extern void radix_tree_init(void);
90extern void free_initmem(void);
91extern void populate_rootfs(void);
92extern void driver_init(void);
93extern void prepare_namespace(void);
94#ifdef CONFIG_ACPI
95extern void acpi_early_init(void);
96#else
97static inline void acpi_early_init(void) { }
98#endif
Arjan van de Ven37b73c82006-01-06 00:12:01 -080099#ifndef CONFIG_DEBUG_RODATA
100static inline void mark_rodata_ro(void) { }
101#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102
103#ifdef CONFIG_TC
104extern void tc_init(void);
105#endif
106
107enum system_states system_state;
108EXPORT_SYMBOL(system_state);
109
110/*
111 * Boot command-line arguments
112 */
113#define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
114#define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
115
116extern void time_init(void);
117/* Default late time init is NULL. archs can override this later. */
118void (*late_time_init)(void);
119extern void softirq_init(void);
120
121/* Untouched command line (eg. for /proc) saved by arch-specific code. */
122char saved_command_line[COMMAND_LINE_SIZE];
123
124static char *execute_command;
Olof Johanssonffdfc402005-09-06 15:17:19 -0700125static char *ramdisk_execute_command;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126
127/* Setup configured maximum number of CPUs to activate */
128static unsigned int max_cpus = NR_CPUS;
129
130/*
Vivek Goyal7e962872006-09-27 01:50:44 -0700131 * If set, this is an indication to the drivers that reset the underlying
132 * device before going ahead with the initialization otherwise driver might
133 * rely on the BIOS and skip the reset operation.
134 *
135 * This is useful if kernel is booting in an unreliable environment.
136 * For ex. kdump situaiton where previous kernel has crashed, BIOS has been
137 * skipped and devices will be in unknown state.
138 */
139unsigned int reset_devices;
140EXPORT_SYMBOL(reset_devices);
141
142/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143 * Setup routine for controlling SMP activation
144 *
145 * Command-line option of "nosmp" or "maxcpus=0" will disable SMP
146 * activation entirely (the MPS table probe still happens, though).
147 *
148 * Command-line option of "maxcpus=<NUM>", where <NUM> is an integer
149 * greater than 0, limits the maximum number of CPUs activated in
150 * SMP mode to <NUM>.
151 */
152static int __init nosmp(char *str)
153{
154 max_cpus = 0;
155 return 1;
156}
157
158__setup("nosmp", nosmp);
159
160static int __init maxcpus(char *str)
161{
162 get_option(&str, &max_cpus);
163 return 1;
164}
165
166__setup("maxcpus=", maxcpus);
167
Vivek Goyal7e962872006-09-27 01:50:44 -0700168static int __init set_reset_devices(char *str)
169{
170 reset_devices = 1;
171 return 1;
172}
173
174__setup("reset_devices", set_reset_devices);
175
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176static char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
177char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
178static const char *panic_later, *panic_param;
179
180extern struct obs_kernel_param __setup_start[], __setup_end[];
181
182static int __init obsolete_checksetup(char *line)
183{
184 struct obs_kernel_param *p;
Rusty Russell33df0d12006-09-26 10:52:32 +0200185 int had_early_param = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186
187 p = __setup_start;
188 do {
189 int n = strlen(p->str);
190 if (!strncmp(line, p->str, n)) {
191 if (p->early) {
Rusty Russell33df0d12006-09-26 10:52:32 +0200192 /* Already done in parse_early_param?
193 * (Needs exact match on param part).
