blob: 9def935ab13a27c829e28bb2830cdbe2c6fd900d [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>
Andrew Morton6168a702007-02-17 21:22:39 -080044#include <linux/interrupt.h>
Shailabh Nagarc7572492006-07-14 00:24:40 -070045#include <linux/taskstats_kern.h>
Shailabh Nagarca74e922006-07-14 00:24:36 -070046#include <linux/delayacct.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070047#include <linux/unistd.h>
48#include <linux/rmap.h>
49#include <linux/mempolicy.h>
50#include <linux/key.h>
Jan Beulich4552d5d2006-06-26 13:57:28 +020051#include <linux/unwind.h>
Adrian Bunkb6cd0b72006-06-27 02:53:54 -070052#include <linux/buffer_head.h>
Ingo Molnar9a11b49a2006-07-03 00:24:33 -070053#include <linux/debug_locks.h>
Ingo Molnarfbb9ce92006-07-03 00:24:50 -070054#include <linux/lockdep.h>
Sukadev Bhattiprolu84d73782006-12-08 02:38:01 -080055#include <linux/pid_namespace.h>
Adrian Bunk1f217822006-12-19 13:01:28 -080056#include <linux/device.h>
Eric W. Biederman73c27992007-05-09 02:34:32 -070057#include <linux/kthread.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070058
59#include <asm/io.h>
60#include <asm/bugs.h>
61#include <asm/setup.h>
Andi Kleena9401992005-07-28 21:15:30 -070062#include <asm/sections.h>
Arjan van de Ven37b73c82006-01-06 00:12:01 -080063#include <asm/cacheflush.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070064
Linus Torvalds1da177e2005-04-16 15:20:36 -070065#ifdef CONFIG_X86_LOCAL_APIC
66#include <asm/smp.h>
67#endif
68
69/*
Coywolf Qi Hunt69c99ac2006-01-14 13:21:11 -080070 * This is one of the first .c files built. Error out early if we have compiler
71 * trouble.
72 *
73 * Versions of gcc older than that listed below may actually compile and link
74 * okay, but the end product can have subtle run time bugs. To avoid associated
75 * bogus bug reports, we flatly refuse to compile with a gcc that is known to be
76 * too old from the very beginning.
Linus Torvalds1da177e2005-04-16 15:20:36 -070077 */
Andrew Mortonfd285bb2006-01-08 01:04:07 -080078#if (__GNUC__ < 3) || (__GNUC__ == 3 && __GNUC_MINOR__ < 2)
Linus Torvalds1da177e2005-04-16 15:20:36 -070079#error Sorry, your GCC is too old. It builds incorrect kernels.
80#endif
81
Andrew Mortonf1a60db2006-12-06 20:39:59 -080082#if __GNUC__ == 4 && __GNUC_MINOR__ == 1 && __GNUC_PATCHLEVEL__ == 0
83#warning gcc-4.1.0 is known to miscompile the kernel. A different compiler version is recommended.
