blob: f605a969ea6141281891bb007edc41938c63e3f1 [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>
Paul Menageddbcc7e2007-10-18 23:39:30 -070042#include <linux/cgroup.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070043#include <linux/efi.h>
Thomas Gleixner906568c2007-02-16 01:28:01 -080044#include <linux/tick.h>
Andrew Morton6168a702007-02-17 21:22:39 -080045#include <linux/interrupt.h>
Shailabh Nagarc7572492006-07-14 00:24:40 -070046#include <linux/taskstats_kern.h>
Shailabh Nagarca74e922006-07-14 00:24:36 -070047#include <linux/delayacct.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070048#include <linux/unistd.h>
49#include <linux/rmap.h>
50#include <linux/mempolicy.h>
51#include <linux/key.h>
Jan Beulich4552d5d2006-06-26 13:57:28 +020052#include <linux/unwind.h>
Adrian Bunkb6cd0b72006-06-27 02:53:54 -070053#include <linux/buffer_head.h>
Ingo Molnar9a11b49a2006-07-03 00:24:33 -070054#include <linux/debug_locks.h>
Ingo Molnarfbb9ce952006-07-03 00:24:50 -070055#include <linux/lockdep.h>
Sukadev Bhattiprolu84d73782006-12-08 02:38:01 -080056#include <linux/pid_namespace.h>
Adrian Bunk1f217822006-12-19 13:01:28 -080057#include <linux/device.h>
Eric W. Biederman73c27992007-05-09 02:34:32 -070058#include <linux/kthread.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070059
60#include <asm/io.h>
61#include <asm/bugs.h>
62#include <asm/setup.h>
Andi Kleena9401992005-07-28 21:15:30 -070063#include <asm/sections.h>
Arjan van de Ven37b73c82006-01-06 00:12:01 -080064#include <asm/cacheflush.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070065
Linus Torvalds1da177e2005-04-16 15:20:36 -070066#ifdef CONFIG_X86_LOCAL_APIC
67#include <asm/smp.h>
68#endif
69
70/*
Coywolf Qi Hunt69c99ac2006-01-14 13:21:11 -080071 * This is one of the first .c files built. Error out early if we have compiler
72 * trouble.
Linus Torvalds1da177e2005-04-16 15:20:36 -070073 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070074
Andrew Mortonf1a60db2006-12-06 20:39:59 -080075#if __GNUC__ == 4 && __GNUC_MINOR__ == 1 && __GNUC_PATCHLEVEL__ == 0
76#warning gcc-4.1.0 is known to miscompile the kernel. A different compiler version is recommended.
77#endif
78
Sam Ravnborgaae5f662007-02-26 16:45:41 +010079static int kernel_init(void *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070080
81extern void init_IRQ(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070082extern void fork_init(unsigned long);
83extern void mca_init(void);
84extern void sbus_init(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070085extern 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);
Linus Torvalds1da177e2005-04-16 15:20:36 -070091#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
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800118/* Untouched command line saved by arch-specific code. */
119char __initdata boot_command_line[COMMAND_LINE_SIZE];
120/* Untouched saved command line (eg. for /proc) */
121char *saved_command_line;
122/* Command line for parameter parsing */
123static char *static_command_line;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124
125static char *execute_command;
Olof Johanssonffdfc402005-09-06 15:17:19 -0700126static char *ramdisk_execute_command;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127
Jan Beulich8b3b2952007-07-15 23:41:07 -0700128#ifdef CONFIG_SMP
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129/* Setup configured maximum number of CPUs to activate */
Jan Beulich8b3b2952007-07-15 23:41:07 -0700130static unsigned int __initdata max_cpus = NR_CPUS;
Vivek Goyal7e962872006-09-27 01:50:44 -0700131
132/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133 * Setup routine for controlling SMP activation
134 *
135 * Command-line option of "nosmp" or "maxcpus=0" will disable SMP
136 * activation entirely (the MPS table probe still happens, though).
137 *
138 * Command-line option of "maxcpus=<NUM>", where <NUM> is an integer
139 * greater than 0, limits the maximum number of CPUs activated in
140 * SMP mode to <NUM>.