194 * Keep iterating, as we can have early
195 * params and __setups of same names 8( */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196 if (line[n] == '\0' || line[n] == '=')
Rusty Russell33df0d12006-09-26 10:52:32 +0200197 had_early_param = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198 } else if (!p->setup_func) {
199 printk(KERN_WARNING "Parameter %s is obsolete,"
200 " ignored\n", p->str);
201 return 1;
202 } else if (p->setup_func(line + n))
203 return 1;
204 }
205 p++;
206 } while (p < __setup_end);
Rusty Russell33df0d12006-09-26 10:52:32 +0200207
208 return had_early_param;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209}
210
211/*
212 * This should be approx 2 Bo*oMips to start (note initial shift), and will
213 * still work even if initially too large, it will just take slightly longer
214 */
215unsigned long loops_per_jiffy = (1<<12);
216
217EXPORT_SYMBOL(loops_per_jiffy);
218
219static int __init debug_kernel(char *str)
220{
221 if (*str)
222 return 0;
223 console_loglevel = 10;
224 return 1;
225}
226
227static int __init quiet_kernel(char *str)
228{
229 if (*str)
230 return 0;
231 console_loglevel = 4;
232 return 1;
233}
234
235__setup("debug", debug_kernel);
236__setup("quiet", quiet_kernel);
237
238static int __init loglevel(char *str)
239{
240 get_option(&str, &console_loglevel);
241 return 1;
242}
243
244__setup("loglevel=", loglevel);
245
246/*
247 * Unknown boot options get handed to init, unless they look like
248 * failed parameters
249 */
250static int __init unknown_bootoption(char *param, char *val)
251{
252 /* Change NUL term back to "=", to make "param" the whole string. */
253 if (val) {
254 /* param=val or param="val"? */
255 if (val == param+strlen(param)+1)
256 val[-1] = '=';
257 else if (val == param+strlen(param)+2) {
258 val[-2] = '=';
259 memmove(val-1, val, strlen(val)+1);
260 val--;
261 } else
262 BUG();
263 }
264
265 /* Handle obsolete-style parameters */
266 if (obsolete_checksetup(param))
267 return 0;
268
269 /*
270 * Preemptive maintenance for "why didn't my mispelled command
271 * line work?"
272 */
273 if (strchr(param, '.') && (!val || strchr(param, '.') < val)) {
274 printk(KERN_ERR "Unknown boot option `%s': ignoring\n", param);
275 return 0;
276 }
277
278 if (panic_later)
279 return 0;
280
281 if (val) {
282 /* Environment option */
283 unsigned int i;
284 for (i = 0; envp_init[i]; i++) {
285 if (i == MAX_INIT_ENVS) {
286 panic_later = "Too many boot env vars at `%s'";
287 panic_param = param;
288 }
289 if (!strncmp(param, envp_init[i], val - param))
290 break;
291 }
292 envp_init[i] = param;
293 } else {
294 /* Command line option */
295 unsigned int i;
296 for (i = 0; argv_init[i]; i++) {
297 if (i == MAX_INIT_ARGS) {
298 panic_later = "Too many boot init vars at `%s'";
299 panic_param = param;
300 }
301 }
302 argv_init[i] = param;
303 }
304 return 0;
305}
306
307static int __init init_setup(char *str)
308{
309 unsigned int i;
310
311 execute_command = str;
312 /*
313 * In case LILO is going to boot us with default command line,
314 * it prepends "auto" before the whole cmdline which makes
315 * the shell think it should execute a script with such name.