84#endif
85
Sam Ravnborgaae5f662007-02-26 16:45:41 +010086static int kernel_init(void *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070087
88extern void init_IRQ(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070089extern void fork_init(unsigned long);
90extern void mca_init(void);
91extern void sbus_init(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070092extern void signals_init(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070093extern void pidhash_init(void);
94extern void pidmap_init(void);
95extern void prio_tree_init(void);
96extern void radix_tree_init(void);
97extern void free_initmem(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070098#ifdef CONFIG_ACPI
99extern void acpi_early_init(void);
100#else
101static inline void acpi_early_init(void) { }
102#endif
Arjan van de Ven37b73c82006-01-06 00:12:01 -0800103#ifndef CONFIG_DEBUG_RODATA
104static inline void mark_rodata_ro(void) { }
105#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106
107#ifdef CONFIG_TC
108extern void tc_init(void);
109#endif
110
111enum system_states system_state;
112EXPORT_SYMBOL(system_state);
113
114/*
115 * Boot command-line arguments
116 */
117#define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
118#define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
119
120extern void time_init(void);
121/* Default late time init is NULL. archs can override this later. */
122void (*late_time_init)(void);
123extern void softirq_init(void);
124
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800125/* Untouched command line saved by arch-specific code. */
126char __initdata boot_command_line[COMMAND_LINE_SIZE];
127/* Untouched saved command line (eg. for /proc) */
128char *saved_command_line;
129/* Command line for parameter parsing */
130static char *static_command_line;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131
132static char *execute_command;
Olof Johanssonffdfc402005-09-06 15:17:19 -0700133static char *ramdisk_execute_command;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134
Jan Beulich8b3b2952007-07-15 23:41:07 -0700135#ifdef CONFIG_SMP
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136/* Setup configured maximum number of CPUs to activate */
Jan Beulich8b3b2952007-07-15 23:41:07 -0700137static unsigned int __initdata max_cpus = NR_CPUS;
Vivek Goyal7e962872006-09-27 01:50:44 -0700138
139/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140 * Setup routine for controlling SMP activation
141 *
142 * Command-line option of "nosmp" or "maxcpus=0" will disable SMP
143 * activation entirely (the MPS table probe still happens, though).
144 *
145 * Command-line option of "maxcpus=<NUM>", where <NUM> is an integer
146 * greater than 0, limits the maximum number of CPUs activated in
147 * SMP mode to <NUM>.
148 */
Len Brown61ec7562007-08-16 03:34:22 -0400149#ifndef CONFIG_X86_IO_APIC
150static inline void disable_ioapic_setup(void) {};
151#endif
152
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153static int __init nosmp(char *str)
154{
155 max_cpus = 0;
Len Brown61ec7562007-08-16 03:34:22 -0400156 disable_ioapic_setup();
Jan Beulich8b3b2952007-07-15 23:41:07 -0700157 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158}
159
Jan Beulich8b3b2952007-07-15 23:41:07 -0700160early_param("nosmp", nosmp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161
162static int __init maxcpus(char *str)
163{
164 get_option(&str, &max_cpus);
Len Brown61ec7562007-08-16 03:34:22 -0400165 if (max_cpus == 0)
166 disable_ioapic_setup();
167
168 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169}
170
Hugh Dickins81340972007-08-27 16:02:12 +0100171early_param("maxcpus", maxcpus);
Jan Beulich8b3b2952007-07-15 23:41:07 -0700172#else
173#define max_cpus NR_CPUS
174#endif
175
176/*
177 * If set, this is an indication to the drivers that reset the underlying
178 * device before going ahead with the initialization otherwise driver might
179 * rely on the BIOS and skip the reset operation.
180 *
181 * This is useful if kernel is booting in an unreliable environment.
182 * For ex. kdump situaiton where previous kernel has crashed, BIOS has been
183 * skipped and devices will be in unknown state.
184 */
185unsigned int reset_devices;
186EXPORT_SYMBOL(reset_devices);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187
Vivek Goyal7e962872006-09-27 01:50:44 -0700188static int __init set_reset_devices(char *str)
189{
190 reset_devices = 1;
191 return 1;
192}
193
194__setup("reset_devices", set_reset_devices);
195
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196static char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
197char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
198static const char *panic_later, *panic_param;
199
200extern struct obs_kernel_param __setup_start[], __setup_end[];
201
202static int __init obsolete_checksetup(char *line)
203{
204 struct obs_kernel_param *p;
Rusty Russell33df0d12006-09-26 10:52:32 +0200205 int had_early_param = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206
207 p = __setup_start;
208 do {
209 int n = strlen(p->str);
210 if (!strncmp(line, p->str, n)) {
211 if (p->early) {
Rusty Russell33df0d12006-09-26 10:52:32 +0200212 /* Already done in parse_early_param?
213 * (Needs exact match on param part).
