blob: 953500b02ac4136f4ad30aa0ea6b285019234131 [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
Linus Torvalds1da177e2005-04-16 15:20:36 -070012#include <linux/types.h>
13#include <linux/module.h>
14#include <linux/proc_fs.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070015#include <linux/kernel.h>
16#include <linux/syscalls.h>
17#include <linux/string.h>
18#include <linux/ctype.h>
19#include <linux/delay.h>
20#include <linux/utsname.h>
21#include <linux/ioport.h>
22#include <linux/init.h>
23#include <linux/smp_lock.h>
24#include <linux/initrd.h>
25#include <linux/hdreg.h>
26#include <linux/bootmem.h>
27#include <linux/tty.h>
28#include <linux/gfp.h>
29#include <linux/percpu.h>
30#include <linux/kmod.h>
31#include <linux/kernel_stat.h>
Rusty Russelld7cd5612006-12-07 02:14:08 +010032#include <linux/start_kernel.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070033#include <linux/security.h>
34#include <linux/workqueue.h>
35#include <linux/profile.h>
36#include <linux/rcupdate.h>
37#include <linux/moduleparam.h>
38#include <linux/kallsyms.h>
39#include <linux/writeback.h>
40#include <linux/cpu.h>
41#include <linux/cpuset.h>
42#include <linux/efi.h>
Thomas Gleixner906568c2007-02-16 01:28:01 -080043#include <linux/tick.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>
Sukadev Bhattiprolu84d73782006-12-08 02:38:01 -080054#include <linux/pid_namespace.h>
Adrian Bunk1f217822006-12-19 13:01:28 -080055#include <linux/device.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070056
57#include <asm/io.h>
58#include <asm/bugs.h>
59#include <asm/setup.h>
Andi Kleena9401992005-07-28 21:15:30 -070060#include <asm/sections.h>
Arjan van de Ven37b73c82006-01-06 00:12:01 -080061#include <asm/cacheflush.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070062
Linus Torvalds1da177e2005-04-16 15:20:36 -070063#ifdef CONFIG_X86_LOCAL_APIC
64#include <asm/smp.h>
65#endif
66
67/*
Coywolf Qi Hunt69c99ac2006-01-14 13:21:11 -080068 * This is one of the first .c files built. Error out early if we have compiler
69 * trouble.
70 *
71 * Versions of gcc older than that listed below may actually compile and link
72 * okay, but the end product can have subtle run time bugs. To avoid associated
73 * bogus bug reports, we flatly refuse to compile with a gcc that is known to be
74 * too old from the very beginning.
Linus Torvalds1da177e2005-04-16 15:20:36 -070075 */
Andrew Mortonfd285bb2006-01-08 01:04:07 -080076#if (__GNUC__ < 3) || (__GNUC__ == 3 && __GNUC_MINOR__ < 2)
Linus Torvalds1da177e2005-04-16 15:20:36 -070077#error Sorry, your GCC is too old. It builds incorrect kernels.
78#endif
79
Andrew Mortonf1a60db2006-12-06 20:39:59 -080080#if __GNUC__ == 4 && __GNUC_MINOR__ == 1 && __GNUC_PATCHLEVEL__ == 0
81#warning gcc-4.1.0 is known to miscompile the kernel. A different compiler version is recommended.
