blob: 22881b5e95e3b00e010b407310539fbd4e1a8a57 [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 Molnar9b5609f2008-02-14 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>
23#include <linux/smp_lock.h>
24#include <linux/initrd.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070025#include <linux/bootmem.h>
Len Brown4a7a16d2009-06-12 20:42:08 -040026#include <linux/acpi.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070027#include <linux/tty.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070028#include <linux/percpu.h>
29#include <linux/kmod.h>
Nick Piggindb64fe02008-10-18 20:27:03 -070030#include <linux/vmalloc.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070031#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>
Jens Axboe3d442232008-06-26 11:21:34 +020034#include <linux/smp.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070035#include <linux/workqueue.h>
36#include <linux/profile.h>
37#include <linux/rcupdate.h>
38#include <linux/moduleparam.h>
39#include <linux/kallsyms.h>
40#include <linux/writeback.h>
41#include <linux/cpu.h>
42#include <linux/cpuset.h>
Paul Menageddbcc7e2007-10-18 23:39:30 -070043#include <linux/cgroup.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070044#include <linux/efi.h>
Thomas Gleixner906568c2007-02-16 01:28:01 -080045#include <linux/tick.h>
Andrew Morton6168a702007-02-17 21:22:39 -080046#include <linux/interrupt.h>
Shailabh Nagarc7572492006-07-14 00:24:40 -070047#include <linux/taskstats_kern.h>
Shailabh Nagarca74e922006-07-14 00:24:36 -070048#include <linux/delayacct.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070049#include <linux/unistd.h>
50#include <linux/rmap.h>
51#include <linux/mempolicy.h>
52#include <linux/key.h>
Adrian Bunkb6cd0b72006-06-27 02:53:54 -070053#include <linux/buffer_head.h>
KAMEZAWA Hiroyuki94b6da52008-10-22 14:15:05 -070054#include <linux/page_cgroup.h>
Ingo Molnar9a11b49a2006-07-03 00:24:33 -070055#include <linux/debug_locks.h>
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -070056#include <linux/debugobjects.h>
Ingo Molnarfbb9ce952006-07-03 00:24:50 -070057#include <linux/lockdep.h>
Catalin Marinas3c7b4e62009-06-11 13:22:39 +010058#include <linux/kmemleak.h>
Sukadev Bhattiprolu84d73782006-12-08 02:38:01 -080059#include <linux/pid_namespace.h>
Adrian Bunk1f217822006-12-19 13:01:28 -080060#include <linux/device.h>
Eric W. Biederman73c27992007-05-09 02:34:32 -070061#include <linux/kthread.h>
Adrian Bunke6fe6642007-11-09 22:39:39 +010062#include <linux/sched.h>
Adrian Bunka1c9eea2008-02-06 01:36:44 -080063#include <linux/signal.h>
Akinobu Mita199f0ca2008-04-29 01:03:13 -070064#include <linux/idr.h>
Jason Wessel0b4b3822010-05-20 21:04:29 -050065#include <linux/kgdb.h>
Steven Rostedt68bf21a2008-08-14 15:45:08 -040066#include <linux/ftrace.h>
Arjan van de Ven22a9d642009-01-07 08:45:46 -080067#include <linux/async.h>
Vegard Nossumdfec0722008-04-04 00:51:41 +020068#include <linux/kmemcheck.h>
Zhaolei02af61b2009-04-10 14:26:18 +080069#include <linux/kmemtrace.h>
Feng Tang6ae69962009-08-14 15:13:46 -040070#include <linux/sfi.h>
Kay Sievers2b2af542009-04-30 15:23:42 +020071#include <linux/shmem_fs.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090072#include <linux/slab.h>
Frederic Weisbecker3f5ec132008-11-11 23:21:31 +010073#include <trace/boot.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070074
75#include <asm/io.h>
76#include <asm/bugs.h>
77#include <asm/setup.h>
Andi Kleena9401992005-07-28 21:15:30 -070078#include <asm/sections.h>
Arjan van de Ven37b73c82006-01-06 00:12:01 -080079#include <asm/cacheflush.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070080
Linus Torvalds1da177e2005-04-16 15:20:36 -070081#ifdef CONFIG_X86_LOCAL_APIC
82#include <asm/smp.h>
83#endif
84
Sam Ravnborgaae5f662007-02-26 16:45:41 +010085static int kernel_init(void *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070086
87extern void init_IRQ(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070088extern void fork_init(unsigned long);
89extern void mca_init(void);
90extern void sbus_init(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070091extern void prio_tree_init(void);
92extern void radix_tree_init(void);
93extern void free_initmem(void);
Arjan van de Ven37b73c82006-01-06 00:12:01 -080094#ifndef CONFIG_DEBUG_RODATA
95static inline void mark_rodata_ro(void) { }
96#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -070097
98#ifdef CONFIG_TC
99extern void tc_init(void);
100#endif
101
Paul E. McKenneya6826042009-02-25 18:03:42 -0800102enum system_states system_state __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103EXPORT_SYMBOL(system_state);
104
105/*
106 * Boot command-line arguments
107 */
108#define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
109#define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
110
111extern void time_init(void);
112/* Default late time init is NULL. archs can override this later. */
Jan Beulichd2e31922009-01-06 14:41:10 -0800113void (*__initdata late_time_init)(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114extern void softirq_init(void);
115
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800116/* Untouched command line saved by arch-specific code. */
117char __initdata boot_command_line[COMMAND_LINE_SIZE];
118/* Untouched saved command line (eg. for /proc) */
119char *saved_command_line;
120/* Command line for parameter parsing */
121static char *static_command_line;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122
123static char *execute_command;
Olof Johanssonffdfc402005-09-06 15:17:19 -0700124static char *ramdisk_execute_command;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125
Jan Beulich8b3b2952007-07-15 23:41:07 -0700126#ifdef CONFIG_SMP
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127/* Setup configured maximum number of CPUs to activate */
Andi Kleenca74a6f2008-01-30 13:33:17 +0100128unsigned int __initdata setup_max_cpus = NR_CPUS;
Vivek Goyal7e962872006-09-27 01:50:44 -0700129
130/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131 * Setup routine for controlling SMP activation
132 *
133 * Command-line option of "nosmp" or "maxcpus=0" will disable SMP
134 * activation entirely (the MPS table probe still happens, though).
