blob: 2d9d6bdfe7c929358dd41ba39f7934929ef5e684 [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>
21#include <linux/utsname.h>
22#include <linux/ioport.h>
23#include <linux/init.h>
24#include <linux/smp_lock.h>
25#include <linux/initrd.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070026#include <linux/bootmem.h>
Len Brown4a7a16d2009-06-12 20:42:08 -040027#include <linux/acpi.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070028#include <linux/tty.h>
29#include <linux/gfp.h>
30#include <linux/percpu.h>
31#include <linux/kmod.h>
Nick Piggindb64fe02008-10-18 20:27:03 -070032#include <linux/vmalloc.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070033#include <linux/kernel_stat.h>
Rusty Russelld7cd5612006-12-07 02:14:08 +010034#include <linux/start_kernel.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070035#include <linux/security.h>
Jens Axboe3d442232008-06-26 11:21:34 +020036#include <linux/smp.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070037#include <linux/workqueue.h>
38#include <linux/profile.h>
39#include <linux/rcupdate.h>
40#include <linux/moduleparam.h>
41#include <linux/kallsyms.h>
42#include <linux/writeback.h>
43#include <linux/cpu.h>
44#include <linux/cpuset.h>
Paul Menageddbcc7e2007-10-18 23:39:30 -070045#include <linux/cgroup.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070046#include <linux/efi.h>
Thomas Gleixner906568c2007-02-16 01:28:01 -080047#include <linux/tick.h>
Andrew Morton6168a702007-02-17 21:22:39 -080048#include <linux/interrupt.h>
Shailabh Nagarc7572492006-07-14 00:24:40 -070049#include <linux/taskstats_kern.h>
Shailabh Nagarca74e922006-07-14 00:24:36 -070050#include <linux/delayacct.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070051#include <linux/unistd.h>
52#include <linux/rmap.h>
53#include <linux/mempolicy.h>
54#include <linux/key.h>
Adrian Bunkb6cd0b72006-06-27 02:53:54 -070055#include <linux/buffer_head.h>
KAMEZAWA Hiroyuki94b6da52008-10-22 14:15:05 -070056#include <linux/page_cgroup.h>
Ingo Molnar9a11b49a2006-07-03 00:24:33 -070057#include <linux/debug_locks.h>
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -070058#include <linux/debugobjects.h>
Ingo Molnarfbb9ce952006-07-03 00:24:50 -070059#include <linux/lockdep.h>
Catalin Marinas3c7b4e62009-06-11 13:22:39 +010060#include <linux/kmemleak.h>
Sukadev Bhattiprolu84d73782006-12-08 02:38:01 -080061#include <linux/pid_namespace.h>
Adrian Bunk1f217822006-12-19 13:01:28 -080062#include <linux/device.h>
Eric W. Biederman73c27992007-05-09 02:34:32 -070063#include <linux/kthread.h>
Adrian Bunke6fe6642007-11-09 22:39:39 +010064#include <linux/sched.h>
Adrian Bunka1c9eea2008-02-06 01:36:44 -080065#include <linux/signal.h>
Akinobu Mita199f0ca2008-04-29 01:03:13 -070066#include <linux/idr.h>
Steven Rostedt68bf21a2008-08-14 15:45:08 -040067#include <linux/ftrace.h>
Arjan van de Ven22a9d642009-01-07 08:45:46 -080068#include <linux/async.h>
Vegard Nossumdfec0722008-04-04 00:51:41 +020069#include <linux/kmemcheck.h>
Zhaolei02af61b2009-04-10 14:26:18 +080070#include <linux/kmemtrace.h>
Frederic Weisbecker3f5ec132008-11-11 23:21:31 +010071#include <trace/boot.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070072
73#include <asm/io.h>
74#include <asm/bugs.h>
75#include <asm/setup.h>
Andi Kleena9401992005-07-28 21:15:30 -070076#include <asm/sections.h>
Arjan van de Ven37b73c82006-01-06 00:12:01 -080077#include <asm/cacheflush.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070078
Linus Torvalds1da177e2005-04-16 15:20:36 -070079#ifdef CONFIG_X86_LOCAL_APIC
80#include <asm/smp.h>
81#endif
82
Sam Ravnborgaae5f662007-02-26 16:45:41 +010083static int kernel_init(void *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070084
85extern void init_IRQ(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070086extern void fork_init(unsigned long);