141 */
Len Brown61ec7562007-08-16 03:34:22 -0400142#ifndef CONFIG_X86_IO_APIC
143static inline void disable_ioapic_setup(void) {};
144#endif
145
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146static int __init nosmp(char *str)
147{
148 max_cpus = 0;
Len Brown61ec7562007-08-16 03:34:22 -0400149 disable_ioapic_setup();
Jan Beulich8b3b2952007-07-15 23:41:07 -0700150 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151}
152
Jan Beulich8b3b2952007-07-15 23:41:07 -0700153early_param("nosmp", nosmp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154
155static int __init maxcpus(char *str)
156{
157 get_option(&str, &max_cpus);
Len Brown61ec7562007-08-16 03:34:22 -0400158 if (max_cpus == 0)
159 disable_ioapic_setup();
160
161 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162}
163
Hugh Dickins81340972007-08-27 16:02:12 +0100164early_param("maxcpus", maxcpus);
Jan Beulich8b3b2952007-07-15 23:41:07 -0700165#else
166#define max_cpus NR_CPUS
167#endif
168
169/*
170 * If set, this is an indication to the drivers that reset the underlying
171 * device before going ahead with the initialization otherwise driver might
172 * rely on the BIOS and skip the reset operation.
173 *
174 * This is useful if kernel is booting in an unreliable environment.
175 * For ex. kdump situaiton where previous kernel has crashed, BIOS has been
176 * skipped and devices will be in unknown state.
177 */
178unsigned int reset_devices;
179EXPORT_SYMBOL(reset_devices);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180
Vivek Goyal7e962872006-09-27 01:50:44 -0700181static int __init set_reset_devices(char *str)
182{
183 reset_devices = 1;
184 return 1;
185}
186
187__setup("reset_devices", set_reset_devices);
188
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189static char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
190char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
191static const char *panic_later, *panic_param;
192
193extern struct obs_kernel_param __setup_start[], __setup_end[];
194
195static int __init obsolete_checksetup(char *line)
196{
197 struct obs_kernel_param *p;
Rusty Russell33df0d12006-09-26 10:52:32 +0200198 int had_early_param = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199
200 p = __setup_start;
201 do {
202 int n = strlen(p->str);
203 if (!strncmp(line, p->str, n)) {
204 if (p->early) {
Rusty Russell33df0d12006-09-26 10:52:32 +0200205 /* Already done in parse_early_param?
206 * (Needs exact match on param part).
207 * Keep iterating, as we can have early
208 * params and __setups of same names 8( */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209 if (line[n] == '\0' || line[n] == '=')
Rusty Russell33df0d12006-09-26 10:52:32 +0200210 had_early_param = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211 } else if (!p->setup_func) {
212 printk(KERN_WARNING "Parameter %s is obsolete,"
213 " ignored\n", p->str);
214 return 1;
215 } else if (p->setup_func(line + n))
216 return 1;
217 }
218 p++;
219 } while (p < __setup_end);
Rusty Russell33df0d12006-09-26 10:52:32 +0200220
221 return had_early_param;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222}
223
224/*
225 * This should be approx 2 Bo*oMips to start (note initial shift), and will
226 * still work even if initially too large, it will just take slightly longer
227 */
228unsigned long loops_per_jiffy = (1<<12);
229
230EXPORT_SYMBOL(loops_per_jiffy);
231
232static int __init debug_kernel(char *str)
233{
234 if (*str)
235 return 0;
236 console_loglevel = 10;
237 return 1;
238}
239
240static int __init quiet_kernel(char *str)
241{
242 if (*str)
243 return 0;
244 console_loglevel = 4;
245 return 1;
246}
247
248__setup("debug", debug_kernel);
249__setup("quiet", quiet_kernel);
250
251static int __init loglevel(char *str)
252{
253 get_option(&str, &console_loglevel);
254 return 1;
255}
256
257__setup("loglevel=", loglevel);
258
259/*
260 * Unknown boot options get handed to init, unless they look like
261 * failed parameters
262 */
263static int __init unknown_bootoption(char *param, char *val)
264{
265 /* Change NUL term back to "=", to make "param" the whole string. */
266 if (val) {
267 /* param=val or param="val"? */
268 if (val == param+strlen(param)+1)
269 val[-1] = '=';
270 else if (val == param+strlen(param)+2) {
271 val[-2] = '=';
272 memmove(val-1, val, strlen(val)+1);
273 val--;
274 } else
275 BUG();
276 }
277
278 /* Handle obsolete-style parameters */
279 if (obsolete_checksetup(param))
280 return 0;
281
282 /*
Simon Arlott211fee82007-10-20 01:28:29 +0200283 * Preemptive maintenance for "why didn't my misspelled command
Linus Torvalds1da177e2005-04-16 15:20:36 -0700284 * line work?"