135 *
136 * Command-line option of "maxcpus=<NUM>", where <NUM> is an integer
137 * greater than 0, limits the maximum number of CPUs activated in
138 * SMP mode to <NUM>.
139 */
Ingo Molnar65a4e572009-01-31 03:36:17 +0100140
141void __weak arch_disable_smp_support(void) { }
Len Brown61ec7562007-08-16 03:34:22 -0400142
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143static int __init nosmp(char *str)
144{
Andi Kleenca74a6f2008-01-30 13:33:17 +0100145 setup_max_cpus = 0;
Ingo Molnar65a4e572009-01-31 03:36:17 +0100146 arch_disable_smp_support();
147
Jan Beulich8b3b2952007-07-15 23:41:07 -0700148 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149}
150
Jan Beulich8b3b2952007-07-15 23:41:07 -0700151early_param("nosmp", nosmp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152
Yinghai Lu2b633e32010-02-10 01:20:37 -0800153/* this is hard limit */
154static int __init nrcpus(char *str)
155{
156 int nr_cpus;
157
158 get_option(&str, &nr_cpus);
159 if (nr_cpus > 0 && nr_cpus < nr_cpu_ids)
160 nr_cpu_ids = nr_cpus;
161
162 return 0;
163}
164
165early_param("nr_cpus", nrcpus);
166
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167static int __init maxcpus(char *str)
168{
Andi Kleenca74a6f2008-01-30 13:33:17 +0100169 get_option(&str, &setup_max_cpus);
170 if (setup_max_cpus == 0)
Ingo Molnar65a4e572009-01-31 03:36:17 +0100171 arch_disable_smp_support();
Len Brown61ec7562007-08-16 03:34:22 -0400172
173 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700174}
175
Hugh Dickins81340972007-08-27 16:02:12 +0100176early_param("maxcpus", maxcpus);
Jan Beulich8b3b2952007-07-15 23:41:07 -0700177#else
H Hartley Sweeten7463e632010-03-05 13:42:46 -0800178static const unsigned int setup_max_cpus = NR_CPUS;
Jan Beulich8b3b2952007-07-15 23:41:07 -0700179#endif
180
181/*
182 * If set, this is an indication to the drivers that reset the underlying
183 * device before going ahead with the initialization otherwise driver might
184 * rely on the BIOS and skip the reset operation.
185 *
186 * This is useful if kernel is booting in an unreliable environment.
187 * For ex. kdump situaiton where previous kernel has crashed, BIOS has been
188 * skipped and devices will be in unknown state.
189 */
190unsigned int reset_devices;
191EXPORT_SYMBOL(reset_devices);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192
Vivek Goyal7e962872006-09-27 01:50:44 -0700193static int __init set_reset_devices(char *str)
194{
195 reset_devices = 1;
196 return 1;
197}
198
199__setup("reset_devices", set_reset_devices);
200
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201static char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
202char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
203static const char *panic_later, *panic_param;
204
205extern struct obs_kernel_param __setup_start[], __setup_end[];
206
207static int __init obsolete_checksetup(char *line)
208{
209 struct obs_kernel_param *p;
Rusty Russell33df0d12006-09-26 10:52:32 +0200210 int had_early_param = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211
212 p = __setup_start;
213 do {
214 int n = strlen(p->str);
215 if (!strncmp(line, p->str, n)) {
216 if (p->early) {
Rusty Russell33df0d12006-09-26 10:52:32 +0200217 /* Already done in parse_early_param?
218 * (Needs exact match on param part).