214 * Keep iterating, as we can have early
215 * params and __setups of same names 8( */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216 if (line[n] == '\0' || line[n] == '=')
Rusty Russell33df0d12006-09-26 10:52:32 +0200217 had_early_param = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218 } else if (!p->setup_func) {
219 printk(KERN_WARNING "Parameter %s is obsolete,"
220 " ignored\n", p->str);
221 return 1;
222 } else if (p->setup_func(line + n))
223 return 1;
224 }
225 p++;
226 } while (p < __setup_end);
Rusty Russell33df0d12006-09-26 10:52:32 +0200227
228 return had_early_param;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229}
230
231/*
232 * This should be approx 2 Bo*oMips to start (note initial shift), and will
233 * still work even if initially too large, it will just take slightly longer
234 */
235unsigned long loops_per_jiffy = (1<<12);
236
237EXPORT_SYMBOL(loops_per_jiffy);
238
239static int __init debug_kernel(char *str)
240{
241 if (*str)
242 return 0;
243 console_loglevel = 10;
244 return 1;
245}
246
247static int __init quiet_kernel(char *str)
248{
249 if (*str)
250 return 0;
251 console_loglevel = 4;
252 return 1;
253}
254
255__setup("debug", debug_kernel);
256__setup("quiet", quiet_kernel);
257
258static int __init loglevel(char *str)
259{
260 get_option(&str, &console_loglevel);
261 return 1;
262}
263
264__setup("loglevel=", loglevel);
265
266/*
267 * Unknown boot options get handed to init, unless they look like
268 * failed parameters
269 */
270static int __init unknown_bootoption(char *param, char *val)
271{
272 /* Change NUL term back to "=", to make "param" the whole string. */
273 if (val) {
274 /* param=val or param="val"? */
275 if (val == param+strlen(param)+1)
276 val[-1] = '=';
277 else if (val == param+strlen(param)+2) {
278 val[-2] = '=';
279 memmove(val-1, val, strlen(val)+1);
280 val--;
281 } else
282 BUG();
283 }
284
285 /* Handle obsolete-style parameters */
286 if (obsolete_checksetup(param))
287 return 0;
288
289 /*
290 * Preemptive maintenance for "why didn't my mispelled command
291 * line work?"
292 */
293 if (strchr(param, '.') && (!val || strchr(param, '.') < val)) {
294 printk(KERN_ERR "Unknown boot option `%s': ignoring\n", param);
295 return 0;
296 }
297
298 if (panic_later)
299 return 0;
300
301 if (val) {
302 /* Environment option */
303 unsigned int i;
304 for (i = 0; envp_init[i]; i++) {
305 if (i == MAX_INIT_ENVS) {
306 panic_later = "Too many boot env vars at `%s'";
307 panic_param = param;
308 }
309 if (!strncmp(param, envp_init[i], val - param))
310 break;
311 }
312 envp_init[i] = param;
313 } else {
314 /* Command line option */
315 unsigned int i;
316 for (i = 0; argv_init[i]; i++) {
317 if (i == MAX_INIT_ARGS) {
318 panic_later = "Too many boot init vars at `%s'";
319 panic_param = param;
320 }
321 }
322 argv_init[i] = param;
323 }
324 return 0;
325}
326
327static int __init init_setup(char *str)
328{
329 unsigned int i;
330
331 execute_command = str;
332 /*
333 * In case LILO is going to boot us with default command line,
334 * it prepends "auto" before the whole cmdline which makes
335 * the shell think it should execute a script with such name.