87extern void mca_init(void);
88extern void sbus_init(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070089extern void prio_tree_init(void);
90extern void radix_tree_init(void);
91extern void free_initmem(void);
Arjan van de Ven37b73c82006-01-06 00:12:01 -080092#ifndef CONFIG_DEBUG_RODATA
93static inline void mark_rodata_ro(void) { }
94#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -070095
96#ifdef CONFIG_TC
97extern void tc_init(void);
98#endif
99
Paul E. McKenneya6826042009-02-25 18:03:42 -0800100enum system_states system_state __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101EXPORT_SYMBOL(system_state);
102
103/*
104 * Boot command-line arguments
105 */
106#define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
107#define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
108
109extern void time_init(void);
110/* Default late time init is NULL. archs can override this later. */
Jan Beulichd2e31922009-01-06 14:41:10 -0800111void (*__initdata late_time_init)(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112extern void softirq_init(void);
113
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800114/* Untouched command line saved by arch-specific code. */
115char __initdata boot_command_line[COMMAND_LINE_SIZE];
116/* Untouched saved command line (eg. for /proc) */
117char *saved_command_line;
118/* Command line for parameter parsing */
119static char *static_command_line;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120
121static char *execute_command;
Olof Johanssonffdfc402005-09-06 15:17:19 -0700122static char *ramdisk_execute_command;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123
Jan Beulich8b3b2952007-07-15 23:41:07 -0700124#ifdef CONFIG_SMP
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125/* Setup configured maximum number of CPUs to activate */
Andi Kleenca74a6f2008-01-30 13:33:17 +0100126unsigned int __initdata setup_max_cpus = NR_CPUS;
Vivek Goyal7e962872006-09-27 01:50:44 -0700127
128/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129 * Setup routine for controlling SMP activation
130 *
131 * Command-line option of "nosmp" or "maxcpus=0" will disable SMP
132 * activation entirely (the MPS table probe still happens, though).
133 *
134 * Command-line option of "maxcpus=<NUM>", where <NUM> is an integer
135 * greater than 0, limits the maximum number of CPUs activated in
136 * SMP mode to <NUM>.
137 */
Ingo Molnar65a4e572009-01-31 03:36:17 +0100138
139void __weak arch_disable_smp_support(void) { }
Len Brown61ec7562007-08-16 03:34:22 -0400140
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141static int __init nosmp(char *str)
142{
Andi Kleenca74a6f2008-01-30 13:33:17 +0100143 setup_max_cpus = 0;
Ingo Molnar65a4e572009-01-31 03:36:17 +0100144 arch_disable_smp_support();
145
Jan Beulich8b3b2952007-07-15 23:41:07 -0700146 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147}
148
Jan Beulich8b3b2952007-07-15 23:41:07 -0700149early_param("nosmp", nosmp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150
151static int __init maxcpus(char *str)
152{
Andi Kleenca74a6f2008-01-30 13:33:17 +0100153 get_option(&str, &setup_max_cpus);
154 if (setup_max_cpus == 0)
Ingo Molnar65a4e572009-01-31 03:36:17 +0100155 arch_disable_smp_support();
Len Brown61ec7562007-08-16 03:34:22 -0400156
157 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158}
159
Hugh Dickins81340972007-08-27 16:02:12 +0100160early_param("maxcpus", maxcpus);
Jan Beulich8b3b2952007-07-15 23:41:07 -0700161#else
Ingo Molnar65a4e572009-01-31 03:36:17 +0100162const unsigned int setup_max_cpus = NR_CPUS;
Jan Beulich8b3b2952007-07-15 23:41:07 -0700163#endif
164
165/*
166 * If set, this is an indication to the drivers that reset the underlying
167 * device before going ahead with the initialization otherwise driver might
168 * rely on the BIOS and skip the reset operation.