82#endif
83
Linus Torvalds1da177e2005-04-16 15:20:36 -070084static int init(void *);
85
86extern void init_IRQ(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070087extern void fork_init(unsigned long);
88extern void mca_init(void);
89extern void sbus_init(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070090extern void signals_init(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070091extern void pidhash_init(void);
92extern void pidmap_init(void);
93extern void prio_tree_init(void);
94extern void radix_tree_init(void);
95extern void free_initmem(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070096extern void prepare_namespace(void);
97#ifdef CONFIG_ACPI
98extern void acpi_early_init(void);
99#else
100static inline void acpi_early_init(void) { }
101#endif
Arjan van de Ven37b73c82006-01-06 00:12:01 -0800102#ifndef CONFIG_DEBUG_RODATA
103static inline void mark_rodata_ro(void) { }
104#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105
106#ifdef CONFIG_TC
107extern void tc_init(void);
108#endif
109
110enum system_states system_state;
111EXPORT_SYMBOL(system_state);
112
113/*
114 * Boot command-line arguments
115 */
116#define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
117#define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
118
119extern void time_init(void);
120/* Default late time init is NULL. archs can override this later. */
121void (*late_time_init)(void);
122extern void softirq_init(void);
123
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800124/* Untouched command line saved by arch-specific code. */
125char __initdata boot_command_line[COMMAND_LINE_SIZE];
126/* Untouched saved command line (eg. for /proc) */
127char *saved_command_line;
128/* Command line for parameter parsing */
129static char *static_command_line;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130
131static char *execute_command;
Olof Johanssonffdfc402005-09-06 15:17:19 -0700132static char *ramdisk_execute_command;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133
134/* Setup configured maximum number of CPUs to activate */
135static unsigned int max_cpus = NR_CPUS;
136
137/*
Vivek Goyal7e962872006-09-27 01:50:44 -0700138 * If set, this is an indication to the drivers that reset the underlying
139 * device before going ahead with the initialization otherwise driver might
140 * rely on the BIOS and skip the reset operation.
141 *
142 * This is useful if kernel is booting in an unreliable environment.
143 * For ex. kdump situaiton where previous kernel has crashed, BIOS has been
144 * skipped and devices will be in unknown state.
145 */
146unsigned int reset_devices;
147EXPORT_SYMBOL(reset_devices);
148
149/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150 * Setup routine for controlling SMP activation
151 *
152 * Command-line option of "nosmp" or "maxcpus=0" will disable SMP
153 * activation entirely (the MPS table probe still happens, though).
154 *
155 * Command-line option of "maxcpus=<NUM>", where <NUM> is an integer
156 * greater than 0, limits the maximum number of CPUs activated in
157 * SMP mode to <NUM>.
158 */
159static int __init nosmp(char *str)
160{
161 max_cpus = 0;
162 return 1;
163}
164
165__setup("nosmp", nosmp);
166
167static int __init maxcpus(char *str)
168{
169 get_option(&str, &max_cpus);
170 return 1;
171}
172
173__setup("maxcpus=", maxcpus);
174
Vivek Goyal7e962872006-09-27 01:50:44 -0700175static int __init set_reset_devices(char *str)
176{
177 reset_devices = 1;
178 return 1;
179}
180
181__setup("reset_devices", set_reset_devices);
182
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183static char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
184char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
185static const char *panic_later, *panic_param;
186
187extern struct obs_kernel_param __setup_start[], __setup_end[];
188
189static int __init obsolete_checksetup(char *line)
190{
191 struct obs_kernel_param *p;
Rusty Russell33df0d12006-09-26 10:52:32 +0200192 int had_early_param = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193
194 p = __setup_start;
195 do {
196 int n = strlen(p->str);
197 if (!strncmp(line, p->str, n)) {
198 if (p->early) {
Rusty Russell33df0d12006-09-26 10:52:32 +0200199 /* Already done in parse_early_param?
200 * (Needs exact match on param part).
