blob: 33c37c379e96458521a0111a968849139edcf586 [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>
Ingo Molnar9b5609fd2008-02-14 09:41:09 +010017#include <linux/stackprotector.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070018#include <linux/string.h>
19#include <linux/ctype.h>
20#include <linux/delay.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070021#include <linux/ioport.h>
22#include <linux/init.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070023#include <linux/initrd.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070024#include <linux/bootmem.h>
Len Brown4a7a16d2009-06-12 20:42:08 -040025#include <linux/acpi.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070026#include <linux/tty.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070027#include <linux/percpu.h>
28#include <linux/kmod.h>
Nick Piggindb64fe02008-10-18 20:27:03 -070029#include <linux/vmalloc.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070030#include <linux/kernel_stat.h>
Rusty Russelld7cd5612006-12-07 02:14:08 +010031#include <linux/start_kernel.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070032#include <linux/security.h>
Jens Axboe3d442232008-06-26 11:21:34 +020033#include <linux/smp.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070034#include <linux/profile.h>
35#include <linux/rcupdate.h>
36#include <linux/moduleparam.h>
37#include <linux/kallsyms.h>
38#include <linux/writeback.h>
39#include <linux/cpu.h>
40#include <linux/cpuset.h>
Paul Menageddbcc7e2007-10-18 23:39:30 -070041#include <linux/cgroup.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070042#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>
Adrian Bunkb6cd0b72006-06-27 02:53:54 -070051#include <linux/buffer_head.h>
KAMEZAWA Hiroyuki94b6da52008-10-22 14:15:05 -070052#include <linux/page_cgroup.h>
Ingo Molnar9a11b49a2006-07-03 00:24:33 -070053#include <linux/debug_locks.h>
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -070054#include <linux/debugobjects.h>
Ingo Molnarfbb9ce92006-07-03 00:24:50 -070055#include <linux/lockdep.h>
Catalin Marinas3c7b4e62009-06-11 13:22:39 +010056#include <linux/kmemleak.h>
Sukadev Bhattiprolu84d73782006-12-08 02:38:01 -080057#include <linux/pid_namespace.h>
Adrian Bunk1f217822006-12-19 13:01:28 -080058#include <linux/device.h>
Eric W. Biederman73c27992007-05-09 02:34:32 -070059#include <linux/kthread.h>
Adrian Bunke6fe6642007-11-09 22:39:39 +010060#include <linux/sched.h>
Adrian Bunka1c9eea2008-02-06 01:36:44 -080061#include <linux/signal.h>
Akinobu Mita199f0ca2008-04-29 01:03:13 -070062#include <linux/idr.h>
Jason Wessel0b4b3822010-05-20 21:04:29 -050063#include <linux/kgdb.h>
Steven Rostedt68bf21a2008-08-14 15:45:08 -040064#include <linux/ftrace.h>
Arjan van de Ven22a9d642009-01-07 08:45:46 -080065#include <linux/async.h>
Vegard Nossumdfec0722008-04-04 00:51:41 +020066#include <linux/kmemcheck.h>
Feng Tang6ae69962009-08-14 15:13:46 -040067#include <linux/sfi.h>
Kay Sievers2b2af542009-04-30 15:23:42 +020068#include <linux/shmem_fs.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090069#include <linux/slab.h>
Peter Zijlstra24a24bb2010-11-17 23:17:33 +010070#include <linux/perf_event.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070071
72#include <asm/io.h>
73#include <asm/bugs.h>
74#include <asm/setup.h>
Andi Kleena9401992005-07-28 21:15:30 -070075#include <asm/sections.h>
Arjan van de Ven37b73c82006-01-06 00:12:01 -080076#include <asm/cacheflush.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070077
Linus Torvalds1da177e2005-04-16 15:20:36 -070078#ifdef CONFIG_X86_LOCAL_APIC
79#include <asm/smp.h>
80#endif
81
Sam Ravnborgaae5f662007-02-26 16:45:41 +010082static int kernel_init(void *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070083
84extern void init_IRQ(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070085extern void fork_init(unsigned long);
86extern void mca_init(void);
87extern void sbus_init(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070088extern void prio_tree_init(void);
89extern void radix_tree_init(void);
90extern void free_initmem(void);
Arjan van de Ven37b73c82006-01-06 00:12:01 -080091#ifndef CONFIG_DEBUG_RODATA
92static inline void mark_rodata_ro(void) { }
93#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -070094
95#ifdef CONFIG_TC
96extern void tc_init(void);
97#endif
98
Tejun Heo2ce802f2011-01-20 12:06:35 +010099/*
100 * Debug helper: via this flag we know that we are in 'early bootup code'
101 * where only the boot processor is running with IRQ disabled. This means
102 * two things - IRQ must not be enabled before the flag is cleared and some
103 * operations which are not allowed with IRQ disabled are allowed while the
104 * flag is set.