169 *
170 * This is useful if kernel is booting in an unreliable environment.
171 * For ex. kdump situaiton where previous kernel has crashed, BIOS has been
172 * skipped and devices will be in unknown state.
173 */
174unsigned int reset_devices;
175EXPORT_SYMBOL(reset_devices);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176
Vivek Goyal7e962872006-09-27 01:50:44 -0700177static int __init set_reset_devices(char *str)
178{
179 reset_devices = 1;
180 return 1;
181}
182
183__setup("reset_devices", set_reset_devices);
184
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185static char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
186char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
187static const char *panic_later, *panic_param;
188
189extern struct obs_kernel_param __setup_start[], __setup_end[];
190
191static int __init obsolete_checksetup(char *line)
192{
193 struct obs_kernel_param *p;
Rusty Russell33df0d12006-09-26 10:52:32 +0200194 int had_early_param = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195
196 p = __setup_start;
197 do {
198 int n = strlen(p->str);
199 if (!strncmp(line, p->str, n)) {
200 if (p->early) {
Rusty Russell33df0d12006-09-26 10:52:32 +0200201 /* Already done in parse_early_param?
202 * (Needs exact match on param part).
203 * Keep iterating, as we can have early
204 * params and __setups of same names 8( */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205 if (line[n] == '\0' || line[n] == '=')
Rusty Russell33df0d12006-09-26 10:52:32 +0200206 had_early_param = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207 } else if (!p->setup_func) {
208 printk(KERN_WARNING "Parameter %s is obsolete,"
209 " ignored\n", p->str);
210 return 1;
211 } else if (p->setup_func(line + n))
212 return 1;
213 }
214 p++;
215 } while (p < __setup_end);
Rusty Russell33df0d12006-09-26 10:52:32 +0200216
217 return had_early_param;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218}
219
220/*
221 * This should be approx 2 Bo*oMips to start (note initial shift), and will
222 * still work even if initially too large, it will just take slightly longer
223 */
224unsigned long loops_per_jiffy = (1<<12);
225
226EXPORT_SYMBOL(loops_per_jiffy);
227
228static int __init debug_kernel(char *str)
229{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230 console_loglevel = 10;
Yinghai Luf6f21c812008-02-08 04:21:58 -0800231 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232}
233
234static int __init quiet_kernel(char *str)
235{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236 console_loglevel = 4;
Yinghai Luf6f21c812008-02-08 04:21:58 -0800237 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700238}
239
Yinghai Luf6f21c812008-02-08 04:21:58 -0800240early_param("debug", debug_kernel);
241early_param("quiet", quiet_kernel);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242
243static int __init loglevel(char *str)
244{
245 get_option(&str, &console_loglevel);
Alex Riesend9d4fcf2008-03-04 14:28:31 -0800246 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247}
248
Yinghai Luf6f21c812008-02-08 04:21:58 -0800249early_param("loglevel", loglevel);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250
251/*
252 * Unknown boot options get handed to init, unless they look like
253 * failed parameters
254 */
255static int __init unknown_bootoption(char *param, char *val)
256{
257 /* Change NUL term back to "=", to make "param" the whole string. */
258 if (val) {
259 /* param=val or param="val"? */
260 if (val == param+strlen(param)+1)
261 val[-1] = '=';
262 else if (val == param+strlen(param)+2) {
263 val[-2] = '=';
264 memmove(val-1, val, strlen(val)+1);
265 val--;
266 } else
267 BUG();
268 }
269
270 /* Handle obsolete-style parameters */
271 if (obsolete_checksetup(param))
272 return 0;
273
274 /*
Simon Arlott211fee82007-10-20 01:28:29 +0200275 * Preemptive maintenance for "why didn't my misspelled command
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276 * line work?"