201 * Keep iterating, as we can have early
202 * params and __setups of same names 8( */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203 if (line[n] == '\0' || line[n] == '=')
Rusty Russell33df0d12006-09-26 10:52:32 +0200204 had_early_param = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205 } else if (!p->setup_func) {
206 printk(KERN_WARNING "Parameter %s is obsolete,"
207 " ignored\n", p->str);
208 return 1;
209 } else if (p->setup_func(line + n))
210 return 1;
211 }
212 p++;
213 } while (p < __setup_end);
Rusty Russell33df0d12006-09-26 10:52:32 +0200214
215 return had_early_param;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216}
217
218/*
219 * This should be approx 2 Bo*oMips to start (note initial shift), and will
220 * still work even if initially too large, it will just take slightly longer
221 */
222unsigned long loops_per_jiffy = (1<<12);
223
224EXPORT_SYMBOL(loops_per_jiffy);
225
226static int __init debug_kernel(char *str)
227{
228 if (*str)
229 return 0;
230 console_loglevel = 10;
231 return 1;
232}
233
234static int __init quiet_kernel(char *str)
235{
236 if (*str)
237 return 0;
238 console_loglevel = 4;
239 return 1;
240}
241
242__setup("debug", debug_kernel);
243__setup("quiet", quiet_kernel);
244
245static int __init loglevel(char *str)
246{
247 get_option(&str, &console_loglevel);
248 return 1;
249}
250
251__setup("loglevel=", loglevel);
252
253/*
254 * Unknown boot options get handed to init, unless they look like
255 * failed parameters
256 */
257static int __init unknown_bootoption(char *param, char *val)
258{
259 /* Change NUL term back to "=", to make "param" the whole string. */
260 if (val) {
261 /* param=val or param="val"? */
262 if (val == param+strlen(param)+1)
263 val[-1] = '=';
264 else if (val == param+strlen(param)+2) {
265 val[-2] = '=';
266 memmove(val-1, val, strlen(val)+1);
267 val--;
268 } else
269 BUG();
270 }
271
272 /* Handle obsolete-style parameters */
273 if (obsolete_checksetup(param))
274 return 0;
275
276 /*
277 * Preemptive maintenance for "why didn't my mispelled command
278 * line work?"
279 */
280 if (strchr(param, '.') && (!val || strchr(param, '.') < val)) {
281 printk(KERN_ERR "Unknown boot option `%s': ignoring\n", param);
282 return 0;
283 }
284
285 if (panic_later)
286 return 0;
287
288 if (val) {
289 /* Environment option */
290 unsigned int i;
291 for (i = 0; envp_init[i]; i++) {
292 if (i == MAX_INIT_ENVS) {
293 panic_later = "Too many boot env vars at `%s'";
294 panic_param = param;
295 }
296 if (!strncmp(param, envp_init[i], val - param))
297 break;
298 }
299 envp_init[i] = param;
300 } else {
301 /* Command line option */
302 unsigned int i;
303 for (i = 0; argv_init[i]; i++) {
304 if (i == MAX_INIT_ARGS) {
305 panic_later = "Too many boot init vars at `%s'";
306 panic_param = param;
307 }
308 }
309 argv_init[i] = param;
310 }
311 return 0;
312}
313
314static int __init init_setup(char *str)
315{
316 unsigned int i;
317
318 execute_command = str;
319 /*
320 * In case LILO is going to boot us with default command line,
321 * it prepends "auto" before the whole cmdline which makes
322 * the shell think it should execute a script with such name.
323 * So we ignore all arguments entered _before_ init=... [MJ]
324 */
325 for (i = 1; i < MAX_INIT_ARGS; i++)
326 argv_init[i] = NULL;
327 return 1;
328}
329__setup("init=", init_setup);
330
Olof Johanssonffdfc402005-09-06 15:17:19 -0700331static int __init rdinit_setup(char *str)
332{
333 unsigned int i;
334
335 ramdisk_execute_command = str;
336 /* See "auto" comment in init_setup */
337 for (i = 1; i < MAX_INIT_ARGS; i++)
338 argv_init[i] = NULL;
339 return 1;
340}
341__setup("rdinit=", rdinit_setup);
342
Linus Torvalds1da177e2005-04-16 15:20:36 -0700343#ifndef CONFIG_SMP
344
345#ifdef CONFIG_X86_LOCAL_APIC
346static void __init smp_init(void)
347{
348 APIC_init_uniprocessor();
349}
350#else
351#define smp_init() do { } while (0)
352#endif
353
354static inline void setup_per_cpu_areas(void) { }
355static inline void smp_prepare_cpus(unsigned int maxcpus) { }
356
357#else
358
359#ifdef __GENERIC_PER_CPU
Eric Dumazetb73b4592006-03-23 03:01:07 -0800360unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700361
362EXPORT_SYMBOL(__per_cpu_offset);
363
364static void __init setup_per_cpu_areas(void)
365{
366 unsigned long size, i;