105 */
106bool early_boot_irqs_disabled __read_mostly;
107
Paul E. McKenneya6826042009-02-25 18:03:42 -0800108enum system_states system_state __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109EXPORT_SYMBOL(system_state);
110
111/*
112 * Boot command-line arguments
113 */
114#define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
115#define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
116
117extern void time_init(void);
118/* Default late time init is NULL. archs can override this later. */
Jan Beulichd2e31922009-01-06 14:41:10 -0800119void (*__initdata late_time_init)(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120extern void softirq_init(void);
121
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800122/* Untouched command line saved by arch-specific code. */
123char __initdata boot_command_line[COMMAND_LINE_SIZE];
124/* Untouched saved command line (eg. for /proc) */
125char *saved_command_line;
126/* Command line for parameter parsing */
127static char *static_command_line;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128
129static char *execute_command;
Olof Johanssonffdfc402005-09-06 15:17:19 -0700130static char *ramdisk_execute_command;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131
Jan Beulich8b3b2952007-07-15 23:41:07 -0700132#ifdef CONFIG_SMP
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133/* Setup configured maximum number of CPUs to activate */
Thomas Renninger75cbfb92010-05-26 17:03:33 +0200134unsigned int setup_max_cpus = NR_CPUS;
135EXPORT_SYMBOL(setup_max_cpus);
136
Vivek Goyal7e962872006-09-27 01:50:44 -0700137
138/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139 * Setup routine for controlling SMP activation
140 *
141 * Command-line option of "nosmp" or "maxcpus=0" will disable SMP
142 * activation entirely (the MPS table probe still happens, though).
143 *
144 * Command-line option of "maxcpus=<NUM>", where <NUM> is an integer
145 * greater than 0, limits the maximum number of CPUs activated in
146 * SMP mode to <NUM>.
147 */
Ingo Molnar65a4e572009-01-31 03:36:17 +0100148
149void __weak arch_disable_smp_support(void) { }
Len Brown61ec7562007-08-16 03:34:22 -0400150
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151static int __init nosmp(char *str)
152{
Andi Kleenca74a6f2008-01-30 13:33:17 +0100153 setup_max_cpus = 0;
Ingo Molnar65a4e572009-01-31 03:36:17 +0100154 arch_disable_smp_support();
155
Jan Beulich8b3b2952007-07-15 23:41:07 -0700156 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157}
158
Jan Beulich8b3b2952007-07-15 23:41:07 -0700159early_param("nosmp", nosmp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160
Yinghai Lu2b633e32010-02-10 01:20:37 -0800161/* this is hard limit */
162static int __init nrcpus(char *str)
163{
164 int nr_cpus;
165
166 get_option(&str, &nr_cpus);
167 if (nr_cpus > 0 && nr_cpus < nr_cpu_ids)
168 nr_cpu_ids = nr_cpus;
169
170 return 0;
171}
172
173early_param("nr_cpus", nrcpus);
174
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175static int __init maxcpus(char *str)
176{
Andi Kleenca74a6f2008-01-30 13:33:17 +0100177 get_option(&str, &setup_max_cpus);
178 if (setup_max_cpus == 0)
Ingo Molnar65a4e572009-01-31 03:36:17 +0100179 arch_disable_smp_support();
Len Brown61ec7562007-08-16 03:34:22 -0400180
181 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182}
183
Hugh Dickins81340972007-08-27 16:02:12 +0100184early_param("maxcpus", maxcpus);
Jan Beulich8b3b2952007-07-15 23:41:07 -0700185#else
H Hartley Sweeten7463e632010-03-05 13:42:46 -0800186static const unsigned int setup_max_cpus = NR_CPUS;
Jan Beulich8b3b2952007-07-15 23:41:07 -0700187#endif
188
189/*
190 * If set, this is an indication to the drivers that reset the underlying
191 * device before going ahead with the initialization otherwise driver might
192 * rely on the BIOS and skip the reset operation.
193 *
194 * This is useful if kernel is booting in an unreliable environment.
195 * For ex. kdump situaiton where previous kernel has crashed, BIOS has been
196 * skipped and devices will be in unknown state.
197 */
198unsigned int reset_devices;
199EXPORT_SYMBOL(reset_devices);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200
Vivek Goyal7e962872006-09-27 01:50:44 -0700201static int __init set_reset_devices(char *str)
202{
203 reset_devices = 1;
204 return 1;
205}
206
207__setup("reset_devices", set_reset_devices);
208
David Howellsd7627462010-08-17 23:52:56 +0100209static const char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
210const char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211static const char *panic_later, *panic_param;
212
Rusty Russell914dcaa2010-08-11 23:04:18 -0600213extern const struct obs_kernel_param __setup_start[], __setup_end[];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214
215static int __init obsolete_checksetup(char *line)
216{
Rusty Russell914dcaa2010-08-11 23:04:18 -0600217 const struct obs_kernel_param *p;
Rusty Russell33df0d12006-09-26 10:52:32 +0200218 int had_early_param = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219
220 p = __setup_start;
221 do {
222 int n = strlen(p->str);
223 if (!strncmp(line, p->str, n)) {
224 if (p->early) {
Rusty Russell33df0d12006-09-26 10:52:32 +0200225 /* Already done in parse_early_param?
226 * (Needs exact match on param part).