285 */
286 if (strchr(param, '.') && (!val || strchr(param, '.') < val)) {
287 printk(KERN_ERR "Unknown boot option `%s': ignoring\n", param);
288 return 0;
289 }
290
291 if (panic_later)
292 return 0;
293
294 if (val) {
295 /* Environment option */
296 unsigned int i;
297 for (i = 0; envp_init[i]; i++) {
298 if (i == MAX_INIT_ENVS) {
299 panic_later = "Too many boot env vars at `%s'";
300 panic_param = param;
301 }
302 if (!strncmp(param, envp_init[i], val - param))
303 break;
304 }
305 envp_init[i] = param;
306 } else {
307 /* Command line option */
308 unsigned int i;
309 for (i = 0; argv_init[i]; i++) {
310 if (i == MAX_INIT_ARGS) {
311 panic_later = "Too many boot init vars at `%s'";
312 panic_param = param;
313 }
314 }
315 argv_init[i] = param;
316 }
317 return 0;
318}
319
320static int __init init_setup(char *str)
321{
322 unsigned int i;
323
324 execute_command = str;
325 /*
326 * In case LILO is going to boot us with default command line,
327 * it prepends "auto" before the whole cmdline which makes
328 * the shell think it should execute a script with such name.
329 * So we ignore all arguments entered _before_ init=... [MJ]
330 */
331 for (i = 1; i < MAX_INIT_ARGS; i++)
332 argv_init[i] = NULL;
333 return 1;
334}
335__setup("init=", init_setup);
336
Olof Johanssonffdfc402005-09-06 15:17:19 -0700337static int __init rdinit_setup(char *str)
338{
339 unsigned int i;
340
341 ramdisk_execute_command = str;
342 /* See "auto" comment in init_setup */
343 for (i = 1; i < MAX_INIT_ARGS; i++)
344 argv_init[i] = NULL;
345 return 1;
346}
347__setup("rdinit=", rdinit_setup);
348
Linus Torvalds1da177e2005-04-16 15:20:36 -0700349#ifndef CONFIG_SMP
350
351#ifdef CONFIG_X86_LOCAL_APIC
352static void __init smp_init(void)
353{
354 APIC_init_uniprocessor();
355}
356#else
357#define smp_init() do { } while (0)
358#endif
359
360static inline void setup_per_cpu_areas(void) { }
361static inline void smp_prepare_cpus(unsigned int maxcpus) { }
362
363#else
364
365#ifdef __GENERIC_PER_CPU
Eric Dumazetb73b4592006-03-23 03:01:07 -0800366unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700367
368EXPORT_SYMBOL(__per_cpu_offset);
369
370static void __init setup_per_cpu_areas(void)
371{
372 unsigned long size, i;
373 char *ptr;
Eric Dumazet63872f82006-03-23 03:01:04 -0800374 unsigned long nr_possible_cpus = num_possible_cpus();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700375
376 /* Copy section for each CPU (we discard the original) */
Jeremy Fitzhardingeb6e35902007-05-02 19:27:12 +0200377 size = ALIGN(PERCPU_ENOUGH_ROOM, PAGE_SIZE);
378 ptr = alloc_bootmem_pages(size * nr_possible_cpus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700379
KAMEZAWA Hiroyuki0a945022006-03-28 01:56:37 -0800380 for_each_possible_cpu(i) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700381 __per_cpu_offset[i] = ptr - __per_cpu_start;
382 memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start);
Eric Dumazet63872f82006-03-23 03:01:04 -0800383 ptr += size;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700384 }
385}
386#endif /* !__GENERIC_PER_CPU */
387
388/* Called by boot processor to activate the rest. */
389static void __init smp_init(void)
390{
Christoph Lameter53b8a312007-02-20 13:57:51 -0800391 unsigned int cpu;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700392
393 /* FIXME: This should be done in userspace --RR */
Christoph Lameter53b8a312007-02-20 13:57:51 -0800394 for_each_present_cpu(cpu) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700395 if (num_online_cpus() >= max_cpus)
396 break;
Christoph Lameter53b8a312007-02-20 13:57:51 -0800397 if (!cpu_online(cpu))
398 cpu_up(cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700399 }
400
401 /* Any cleanup work */
402 printk(KERN_INFO "Brought up %ld CPUs\n", (long)num_online_cpus());
403 smp_cpus_done(max_cpus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700404}
405
406#endif
407
408/*
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800409 * We need to store the untouched command line for future reference.