367 char *ptr;
Eric Dumazet63872f82006-03-23 03:01:04 -0800368 unsigned long nr_possible_cpus = num_possible_cpus();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700369
370 /* Copy section for each CPU (we discard the original) */
371 size = ALIGN(__per_cpu_end - __per_cpu_start, SMP_CACHE_BYTES);
372#ifdef CONFIG_MODULES
373 if (size < PERCPU_ENOUGH_ROOM)
374 size = PERCPU_ENOUGH_ROOM;
375#endif
Eric Dumazet63872f82006-03-23 03:01:04 -0800376 ptr = alloc_bootmem(size * nr_possible_cpus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700377
KAMEZAWA Hiroyuki0a945022006-03-28 01:56:37 -0800378 for_each_possible_cpu(i) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700379 __per_cpu_offset[i] = ptr - __per_cpu_start;
380 memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start);
Eric Dumazet63872f82006-03-23 03:01:04 -0800381 ptr += size;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700382 }
383}
384#endif /* !__GENERIC_PER_CPU */
385
386/* Called by boot processor to activate the rest. */
387static void __init smp_init(void)
388{
389 unsigned int i;
390
391 /* FIXME: This should be done in userspace --RR */
392 for_each_present_cpu(i) {
393 if (num_online_cpus() >= max_cpus)
394 break;
395 if (!cpu_online(i))
396 cpu_up(i);
397 }
398
399 /* Any cleanup work */
400 printk(KERN_INFO "Brought up %ld CPUs\n", (long)num_online_cpus());
401 smp_cpus_done(max_cpus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402}
403
404#endif
405
406/*
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800407 * We need to store the untouched command line for future reference.
408 * We also need to store the touched command line since the parameter
409 * parsing is performed in place, and we should allow a component to
410 * store reference of name/value for future reference.
411 */
412static void __init setup_command_line(char *command_line)
413{
414 saved_command_line = alloc_bootmem(strlen (boot_command_line)+1);
415 static_command_line = alloc_bootmem(strlen (command_line)+1);
416 strcpy (saved_command_line, boot_command_line);
417 strcpy (static_command_line, command_line);
418}
419
420/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700421 * We need to finalize in a non-__init function or else race conditions
422 * between the root thread and the init thread may cause start_kernel to
423 * be reaped by free_initmem before the root thread has proceeded to
424 * cpu_idle.
425 *
426 * gcc-3.4 accidentally inlines this function, so use noinline.
427 */
428
429static void noinline rest_init(void)
430 __releases(kernel_lock)
431{
432 kernel_thread(init, NULL, CLONE_FS | CLONE_SIGHAND);
433 numa_default_policy();
434 unlock_kernel();
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200435
436 /*
437 * The boot idle thread must execute schedule()
438 * at least one to get things moving:
439 */
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800440 preempt_enable_no_resched();
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200441 schedule();
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800442 preempt_disable();
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200443
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800444 /* Call into cpu_idle with preempt disabled */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445 cpu_idle();
446}
447
448/* Check for early params. */
449static int __init do_early_param(char *param, char *val)
450{
451 struct obs_kernel_param *p;
452
453 for (p = __setup_start; p < __setup_end; p++) {
454 if (p->early && strcmp(param, p->str) == 0) {
455 if (p->setup_func(val) != 0)
456 printk(KERN_WARNING
457 "Malformed early option '%s'\n", param);
458 }
459 }
460 /* We accept everything at this stage. */
461 return 0;
462}
463
464/* Arch code calls this early on, or if not, just before other parsing. */
465void __init parse_early_param(void)
466{
467 static __initdata int done = 0;
468 static __initdata char tmp_cmdline[COMMAND_LINE_SIZE];
469
470 if (done)
471 return;
472
473 /* All fall through to do_early_param. */
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800474 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700475 parse_args("early options", tmp_cmdline, NULL, 0, do_early_param);
476 done = 1;
477}
478
479/*
480 * Activate the first processor.