227 * Keep iterating, as we can have early
228 * params and __setups of same names 8( */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229 if (line[n] == '\0' || line[n] == '=')
Rusty Russell33df0d12006-09-26 10:52:32 +0200230 had_early_param = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231 } else if (!p->setup_func) {
232 printk(KERN_WARNING "Parameter %s is obsolete,"
233 " ignored\n", p->str);
234 return 1;
235 } else if (p->setup_func(line + n))
236 return 1;
237 }
238 p++;
239 } while (p < __setup_end);
Rusty Russell33df0d12006-09-26 10:52:32 +0200240
241 return had_early_param;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242}
243
244/*
245 * This should be approx 2 Bo*oMips to start (note initial shift), and will
246 * still work even if initially too large, it will just take slightly longer
247 */
248unsigned long loops_per_jiffy = (1<<12);
249
250EXPORT_SYMBOL(loops_per_jiffy);
251
252static int __init debug_kernel(char *str)
253{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254 console_loglevel = 10;
Yinghai Luf6f21c812008-02-08 04:21:58 -0800255 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256}
257
258static int __init quiet_kernel(char *str)
259{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260 console_loglevel = 4;
Yinghai Luf6f21c812008-02-08 04:21:58 -0800261 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262}
263
Yinghai Luf6f21c812008-02-08 04:21:58 -0800264early_param("debug", debug_kernel);
265early_param("quiet", quiet_kernel);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266
267static int __init loglevel(char *str)
268{
269 get_option(&str, &console_loglevel);
Alex Riesend9d4fcf2008-03-04 14:28:31 -0800270 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700271}
272
Yinghai Luf6f21c812008-02-08 04:21:58 -0800273early_param("loglevel", loglevel);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274
275/*
276 * Unknown boot options get handed to init, unless they look like
Rusty Russellf066a4f2009-12-01 14:56:44 +1030277 * unused parameters (modprobe will find them in /proc/cmdline).
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278 */
279static int __init unknown_bootoption(char *param, char *val)
280{
281 /* Change NUL term back to "=", to make "param" the whole string. */
282 if (val) {
283 /* param=val or param="val"? */
284 if (val == param+strlen(param)+1)
285 val[-1] = '=';
286 else if (val == param+strlen(param)+2) {
287 val[-2] = '=';
288 memmove(val-1, val, strlen(val)+1);
289 val--;
290 } else
291 BUG();
292 }
293
294 /* Handle obsolete-style parameters */
295 if (obsolete_checksetup(param))
296 return 0;
297
Rusty Russellf066a4f2009-12-01 14:56:44 +1030298 /* Unused module parameter. */
299 if (strchr(param, '.') && (!val || strchr(param, '.') < val))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700300 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301
302 if (panic_later)
303 return 0;
304
305 if (val) {
306 /* Environment option */
307 unsigned int i;
308 for (i = 0; envp_init[i]; i++) {
309 if (i == MAX_INIT_ENVS) {
310 panic_later = "Too many boot env vars at `%s'";
311 panic_param = param;
312 }
313 if (!strncmp(param, envp_init[i], val - param))
314 break;
315 }
316 envp_init[i] = param;
317 } else {
318 /* Command line option */
319 unsigned int i;
320 for (i = 0; argv_init[i]; i++) {
321 if (i == MAX_INIT_ARGS) {
322 panic_later = "Too many boot init vars at `%s'";
323 panic_param = param;
324 }
325 }
326 argv_init[i] = param;
327 }
328 return 0;
329}
330
Ingo Molnar12d6f212008-01-30 13:33:58 +0100331#ifdef CONFIG_DEBUG_PAGEALLOC
332int __read_mostly debug_pagealloc_enabled = 0;
333#endif
334
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335static int __init init_setup(char *str)
336{
337 unsigned int i;
338
339 execute_command = str;
340 /*
341 * In case LILO is going to boot us with default command line,
342 * it prepends "auto" before the whole cmdline which makes
343 * the shell think it should execute a script with such name.
344 * So we ignore all arguments entered _before_ init=... [MJ]
345 */
346 for (i = 1; i < MAX_INIT_ARGS; i++)
347 argv_init[i] = NULL;
348 return 1;
349}
350__setup("init=", init_setup);
351
Olof Johanssonffdfc402005-09-06 15:17:19 -0700352static int __init rdinit_setup(char *str)
353{
354 unsigned int i;
355
356 ramdisk_execute_command = str;
357 /* See "auto" comment in init_setup */
358 for (i = 1; i < MAX_INIT_ARGS; i++)
359 argv_init[i] = NULL;
360 return 1;
361}
362__setup("rdinit=", rdinit_setup);
363
Linus Torvalds1da177e2005-04-16 15:20:36 -0700364#ifndef CONFIG_SMP
365
366#ifdef CONFIG_X86_LOCAL_APIC
367static void __init smp_init(void)
368{
369 APIC_init_uniprocessor();
370}
371#else
372#define smp_init() do { } while (0)
373#endif
374
Mike Travise0982e92008-03-26 14:23:48 -0700375static inline void setup_nr_cpu_ids(void) { }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700376static inline void smp_prepare_cpus(unsigned int maxcpus) { }
377
378#else
379
Mike Travise0982e92008-03-26 14:23:48 -0700380/* Setup number of possible processor ids */
381int nr_cpu_ids __read_mostly = NR_CPUS;
382EXPORT_SYMBOL(nr_cpu_ids);
383
384/* An arch may set nr_cpu_ids earlier if needed, so this would be redundant */
385static void __init setup_nr_cpu_ids(void)
386{
Rusty Russelle0c0ba72009-01-01 10:12:19 +1030387 nr_cpu_ids = find_last_bit(cpumask_bits(cpu_possible_mask),NR_CPUS) + 1;
Mike Travise0982e92008-03-26 14:23:48 -0700388}
389
Linus Torvalds1da177e2005-04-16 15:20:36 -0700390/* Called by boot processor to activate the rest. */
391static void __init smp_init(void)
392{
Christoph Lameter53b8a312007-02-20 13:57:51 -0800393 unsigned int cpu;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394
395 /* FIXME: This should be done in userspace --RR */
Christoph Lameter53b8a312007-02-20 13:57:51 -0800396 for_each_present_cpu(cpu) {
Andi Kleenca74a6f2008-01-30 13:33:17 +0100397 if (num_online_cpus() >= setup_max_cpus)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700398 break;
Christoph Lameter53b8a312007-02-20 13:57:51 -0800399 if (!cpu_online(cpu))
400 cpu_up(cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700401 }
402
403 /* Any cleanup work */
404 printk(KERN_INFO "Brought up %ld CPUs\n", (long)num_online_cpus());
Andi Kleenca74a6f2008-01-30 13:33:17 +0100405 smp_cpus_done(setup_max_cpus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700406}
407
408#endif
409
410/*
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800411 * We need to store the untouched command line for future reference.