410 * We also need to store the touched command line since the parameter
411 * parsing is performed in place, and we should allow a component to
412 * store reference of name/value for future reference.
413 */
414static void __init setup_command_line(char *command_line)
415{
416 saved_command_line = alloc_bootmem(strlen (boot_command_line)+1);
417 static_command_line = alloc_bootmem(strlen (command_line)+1);
418 strcpy (saved_command_line, boot_command_line);
419 strcpy (static_command_line, command_line);
420}
421
422/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700423 * We need to finalize in a non-__init function or else race conditions
424 * between the root thread and the init thread may cause start_kernel to
425 * be reaped by free_initmem before the root thread has proceeded to
426 * cpu_idle.
427 *
428 * gcc-3.4 accidentally inlines this function, so use noinline.
429 */
430
Sam Ravnborg92080302007-05-17 20:43:54 +0200431static void noinline __init_refok rest_init(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700432 __releases(kernel_lock)
433{
Eric W. Biederman73c27992007-05-09 02:34:32 -0700434 int pid;
435
Sam Ravnborgaae5f662007-02-26 16:45:41 +0100436 kernel_thread(kernel_init, NULL, CLONE_FS | CLONE_SIGHAND);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700437 numa_default_policy();
Eric W. Biederman73c27992007-05-09 02:34:32 -0700438 pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
439 kthreadd_task = find_task_by_pid(pid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700440 unlock_kernel();
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200441
442 /*
443 * The boot idle thread must execute schedule()
Ingo Molnar1df21052007-07-09 18:51:58 +0200444 * at least once to get things moving:
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200445 */
Ingo Molnar1df21052007-07-09 18:51:58 +0200446 init_idle_bootup_task(current);
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800447 preempt_enable_no_resched();
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200448 schedule();
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800449 preempt_disable();
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200450
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800451 /* Call into cpu_idle with preempt disabled */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700452 cpu_idle();
Ingo Molnar1df21052007-07-09 18:51:58 +0200453}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700454
455/* Check for early params. */
456static int __init do_early_param(char *param, char *val)
457{
458 struct obs_kernel_param *p;
459
460 for (p = __setup_start; p < __setup_end; p++) {
Yinghai Lu18a8bd92007-07-15 23:37:59 -0700461 if ((p->early && strcmp(param, p->str) == 0) ||
462 (strcmp(param, "console") == 0 &&
463 strcmp(p->str, "earlycon") == 0)
464 ) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465 if (p->setup_func(val) != 0)
466 printk(KERN_WARNING
467 "Malformed early option '%s'\n", param);
468 }
469 }
470 /* We accept everything at this stage. */
471 return 0;
472}
473
474/* Arch code calls this early on, or if not, just before other parsing. */
475void __init parse_early_param(void)
476{
477 static __initdata int done = 0;
478 static __initdata char tmp_cmdline[COMMAND_LINE_SIZE];
479
480 if (done)
481 return;
482
483 /* All fall through to do_early_param. */
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800484 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700485 parse_args("early options", tmp_cmdline, NULL, 0, do_early_param);
486 done = 1;
487}
488
489/*
490 * Activate the first processor.