481 */
482
Stas Sergeev44fd2292006-03-23 02:59:44 -0800483static void __init boot_cpu_init(void)
484{
485 int cpu = smp_processor_id();
486 /* Mark the boot cpu "present", "online" etc for SMP and UP case */
487 cpu_set(cpu, cpu_online_map);
488 cpu_set(cpu, cpu_present_map);
489 cpu_set(cpu, cpu_possible_map);
490}
491
Andrew Morton033ab7f2006-06-30 01:55:50 -0700492void __init __attribute__((weak)) smp_setup_processor_id(void)
493{
494}
495
Linus Torvalds1da177e2005-04-16 15:20:36 -0700496asmlinkage void __init start_kernel(void)
497{
498 char * command_line;
499 extern struct kernel_param __start___param[], __stop___param[];
Andrew Morton033ab7f2006-06-30 01:55:50 -0700500
501 smp_setup_processor_id();
502
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700503 /*
504 * Need to run as early as possible, to initialize the
505 * lockdep hash:
506 */
Andi Kleenc9538ed2006-09-26 10:52:34 +0200507 unwind_init();
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700508 lockdep_init();
509
510 local_irq_disable();
511 early_boot_irqs_off();
Ingo Molnar243c7622006-07-03 00:25:06 -0700512 early_init_irq_lock_class();
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700513
Linus Torvalds1da177e2005-04-16 15:20:36 -0700514/*
515 * Interrupts are still disabled. Do necessary setups, then
516 * enable them
517 */
518 lock_kernel();
Thomas Gleixner906568c2007-02-16 01:28:01 -0800519 tick_init();
Stas Sergeev44fd2292006-03-23 02:59:44 -0800520 boot_cpu_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700521 page_address_init();
522 printk(KERN_NOTICE);
Linus Torvalds89937802006-12-11 09:28:46 -0800523 printk(linux_banner);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700524 setup_arch(&command_line);
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800525 setup_command_line(command_line);
Jan Beulich690a9732006-10-21 18:37:01 +0200526 unwind_setup();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700527 setup_per_cpu_areas();
Stas Sergeev44fd2292006-03-23 02:59:44 -0800528 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700529
530 /*
531 * Set up the scheduler prior starting any interrupts (such as the
532 * timer interrupt). Full topology setup happens at smp_init()
533 * time - but meanwhile we still have a functioning scheduler.
534 */
535 sched_init();
536 /*
537 * Disable preemption - early bootup scheduling is extremely
538 * fragile until we cpu_idle() for the first time.
539 */
540 preempt_disable();
541 build_all_zonelists();
542 page_alloc_init();
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800543 printk(KERN_NOTICE "Kernel command line: %s\n", boot_command_line);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700544 parse_early_param();
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800545 parse_args("Booting kernel", static_command_line, __start___param,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700546 __stop___param - __start___param,
547 &unknown_bootoption);
Ard van Breemenc4a68302007-01-05 16:36:19 -0800548 if (!irqs_disabled()) {
549 printk(KERN_WARNING "start_kernel(): bug: interrupts were "
550 "enabled *very* early, fixing it\n");
551 local_irq_disable();
552 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700553 sort_main_extable();
554 trap_init();
555 rcu_init();
556 init_IRQ();
557 pidhash_init();
558 init_timers();
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800559 hrtimers_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700560 softirq_init();
john stultzad596172006-06-26 00:25:06 -0700561 timekeeping_init();
john stultz88fecaa2006-07-03 00:24:04 -0700562 time_init();
Heiko Carstens93e02812006-07-03 00:24:24 -0700563 profile_init();
564 if (!irqs_disabled())
565 printk("start_kernel(): bug: interrupts were enabled early\n");
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700566 early_boot_irqs_on();
Heiko Carstens93e02812006-07-03 00:24:24 -0700567 local_irq_enable();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700568
569 /*
570 * HACK ALERT! This is early. We're enabling the console before
571 * we've done PCI setups etc, and console_init() must be aware of
572 * this. But we do want output early, in case something goes wrong.