412 * We also need to store the touched command line since the parameter
413 * parsing is performed in place, and we should allow a component to
414 * store reference of name/value for future reference.
415 */
416static void __init setup_command_line(char *command_line)
417{
418 saved_command_line = alloc_bootmem(strlen (boot_command_line)+1);
419 static_command_line = alloc_bootmem(strlen (command_line)+1);
420 strcpy (saved_command_line, boot_command_line);
421 strcpy (static_command_line, command_line);
422}
423
424/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700425 * We need to finalize in a non-__init function or else race conditions
426 * between the root thread and the init thread may cause start_kernel to
427 * be reaped by free_initmem before the root thread has proceeded to
428 * cpu_idle.
429 *
430 * gcc-3.4 accidentally inlines this function, so use noinline.
431 */
432
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200433static __initdata DECLARE_COMPLETION(kthreadd_done);
434
Rakib Mullickf99ebf02009-01-06 14:40:38 -0800435static noinline void __init_refok rest_init(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700436{
Eric W. Biederman73c27992007-05-09 02:34:32 -0700437 int pid;
438
Paul E. McKenney7db905e2009-09-02 14:01:24 -0700439 rcu_scheduler_starting();
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200440 /*
Peter Zijlstra97158562010-06-30 10:37:11 +0200441 * We need to spawn init first so that it obtains pid 1, however
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200442 * the init task will end up wanting to create kthreads, which, if
443 * we schedule it before we create kthreadd, will OOPS.
444 */
Sam Ravnborgaae5f662007-02-26 16:45:41 +0100445 kernel_thread(kernel_init, NULL, CLONE_FS | CLONE_SIGHAND);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700446 numa_default_policy();
Eric W. Biederman73c27992007-05-09 02:34:32 -0700447 pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
Paul E. McKenneyd11c5632010-02-22 17:04:50 -0800448 rcu_read_lock();
Pavel Emelyanov5cd20452008-04-30 00:54:24 -0700449 kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
Paul E. McKenneyd11c5632010-02-22 17:04:50 -0800450 rcu_read_unlock();
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200451 complete(&kthreadd_done);
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200452
453 /*
454 * The boot idle thread must execute schedule()
Ingo Molnar1df21052007-07-09 18:51:58 +0200455 * at least once to get things moving:
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200456 */
Ingo Molnar1df21052007-07-09 18:51:58 +0200457 init_idle_bootup_task(current);
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800458 preempt_enable_no_resched();
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200459 schedule();
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800460 preempt_disable();
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200461
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800462 /* Call into cpu_idle with preempt disabled */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700463 cpu_idle();
Ingo Molnar1df21052007-07-09 18:51:58 +0200464}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465
466/* Check for early params. */
467static int __init do_early_param(char *param, char *val)
468{
Rusty Russell914dcaa2010-08-11 23:04:18 -0600469 const struct obs_kernel_param *p;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700470
471 for (p = __setup_start; p < __setup_end; p++) {
Yinghai Lu18a8bd92007-07-15 23:37:59 -0700472 if ((p->early && strcmp(param, p->str) == 0) ||
473 (strcmp(param, "console") == 0 &&
474 strcmp(p->str, "earlycon") == 0)
475 ) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700476 if (p->setup_func(val) != 0)
477 printk(KERN_WARNING
478 "Malformed early option '%s'\n", param);
479 }
480 }
481 /* We accept everything at this stage. */
482 return 0;
483}
484
Magnus Damm13977092009-03-30 14:37:25 -0700485void __init parse_early_options(char *cmdline)
486{
487 parse_args("early options", cmdline, NULL, 0, do_early_param);
488}
489
Linus Torvalds1da177e2005-04-16 15:20:36 -0700490/* Arch code calls this early on, or if not, just before other parsing. */
491void __init parse_early_param(void)
492{
493 static __initdata int done = 0;
494 static __initdata char tmp_cmdline[COMMAND_LINE_SIZE];
495
496 if (done)
497 return;
498
499 /* All fall through to do_early_param. */
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800500 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
Magnus Damm13977092009-03-30 14:37:25 -0700501 parse_early_options(tmp_cmdline);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700502 done = 1;
503}
504
505/*
506 * Activate the first processor.