336 * So we ignore all arguments entered _before_ init=... [MJ]
337 */
338 for (i = 1; i < MAX_INIT_ARGS; i++)
339 argv_init[i] = NULL;
340 return 1;
341}
342__setup("init=", init_setup);
343
Olof Johanssonffdfc402005-09-06 15:17:19 -0700344static int __init rdinit_setup(char *str)
345{
346 unsigned int i;
347
348 ramdisk_execute_command = str;
349 /* See "auto" comment in init_setup */
350 for (i = 1; i < MAX_INIT_ARGS; i++)
351 argv_init[i] = NULL;
352 return 1;
353}
354__setup("rdinit=", rdinit_setup);
355
Linus Torvalds1da177e2005-04-16 15:20:36 -0700356#ifndef CONFIG_SMP
357
358#ifdef CONFIG_X86_LOCAL_APIC
359static void __init smp_init(void)
360{
361 APIC_init_uniprocessor();
362}
363#else
364#define smp_init() do { } while (0)
365#endif
366
367static inline void setup_per_cpu_areas(void) { }
368static inline void smp_prepare_cpus(unsigned int maxcpus) { }
369
370#else
371
372#ifdef __GENERIC_PER_CPU
Eric Dumazetb73b4592006-03-23 03:01:07 -0800373unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700374
375EXPORT_SYMBOL(__per_cpu_offset);
376
377static void __init setup_per_cpu_areas(void)
378{
379 unsigned long size, i;
380 char *ptr;
Eric Dumazet63872f82006-03-23 03:01:04 -0800381 unsigned long nr_possible_cpus = num_possible_cpus();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700382
383 /* Copy section for each CPU (we discard the original) */
Jeremy Fitzhardingeb6e35902007-05-02 19:27:12 +0200384 size = ALIGN(PERCPU_ENOUGH_ROOM, PAGE_SIZE);
385 ptr = alloc_bootmem_pages(size * nr_possible_cpus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700386
KAMEZAWA Hiroyuki0a945022006-03-28 01:56:37 -0800387 for_each_possible_cpu(i) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700388 __per_cpu_offset[i] = ptr - __per_cpu_start;
389 memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start);
Eric Dumazet63872f82006-03-23 03:01:04 -0800390 ptr += size;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391 }
392}
393#endif /* !__GENERIC_PER_CPU */
394
395/* Called by boot processor to activate the rest. */
396static void __init smp_init(void)
397{
Christoph Lameter53b8a312007-02-20 13:57:51 -0800398 unsigned int cpu;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700399
400 /* FIXME: This should be done in userspace --RR */
Christoph Lameter53b8a312007-02-20 13:57:51 -0800401 for_each_present_cpu(cpu) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402 if (num_online_cpus() >= max_cpus)
403 break;
Christoph Lameter53b8a312007-02-20 13:57:51 -0800404 if (!cpu_online(cpu))
405 cpu_up(cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700406 }
407
408 /* Any cleanup work */
409 printk(KERN_INFO "Brought up %ld CPUs\n", (long)num_online_cpus());
410 smp_cpus_done(max_cpus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700411}
412
413#endif
414
415/*
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800416 * We need to store the untouched command line for future reference.
417 * We also need to store the touched command line since the parameter
418 * parsing is performed in place, and we should allow a component to
419 * store reference of name/value for future reference.
420 */
421static void __init setup_command_line(char *command_line)
422{
423 saved_command_line = alloc_bootmem(strlen (boot_command_line)+1);
424 static_command_line = alloc_bootmem(strlen (command_line)+1);
425 strcpy (saved_command_line, boot_command_line);
426 strcpy (static_command_line, command_line);
427}
428
429/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700430 * We need to finalize in a non-__init function or else race conditions
431 * between the root thread and the init thread may cause start_kernel to
432 * be reaped by free_initmem before the root thread has proceeded to
433 * cpu_idle.
434 *
435 * gcc-3.4 accidentally inlines this function, so use noinline.