219 * Keep iterating, as we can have early
220 * params and __setups of same names 8( */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221 if (line[n] == '\0' || line[n] == '=')
Rusty Russell33df0d12006-09-26 10:52:32 +0200222 had_early_param = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223 } else if (!p->setup_func) {
224 printk(KERN_WARNING "Parameter %s is obsolete,"
225 " ignored\n", p->str);
226 return 1;
227 } else if (p->setup_func(line + n))
228 return 1;
229 }
230 p++;
231 } while (p < __setup_end);
Rusty Russell33df0d12006-09-26 10:52:32 +0200232
233 return had_early_param;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234}
235
236/*
237 * This should be approx 2 Bo*oMips to start (note initial shift), and will
238 * still work even if initially too large, it will just take slightly longer
239 */
240unsigned long loops_per_jiffy = (1<<12);
241
242EXPORT_SYMBOL(loops_per_jiffy);
243
244static int __init debug_kernel(char *str)
245{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246 console_loglevel = 10;
Yinghai Luf6f21c812008-02-08 04:21:58 -0800247 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248}
249
250static int __init quiet_kernel(char *str)
251{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252 console_loglevel = 4;
Yinghai Luf6f21c812008-02-08 04:21:58 -0800253 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254}
255
Yinghai Luf6f21c812008-02-08 04:21:58 -0800256early_param("debug", debug_kernel);
257early_param("quiet", quiet_kernel);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700258
259static int __init loglevel(char *str)
260{
261 get_option(&str, &console_loglevel);
Alex Riesend9d4fcf2008-03-04 14:28:31 -0800262 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700263}
264
Yinghai Luf6f21c812008-02-08 04:21:58 -0800265early_param("loglevel", loglevel);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700266
267/*
268 * Unknown boot options get handed to init, unless they look like
Rusty Russellf066a4f2009-12-01 14:56:44 +1030269 * unused parameters (modprobe will find them in /proc/cmdline).
Linus Torvalds1da177e2005-04-16 15:20:36 -0700270 */
271static int __init unknown_bootoption(char *param, char *val)
272{
273 /* Change NUL term back to "=", to make "param" the whole string. */
274 if (val) {
275 /* param=val or param="val"? */
276 if (val == param+strlen(param)+1)
277 val[-1] = '=';
278 else if (val == param+strlen(param)+2) {
279 val[-2] = '=';
280 memmove(val-1, val, strlen(val)+1);
281 val--;
282 } else
283 BUG();
284 }
285
286 /* Handle obsolete-style parameters */
287 if (obsolete_checksetup(param))
288 return 0;
289
Rusty Russellf066a4f2009-12-01 14:56:44 +1030290 /* Unused module parameter. */
291 if (strchr(param, '.') && (!val || strchr(param, '.') < val))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700293
294 if (panic_later)
295 return 0;
296
297 if (val) {
298 /* Environment option */
299 unsigned int i;
300 for (i = 0; envp_init[i]; i++) {
301 if (i == MAX_INIT_ENVS) {
302 panic_later = "Too many boot env vars at `%s'";
303 panic_param = param;
304 }
305 if (!strncmp(param, envp_init[i], val - param))
306 break;
307 }
308 envp_init[i] = param;
309 } else {
310 /* Command line option */
311 unsigned int i;
312 for (i = 0; argv_init[i]; i++) {
313 if (i == MAX_INIT_ARGS) {
314 panic_later = "Too many boot init vars at `%s'";
315 panic_param = param;
316 }
317 }
318 argv_init[i] = param;
319 }
320 return 0;
321}
322
Ingo Molnar12d6f212008-01-30 13:33:58 +0100323#ifdef CONFIG_DEBUG_PAGEALLOC
324int __read_mostly debug_pagealloc_enabled = 0;
325#endif
326
Linus Torvalds1da177e2005-04-16 15:20:36 -0700327static 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
Mike Travise0982e92008-03-26 14:23:48 -0700367static inline void setup_nr_cpu_ids(void) { }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700368static inline void smp_prepare_cpus(unsigned int maxcpus) { }
369
370#else
371
Mike Travise0982e92008-03-26 14:23:48 -0700372/* Setup number of possible processor ids */
373int nr_cpu_ids __read_mostly = NR_CPUS;
374EXPORT_SYMBOL(nr_cpu_ids);
375
376/* An arch may set nr_cpu_ids earlier if needed, so this would be redundant */
377static void __init setup_nr_cpu_ids(void)
378{
Rusty Russelle0c0ba72009-01-01 10:12:19 +1030379 nr_cpu_ids = find_last_bit(cpumask_bits(cpu_possible_mask),NR_CPUS) + 1;
Mike Travise0982e92008-03-26 14:23:48 -0700380}
381
Linus Torvalds1da177e2005-04-16 15:20:36 -0700382/* Called by boot processor to activate the rest. */
383static void __init smp_init(void)
384{
Christoph Lameter53b8a312007-02-20 13:57:51 -0800385 unsigned int cpu;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700386
387 /* FIXME: This should be done in userspace --RR */
Christoph Lameter53b8a312007-02-20 13:57:51 -0800388 for_each_present_cpu(cpu) {
Andi Kleenca74a6f2008-01-30 13:33:17 +0100389 if (num_online_cpus() >= setup_max_cpus)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700390 break;
Christoph Lameter53b8a312007-02-20 13:57:51 -0800391 if (!cpu_online(cpu))
392 cpu_up(cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700393 }
394
395 /* Any cleanup work */
396 printk(KERN_INFO "Brought up %ld CPUs\n", (long)num_online_cpus());
Andi Kleenca74a6f2008-01-30 13:33:17 +0100397 smp_cpus_done(setup_max_cpus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700398}
399
400#endif
401
402/*
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800403 * We need to store the untouched command line for future reference.