277 */
278 if (strchr(param, '.') && (!val || strchr(param, '.') < val)) {
279 printk(KERN_ERR "Unknown boot option `%s': ignoring\n", param);
280 return 0;
281 }
282
283 if (panic_later)
284 return 0;
285
286 if (val) {
287 /* Environment option */
288 unsigned int i;
289 for (i = 0; envp_init[i]; i++) {
290 if (i == MAX_INIT_ENVS) {
291 panic_later = "Too many boot env vars at `%s'";
292 panic_param = param;
293 }
294 if (!strncmp(param, envp_init[i], val - param))
295 break;
296 }
297 envp_init[i] = param;
298 } else {
299 /* Command line option */
300 unsigned int i;
301 for (i = 0; argv_init[i]; i++) {
302 if (i == MAX_INIT_ARGS) {
303 panic_later = "Too many boot init vars at `%s'";
304 panic_param = param;
305 }
306 }
307 argv_init[i] = param;
308 }
309 return 0;
310}
311
Ingo Molnar12d6f212008-01-30 13:33:58 +0100312#ifdef CONFIG_DEBUG_PAGEALLOC
313int __read_mostly debug_pagealloc_enabled = 0;
314#endif
315
Linus Torvalds1da177e2005-04-16 15:20:36 -0700316static int __init init_setup(char *str)
317{
318 unsigned int i;
319
320 execute_command = str;
321 /*
322 * In case LILO is going to boot us with default command line,
323 * it prepends "auto" before the whole cmdline which makes
324 * the shell think it should execute a script with such name.
325 * So we ignore all arguments entered _before_ init=... [MJ]
326 */
327 for (i = 1; i < MAX_INIT_ARGS; i++)
328 argv_init[i] = NULL;
329 return 1;
330}
331__setup("init=", init_setup);
332
Olof Johanssonffdfc402005-09-06 15:17:19 -0700333static int __init rdinit_setup(char *str)
334{
335 unsigned int i;
336
337 ramdisk_execute_command = str;
338 /* See "auto" comment in init_setup */
339 for (i = 1; i < MAX_INIT_ARGS; i++)
340 argv_init[i] = NULL;
341 return 1;
342}
343__setup("rdinit=", rdinit_setup);
344
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345#ifndef CONFIG_SMP
346
347#ifdef CONFIG_X86_LOCAL_APIC
348static void __init smp_init(void)
349{
350 APIC_init_uniprocessor();
351}
352#else
353#define smp_init() do { } while (0)
354#endif
355
356static inline void setup_per_cpu_areas(void) { }
Mike Travise0982e92008-03-26 14:23:48 -0700357static inline void setup_nr_cpu_ids(void) { }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700358static inline void smp_prepare_cpus(unsigned int maxcpus) { }
359
360#else
361
Mike Travis321a8e92008-04-04 18:11:02 -0700362#if NR_CPUS > BITS_PER_LONG
363cpumask_t cpu_mask_all __read_mostly = CPU_MASK_ALL;
364EXPORT_SYMBOL(cpu_mask_all);
365#endif
366
Mike Travise0982e92008-03-26 14:23:48 -0700367/* Setup number of possible processor ids */
368int nr_cpu_ids __read_mostly = NR_CPUS;
369EXPORT_SYMBOL(nr_cpu_ids);
370
371/* An arch may set nr_cpu_ids earlier if needed, so this would be redundant */
372static void __init setup_nr_cpu_ids(void)
373{
Rusty Russelle0c0ba72009-01-01 10:12:19 +1030374 nr_cpu_ids = find_last_bit(cpumask_bits(cpu_possible_mask),NR_CPUS) + 1;
Mike Travise0982e92008-03-26 14:23:48 -0700375}
376
Mike Travisdd5af902008-01-30 13:33:32 +0100377#ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA
Eric Dumazetb73b4592006-03-23 03:01:07 -0800378unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700379
380EXPORT_SYMBOL(__per_cpu_offset);
381
382static void __init setup_per_cpu_areas(void)
383{
384 unsigned long size, i;
385 char *ptr;
Eric Dumazet63872f82006-03-23 03:01:04 -0800386 unsigned long nr_possible_cpus = num_possible_cpus();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387
388 /* Copy section for each CPU (we discard the original) */
Jeremy Fitzhardingeb6e35902007-05-02 19:27:12 +0200389 size = ALIGN(PERCPU_ENOUGH_ROOM, PAGE_SIZE);
390 ptr = alloc_bootmem_pages(size * nr_possible_cpus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391
KAMEZAWA Hiroyuki0a945022006-03-28 01:56:37 -0800392 for_each_possible_cpu(i) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700393 __per_cpu_offset[i] = ptr - __per_cpu_start;
394 memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start);
Eric Dumazet63872f82006-03-23 03:01:04 -0800395 ptr += size;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700396 }
397}
Mike Travisdd5af902008-01-30 13:33:32 +0100398#endif /* CONFIG_HAVE_SETUP_PER_CPU_AREA */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700399
400/* Called by boot processor to activate the rest. */
401static void __init smp_init(void)
402{
Christoph Lameter53b8a312007-02-20 13:57:51 -0800403 unsigned int cpu;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700404
Max Krasnyanskye761b772008-07-15 04:43:49 -0700405 /*
406 * Set up the current CPU as possible to migrate to.