491 */
492
Stas Sergeev44fd2292006-03-23 02:59:44 -0800493static void __init boot_cpu_init(void)
494{
495 int cpu = smp_processor_id();
496 /* Mark the boot cpu "present", "online" etc for SMP and UP case */
497 cpu_set(cpu, cpu_online_map);
498 cpu_set(cpu, cpu_present_map);
499 cpu_set(cpu, cpu_possible_map);
500}
501
Andrew Morton033ab7f2006-06-30 01:55:50 -0700502void __init __attribute__((weak)) smp_setup_processor_id(void)
503{
504}
505
Linus Torvalds1da177e2005-04-16 15:20:36 -0700506asmlinkage void __init start_kernel(void)
507{
508 char * command_line;
509 extern struct kernel_param __start___param[], __stop___param[];
Andrew Morton033ab7f2006-06-30 01:55:50 -0700510
511 smp_setup_processor_id();
512
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700513 /*
514 * Need to run as early as possible, to initialize the
515 * lockdep hash:
516 */
Andi Kleenc9538ed2006-09-26 10:52:34 +0200517 unwind_init();
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700518 lockdep_init();
Paul Menageddbcc7e2007-10-18 23:39:30 -0700519 cgroup_init_early();
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700520
521 local_irq_disable();
522 early_boot_irqs_off();
Ingo Molnar243c7622006-07-03 00:25:06 -0700523 early_init_irq_lock_class();
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700524
Linus Torvalds1da177e2005-04-16 15:20:36 -0700525/*
526 * Interrupts are still disabled. Do necessary setups, then
527 * enable them
528 */
529 lock_kernel();
Thomas Gleixner906568c2007-02-16 01:28:01 -0800530 tick_init();
Stas Sergeev44fd2292006-03-23 02:59:44 -0800531 boot_cpu_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700532 page_address_init();
533 printk(KERN_NOTICE);
Linus Torvalds89937802006-12-11 09:28:46 -0800534 printk(linux_banner);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700535 setup_arch(&command_line);
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800536 setup_command_line(command_line);
Jan Beulich690a9732006-10-21 18:37:01 +0200537 unwind_setup();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700538 setup_per_cpu_areas();
Stas Sergeev44fd2292006-03-23 02:59:44 -0800539 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700540
541 /*
542 * Set up the scheduler prior starting any interrupts (such as the
543 * timer interrupt). Full topology setup happens at smp_init()
544 * time - but meanwhile we still have a functioning scheduler.
545 */
546 sched_init();
547 /*
548 * Disable preemption - early bootup scheduling is extremely
549 * fragile until we cpu_idle() for the first time.
550 */
551 preempt_disable();
552 build_all_zonelists();
553 page_alloc_init();
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800554 printk(KERN_NOTICE "Kernel command line: %s\n", boot_command_line);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700555 parse_early_param();
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800556 parse_args("Booting kernel", static_command_line, __start___param,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700557 __stop___param - __start___param,
558 &unknown_bootoption);
Ard van Breemenc4a68302007-01-05 16:36:19 -0800559 if (!irqs_disabled()) {
560 printk(KERN_WARNING "start_kernel(): bug: interrupts were "
561 "enabled *very* early, fixing it\n");
562 local_irq_disable();
563 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700564 sort_main_extable();
565 trap_init();
566 rcu_init();
567 init_IRQ();
568 pidhash_init();
569 init_timers();
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800570 hrtimers_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700571 softirq_init();
john stultzad596172006-06-26 00:25:06 -0700572 timekeeping_init();
john stultz88fecaa2006-07-03 00:24:04 -0700573 time_init();
Heiko Carstens93e02812006-07-03 00:24:24 -0700574 profile_init();
575 if (!irqs_disabled())
576 printk("start_kernel(): bug: interrupts were enabled early\n");
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700577 early_boot_irqs_on();
Heiko Carstens93e02812006-07-03 00:24:24 -0700578 local_irq_enable();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700579
580 /*
581 * HACK ALERT! This is early. We're enabling the console before
582 * we've done PCI setups etc, and console_init() must be aware of
583 * this. But we do want output early, in case something goes wrong.
584 */
585 console_init();
586 if (panic_later)
587 panic(panic_later, panic_param);
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700588
589 lockdep_info();
590
Ingo Molnar9a11b49a2006-07-03 00:24:33 -0700591 /*
592 * Need to run this when irqs are enabled, because it wants