436 */
437
Sam Ravnborg92080302007-05-17 20:43:54 +0200438static void noinline __init_refok rest_init(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700439 __releases(kernel_lock)
440{
Eric W. Biederman73c27992007-05-09 02:34:32 -0700441 int pid;
442
Sam Ravnborgaae5f662007-02-26 16:45:41 +0100443 kernel_thread(kernel_init, NULL, CLONE_FS | CLONE_SIGHAND);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700444 numa_default_policy();
Eric W. Biederman73c27992007-05-09 02:34:32 -0700445 pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
446 kthreadd_task = find_task_by_pid(pid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700447 unlock_kernel();
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200448
449 /*
450 * The boot idle thread must execute schedule()
Ingo Molnar1df21052007-07-09 18:51:58 +0200451 * at least once to get things moving:
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200452 */
Ingo Molnar1df21052007-07-09 18:51:58 +0200453 init_idle_bootup_task(current);
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800454 preempt_enable_no_resched();
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200455 schedule();
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800456 preempt_disable();
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200457
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800458 /* Call into cpu_idle with preempt disabled */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700459 cpu_idle();
Ingo Molnar1df21052007-07-09 18:51:58 +0200460}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700461
462/* Check for early params. */
463static int __init do_early_param(char *param, char *val)
464{
465 struct obs_kernel_param *p;
466
467 for (p = __setup_start; p < __setup_end; p++) {
Yinghai Lu18a8bd92007-07-15 23:37:59 -0700468 if ((p->early && strcmp(param, p->str) == 0) ||
469 (strcmp(param, "console") == 0 &&
470 strcmp(p->str, "earlycon") == 0)
471 ) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700472 if (p->setup_func(val) != 0)
473 printk(KERN_WARNING
474 "Malformed early option '%s'\n", param);
475 }
476 }
477 /* We accept everything at this stage. */
478 return 0;
479}
480
481/* Arch code calls this early on, or if not, just before other parsing. */
482void __init parse_early_param(void)
483{
484 static __initdata int done = 0;
485 static __initdata char tmp_cmdline[COMMAND_LINE_SIZE];
486
487 if (done)
488 return;
489
490 /* All fall through to do_early_param. */
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800491 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700492 parse_args("early options", tmp_cmdline, NULL, 0, do_early_param);
493 done = 1;
494}
495
496/*
497 * Activate the first processor.
498 */
499
Stas Sergeev44fd2292006-03-23 02:59:44 -0800500static void __init boot_cpu_init(void)
501{
502 int cpu = smp_processor_id();
503 /* Mark the boot cpu "present", "online" etc for SMP and UP case */
504 cpu_set(cpu, cpu_online_map);
505 cpu_set(cpu, cpu_present_map);
506 cpu_set(cpu, cpu_possible_map);
507}
508
Andrew Morton033ab7f2006-06-30 01:55:50 -0700509void __init __attribute__((weak)) smp_setup_processor_id(void)
510{
511}
512
Linus Torvalds1da177e2005-04-16 15:20:36 -0700513asmlinkage void __init start_kernel(void)
514{
515 char * command_line;
516 extern struct kernel_param __start___param[], __stop___param[];
Andrew Morton033ab7f2006-06-30 01:55:50 -0700517
518 smp_setup_processor_id();
519
Ingo Molnarfbb9ce92006-07-03 00:24:50 -0700520 /*
521 * Need to run as early as possible, to initialize the
522 * lockdep hash:
523 */
Andi Kleenc9538ed2006-09-26 10:52:34 +0200524 unwind_init();
Ingo Molnarfbb9ce92006-07-03 00:24:50 -0700525 lockdep_init();
526
527 local_irq_disable();
528 early_boot_irqs_off();
Ingo Molnar243c7622006-07-03 00:25:06 -0700529 early_init_irq_lock_class();
Ingo Molnarfbb9ce92006-07-03 00:24:50 -0700530
Linus Torvalds1da177e2005-04-16 15:20:36 -0700531/*
532 * Interrupts are still disabled. Do necessary setups, then
533 * enable them
534 */
535 lock_kernel();
Thomas Gleixner906568c2007-02-16 01:28:01 -0800536 tick_init();
Stas Sergeev44fd2292006-03-23 02:59:44 -0800537 boot_cpu_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700538 page_address_init();
539 printk(KERN_NOTICE);
Linus Torvalds89937802006-12-11 09:28:46 -0800540 printk(linux_banner);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700541 setup_arch(&command_line);
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800542 setup_command_line(command_line);
Jan Beulich690a9732006-10-21 18:37:01 +0200543 unwind_setup();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700544 setup_per_cpu_areas();
Stas Sergeev44fd2292006-03-23 02:59:44 -0800545 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700546
547 /*
548 * Set up the scheduler prior starting any interrupts (such as the
549 * timer interrupt). Full topology setup happens at smp_init()
550 * time - but meanwhile we still have a functioning scheduler.