507 */
508
Stas Sergeev44fd2292006-03-23 02:59:44 -0800509static void __init boot_cpu_init(void)
510{
511 int cpu = smp_processor_id();
512 /* Mark the boot cpu "present", "online" etc for SMP and UP case */
Rusty Russell915441b2009-01-01 10:12:15 +1030513 set_cpu_online(cpu, true);
Peter Zijlstra933b0612009-12-16 18:04:31 +0100514 set_cpu_active(cpu, true);
Rusty Russell915441b2009-01-01 10:12:15 +1030515 set_cpu_present(cpu, true);
516 set_cpu_possible(cpu, true);
Stas Sergeev44fd2292006-03-23 02:59:44 -0800517}
518
Benjamin Herrenschmidt839ad622008-04-18 16:56:18 +1000519void __init __weak smp_setup_processor_id(void)
Andrew Morton033ab7f2006-06-30 01:55:50 -0700520{
521}
522
Benjamin Herrenschmidt8c9843e2008-04-18 16:56:15 +1000523void __init __weak thread_info_cache_init(void)
524{
525}
526
Pekka Enberg444f4782009-06-11 18:29:06 +0300527/*
528 * Set up kernel memory allocators
529 */
530static void __init mm_init(void)
531{
KAMEZAWA Hiroyukica371c02009-06-12 10:33:53 +0300532 /*
533 * page_cgroup requires countinous pages as memmap
534 * and it's bigger than MAX_ORDER unless SPARSEMEM.
535 */
536 page_cgroup_init_flatmem();
Pekka Enberg444f4782009-06-11 18:29:06 +0300537 mem_init();
538 kmem_cache_init();
Tejun Heo099a19d2010-06-27 18:50:00 +0200539 percpu_init_late();
Benjamin Herrenschmidtc868d552009-06-17 13:48:39 +1000540 pgtable_cache_init();
Pekka Enberg444f4782009-06-11 18:29:06 +0300541 vmalloc_init();
542}
543
Linus Torvalds1da177e2005-04-16 15:20:36 -0700544asmlinkage void __init start_kernel(void)
545{
546 char * command_line;
Rusty Russell914dcaa2010-08-11 23:04:18 -0600547 extern const struct kernel_param __start___param[], __stop___param[];
Andrew Morton033ab7f2006-06-30 01:55:50 -0700548
549 smp_setup_processor_id();
550
Ingo Molnarfbb9ce92006-07-03 00:24:50 -0700551 /*
552 * Need to run as early as possible, to initialize the
553 * lockdep hash:
554 */
555 lockdep_init();
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700556 debug_objects_early_init();
Ingo Molnar42059422008-02-14 09:44:08 +0100557
558 /*
559 * Set up the the initial canary ASAP:
560 */
561 boot_init_stack_canary();
562
Paul Menageddbcc7e2007-10-18 23:39:30 -0700563 cgroup_init_early();
Ingo Molnarfbb9ce92006-07-03 00:24:50 -0700564
565 local_irq_disable();
Tejun Heo2ce802f2011-01-20 12:06:35 +0100566 early_boot_irqs_disabled = true;
Ingo Molnarfbb9ce92006-07-03 00:24:50 -0700567
Linus Torvalds1da177e2005-04-16 15:20:36 -0700568/*
569 * Interrupts are still disabled. Do necessary setups, then
570 * enable them
571 */
Thomas Gleixner906568c2007-02-16 01:28:01 -0800572 tick_init();
Stas Sergeev44fd2292006-03-23 02:59:44 -0800573 boot_cpu_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700574 page_address_init();
Alex Riesen657cafa2009-05-24 15:30:48 +0200575 printk(KERN_NOTICE "%s", linux_banner);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700576 setup_arch(&command_line);
Balbir Singhcf475ad2008-04-29 01:00:16 -0700577 mm_init_owner(&init_mm, &init_task);
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800578 setup_command_line(command_line);
Mike Travise0982e92008-03-26 14:23:48 -0700579 setup_nr_cpu_ids();
Tejun Heod6647bd2009-07-21 17:11:50 +0900580 setup_per_cpu_areas();
Stas Sergeev44fd2292006-03-23 02:59:44 -0800581 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700582
Haicheng Li1f522502010-05-24 14:32:51 -0700583 build_all_zonelists(NULL);
Pekka Enberg83b519e2009-06-10 19:40:04 +0300584 page_alloc_init();
585
586 printk(KERN_NOTICE "Kernel command line: %s\n", boot_command_line);
587 parse_early_param();
588 parse_args("Booting kernel", static_command_line, __start___param,
589 __stop___param - __start___param,
590 &unknown_bootoption);
591 /*
592 * These use large bootmem allocations and must precede
593 * kmem_cache_init()
594 */
595 pidhash_init();
Pekka Enberg83b519e2009-06-10 19:40:04 +0300596 vfs_caches_init_early();
597 sort_main_extable();
598 trap_init();
Pekka Enberg444f4782009-06-11 18:29:06 +0300599 mm_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700600 /*
601 * Set up the scheduler prior starting any interrupts (such as the
602 * timer interrupt). Full topology setup happens at smp_init()
603 * time - but meanwhile we still have a functioning scheduler.
604 */
605 sched_init();
606 /*
607 * Disable preemption - early bootup scheduling is extremely
608 * fragile until we cpu_idle() for the first time.