573 */
574 console_init();
575 if (panic_later)
576 panic(panic_later, panic_param);
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700577
578 lockdep_info();
579
Ingo Molnar9a11b49a2006-07-03 00:24:33 -0700580 /*
581 * Need to run this when irqs are enabled, because it wants
582 * to self-test [hard/soft]-irqs on/off lock inversion bugs
583 * too:
584 */
585 locking_selftest();
586
Linus Torvalds1da177e2005-04-16 15:20:36 -0700587#ifdef CONFIG_BLK_DEV_INITRD
588 if (initrd_start && !initrd_below_start_ok &&
589 initrd_start < min_low_pfn << PAGE_SHIFT) {
590 printk(KERN_CRIT "initrd overwritten (0x%08lx < 0x%08lx) - "
591 "disabling it.\n",initrd_start,min_low_pfn << PAGE_SHIFT);
592 initrd_start = 0;
593 }
594#endif
595 vfs_caches_init_early();
Paul Jacksonc417f022006-01-08 01:02:01 -0800596 cpuset_init_early();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700597 mem_init();
598 kmem_cache_init();
Christoph Lametere7c8d5c2005-06-21 17:14:47 -0700599 setup_per_cpu_pageset();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700600 numa_policy_init();
601 if (late_time_init)
602 late_time_init();
603 calibrate_delay();
604 pidmap_init();
605 pgtable_cache_init();
606 prio_tree_init();
607 anon_vma_init();
608#ifdef CONFIG_X86
609 if (efi_enabled)
610 efi_enter_virtual_mode();
611#endif
612 fork_init(num_physpages);
613 proc_caches_init();
614 buffer_init();
615 unnamed_dev_init();
616 key_init();
617 security_init();
618 vfs_caches_init(num_physpages);
619 radix_tree_init();
620 signals_init();
621 /* rootfs populating might need page-writeback */
622 page_writeback_init();
623#ifdef CONFIG_PROC_FS
624 proc_root_init();
625#endif
626 cpuset_init();
Shailabh Nagarc7572492006-07-14 00:24:40 -0700627 taskstats_init_early();
Shailabh Nagarca74e922006-07-14 00:24:36 -0700628 delayacct_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700629
630 check_bugs();
631
632 acpi_early_init(); /* before LAPIC and SMP init */
633
634 /* Do the rest non-__init'ed, we're now alive */
635 rest_init();
636}
637
638static int __initdata initcall_debug;
639
640static int __init initcall_debug_setup(char *str)
641{
642 initcall_debug = 1;
643 return 1;
644}
645__setup("initcall_debug", initcall_debug_setup);
646
Linus Torvalds1da177e2005-04-16 15:20:36 -0700647extern initcall_t __initcall_start[], __initcall_end[];
648
649static void __init do_initcalls(void)
650{
651 initcall_t *call;
652 int count = preempt_count();
653
654 for (call = __initcall_start; call < __initcall_end; call++) {
Andrew Mortonc1cda482006-03-25 03:07:15 -0800655 char *msg = NULL;
656 char msgbuf[40];
657 int result;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700658
659 if (initcall_debug) {
Andrew Mortonc1cda482006-03-25 03:07:15 -0800660 printk("Calling initcall 0x%p", *call);
661 print_fn_descriptor_symbol(": %s()",
662 (unsigned long) *call);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700663 printk("\n");
664 }
665
Andrew Mortonc1cda482006-03-25 03:07:15 -0800666 result = (*call)();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700667
Andrew Mortonf3a19cb2006-05-01 12:15:52 -0700668 if (result && result != -ENODEV && initcall_debug) {
Andrew Mortonc1cda482006-03-25 03:07:15 -0800669 sprintf(msgbuf, "error code %d", result);
670 msg = msgbuf;
671 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700672 if (preempt_count() != count) {
673 msg = "preemption imbalance";
674 preempt_count() = count;
675 }
676 if (irqs_disabled()) {
677 msg = "disabled interrupts";
678 local_irq_enable();
679 }
680 if (msg) {
Andrew Mortonc1cda482006-03-25 03:07:15 -0800681 printk(KERN_WARNING "initcall at 0x%p", *call);
682 print_fn_descriptor_symbol(": %s()",
683 (unsigned long) *call);
684 printk(": returned with %s\n", msg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700685 }
686 }
687
688 /* Make sure there is no pending stuff from the initcall sequence */
689 flush_scheduled_work();
690}
691
692/*
693 * Ok, the machine is now initialized. None of the devices
694 * have been touched yet, but the CPU subsystem is up and
695 * running, and memory and process management works.
696 *
697 * Now we can finally start doing some real work..