551 */
552 sched_init();
553 /*
554 * Disable preemption - early bootup scheduling is extremely
555 * fragile until we cpu_idle() for the first time.
556 */
557 preempt_disable();
558 build_all_zonelists();
559 page_alloc_init();
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800560 printk(KERN_NOTICE "Kernel command line: %s\n", boot_command_line);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700561 parse_early_param();
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800562 parse_args("Booting kernel", static_command_line, __start___param,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700563 __stop___param - __start___param,
564 &unknown_bootoption);
Ard van Breemenc4a68302007-01-05 16:36:19 -0800565 if (!irqs_disabled()) {
566 printk(KERN_WARNING "start_kernel(): bug: interrupts were "
567 "enabled *very* early, fixing it\n");
568 local_irq_disable();
569 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700570 sort_main_extable();
571 trap_init();
572 rcu_init();
573 init_IRQ();
574 pidhash_init();
575 init_timers();
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800576 hrtimers_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700577 softirq_init();
john stultzad596172006-06-26 00:25:06 -0700578 timekeeping_init();
john stultz88fecaa2006-07-03 00:24:04 -0700579 time_init();
Heiko Carstens93e02812006-07-03 00:24:24 -0700580 profile_init();
581 if (!irqs_disabled())
582 printk("start_kernel(): bug: interrupts were enabled early\n");
Ingo Molnarfbb9ce92006-07-03 00:24:50 -0700583 early_boot_irqs_on();
Heiko Carstens93e02812006-07-03 00:24:24 -0700584 local_irq_enable();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700585
586 /*
587 * HACK ALERT! This is early. We're enabling the console before
588 * we've done PCI setups etc, and console_init() must be aware of
589 * this. But we do want output early, in case something goes wrong.
590 */
591 console_init();
592 if (panic_later)
593 panic(panic_later, panic_param);
Ingo Molnarfbb9ce92006-07-03 00:24:50 -0700594
595 lockdep_info();
596
Ingo Molnar9a11b49a2006-07-03 00:24:33 -0700597 /*
598 * Need to run this when irqs are enabled, because it wants
599 * to self-test [hard/soft]-irqs on/off lock inversion bugs
600 * too:
601 */
602 locking_selftest();
603
Linus Torvalds1da177e2005-04-16 15:20:36 -0700604#ifdef CONFIG_BLK_DEV_INITRD
605 if (initrd_start && !initrd_below_start_ok &&
606 initrd_start < min_low_pfn << PAGE_SHIFT) {
607 printk(KERN_CRIT "initrd overwritten (0x%08lx < 0x%08lx) - "
608 "disabling it.\n",initrd_start,min_low_pfn << PAGE_SHIFT);
609 initrd_start = 0;
610 }
611#endif
612 vfs_caches_init_early();
Paul Jacksonc417f022006-01-08 01:02:01 -0800613 cpuset_init_early();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700614 mem_init();
615 kmem_cache_init();
Christoph Lametere7c8d5c2005-06-21 17:14:47 -0700616 setup_per_cpu_pageset();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700617 numa_policy_init();
618 if (late_time_init)
619 late_time_init();
620 calibrate_delay();
621 pidmap_init();
622 pgtable_cache_init();
623 prio_tree_init();
624 anon_vma_init();
625#ifdef CONFIG_X86
626 if (efi_enabled)
627 efi_enter_virtual_mode();
628#endif
629 fork_init(num_physpages);
630 proc_caches_init();
631 buffer_init();
632 unnamed_dev_init();
633 key_init();
634 security_init();