404 * We also need to store the touched command line since the parameter
405 * parsing is performed in place, and we should allow a component to
406 * store reference of name/value for future reference.
407 */
408static void __init setup_command_line(char *command_line)
409{
410 saved_command_line = alloc_bootmem(strlen (boot_command_line)+1);
411 static_command_line = alloc_bootmem(strlen (command_line)+1);
412 strcpy (saved_command_line, boot_command_line);
413 strcpy (static_command_line, command_line);
414}
415
416/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700417 * We need to finalize in a non-__init function or else race conditions
418 * between the root thread and the init thread may cause start_kernel to
419 * be reaped by free_initmem before the root thread has proceeded to
420 * cpu_idle.
421 *
422 * gcc-3.4 accidentally inlines this function, so use noinline.
423 */
424
Rakib Mullickf99ebf02009-01-06 14:40:38 -0800425static noinline void __init_refok rest_init(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700426 __releases(kernel_lock)
427{
Eric W. Biederman73c27992007-05-09 02:34:32 -0700428 int pid;
429
Paul E. McKenney7db905e2009-09-02 14:01:24 -0700430 rcu_scheduler_starting();
Sam Ravnborgaae5f662007-02-26 16:45:41 +0100431 kernel_thread(kernel_init, NULL, CLONE_FS | CLONE_SIGHAND);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700432 numa_default_policy();
Eric W. Biederman73c27992007-05-09 02:34:32 -0700433 pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
Paul E. McKenneyd11c5632010-02-22 17:04:50 -0800434 rcu_read_lock();
Pavel Emelyanov5cd20452008-04-30 00:54:24 -0700435 kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
Paul E. McKenneyd11c5632010-02-22 17:04:50 -0800436 rcu_read_unlock();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700437 unlock_kernel();
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200438
439 /*
440 * The boot idle thread must execute schedule()
Ingo Molnar1df21052007-07-09 18:51:58 +0200441 * at least once to get things moving:
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200442 */
Ingo Molnar1df21052007-07-09 18:51:58 +0200443 init_idle_bootup_task(current);
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800444 preempt_enable_no_resched();
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200445 schedule();
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800446 preempt_disable();
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200447
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800448 /* Call into cpu_idle with preempt disabled */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700449 cpu_idle();
Ingo Molnar1df21052007-07-09 18:51:58 +0200450}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700451
452/* Check for early params. */
453static int __init do_early_param(char *param, char *val)
454{
455 struct obs_kernel_param *p;
456
457 for (p = __setup_start; p < __setup_end; p++) {
Yinghai Lu18a8bd92007-07-15 23:37:59 -0700458 if ((p->early && strcmp(param, p->str) == 0) ||
459 (strcmp(param, "console") == 0 &&
460 strcmp(p->str, "earlycon") == 0)
461 ) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700462 if (p->setup_func(val) != 0)
463 printk(KERN_WARNING
464 "Malformed early option '%s'\n", param);
465 }
466 }
467 /* We accept everything at this stage. */
468 return 0;
469}
470
Magnus Damm13977092009-03-30 14:37:25 -0700471void __init parse_early_options(char *cmdline)
472{
473 parse_args("early options", cmdline, NULL, 0, do_early_param);
474}
475
Linus Torvalds1da177e2005-04-16 15:20:36 -0700476/* Arch code calls this early on, or if not, just before other parsing. */
477void __init parse_early_param(void)
478{
479 static __initdata int done = 0;
480 static __initdata char tmp_cmdline[COMMAND_LINE_SIZE];
481
482 if (done)
483 return;
484
485 /* All fall through to do_early_param. */
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800486 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
Magnus Damm13977092009-03-30 14:37:25 -0700487 parse_early_options(tmp_cmdline);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700488 done = 1;
489}
490
491/*
492 * Activate the first processor.
493 */
494
Stas Sergeev44fd2292006-03-23 02:59:44 -0800495static void __init boot_cpu_init(void)
496{
497 int cpu = smp_processor_id();
498 /* Mark the boot cpu "present", "online" etc for SMP and UP case */
Rusty Russell915441b2009-01-01 10:12:15 +1030499 set_cpu_online(cpu, true);
Peter Zijlstra933b0612009-12-16 18:04:31 +0100500 set_cpu_active(cpu, true);
Rusty Russell915441b2009-01-01 10:12:15 +1030501 set_cpu_present(cpu, true);
502 set_cpu_possible(cpu, true);
Stas Sergeev44fd2292006-03-23 02:59:44 -0800503}
504
Benjamin Herrenschmidt839ad622008-04-18 16:56:18 +1000505void __init __weak smp_setup_processor_id(void)
Andrew Morton033ab7f2006-06-30 01:55:50 -0700506{
507}
508
Benjamin Herrenschmidt8c9843e2008-04-18 16:56:15 +1000509void __init __weak thread_info_cache_init(void)
510{
511}
512
Pekka Enberg444f4782009-06-11 18:29:06 +0300513/*
514 * Set up kernel memory allocators
515 */
516static void __init mm_init(void)
517{
KAMEZAWA Hiroyukica371c02009-06-12 10:33:53 +0300518 /*
519 * page_cgroup requires countinous pages as memmap
520 * and it's bigger than MAX_ORDER unless SPARSEMEM.