407 * The other ones will be done by cpu_up/cpu_down()
408 */
Rusty Russell2b17fa52009-03-30 22:05:12 -0600409 set_cpu_active(smp_processor_id(), true);
Max Krasnyanskye761b772008-07-15 04:43:49 -0700410
Linus Torvalds1da177e2005-04-16 15:20:36 -0700411 /* FIXME: This should be done in userspace --RR */
Christoph Lameter53b8a312007-02-20 13:57:51 -0800412 for_each_present_cpu(cpu) {
Andi Kleenca74a6f2008-01-30 13:33:17 +0100413 if (num_online_cpus() >= setup_max_cpus)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700414 break;
Christoph Lameter53b8a312007-02-20 13:57:51 -0800415 if (!cpu_online(cpu))
416 cpu_up(cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700417 }
418
419 /* Any cleanup work */
420 printk(KERN_INFO "Brought up %ld CPUs\n", (long)num_online_cpus());
Andi Kleenca74a6f2008-01-30 13:33:17 +0100421 smp_cpus_done(setup_max_cpus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700422}
423
424#endif
425
426/*
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800427 * We need to store the untouched command line for future reference.
428 * We also need to store the touched command line since the parameter
429 * parsing is performed in place, and we should allow a component to
430 * store reference of name/value for future reference.
431 */
432static void __init setup_command_line(char *command_line)
433{
434 saved_command_line = alloc_bootmem(strlen (boot_command_line)+1);
435 static_command_line = alloc_bootmem(strlen (command_line)+1);
436 strcpy (saved_command_line, boot_command_line);
437 strcpy (static_command_line, command_line);
438}
439
440/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700441 * We need to finalize in a non-__init function or else race conditions
442 * between the root thread and the init thread may cause start_kernel to
443 * be reaped by free_initmem before the root thread has proceeded to
444 * cpu_idle.
445 *
446 * gcc-3.4 accidentally inlines this function, so use noinline.