593 * to self-test [hard/soft]-irqs on/off lock inversion bugs
594 * too:
595 */
596 locking_selftest();
597
Linus Torvalds1da177e2005-04-16 15:20:36 -0700598#ifdef CONFIG_BLK_DEV_INITRD
599 if (initrd_start && !initrd_below_start_ok &&
600 initrd_start < min_low_pfn << PAGE_SHIFT) {
601 printk(KERN_CRIT "initrd overwritten (0x%08lx < 0x%08lx) - "
602 "disabling it.\n",initrd_start,min_low_pfn << PAGE_SHIFT);
603 initrd_start = 0;
604 }
605#endif
606 vfs_caches_init_early();
Paul Jacksonc417f022006-01-08 01:02:01 -0800607 cpuset_init_early();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700608 mem_init();
609 kmem_cache_init();
Christoph Lametere7c8d5c2005-06-21 17:14:47 -0700610 setup_per_cpu_pageset();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700611 numa_policy_init();
612 if (late_time_init)
613 late_time_init();
614 calibrate_delay();
615 pidmap_init();
616 pgtable_cache_init();
617 prio_tree_init();
618 anon_vma_init();
619#ifdef CONFIG_X86
620 if (efi_enabled)
621 efi_enter_virtual_mode();
622#endif
623 fork_init(num_physpages);
624 proc_caches_init();
625 buffer_init();
626 unnamed_dev_init();
627 key_init();
628 security_init();
629 vfs_caches_init(num_physpages);
630 radix_tree_init();
631 signals_init();
632 /* rootfs populating might need page-writeback */
633 page_writeback_init();
634#ifdef CONFIG_PROC_FS
635 proc_root_init();
636#endif
Paul Menageddbcc7e2007-10-18 23:39:30 -0700637 cgroup_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700638 cpuset_init();
Shailabh Nagarc7572492006-07-14 00:24:40 -0700639 taskstats_init_early();
Shailabh Nagarca74e922006-07-14 00:24:36 -0700640 delayacct_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700641
642 check_bugs();
643
644 acpi_early_init(); /* before LAPIC and SMP init */
645
646 /* Do the rest non-__init'ed, we're now alive */
647 rest_init();
648}
649
650static int __initdata initcall_debug;
651
652static int __init initcall_debug_setup(char *str)
653{
654 initcall_debug = 1;
655 return 1;
656}
657__setup("initcall_debug", initcall_debug_setup);
658
Linus Torvalds1da177e2005-04-16 15:20:36 -0700659extern initcall_t __initcall_start[], __initcall_end[];
660
661static void __init do_initcalls(void)
662{
663 initcall_t *call;
664 int count = preempt_count();
665
666 for (call = __initcall_start; call < __initcall_end; call++) {
Ingo Molnar8f0c45c2007-05-08 00:28:26 -0700667 ktime_t t0, t1, delta;
Andrew Mortonc1cda482006-03-25 03:07:15 -0800668 char *msg = NULL;
669 char msgbuf[40];
670 int result;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700671
672 if (initcall_debug) {
Andrew Mortonc1cda482006-03-25 03:07:15 -0800673 printk("Calling initcall 0x%p", *call);
674 print_fn_descriptor_symbol(": %s()",
675 (unsigned long) *call);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700676 printk("\n");
Ingo Molnar8f0c45c2007-05-08 00:28:26 -0700677 t0 = ktime_get();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700678 }
679
Andrew Mortonc1cda482006-03-25 03:07:15 -0800680 result = (*call)();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700681
Ingo Molnar8f0c45c2007-05-08 00:28:26 -0700682 if (initcall_debug) {
683 t1 = ktime_get();
684 delta = ktime_sub(t1, t0);
685
686 printk("initcall 0x%p", *call);
687 print_fn_descriptor_symbol(": %s()",
688 (unsigned long) *call);
689 printk(" returned %d.\n", result);
690
691 printk("initcall 0x%p ran for %Ld msecs: ",
692 *call, (unsigned long long)delta.tv64 >> 20);
693 print_fn_descriptor_symbol("%s()\n",
694 (unsigned long) *call);
695 }
696
Andrew Mortonf3a19cb2006-05-01 12:15:52 -0700697 if (result && result != -ENODEV && initcall_debug) {
Andrew Mortonc1cda482006-03-25 03:07:15 -0800698 sprintf(msgbuf, "error code %d", result);
699 msg = msgbuf;
700 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700701 if (preempt_count() != count) {
702 msg = "preemption imbalance";
703 preempt_count() = count;
704 }
705 if (irqs_disabled()) {
706 msg = "disabled interrupts";
707 local_irq_enable();
708 }
709 if (msg) {
Andrew Mortonc1cda482006-03-25 03:07:15 -0800710 printk(KERN_WARNING "initcall at 0x%p", *call);
711 print_fn_descriptor_symbol(": %s()",
712 (unsigned long) *call);
713 printk(": returned with %s\n", msg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700714 }
715 }
716
717 /* Make sure there is no pending stuff from the initcall sequence */
718 flush_scheduled_work();
719}
720
721/*
722 * Ok, the machine is now initialized. None of the devices
723 * have been touched yet, but the CPU subsystem is up and
724 * running, and memory and process management works.
725 *
726 * Now we can finally start doing some real work..