521 */
522 page_cgroup_init_flatmem();
Pekka Enberg444f4782009-06-11 18:29:06 +0300523 mem_init();
524 kmem_cache_init();
Benjamin Herrenschmidtc868d552009-06-17 13:48:39 +1000525 pgtable_cache_init();
Pekka Enberg444f4782009-06-11 18:29:06 +0300526 vmalloc_init();
527}
528
Linus Torvalds1da177e2005-04-16 15:20:36 -0700529asmlinkage void __init start_kernel(void)
530{
531 char * command_line;
532 extern struct kernel_param __start___param[], __stop___param[];
Andrew Morton033ab7f2006-06-30 01:55:50 -0700533
534 smp_setup_processor_id();
535
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700536 /*
537 * Need to run as early as possible, to initialize the
538 * lockdep hash:
539 */
540 lockdep_init();
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700541 debug_objects_early_init();
Ingo Molnar42059422008-02-14 09:44:08 +0100542
543 /*
544 * Set up the the initial canary ASAP:
545 */
546 boot_init_stack_canary();
547
Paul Menageddbcc7e2007-10-18 23:39:30 -0700548 cgroup_init_early();
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700549
550 local_irq_disable();
551 early_boot_irqs_off();
Ingo Molnar243c7622006-07-03 00:25:06 -0700552 early_init_irq_lock_class();
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700553
Linus Torvalds1da177e2005-04-16 15:20:36 -0700554/*
555 * Interrupts are still disabled. Do necessary setups, then
556 * enable them
557 */
558 lock_kernel();
Thomas Gleixner906568c2007-02-16 01:28:01 -0800559 tick_init();
Stas Sergeev44fd2292006-03-23 02:59:44 -0800560 boot_cpu_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700561 page_address_init();
Alex Riesen657cafa2009-05-24 15:30:48 +0200562 printk(KERN_NOTICE "%s", linux_banner);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700563 setup_arch(&command_line);
Balbir Singhcf475ad2008-04-29 01:00:16 -0700564 mm_init_owner(&init_mm, &init_task);
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800565 setup_command_line(command_line);
Mike Travise0982e92008-03-26 14:23:48 -0700566 setup_nr_cpu_ids();
Tejun Heod6647bd2009-07-21 17:11:50 +0900567 setup_per_cpu_areas();
Stas Sergeev44fd2292006-03-23 02:59:44 -0800568 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700569
Pekka Enberg83b519e2009-06-10 19:40:04 +0300570 build_all_zonelists();
571 page_alloc_init();
572
573 printk(KERN_NOTICE "Kernel command line: %s\n", boot_command_line);
574 parse_early_param();
575 parse_args("Booting kernel", static_command_line, __start___param,
576 __stop___param - __start___param,
577 &unknown_bootoption);
578 /*
579 * These use large bootmem allocations and must precede
580 * kmem_cache_init()
581 */
582 pidhash_init();
Pekka Enberg83b519e2009-06-10 19:40:04 +0300583 vfs_caches_init_early();
584 sort_main_extable();
585 trap_init();
Pekka Enberg444f4782009-06-11 18:29:06 +0300586 mm_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700587 /*
588 * Set up the scheduler prior starting any interrupts (such as the
589 * timer interrupt). Full topology setup happens at smp_init()
590 * time - but meanwhile we still have a functioning scheduler.
591 */
592 sched_init();
593 /*
594 * Disable preemption - early bootup scheduling is extremely
595 * fragile until we cpu_idle() for the first time.