447 */
448
Rakib Mullickf99ebf02009-01-06 14:40:38 -0800449static noinline void __init_refok rest_init(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700450 __releases(kernel_lock)
451{
Eric W. Biederman73c27992007-05-09 02:34:32 -0700452 int pid;
453
Sam Ravnborgaae5f662007-02-26 16:45:41 +0100454 kernel_thread(kernel_init, NULL, CLONE_FS | CLONE_SIGHAND);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700455 numa_default_policy();
Eric W. Biederman73c27992007-05-09 02:34:32 -0700456 pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
Pavel Emelyanov5cd20452008-04-30 00:54:24 -0700457 kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700458 unlock_kernel();
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200459
460 /*
461 * The boot idle thread must execute schedule()
Ingo Molnar1df21052007-07-09 18:51:58 +0200462 * at least once to get things moving:
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200463 */
Ingo Molnar1df21052007-07-09 18:51:58 +0200464 init_idle_bootup_task(current);
Paul E. McKenneya6826042009-02-25 18:03:42 -0800465 rcu_scheduler_starting();
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800466 preempt_enable_no_resched();
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200467 schedule();
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800468 preempt_disable();
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200469
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800470 /* Call into cpu_idle with preempt disabled */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700471 cpu_idle();
Ingo Molnar1df21052007-07-09 18:51:58 +0200472}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700473
474/* Check for early params. */
475static int __init do_early_param(char *param, char *val)
476{
477 struct obs_kernel_param *p;
478
479 for (p = __setup_start; p < __setup_end; p++) {
Yinghai Lu18a8bd92007-07-15 23:37:59 -0700480 if ((p->early && strcmp(param, p->str) == 0) ||
481 (strcmp(param, "console") == 0 &&
482 strcmp(p->str, "earlycon") == 0)
483 ) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700484 if (p->setup_func(val) != 0)
485 printk(KERN_WARNING
486 "Malformed early option '%s'\n", param);
487 }
488 }
489 /* We accept everything at this stage. */
490 return 0;
491}
492
Magnus Damm13977092009-03-30 14:37:25 -0700493void __init parse_early_options(char *cmdline)
494{
495 parse_args("early options", cmdline, NULL, 0, do_early_param);
496}
497
Linus Torvalds1da177e2005-04-16 15:20:36 -0700498/* Arch code calls this early on, or if not, just before other parsing. */
499void __init parse_early_param(void)
500{
501 static __initdata int done = 0;
502 static __initdata char tmp_cmdline[COMMAND_LINE_SIZE];
503
504 if (done)
505 return;
506
507 /* All fall through to do_early_param. */
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800508 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
Magnus Damm13977092009-03-30 14:37:25 -0700509 parse_early_options(tmp_cmdline);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700510 done = 1;
511}
512
513/*
514 * Activate the first processor.
515 */
516
Stas Sergeev44fd2292006-03-23 02:59:44 -0800517static void __init boot_cpu_init(void)
518{
519 int cpu = smp_processor_id();
520 /* Mark the boot cpu "present", "online" etc for SMP and UP case */
Rusty Russell915441b2009-01-01 10:12:15 +1030521 set_cpu_online(cpu, true);
522 set_cpu_present(cpu, true);
523 set_cpu_possible(cpu, true);
Stas Sergeev44fd2292006-03-23 02:59:44 -0800524}
525
Benjamin Herrenschmidt839ad622008-04-18 16:56:18 +1000526void __init __weak smp_setup_processor_id(void)
Andrew Morton033ab7f2006-06-30 01:55:50 -0700527{
528}
529
Benjamin Herrenschmidt8c9843e2008-04-18 16:56:15 +1000530void __init __weak thread_info_cache_init(void)
531{
532}
533
Pekka Enberg444f4782009-06-11 18:29:06 +0300534/*
535 * Set up kernel memory allocators
536 */
537static void __init mm_init(void)
538{
KAMEZAWA Hiroyukica371c02009-06-12 10:33:53 +0300539 /*
540 * page_cgroup requires countinous pages as memmap
541 * and it's bigger than MAX_ORDER unless SPARSEMEM.