316 * So we ignore all arguments entered _before_ init=... [MJ]
317 */
318 for (i = 1; i < MAX_INIT_ARGS; i++)
319 argv_init[i] = NULL;
320 return 1;
321}
322__setup("init=", init_setup);
323
Olof Johanssonffdfc402005-09-06 15:17:19 -0700324static int __init rdinit_setup(char *str)
325{
326 unsigned int i;
327
328 ramdisk_execute_command = str;
329 /* See "auto" comment in init_setup */
330 for (i = 1; i < MAX_INIT_ARGS; i++)
331 argv_init[i] = NULL;
332 return 1;
333}
334__setup("rdinit=", rdinit_setup);
335
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336#ifndef CONFIG_SMP
337
338#ifdef CONFIG_X86_LOCAL_APIC
339static void __init smp_init(void)
340{
341 APIC_init_uniprocessor();
342}
343#else
344#define smp_init() do { } while (0)
345#endif
346
347static inline void setup_per_cpu_areas(void) { }
348static inline void smp_prepare_cpus(unsigned int maxcpus) { }
349
350#else
351
352#ifdef __GENERIC_PER_CPU
Eric Dumazetb73b4592006-03-23 03:01:07 -0800353unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700354
355EXPORT_SYMBOL(__per_cpu_offset);
356
357static void __init setup_per_cpu_areas(void)
358{
359 unsigned long size, i;
360 char *ptr;
Eric Dumazet63872f82006-03-23 03:01:04 -0800361 unsigned long nr_possible_cpus = num_possible_cpus();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700362
363 /* Copy section for each CPU (we discard the original) */
364 size = ALIGN(__per_cpu_end - __per_cpu_start, SMP_CACHE_BYTES);
365#ifdef CONFIG_MODULES
366 if (size < PERCPU_ENOUGH_ROOM)
367 size = PERCPU_ENOUGH_ROOM;
368#endif
Eric Dumazet63872f82006-03-23 03:01:04 -0800369 ptr = alloc_bootmem(size * nr_possible_cpus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700370
KAMEZAWA Hiroyuki0a945022006-03-28 01:56:37 -0800371 for_each_possible_cpu(i) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700372 __per_cpu_offset[i] = ptr - __per_cpu_start;
373 memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start);
Eric Dumazet63872f82006-03-23 03:01:04 -0800374 ptr += size;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700375 }
376}
377#endif /* !__GENERIC_PER_CPU */
378
379/* Called by boot processor to activate the rest. */
380static void __init smp_init(void)
381{
382 unsigned int i;
383
384 /* FIXME: This should be done in userspace --RR */
385 for_each_present_cpu(i) {
386 if (num_online_cpus() >= max_cpus)
387 break;
388 if (!cpu_online(i))
389 cpu_up(i);
390 }
391
392 /* Any cleanup work */
393 printk(KERN_INFO "Brought up %ld CPUs\n", (long)num_online_cpus());
394 smp_cpus_done(max_cpus);
395#if 0
396 /* Get other processors into their bootup holding patterns. */
397
398 smp_commence();
399#endif
400}
401
402#endif
403
404/*
405 * We need to finalize in a non-__init function or else race conditions
406 * between the root thread and the init thread may cause start_kernel to
407 * be reaped by free_initmem before the root thread has proceeded to
408 * cpu_idle.
409 *
410 * gcc-3.4 accidentally inlines this function, so use noinline.
411 */
412
413static void noinline rest_init(void)
414 __releases(kernel_lock)
415{
416 kernel_thread(init, NULL, CLONE_FS | CLONE_SIGHAND);
417 numa_default_policy();
418 unlock_kernel();
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200419
420 /*
421 * The boot idle thread must execute schedule()
422 * at least one to get things moving:
423 */
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800424 preempt_enable_no_resched();
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200425 schedule();
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800426 preempt_disable();
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200427
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800428 /* Call into cpu_idle with preempt disabled */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429 cpu_idle();
430}
431
432/* Check for early params. */
433static int __init do_early_param(char *param, char *val)
434{
435 struct obs_kernel_param *p;
436
437 for (p = __setup_start; p < __setup_end; p++) {
438 if (p->early && strcmp(param, p->str) == 0) {
439 if (p->setup_func(val) != 0)
440 printk(KERN_WARNING
441 "Malformed early option '%s'\n", param);
442 }
443 }
444 /* We accept everything at this stage. */
445 return 0;
446}
447
448/* Arch code calls this early on, or if not, just before other parsing. */
449void __init parse_early_param(void)
450{
451 static __initdata int done = 0;
452 static __initdata char tmp_cmdline[COMMAND_LINE_SIZE];
453
454 if (done)
455 return;
456
457 /* All fall through to do_early_param. */
458 strlcpy(tmp_cmdline, saved_command_line, COMMAND_LINE_SIZE);
459 parse_args("early options", tmp_cmdline, NULL, 0, do_early_param);
460 done = 1;
461}
462
463/*
464 * Activate the first processor.