698 */
699static void __init do_basic_setup(void)
700{
701 /* drivers will send hotplug events */
702 init_workqueues();
703 usermodehelper_init();
704 driver_init();
705
Eric W. Biedermanb04c3af2007-02-14 00:33:57 -0800706#ifdef CONFIG_PROC_FS
707 init_irq_proc();
708#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700709
Linus Torvalds1da177e2005-04-16 15:20:36 -0700710 do_initcalls();
711}
712
Vivek Goyal88d20322007-01-11 01:52:44 +0100713static void __init do_pre_smp_initcalls(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700714{
715 extern int spawn_ksoftirqd(void);
716#ifdef CONFIG_SMP
717 extern int migration_init(void);
718
719 migration_init();
720#endif
721 spawn_ksoftirqd();
Ingo Molnar8446f1d2005-09-06 15:16:27 -0700722 spawn_softlockup_task();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700723}
724
725static void run_init_process(char *init_filename)
726{
727 argv_init[0] = init_filename;
Arnd Bergmann67608562006-10-02 02:18:26 -0700728 kernel_execve(init_filename, argv_init, envp_init);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700729}
730
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100731/* This is a non __init function. Force it to be noinline otherwise gcc
732 * makes it inline to init() and it becomes part of init.text section
733 */
734static int noinline init_post(void)
735{
736 free_initmem();
737 unlock_kernel();
738 mark_rodata_ro();
739 system_state = SYSTEM_RUNNING;
740 numa_default_policy();
741
742 if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
743 printk(KERN_WARNING "Warning: unable to open an initial console.\n");
744
745 (void) sys_dup(0);
746 (void) sys_dup(0);
747
748 if (ramdisk_execute_command) {
749 run_init_process(ramdisk_execute_command);
750 printk(KERN_WARNING "Failed to execute %s\n",
751 ramdisk_execute_command);
752 }
753
754 /*
755 * We try each of these until one succeeds.
756 *
757 * The Bourne shell can be used instead of init if we are
758 * trying to recover a really broken machine.
759 */
760 if (execute_command) {
761 run_init_process(execute_command);
762 printk(KERN_WARNING "Failed to execute %s. Attempting "
763 "defaults...\n", execute_command);
764 }
765 run_init_process("/sbin/init");
766 run_init_process("/etc/init");
767 run_init_process("/bin/init");
768 run_init_process("/bin/sh");
769
770 panic("No init found. Try passing init= option to kernel.");
771}
772
773static int __init init(void * unused)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700774{
775 lock_kernel();
776 /*
777 * init can run on any cpu.
778 */
779 set_cpus_allowed(current, CPU_MASK_ALL);
780 /*
781 * Tell the world that we're going to be the grim
782 * reaper of innocent orphaned children.
783 *
784 * We don't want people to have to make incorrect
785 * assumptions about where in the task array this
786 * can be found.
787 */
Sukadev Bhattiprolu84d73782006-12-08 02:38:01 -0800788 init_pid_ns.child_reaper = current;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700789
Cedric Le Goater9ec52092006-10-02 02:19:00 -0700790 cad_pid = task_pid(current);
791
Linus Torvalds1da177e2005-04-16 15:20:36 -0700792 smp_prepare_cpus(max_cpus);
793
794 do_pre_smp_initcalls();
795
Linus Torvalds1da177e2005-04-16 15:20:36 -0700796 smp_init();
797 sched_init_smp();
798
799 cpuset_init_smp();
800
Linus Torvalds1da177e2005-04-16 15:20:36 -0700801 do_basic_setup();
802
803 /*
804 * check if there is an early userspace init. If yes, let it do all
805 * the work
806 */
Olof Johanssonffdfc402005-09-06 15:17:19 -0700807
808 if (!ramdisk_execute_command)
809 ramdisk_execute_command = "/init";
810
811 if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
812 ramdisk_execute_command = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700813 prepare_namespace();
Olof Johanssonffdfc402005-09-06 15:17:19 -0700814 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700815
816 /*
817 * Ok, we have completed the initial bootup, and
818 * we're essentially up and running. Get rid of the
819 * initmem segments and start the user-mode stuff..
820 */
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100821 init_post();
822 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700823}