727 */
728static void __init do_basic_setup(void)
729{
730 /* drivers will send hotplug events */
731 init_workqueues();
732 usermodehelper_init();
733 driver_init();
Eric W. Biedermanb04c3af2007-02-14 00:33:57 -0800734 init_irq_proc();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700735 do_initcalls();
736}
737
Dave Jones97842212007-07-15 23:41:05 -0700738static int __initdata nosoftlockup;
739
740static int __init nosoftlockup_setup(char *str)
741{
742 nosoftlockup = 1;
743 return 1;
744}
745__setup("nosoftlockup", nosoftlockup_setup);
746
Vivek Goyal88d20322007-01-11 01:52:44 +0100747static void __init do_pre_smp_initcalls(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700748{
749 extern int spawn_ksoftirqd(void);
750#ifdef CONFIG_SMP
751 extern int migration_init(void);
752
753 migration_init();
754#endif
755 spawn_ksoftirqd();
Dave Jones97842212007-07-15 23:41:05 -0700756 if (!nosoftlockup)
757 spawn_softlockup_task();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700758}
759
760static void run_init_process(char *init_filename)
761{
762 argv_init[0] = init_filename;
Arnd Bergmann67608562006-10-02 02:18:26 -0700763 kernel_execve(init_filename, argv_init, envp_init);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700764}
765
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100766/* This is a non __init function. Force it to be noinline otherwise gcc
767 * makes it inline to init() and it becomes part of init.text section
768 */
769static int noinline init_post(void)
770{
771 free_initmem();
772 unlock_kernel();
773 mark_rodata_ro();
774 system_state = SYSTEM_RUNNING;
775 numa_default_policy();
776
777 if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
778 printk(KERN_WARNING "Warning: unable to open an initial console.\n");
779
780 (void) sys_dup(0);
781 (void) sys_dup(0);
782
783 if (ramdisk_execute_command) {
784 run_init_process(ramdisk_execute_command);
785 printk(KERN_WARNING "Failed to execute %s\n",
786 ramdisk_execute_command);
787 }
788
789 /*
790 * We try each of these until one succeeds.
791 *
792 * The Bourne shell can be used instead of init if we are
793 * trying to recover a really broken machine.
794 */
795 if (execute_command) {
796 run_init_process(execute_command);
797 printk(KERN_WARNING "Failed to execute %s. Attempting "
798 "defaults...\n", execute_command);
799 }
800 run_init_process("/sbin/init");
801 run_init_process("/etc/init");
802 run_init_process("/bin/init");
803 run_init_process("/bin/sh");
804
805 panic("No init found. Try passing init= option to kernel.");
806}
807
Sam Ravnborgaae5f662007-02-26 16:45:41 +0100808static int __init kernel_init(void * unused)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700809{
810 lock_kernel();
811 /*
812 * init can run on any cpu.
813 */
814 set_cpus_allowed(current, CPU_MASK_ALL);
815 /*
816 * Tell the world that we're going to be the grim
817 * reaper of innocent orphaned children.
818 *
819 * We don't want people to have to make incorrect
820 * assumptions about where in the task array this
821 * can be found.
822 */
Sukadev Bhattiprolu84d73782006-12-08 02:38:01 -0800823 init_pid_ns.child_reaper = current;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700824
Sukadev Bhattiprolu0e29b242007-05-10 22:23:01 -0700825 __set_special_pids(1, 1);
Cedric Le Goater9ec52092006-10-02 02:19:00 -0700826 cad_pid = task_pid(current);
827
Linus Torvalds1da177e2005-04-16 15:20:36 -0700828 smp_prepare_cpus(max_cpus);
829
830 do_pre_smp_initcalls();
831
Linus Torvalds1da177e2005-04-16 15:20:36 -0700832 smp_init();
833 sched_init_smp();
834
835 cpuset_init_smp();
836
Linus Torvalds1da177e2005-04-16 15:20:36 -0700837 do_basic_setup();
838
839 /*
840 * check if there is an early userspace init. If yes, let it do all
841 * the work
842 */
Olof Johanssonffdfc402005-09-06 15:17:19 -0700843
844 if (!ramdisk_execute_command)
845 ramdisk_execute_command = "/init";
846
847 if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
848 ramdisk_execute_command = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700849 prepare_namespace();
Olof Johanssonffdfc402005-09-06 15:17:19 -0700850 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700851
852 /*
853 * Ok, we have completed the initial bootup, and
854 * we're essentially up and running. Get rid of the
855 * initmem segments and start the user-mode stuff..
856 */
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100857 init_post();
858 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700859}