465 */
466
Stas Sergeev44fd2292006-03-23 02:59:44 -0800467static void __init boot_cpu_init(void)
468{
469 int cpu = smp_processor_id();
470 /* Mark the boot cpu "present", "online" etc for SMP and UP case */
471 cpu_set(cpu, cpu_online_map);
472 cpu_set(cpu, cpu_present_map);
473 cpu_set(cpu, cpu_possible_map);
474}
475
Andrew Morton033ab7f2006-06-30 01:55:50 -0700476void __init __attribute__((weak)) smp_setup_processor_id(void)
477{
478}
479
Linus Torvalds1da177e2005-04-16 15:20:36 -0700480asmlinkage void __init start_kernel(void)
481{
482 char * command_line;
483 extern struct kernel_param __start___param[], __stop___param[];
Andrew Morton033ab7f2006-06-30 01:55:50 -0700484
485 smp_setup_processor_id();
486
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700487 /*
488 * Need to run as early as possible, to initialize the
489 * lockdep hash:
490 */
Andi Kleenc9538ed2006-09-26 10:52:34 +0200491 unwind_init();
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700492 lockdep_init();
493
494 local_irq_disable();
495 early_boot_irqs_off();
Ingo Molnar243c7622006-07-03 00:25:06 -0700496 early_init_irq_lock_class();
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700497
Linus Torvalds1da177e2005-04-16 15:20:36 -0700498/*
499 * Interrupts are still disabled. Do necessary setups, then
500 * enable them
501 */
502 lock_kernel();
Stas Sergeev44fd2292006-03-23 02:59:44 -0800503 boot_cpu_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700504 page_address_init();
505 printk(KERN_NOTICE);
506 printk(linux_banner);
507 setup_arch(&command_line);
508 setup_per_cpu_areas();
Stas Sergeev44fd2292006-03-23 02:59:44 -0800509 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700510
511 /*
512 * Set up the scheduler prior starting any interrupts (such as the
513 * timer interrupt). Full topology setup happens at smp_init()
514 * time - but meanwhile we still have a functioning scheduler.
515 */
516 sched_init();
517 /*
518 * Disable preemption - early bootup scheduling is extremely
519 * fragile until we cpu_idle() for the first time.
520 */
521 preempt_disable();
522 build_all_zonelists();
523 page_alloc_init();
524 printk(KERN_NOTICE "Kernel command line: %s\n", saved_command_line);
525 parse_early_param();
526 parse_args("Booting kernel", command_line, __start___param,
527 __stop___param - __start___param,
528 &unknown_bootoption);
529 sort_main_extable();
530 trap_init();
531 rcu_init();
532 init_IRQ();
533 pidhash_init();
534 init_timers();
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800535 hrtimers_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700536 softirq_init();
john stultzad596172006-06-26 00:25:06 -0700537 timekeeping_init();
john stultz88fecaa2006-07-03 00:24:04 -0700538 time_init();
Heiko Carstens93e02812006-07-03 00:24:24 -0700539 profile_init();
540 if (!irqs_disabled())
541 printk("start_kernel(): bug: interrupts were enabled early\n");
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700542 early_boot_irqs_on();
Heiko Carstens93e02812006-07-03 00:24:24 -0700543 local_irq_enable();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700544
545 /*
546 * HACK ALERT! This is early. We're enabling the console before
547 * we've done PCI setups etc, and console_init() must be aware of
548 * this. But we do want output early, in case something goes wrong.