635 vfs_caches_init(num_physpages);
636 radix_tree_init();
637 signals_init();
638 /* rootfs populating might need page-writeback */
639 page_writeback_init();
640#ifdef CONFIG_PROC_FS
641 proc_root_init();
642#endif
643 cpuset_init();
Shailabh Nagarc7572492006-07-14 00:24:40 -0700644 taskstats_init_early();
Shailabh Nagarca74e922006-07-14 00:24:36 -0700645 delayacct_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700646
647 check_bugs();
648
649 acpi_early_init(); /* before LAPIC and SMP init */
650
651 /* Do the rest non-__init'ed, we're now alive */
652 rest_init();
653}
654
655static int __initdata initcall_debug;
656
657static int __init initcall_debug_setup(char *str)
658{
659 initcall_debug = 1;
660 return 1;
661}
662__setup("initcall_debug", initcall_debug_setup);
663
Linus Torvalds1da177e2005-04-16 15:20:36 -0700664extern initcall_t __initcall_start[], __initcall_end[];
665
666static void __init do_initcalls(void)
667{
668 initcall_t *call;
669 int count = preempt_count();
670
671 for (call = __initcall_start; call < __initcall_end; call++) {
Ingo Molnar8f0c45c2007-05-08 00:28:26 -0700672 ktime_t t0, t1, delta;
Andrew Mortonc1cda482006-03-25 03:07:15 -0800673 char *msg = NULL;
674 char msgbuf[40];
675 int result;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700676
677 if (initcall_debug) {
Andrew Mortonc1cda482006-03-25 03:07:15 -0800678 printk("Calling initcall 0x%p", *call);
679 print_fn_descriptor_symbol(": %s()",
680 (unsigned long) *call);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700681 printk("\n");
Ingo Molnar8f0c45c2007-05-08 00:28:26 -0700682 t0 = ktime_get();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700683 }
684
Andrew Mortonc1cda482006-03-25 03:07:15 -0800685 result = (*call)();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700686
Ingo Molnar8f0c45c2007-05-08 00:28:26 -0700687 if (initcall_debug) {
688 t1 = ktime_get();
689 delta = ktime_sub(t1, t0);
690
691 printk("initcall 0x%p", *call);
692 print_fn_descriptor_symbol(": %s()",
693 (unsigned long) *call);
694 printk(" returned %d.\n", result);
695
696 printk("initcall 0x%p ran for %Ld msecs: ",
697 *call, (unsigned long long)delta.tv64 >> 20);
698 print_fn_descriptor_symbol("%s()\n",
699 (unsigned long) *call);
700 }
701
Andrew Mortonf3a19cb2006-05-01 12:15:52 -0700702 if (result && result != -ENODEV && initcall_debug) {
Andrew Mortonc1cda482006-03-25 03:07:15 -0800703 sprintf(msgbuf, "error code %d", result);
704 msg = msgbuf;
705 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700706 if (preempt_count() != count) {
707 msg = "preemption imbalance";
708 preempt_count() = count;
709 }
710 if (irqs_disabled()) {
711 msg = "disabled interrupts";
712 local_irq_enable();
713 }
714 if (msg) {
Andrew Mortonc1cda482006-03-25 03:07:15 -0800715 printk(KERN_WARNING "initcall at 0x%p", *call);
716 print_fn_descriptor_symbol(": %s()",
717 (unsigned long) *call);
718 printk(": returned with %s\n", msg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700719 }
720 }
721
722 /* Make sure there is no pending stuff from the initcall sequence */
723 flush_scheduled_work();
724}
725
726/*
727 * Ok, the machine is now initialized. None of the devices
728 * have been touched yet, but the CPU subsystem is up and
729 * running, and memory and process management works.
730 *
731 * Now we can finally start doing some real work..