609 */
610 preempt_disable();
Ard van Breemenc4a68302007-01-05 16:36:19 -0800611 if (!irqs_disabled()) {
612 printk(KERN_WARNING "start_kernel(): bug: interrupts were "
613 "enabled *very* early, fixing it\n");
614 local_irq_disable();
615 }
Peter Zijlstra9f58a202010-11-17 23:17:35 +0100616 idr_init_cache();
Peter Zijlstra24a24bb2010-11-17 23:17:33 +0100617 perf_event_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700618 rcu_init();
Yinghai Lu773e3eb2010-02-10 01:20:33 -0800619 radix_tree_init();
Yinghai Lu0b8f1ef2008-12-05 18:58:31 -0800620 /* init some links before init_ISA_irqs() */
621 early_irq_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700622 init_IRQ();
Catalin Marinas3c7b4e62009-06-11 13:22:39 +0100623 prio_tree_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700624 init_timers();
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800625 hrtimers_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700626 softirq_init();
john stultzad596172006-06-26 00:25:06 -0700627 timekeeping_init();
john stultz88fecaa2006-07-03 00:24:04 -0700628 time_init();
Heiko Carstens93e02812006-07-03 00:24:24 -0700629 profile_init();
630 if (!irqs_disabled())
Ron Lee24d431d2008-11-27 02:31:57 +1030631 printk(KERN_CRIT "start_kernel(): bug: interrupts were "
632 "enabled early\n");
Tejun Heo2ce802f2011-01-20 12:06:35 +0100633 early_boot_irqs_disabled = false;
Heiko Carstens93e02812006-07-03 00:24:24 -0700634 local_irq_enable();
Benjamin Herrenschmidtdcce2842009-06-18 13:24:12 +1000635
636 /* Interrupts are enabled now so all GFP allocations are safe. */
Rafael J. Wysocki452aa692010-03-05 13:42:13 -0800637 gfp_allowed_mask = __GFP_BITS_MASK;
Benjamin Herrenschmidtdcce2842009-06-18 13:24:12 +1000638
Pekka Enberg7e85ee02009-06-12 14:03:06 +0300639 kmem_cache_init_late();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700640
641 /*
642 * HACK ALERT! This is early. We're enabling the console before
643 * we've done PCI setups etc, and console_init() must be aware of
644 * this. But we do want output early, in case something goes wrong.
645 */
646 console_init();
647 if (panic_later)
648 panic(panic_later, panic_param);
Ingo Molnarfbb9ce92006-07-03 00:24:50 -0700649
650 lockdep_info();
651
Ingo Molnar9a11b49a2006-07-03 00:24:33 -0700652 /*
653 * Need to run this when irqs are enabled, because it wants
654 * to self-test [hard/soft]-irqs on/off lock inversion bugs
655 * too:
656 */
657 locking_selftest();
658
Linus Torvalds1da177e2005-04-16 15:20:36 -0700659#ifdef CONFIG_BLK_DEV_INITRD
660 if (initrd_start && !initrd_below_start_ok &&
Geert Uytterhoevenbd673c72008-07-29 22:33:36 -0700661 page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700662 printk(KERN_CRIT "initrd overwritten (0x%08lx < 0x%08lx) - "
Geert Uytterhoevenfb6624e2008-07-17 21:16:36 +0200663 "disabling it.\n",
Geert Uytterhoevenbd673c72008-07-29 22:33:36 -0700664 page_to_pfn(virt_to_page((void *)initrd_start)),
665 min_low_pfn);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700666 initrd_start = 0;
667 }
668#endif
KAMEZAWA Hiroyuki94b6da52008-10-22 14:15:05 -0700669 page_cgroup_init();
Thomas Gleixnera03c2a42008-02-09 23:24:09 +0100670 enable_debug_pagealloc();
Catalin Marinas3c7b4e62009-06-11 13:22:39 +0100671 kmemleak_init();
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700672 debug_objects_mem_init();
Christoph Lametere7c8d5c2005-06-21 17:14:47 -0700673 setup_per_cpu_pageset();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700674 numa_policy_init();
675 if (late_time_init)
676 late_time_init();
Thomas Gleixnerfa84e9e2009-08-21 22:01:12 +0200677 sched_clock_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700678 calibrate_delay();
679 pidmap_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700680 anon_vma_init();
681#ifdef CONFIG_X86
682 if (efi_enabled)
683 efi_enter_virtual_mode();
684#endif
Benjamin Herrenschmidt8c9843e2008-04-18 16:56:15 +1000685 thread_info_cache_init();
David Howellsd84f4f92008-11-14 10:39:23 +1100686 cred_init();
Jan Beulich44813742009-09-21 17:03:05 -0700687 fork_init(totalram_pages);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700688 proc_caches_init();
689 buffer_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700690 key_init();
691 security_init();
Jason Wessel0b4b3822010-05-20 21:04:29 -0500692 dbg_late_init();
Jan Beulich44813742009-09-21 17:03:05 -0700693 vfs_caches_init(totalram_pages);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700694 signals_init();
695 /* rootfs populating might need page-writeback */
696 page_writeback_init();
697#ifdef CONFIG_PROC_FS
698 proc_root_init();
699#endif