549 */
550 console_init();
551 if (panic_later)
552 panic(panic_later, panic_param);
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700553
554 lockdep_info();
555
Ingo Molnar9a11b49a2006-07-03 00:24:33 -0700556 /*
557 * Need to run this when irqs are enabled, because it wants
558 * to self-test [hard/soft]-irqs on/off lock inversion bugs
559 * too:
560 */
561 locking_selftest();
562
Linus Torvalds1da177e2005-04-16 15:20:36 -0700563#ifdef CONFIG_BLK_DEV_INITRD
564 if (initrd_start && !initrd_below_start_ok &&
565 initrd_start < min_low_pfn << PAGE_SHIFT) {
566 printk(KERN_CRIT "initrd overwritten (0x%08lx < 0x%08lx) - "
567 "disabling it.\n",initrd_start,min_low_pfn << PAGE_SHIFT);
568 initrd_start = 0;
569 }
570#endif
571 vfs_caches_init_early();
Paul Jacksonc417f022006-01-08 01:02:01 -0800572 cpuset_init_early();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700573 mem_init();
574 kmem_cache_init();
Christoph Lametere7c8d5c2005-06-21 17:14:47 -0700575 setup_per_cpu_pageset();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700576 numa_policy_init();
577 if (late_time_init)
578 late_time_init();
579 calibrate_delay();
580 pidmap_init();
581 pgtable_cache_init();
582 prio_tree_init();
583 anon_vma_init();
584#ifdef CONFIG_X86
585 if (efi_enabled)
586 efi_enter_virtual_mode();
587#endif
588 fork_init(num_physpages);
589 proc_caches_init();
590 buffer_init();
591 unnamed_dev_init();
592 key_init();
593 security_init();
594 vfs_caches_init(num_physpages);
595 radix_tree_init();
596 signals_init();
597 /* rootfs populating might need page-writeback */
598 page_writeback_init();
599#ifdef CONFIG_PROC_FS
600 proc_root_init();
601#endif
602 cpuset_init();
Shailabh Nagarc7572492006-07-14 00:24:40 -0700603 taskstats_init_early();
Shailabh Nagarca74e922006-07-14 00:24:36 -0700604 delayacct_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700605
606 check_bugs();
607
608 acpi_early_init(); /* before LAPIC and SMP init */
609
610 /* Do the rest non-__init'ed, we're now alive */
611 rest_init();
612}
613
614static int __initdata initcall_debug;
615
616static int __init initcall_debug_setup(char *str)
617{
618 initcall_debug = 1;
619 return 1;
620}
621__setup("initcall_debug", initcall_debug_setup);
622
623struct task_struct *child_reaper = &init_task;
624
625extern initcall_t __initcall_start[], __initcall_end[];
626
627static void __init do_initcalls(void)
628{
629 initcall_t *call;
630 int count = preempt_count();
631
632 for (call = __initcall_start; call < __initcall_end; call++) {
Andrew Mortonc1cda482006-03-25 03:07:15 -0800633 char *msg = NULL;
634 char msgbuf[40];
635 int result;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700636
637 if (initcall_debug) {
Andrew Mortonc1cda482006-03-25 03:07:15 -0800638 printk("Calling initcall 0x%p", *call);
639 print_fn_descriptor_symbol(": %s()",
640 (unsigned long) *call);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700641 printk("\n");
642 }
643
Andrew Mortonc1cda482006-03-25 03:07:15 -0800644 result = (*call)();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700645
Andrew Mortonf3a19cb2006-05-01 12:15:52 -0700646 if (result && result != -ENODEV && initcall_debug) {
Andrew Mortonc1cda482006-03-25 03:07:15 -0800647 sprintf(msgbuf, "error code %d", result);
648 msg = msgbuf;
649 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700650 if (preempt_count() != count) {
651 msg = "preemption imbalance";
652 preempt_count() = count;
653 }
654 if (irqs_disabled()) {
655 msg = "disabled interrupts";
656 local_irq_enable();
657 }
658 if (msg) {
Andrew Mortonc1cda482006-03-25 03:07:15 -0800659 printk(KERN_WARNING "initcall at 0x%p", *call);
660 print_fn_descriptor_symbol(": %s()",
661 (unsigned long) *call);
662 printk(": returned with %s\n", msg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700663 }
664 }
665
666 /* Make sure there is no pending stuff from the initcall sequence */
667 flush_scheduled_work();
668}
669
670/*
671 * Ok, the machine is now initialized. None of the devices
672 * have been touched yet, but the CPU subsystem is up and
673 * running, and memory and process management works.
674 *
675 * Now we can finally start doing some real work..