732 */
733static void __init do_basic_setup(void)
734{
735 /* drivers will send hotplug events */
736 init_workqueues();
737 usermodehelper_init();
738 driver_init();
Eric W. Biedermanb04c3af2007-02-14 00:33:57 -0800739 init_irq_proc();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700740 do_initcalls();
741}
742
Dave Jones97842212007-07-15 23:41:05 -0700743static int __initdata nosoftlockup;
744
745static int __init nosoftlockup_setup(char *str)
746{
747 nosoftlockup = 1;
748 return 1;
749}
750__setup("nosoftlockup", nosoftlockup_setup);
751
Vivek Goyal88d20322007-01-11 01:52:44 +0100752static void __init do_pre_smp_initcalls(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700753{
754 extern int spawn_ksoftirqd(void);
755#ifdef CONFIG_SMP
756 extern int migration_init(void);
757
758 migration_init();
759#endif
760 spawn_ksoftirqd();
Dave Jones97842212007-07-15 23:41:05 -0700761 if (!nosoftlockup)
762 spawn_softlockup_task();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700763}
764
765static void run_init_process(char *init_filename)
766{
767 argv_init[0] = init_filename;
Arnd Bergmann67608562006-10-02 02:18:26 -0700768 kernel_execve(init_filename, argv_init, envp_init);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700769}
770
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100771/* This is a non __init function. Force it to be noinline otherwise gcc
772 * makes it inline to init() and it becomes part of init.text section
773 */
774static int noinline init_post(void)
775{
776 free_initmem();
777 unlock_kernel();
778 mark_rodata_ro();
779 system_state = SYSTEM_RUNNING;
780 numa_default_policy();
781
782 if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
783 printk(KERN_WARNING "Warning: unable to open an initial console.\n");
784
785 (void) sys_dup(0);
786 (void) sys_dup(0);
787
788 if (ramdisk_execute_command) {
789 run_init_process(ramdisk_execute_command);
790 printk(KERN_WARNING "Failed to execute %s\n",
791 ramdisk_execute_command);
792 }
793
794 /*
795 * We try each of these until one succeeds.
796 *
797 * The Bourne shell can be used instead of init if we are
798 * trying to recover a really broken machine.
799 */
800 if (execute_command) {
801 run_init_process(execute_command);
802 printk(KERN_WARNING "Failed to execute %s. Attempting "
803 "defaults...\n", execute_command);
804 }
805 run_init_process("/sbin/init");
806 run_init_process("/etc/init");
807 run_init_process("/bin/init");
808 run_init_process("/bin/sh");
809
810 panic("No init found. Try passing init= option to kernel.");
811}
812
Sam Ravnborgaae5f662007-02-26 16:45:41 +0100813static int __init kernel_init(void * unused)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700814{
815 lock_kernel();
816 /*
817 * init can run on any cpu.
818 */
819 set_cpus_allowed(current, CPU_MASK_ALL);
820 /*
821 * Tell the world that we're going to be the grim
822 * reaper of innocent orphaned children.
823 *
824 * We don't want people to have to make incorrect
825 * assumptions about where in the task array this
826 * can be found.
827 */
Sukadev Bhattiprolu84d73782006-12-08 02:38:01 -0800828 init_pid_ns.child_reaper = current;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700829
Sukadev Bhattiprolu0e29b242007-05-10 22:23:01 -0700830 __set_special_pids(1, 1);
Cedric Le Goater9ec52092006-10-02 02:19:00 -0700831 cad_pid = task_pid(current);
832
Linus Torvalds1da177e2005-04-16 15:20:36 -0700833 smp_prepare_cpus(max_cpus);
834
835 do_pre_smp_initcalls();
836
Linus Torvalds1da177e2005-04-16 15:20:36 -0700837 smp_init();
838 sched_init_smp();
839
840 cpuset_init_smp();
841
Linus Torvalds1da177e2005-04-16 15:20:36 -0700842 do_basic_setup();
843
844 /*
845 * check if there is an early userspace init. If yes, let it do all
846 * the work
847 */
Olof Johanssonffdfc402005-09-06 15:17:19 -0700848
849 if (!ramdisk_execute_command)
850 ramdisk_execute_command = "/init";
851
852 if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
853 ramdisk_execute_command = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700854 prepare_namespace();
Olof Johanssonffdfc402005-09-06 15:17:19 -0700855 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700856
857 /*
858 * Ok, we have completed the initial bootup, and
859 * we're essentially up and running. Get rid of the
860 * initmem segments and start the user-mode stuff..
861 */
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100862 init_post();
863 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700864}