596 */
597 preempt_disable();
Ard van Breemenc4a68302007-01-05 16:36:19 -0800598 if (!irqs_disabled()) {
599 printk(KERN_WARNING "start_kernel(): bug: interrupts were "
600 "enabled *very* early, fixing it\n");
601 local_irq_disable();
602 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700603 rcu_init();
Yinghai Lu773e3eb2010-02-10 01:20:33 -0800604 radix_tree_init();
Yinghai Lu0b8f1ef2008-12-05 18:58:31 -0800605 /* init some links before init_ISA_irqs() */
606 early_irq_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700607 init_IRQ();
Catalin Marinas3c7b4e62009-06-11 13:22:39 +0100608 prio_tree_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700609 init_timers();
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800610 hrtimers_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700611 softirq_init();
john stultzad596172006-06-26 00:25:06 -0700612 timekeeping_init();
john stultz88fecaa2006-07-03 00:24:04 -0700613 time_init();
Heiko Carstens93e02812006-07-03 00:24:24 -0700614 profile_init();
615 if (!irqs_disabled())
Ron Lee24d431d2008-11-27 02:31:57 +1030616 printk(KERN_CRIT "start_kernel(): bug: interrupts were "
617 "enabled early\n");
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700618 early_boot_irqs_on();
Heiko Carstens93e02812006-07-03 00:24:24 -0700619 local_irq_enable();
Benjamin Herrenschmidtdcce2842009-06-18 13:24:12 +1000620
621 /* Interrupts are enabled now so all GFP allocations are safe. */
Rafael J. Wysocki452aa692010-03-05 13:42:13 -0800622 gfp_allowed_mask = __GFP_BITS_MASK;
Benjamin Herrenschmidtdcce2842009-06-18 13:24:12 +1000623
Pekka Enberg7e85ee02009-06-12 14:03:06 +0300624 kmem_cache_init_late();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700625
626 /*
627 * HACK ALERT! This is early. We're enabling the console before
628 * we've done PCI setups etc, and console_init() must be aware of
629 * this. But we do want output early, in case something goes wrong.
630 */
631 console_init();
632 if (panic_later)
633 panic(panic_later, panic_param);
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700634
635 lockdep_info();
636
Ingo Molnar9a11b49a2006-07-03 00:24:33 -0700637 /*
638 * Need to run this when irqs are enabled, because it wants
639 * to self-test [hard/soft]-irqs on/off lock inversion bugs
640 * too:
641 */
642 locking_selftest();
643
Linus Torvalds1da177e2005-04-16 15:20:36 -0700644#ifdef CONFIG_BLK_DEV_INITRD
645 if (initrd_start && !initrd_below_start_ok &&
Geert Uytterhoevenbd673c72008-07-29 22:33:36 -0700646 page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700647 printk(KERN_CRIT "initrd overwritten (0x%08lx < 0x%08lx) - "
Geert Uytterhoevenfb6624e2008-07-17 21:16:36 +0200648 "disabling it.\n",
Geert Uytterhoevenbd673c72008-07-29 22:33:36 -0700649 page_to_pfn(virt_to_page((void *)initrd_start)),
650 min_low_pfn);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700651 initrd_start = 0;
652 }
653#endif
KAMEZAWA Hiroyuki94b6da52008-10-22 14:15:05 -0700654 page_cgroup_init();
Thomas Gleixnera03c2a42008-02-09 23:24:09 +0100655 enable_debug_pagealloc();
Eduard - Gabriel Munteanub9ce08c2008-08-10 20:14:03 +0300656 kmemtrace_init();
Catalin Marinas3c7b4e62009-06-11 13:22:39 +0100657 kmemleak_init();
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700658 debug_objects_mem_init();
Akinobu Mita199f0ca2008-04-29 01:03:13 -0700659 idr_init_cache();
Christoph Lametere7c8d5c2005-06-21 17:14:47 -0700660 setup_per_cpu_pageset();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700661 numa_policy_init();
662 if (late_time_init)
663 late_time_init();
Thomas Gleixnerfa84e9e2009-08-21 22:01:12 +0200664 sched_clock_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700665 calibrate_delay();
666 pidmap_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700667 anon_vma_init();
668#ifdef CONFIG_X86
669 if (efi_enabled)
670 efi_enter_virtual_mode();
671#endif
Benjamin Herrenschmidt8c9843e2008-04-18 16:56:15 +1000672 thread_info_cache_init();
David Howellsd84f4f92008-11-14 10:39:23 +1100673 cred_init();
Jan Beulich44813742009-09-21 17:03:05 -0700674 fork_init(totalram_pages);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700675 proc_caches_init();
676 buffer_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700677 key_init();
678 security_init();
Jason Wessel0b4b3822010-05-20 21:04:29 -0500679 dbg_late_init();
Jan Beulich44813742009-09-21 17:03:05 -0700680 vfs_caches_init(totalram_pages);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700681 signals_init();
682 /* rootfs populating might need page-writeback */
683 page_writeback_init();
684#ifdef CONFIG_PROC_FS
685 proc_root_init();
686#endif
Paul Menageddbcc7e2007-10-18 23:39:30 -0700687 cgroup_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700688 cpuset_init();
Shailabh Nagarc7572492006-07-14 00:24:40 -0700689 taskstats_init_early();