Paul Menageddbcc7e2007-10-18 23:39:30 -0700700 cgroup_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700701 cpuset_init();
Shailabh Nagarc7572492006-07-14 00:24:40 -0700702 taskstats_init_early();
Shailabh Nagarca74e922006-07-14 00:24:36 -0700703 delayacct_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700704
705 check_bugs();
706
707 acpi_early_init(); /* before LAPIC and SMP init */
Feng Tang6ae69962009-08-14 15:13:46 -0400708 sfi_init_late();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700709
Steven Rostedt68bf21a2008-08-14 15:45:08 -0400710 ftrace_init();
711
Linus Torvalds1da177e2005-04-16 15:20:36 -0700712 /* Do the rest non-__init'ed, we're now alive */
713 rest_init();
714}
715
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700716/* Call all constructor functions linked into the kernel. */
717static void __init do_ctors(void)
718{
719#ifdef CONFIG_CONSTRUCTORS
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800720 ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700721
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800722 for (; fn < (ctor_fn_t *) __ctors_end; fn++)
723 (*fn)();
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700724#endif
725}
726
Arjan van de Ven22a9d642009-01-07 08:45:46 -0800727int initcall_debug;
Rusty Russelld0ea3d72008-10-22 10:00:23 -0500728core_param(initcall_debug, initcall_debug, bool, 0644);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700729
Ingo Molnar4a683bf2009-08-21 12:53:36 +0200730static char msgbuf[64];
Ingo Molnar4a683bf2009-08-21 12:53:36 +0200731
Kevin Winchestere4461272010-08-09 17:20:32 -0700732static int __init_or_module do_one_initcall_debug(initcall_t fn)
Linus Torvaldse0df1542008-05-15 18:14:01 -0700733{
Frederic Weisbecker74239072008-11-11 23:24:42 +0100734 ktime_t calltime, delta, rettime;
Américo Wang30dbb20e2010-05-26 18:57:53 +0800735 unsigned long long duration;
736 int ret;
Linus Torvaldse0df1542008-05-15 18:14:01 -0700737
Kevin Winchester22c5c032010-08-09 17:20:32 -0700738 printk(KERN_DEBUG "calling %pF @ %i\n", fn, task_pid_nr(current));
739 calltime = ktime_get();
Américo Wang30dbb20e2010-05-26 18:57:53 +0800740 ret = fn();
Kevin Winchester22c5c032010-08-09 17:20:32 -0700741 rettime = ktime_get();
742 delta = ktime_sub(rettime, calltime);
743 duration = (unsigned long long) ktime_to_ns(delta) >> 10;
744 printk(KERN_DEBUG "initcall %pF returned %d after %lld usecs\n", fn,
745 ret, duration);
Linus Torvaldse0df1542008-05-15 18:14:01 -0700746
Kevin Winchester22c5c032010-08-09 17:20:32 -0700747 return ret;
748}
749
Kevin Winchestere4461272010-08-09 17:20:32 -0700750int __init_or_module do_one_initcall(initcall_t fn)
Kevin Winchester22c5c032010-08-09 17:20:32 -0700751{
752 int count = preempt_count();
753 int ret;
754
755 if (initcall_debug)
756 ret = do_one_initcall_debug(fn);
757 else
758 ret = fn();
Linus Torvaldse0df1542008-05-15 18:14:01 -0700759
760 msgbuf[0] = 0;
761
Américo Wang30dbb20e2010-05-26 18:57:53 +0800762 if (ret && ret != -ENODEV && initcall_debug)
763 sprintf(msgbuf, "error code %d ", ret);
Linus Torvaldse0df1542008-05-15 18:14:01 -0700764
765 if (preempt_count() != count) {
Cyrill Gorcunova76bfd02008-05-15 13:52:41 -0700766 strlcat(msgbuf, "preemption imbalance ", sizeof(msgbuf));
Linus Torvaldse0df1542008-05-15 18:14:01 -0700767 preempt_count() = count;
768 }
769 if (irqs_disabled()) {
Cyrill Gorcunova76bfd02008-05-15 13:52:41 -0700770 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
Linus Torvaldse0df1542008-05-15 18:14:01 -0700771 local_irq_enable();
772 }
773 if (msgbuf[0]) {
Linus Torvalds96d746c2008-10-03 13:38:07 -0700774 printk("initcall %pF returned with %s\n", fn, msgbuf);
Linus Torvaldse0df1542008-05-15 18:14:01 -0700775 }
Arjan van de Ven59f94152008-07-30 12:49:02 -0700776
Américo Wang30dbb20e2010-05-26 18:57:53 +0800777 return ret;
Linus Torvaldse0df1542008-05-15 18:14:01 -0700778}
779
780
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700781extern initcall_t __initcall_start[], __initcall_end[], __early_initcall_end[];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700782
783static void __init do_initcalls(void)
784{
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800785 initcall_t *fn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700786
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800787 for (fn = __early_initcall_end; fn < __initcall_end; fn++)
788 do_one_initcall(*fn);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700789}
790
791/*
792 * Ok, the machine is now initialized. None of the devices
793 * have been touched yet, but the CPU subsystem is up and
794 * running, and memory and process management works.
795 *
796 * Now we can finally start doing some real work..