676 */
677static void __init do_basic_setup(void)
678{
679 /* drivers will send hotplug events */
680 init_workqueues();
681 usermodehelper_init();
682 driver_init();
683
684#ifdef CONFIG_SYSCTL
685 sysctl_init();
686#endif
687
Linus Torvalds1da177e2005-04-16 15:20:36 -0700688 do_initcalls();
689}
690
691static void do_pre_smp_initcalls(void)
692{
693 extern int spawn_ksoftirqd(void);
694#ifdef CONFIG_SMP
695 extern int migration_init(void);
696
697 migration_init();
698#endif
699 spawn_ksoftirqd();
Ingo Molnar8446f1d2005-09-06 15:16:27 -0700700 spawn_softlockup_task();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700701}
702
703static void run_init_process(char *init_filename)
704{
705 argv_init[0] = init_filename;
706 execve(init_filename, argv_init, envp_init);
707}
708
Linus Torvalds1da177e2005-04-16 15:20:36 -0700709static int init(void * unused)
710{
711 lock_kernel();
712 /*
713 * init can run on any cpu.
714 */
715 set_cpus_allowed(current, CPU_MASK_ALL);
716 /*
717 * Tell the world that we're going to be the grim
718 * reaper of innocent orphaned children.
719 *
720 * We don't want people to have to make incorrect
721 * assumptions about where in the task array this
722 * can be found.
723 */
724 child_reaper = current;
725
Linus Torvalds1da177e2005-04-16 15:20:36 -0700726 smp_prepare_cpus(max_cpus);
727
728 do_pre_smp_initcalls();
729
Linus Torvalds1da177e2005-04-16 15:20:36 -0700730 smp_init();
731 sched_init_smp();
732
733 cpuset_init_smp();
734
735 /*
736 * Do this before initcalls, because some drivers want to access
737 * firmware files.
738 */
739 populate_rootfs();
740
741 do_basic_setup();
742
743 /*
744 * check if there is an early userspace init. If yes, let it do all
745 * the work
746 */
Olof Johanssonffdfc402005-09-06 15:17:19 -0700747
748 if (!ramdisk_execute_command)
749 ramdisk_execute_command = "/init";
750
751 if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
752 ramdisk_execute_command = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700753 prepare_namespace();
Olof Johanssonffdfc402005-09-06 15:17:19 -0700754 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700755
756 /*
757 * Ok, we have completed the initial bootup, and
758 * we're essentially up and running. Get rid of the
759 * initmem segments and start the user-mode stuff..
760 */
761 free_initmem();
762 unlock_kernel();
Arjan van de Ven37b73c82006-01-06 00:12:01 -0800763 mark_rodata_ro();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700764 system_state = SYSTEM_RUNNING;
765 numa_default_policy();
766
767 if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
768 printk(KERN_WARNING "Warning: unable to open an initial console.\n");
769
770 (void) sys_dup(0);
771 (void) sys_dup(0);
Olof Johanssonffdfc402005-09-06 15:17:19 -0700772
773 if (ramdisk_execute_command) {
774 run_init_process(ramdisk_execute_command);
775 printk(KERN_WARNING "Failed to execute %s\n",
776 ramdisk_execute_command);
777 }
778
Linus Torvalds1da177e2005-04-16 15:20:36 -0700779 /*
780 * We try each of these until one succeeds.
781 *
782 * The Bourne shell can be used instead of init if we are
783 * trying to recover a really broken machine.
784 */
Avery, Brianc1d7ef72005-09-06 15:16:56 -0700785 if (execute_command) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700786 run_init_process(execute_command);
Avery, Brianc1d7ef72005-09-06 15:16:56 -0700787 printk(KERN_WARNING "Failed to execute %s. Attempting "
788 "defaults...\n", execute_command);
789 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700790 run_init_process("/sbin/init");
791 run_init_process("/etc/init");
792 run_init_process("/bin/init");
793 run_init_process("/bin/sh");
794
795 panic("No init found. Try passing init= option to kernel.");
796}