Shailabh Nagarca74e922006-07-14 00:24:36 -0700690 delayacct_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700691
692 check_bugs();
693
694 acpi_early_init(); /* before LAPIC and SMP init */
Feng Tang6ae69962009-08-14 15:13:46 -0400695 sfi_init_late();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700696
Steven Rostedt68bf21a2008-08-14 15:45:08 -0400697 ftrace_init();
698
Linus Torvalds1da177e2005-04-16 15:20:36 -0700699 /* Do the rest non-__init'ed, we're now alive */
700 rest_init();
701}
702
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700703/* Call all constructor functions linked into the kernel. */
704static void __init do_ctors(void)
705{
706#ifdef CONFIG_CONSTRUCTORS
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800707 ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700708
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800709 for (; fn < (ctor_fn_t *) __ctors_end; fn++)
710 (*fn)();
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700711#endif
712}
713
Arjan van de Ven22a9d642009-01-07 08:45:46 -0800714int initcall_debug;
Rusty Russelld0ea3d72008-10-22 10:00:23 -0500715core_param(initcall_debug, initcall_debug, bool, 0644);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700716
Ingo Molnar4a683bf2009-08-21 12:53:36 +0200717static char msgbuf[64];
718static struct boot_trace_call call;
719static struct boot_trace_ret ret;
720
Arjan van de Ven59f94152008-07-30 12:49:02 -0700721int do_one_initcall(initcall_t fn)
Linus Torvaldse0df1542008-05-15 18:14:01 -0700722{
723 int count = preempt_count();
Frederic Weisbecker74239072008-11-11 23:24:42 +0100724 ktime_t calltime, delta, rettime;
Linus Torvaldse0df1542008-05-15 18:14:01 -0700725
726 if (initcall_debug) {
Frederic Weisbecker74239072008-11-11 23:24:42 +0100727 call.caller = task_pid_nr(current);
728 printk("calling %pF @ %i\n", fn, call.caller);
729 calltime = ktime_get();
730 trace_boot_call(&call, fn);
Frederic Weisbecker71566a02008-10-31 12:57:20 +0100731 enable_boot_trace();
Linus Torvaldse0df1542008-05-15 18:14:01 -0700732 }
733
Frederic Weisbecker74239072008-11-11 23:24:42 +0100734 ret.result = fn();
Linus Torvaldse0df1542008-05-15 18:14:01 -0700735
736 if (initcall_debug) {
Frederic Weisbecker71566a02008-10-31 12:57:20 +0100737 disable_boot_trace();
Frederic Weisbecker74239072008-11-11 23:24:42 +0100738 rettime = ktime_get();
739 delta = ktime_sub(rettime, calltime);
Will Newton1d926f22008-11-21 14:08:59 -0800740 ret.duration = (unsigned long long) ktime_to_ns(delta) >> 10;
Frederic Weisbecker74239072008-11-11 23:24:42 +0100741 trace_boot_ret(&ret, fn);
Tim Birdca538f62008-10-09 15:23:05 -0700742 printk("initcall %pF returned %d after %Ld usecs\n", fn,
Frederic Weisbecker74239072008-11-11 23:24:42 +0100743 ret.result, ret.duration);
Linus Torvaldse0df1542008-05-15 18:14:01 -0700744 }
745
746 msgbuf[0] = 0;
747
Frederic Weisbecker74239072008-11-11 23:24:42 +0100748 if (ret.result && ret.result != -ENODEV && initcall_debug)
749 sprintf(msgbuf, "error code %d ", ret.result);
Linus Torvaldse0df1542008-05-15 18:14:01 -0700750
751 if (preempt_count() != count) {
Cyrill Gorcunova76bfd02008-05-15 13:52:41 -0700752 strlcat(msgbuf, "preemption imbalance ", sizeof(msgbuf));
Linus Torvaldse0df1542008-05-15 18:14:01 -0700753 preempt_count() = count;
754 }
755 if (irqs_disabled()) {
Cyrill Gorcunova76bfd02008-05-15 13:52:41 -0700756 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
Linus Torvaldse0df1542008-05-15 18:14:01 -0700757 local_irq_enable();
758 }
759 if (msgbuf[0]) {
Linus Torvalds96d746c2008-10-03 13:38:07 -0700760 printk("initcall %pF returned with %s\n", fn, msgbuf);
Linus Torvaldse0df1542008-05-15 18:14:01 -0700761 }
Arjan van de Ven59f94152008-07-30 12:49:02 -0700762
Frederic Weisbecker74239072008-11-11 23:24:42 +0100763 return ret.result;
Linus Torvaldse0df1542008-05-15 18:14:01 -0700764}
765
766
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700767extern initcall_t __initcall_start[], __initcall_end[], __early_initcall_end[];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700768
769static void __init do_initcalls(void)
770{
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800771 initcall_t *fn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700772
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800773 for (fn = __early_initcall_end; fn < __initcall_end; fn++)
774 do_one_initcall(*fn);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700775
776 /* Make sure there is no pending stuff from the initcall sequence */
777 flush_scheduled_work();
778}
779
780/*
781 * Ok, the machine is now initialized. None of the devices
782 * have been touched yet, but the CPU subsystem is up and
783 * running, and memory and process management works.
784 *
785 * Now we can finally start doing some real work..