797 */
798static void __init do_basic_setup(void)
799{
Lai Jiangshan759ee092009-03-25 17:06:30 +0800800 cpuset_init_smp();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700801 usermodehelper_init();
Kay Sievers2b2af542009-04-30 15:23:42 +0200802 init_tmpfs();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700803 driver_init();
Eric W. Biedermanb04c3af2007-02-14 00:33:57 -0800804 init_irq_proc();
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700805 do_ctors();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700806 do_initcalls();
807}
808
Eduard - Gabriel Munteanu7babe8d2008-07-25 19:45:11 -0700809static void __init do_pre_smp_initcalls(void)
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700810{
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800811 initcall_t *fn;
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700812
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800813 for (fn = __initcall_start; fn < __early_initcall_end; fn++)
814 do_one_initcall(*fn);
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700815}
816
David Howellsd7627462010-08-17 23:52:56 +0100817static void run_init_process(const char *init_filename)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700818{
819 argv_init[0] = init_filename;
Arnd Bergmann67608562006-10-02 02:18:26 -0700820 kernel_execve(init_filename, argv_init, envp_init);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700821}
822
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100823/* This is a non __init function. Force it to be noinline otherwise gcc
824 * makes it inline to init() and it becomes part of init.text section
825 */
Rakib Mullickf99ebf02009-01-06 14:40:38 -0800826static noinline int init_post(void)
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100827{
Arjan van de Ven22a9d642009-01-07 08:45:46 -0800828 /* need to finish all async __init code before freeing the memory */
829 async_synchronize_full();
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100830 free_initmem();
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100831 mark_rodata_ro();
832 system_state = SYSTEM_RUNNING;
833 numa_default_policy();
834
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100835
Oleg Nesterovfae5fa42008-04-30 00:53:03 -0700836 current->signal->flags |= SIGNAL_UNKILLABLE;
837
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100838 if (ramdisk_execute_command) {
839 run_init_process(ramdisk_execute_command);
840 printk(KERN_WARNING "Failed to execute %s\n",
841 ramdisk_execute_command);
842 }
843
844 /*
845 * We try each of these until one succeeds.
846 *
847 * The Bourne shell can be used instead of init if we are
848 * trying to recover a really broken machine.
849 */
850 if (execute_command) {
851 run_init_process(execute_command);
852 printk(KERN_WARNING "Failed to execute %s. Attempting "
853 "defaults...\n", execute_command);
854 }
855 run_init_process("/sbin/init");
856 run_init_process("/etc/init");
857 run_init_process("/bin/init");
858 run_init_process("/bin/sh");
859
Andreas Mohr9a85b8d2010-03-05 13:42:39 -0800860 panic("No init found. Try passing init= option to kernel. "
861 "See Linux Documentation/init.txt for guidance.");
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100862}
863
Sam Ravnborgaae5f662007-02-26 16:45:41 +0100864static int __init kernel_init(void * unused)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700865{
Peter Zijlstrab433c3d2010-06-28 16:51:01 +0200866 /*
867 * Wait until kthreadd is all set-up.
868 */
869 wait_for_completion(&kthreadd_done);
Miao Xie58568d22009-06-16 15:31:49 -0700870 /*
871 * init can allocate pages on any node
872 */
Miao Xie5ab116c2010-03-23 13:35:34 -0700873 set_mems_allowed(node_states[N_HIGH_MEMORY]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700874 /*
875 * init can run on any cpu.
876 */
Rusty Russell1a2142a2009-03-30 22:05:10 -0600877 set_cpus_allowed_ptr(current, cpu_all_mask);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700878 /*
879 * Tell the world that we're going to be the grim
880 * reaper of innocent orphaned children.
881 *
882 * We don't want people to have to make incorrect
883 * assumptions about where in the task array this
884 * can be found.
885 */
Sukadev Bhattiprolu84d73782006-12-08 02:38:01 -0800886 init_pid_ns.child_reaper = current;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700887
Cedric Le Goater9ec52092006-10-02 02:19:00 -0700888 cad_pid = task_pid(current);
889
Andi Kleenca74a6f2008-01-30 13:33:17 +0100890 smp_prepare_cpus(setup_max_cpus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700891
892 do_pre_smp_initcalls();
Peter Zijlstra004417a2010-11-25 18:38:29 +0100893 lockup_detector_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700894
Linus Torvalds1da177e2005-04-16 15:20:36 -0700895 smp_init();
896 sched_init_smp();
897
Linus Torvalds1da177e2005-04-16 15:20:36 -0700898 do_basic_setup();
899
Eric W. Biederman2bd3a9972010-03-02 23:53:19 -0800900 /* Open the /dev/console on the rootfs, this should never fail */
901 if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
902 printk(KERN_WARNING "Warning: unable to open an initial console.\n");
903
904 (void) sys_dup(0);
905 (void) sys_dup(0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700906 /*
907 * check if there is an early userspace init. If yes, let it do all
908 * the work
909 */
Olof Johanssonffdfc402005-09-06 15:17:19 -0700910
911 if (!ramdisk_execute_command)
912 ramdisk_execute_command = "/init";
913
914 if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
915 ramdisk_execute_command = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700916 prepare_namespace();
Olof Johanssonffdfc402005-09-06 15:17:19 -0700917 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700918
919 /*
920 * Ok, we have completed the initial bootup, and
921 * we're essentially up and running. Get rid of the
922 * initmem segments and start the user-mode stuff..
923 */
Frederic Weisbecker71566a02008-10-31 12:57:20 +0100924
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100925 init_post();
926 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700927}