786 */
787static void __init do_basic_setup(void)
788{
Linus Torvalds4403b402008-10-25 19:53:38 -0700789 init_workqueues();
Lai Jiangshan759ee092009-03-25 17:06:30 +0800790 cpuset_init_smp();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700791 usermodehelper_init();
Kay Sievers2b2af542009-04-30 15:23:42 +0200792 init_tmpfs();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700793 driver_init();
Eric W. Biedermanb04c3af2007-02-14 00:33:57 -0800794 init_irq_proc();
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700795 do_ctors();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700796 do_initcalls();
797}
798
Eduard - Gabriel Munteanu7babe8d2008-07-25 19:45:11 -0700799static void __init do_pre_smp_initcalls(void)
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700800{
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800801 initcall_t *fn;
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700802
H Hartley Sweeten196a15b2009-12-14 18:00:18 -0800803 for (fn = __initcall_start; fn < __early_initcall_end; fn++)
804 do_one_initcall(*fn);
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700805}
806
Linus Torvalds1da177e2005-04-16 15:20:36 -0700807static void run_init_process(char *init_filename)
808{
809 argv_init[0] = init_filename;
Arnd Bergmann67608562006-10-02 02:18:26 -0700810 kernel_execve(init_filename, argv_init, envp_init);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700811}
812
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100813/* This is a non __init function. Force it to be noinline otherwise gcc
814 * makes it inline to init() and it becomes part of init.text section
815 */
Rakib Mullickf99ebf02009-01-06 14:40:38 -0800816static noinline int init_post(void)
Hannes Ederacdd0522009-03-31 15:23:50 -0700817 __releases(kernel_lock)
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100818{
Arjan van de Ven22a9d642009-01-07 08:45:46 -0800819 /* need to finish all async __init code before freeing the memory */
820 async_synchronize_full();
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100821 free_initmem();
822 unlock_kernel();
823 mark_rodata_ro();
824 system_state = SYSTEM_RUNNING;
825 numa_default_policy();
826
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100827
Oleg Nesterovfae5fa42008-04-30 00:53:03 -0700828 current->signal->flags |= SIGNAL_UNKILLABLE;
829
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100830 if (ramdisk_execute_command) {
831 run_init_process(ramdisk_execute_command);
832 printk(KERN_WARNING "Failed to execute %s\n",
833 ramdisk_execute_command);
834 }
835
836 /*
837 * We try each of these until one succeeds.
838 *
839 * The Bourne shell can be used instead of init if we are
840 * trying to recover a really broken machine.
841 */
842 if (execute_command) {
843 run_init_process(execute_command);
844 printk(KERN_WARNING "Failed to execute %s. Attempting "
845 "defaults...\n", execute_command);
846 }
847 run_init_process("/sbin/init");
848 run_init_process("/etc/init");
849 run_init_process("/bin/init");
850 run_init_process("/bin/sh");
851
Andreas Mohr9a85b8d2010-03-05 13:42:39 -0800852 panic("No init found. Try passing init= option to kernel. "
853 "See Linux Documentation/init.txt for guidance.");
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100854}
855
Sam Ravnborgaae5f662007-02-26 16:45:41 +0100856static int __init kernel_init(void * unused)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700857{
858 lock_kernel();
Miao Xie58568d22009-06-16 15:31:49 -0700859
860 /*
861 * init can allocate pages on any node
862 */
Miao Xie5ab116c2010-03-23 13:35:34 -0700863 set_mems_allowed(node_states[N_HIGH_MEMORY]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700864 /*
865 * init can run on any cpu.
866 */
Rusty Russell1a2142a2009-03-30 22:05:10 -0600867 set_cpus_allowed_ptr(current, cpu_all_mask);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700868 /*
869 * Tell the world that we're going to be the grim
870 * reaper of innocent orphaned children.
871 *
872 * We don't want people to have to make incorrect
873 * assumptions about where in the task array this
874 * can be found.
875 */
Sukadev Bhattiprolu84d73782006-12-08 02:38:01 -0800876 init_pid_ns.child_reaper = current;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700877
Cedric Le Goater9ec52092006-10-02 02:19:00 -0700878 cad_pid = task_pid(current);
879
Andi Kleenca74a6f2008-01-30 13:33:17 +0100880 smp_prepare_cpus(setup_max_cpus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700881
882 do_pre_smp_initcalls();
Frédéric Weisbecker3bf77af2008-09-23 11:38:18 +0100883 start_boot_trace();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700884
Linus Torvalds1da177e2005-04-16 15:20:36 -0700885 smp_init();
886 sched_init_smp();
887
Linus Torvalds1da177e2005-04-16 15:20:36 -0700888 do_basic_setup();
889
Eric W. Biederman2bd3a9972010-03-02 23:53:19 -0800890 /* Open the /dev/console on the rootfs, this should never fail */
891 if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
892 printk(KERN_WARNING "Warning: unable to open an initial console.\n");
893
894 (void) sys_dup(0);
895 (void) sys_dup(0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700896 /*
897 * check if there is an early userspace init. If yes, let it do all
898 * the work
899 */
Olof Johanssonffdfc402005-09-06 15:17:19 -0700900
901 if (!ramdisk_execute_command)
902 ramdisk_execute_command = "/init";
903
904 if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
905 ramdisk_execute_command = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700906 prepare_namespace();
Olof Johanssonffdfc402005-09-06 15:17:19 -0700907 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700908
909 /*
910 * Ok, we have completed the initial bootup, and
911 * we're essentially up and running. Get rid of the
912 * initmem segments and start the user-mode stuff..
913 */
Frederic Weisbecker71566a02008-10-31 12:57:20 +0100914
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100915 init_post();
916 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700917}