542 */
543 page_cgroup_init_flatmem();
Pekka Enberg444f4782009-06-11 18:29:06 +0300544 mem_init();
545 kmem_cache_init();
Benjamin Herrenschmidtc868d552009-06-17 13:48:39 +1000546 pgtable_cache_init();
Pekka Enberg444f4782009-06-11 18:29:06 +0300547 vmalloc_init();
548}
549
Linus Torvalds1da177e2005-04-16 15:20:36 -0700550asmlinkage void __init start_kernel(void)
551{
552 char * command_line;
553 extern struct kernel_param __start___param[], __stop___param[];
Andrew Morton033ab7f2006-06-30 01:55:50 -0700554
555 smp_setup_processor_id();
556
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700557 /*
558 * Need to run as early as possible, to initialize the
559 * lockdep hash:
560 */
561 lockdep_init();
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700562 debug_objects_early_init();
Ingo Molnar42059422008-02-14 09:44:08 +0100563
564 /*
565 * Set up the the initial canary ASAP:
566 */
567 boot_init_stack_canary();
568
Paul Menageddbcc7e2007-10-18 23:39:30 -0700569 cgroup_init_early();
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700570
571 local_irq_disable();
572 early_boot_irqs_off();
Ingo Molnar243c7622006-07-03 00:25:06 -0700573 early_init_irq_lock_class();
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700574
Linus Torvalds1da177e2005-04-16 15:20:36 -0700575/*
576 * Interrupts are still disabled. Do necessary setups, then
577 * enable them
578 */
579 lock_kernel();
Thomas Gleixner906568c2007-02-16 01:28:01 -0800580 tick_init();
Stas Sergeev44fd2292006-03-23 02:59:44 -0800581 boot_cpu_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700582 page_address_init();
Alex Riesen657cafa2009-05-24 15:30:48 +0200583 printk(KERN_NOTICE "%s", linux_banner);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700584 setup_arch(&command_line);
Balbir Singhcf475ad2008-04-29 01:00:16 -0700585 mm_init_owner(&init_mm, &init_task);
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800586 setup_command_line(command_line);
Mike Travise0982e92008-03-26 14:23:48 -0700587 setup_nr_cpu_ids();
Tejun Heod6647bd2009-07-21 17:11:50 +0900588 setup_per_cpu_areas();
Stas Sergeev44fd2292006-03-23 02:59:44 -0800589 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700590
Pekka Enberg83b519e2009-06-10 19:40:04 +0300591 build_all_zonelists();
592 page_alloc_init();
593
594 printk(KERN_NOTICE "Kernel command line: %s\n", boot_command_line);
595 parse_early_param();
596 parse_args("Booting kernel", static_command_line, __start___param,
597 __stop___param - __start___param,
598 &unknown_bootoption);
599 /*
600 * These use large bootmem allocations and must precede
601 * kmem_cache_init()
602 */
603 pidhash_init();
Pekka Enberg83b519e2009-06-10 19:40:04 +0300604 vfs_caches_init_early();
605 sort_main_extable();
606 trap_init();
Pekka Enberg444f4782009-06-11 18:29:06 +0300607 mm_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700608 /*
609 * Set up the scheduler prior starting any interrupts (such as the
610 * timer interrupt). Full topology setup happens at smp_init()
611 * time - but meanwhile we still have a functioning scheduler.
612 */
613 sched_init();
614 /*
615 * Disable preemption - early bootup scheduling is extremely
616 * fragile until we cpu_idle() for the first time.
617 */
618 preempt_disable();
Ard van Breemenc4a68302007-01-05 16:36:19 -0800619 if (!irqs_disabled()) {
620 printk(KERN_WARNING "start_kernel(): bug: interrupts were "
621 "enabled *very* early, fixing it\n");
622 local_irq_disable();
623 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700624 rcu_init();
Yinghai Lu0b8f1ef2008-12-05 18:58:31 -0800625 /* init some links before init_ISA_irqs() */
626 early_irq_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700627 init_IRQ();
Catalin Marinas3c7b4e62009-06-11 13:22:39 +0100628 prio_tree_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700629 init_timers();
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800630 hrtimers_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700631 softirq_init();
john stultzad596172006-06-26 00:25:06 -0700632 timekeeping_init();
john stultz88fecaa2006-07-03 00:24:04 -0700633 time_init();
Peter Zijlstra3e51f332008-05-03 18:29:28 +0200634 sched_clock_init();
Heiko Carstens93e02812006-07-03 00:24:24 -0700635 profile_init();
636 if (!irqs_disabled())
Ron Lee24d431d2008-11-27 02:31:57 +1030637 printk(KERN_CRIT "start_kernel(): bug: interrupts were "
638 "enabled early\n");
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700639 early_boot_irqs_on();
Heiko Carstens93e02812006-07-03 00:24:24 -0700640 local_irq_enable();
Benjamin Herrenschmidtdcce2842009-06-18 13:24:12 +1000641
642 /* Interrupts are enabled now so all GFP allocations are safe. */
643 set_gfp_allowed_mask(__GFP_BITS_MASK);
644
Pekka Enberg7e85ee02009-06-12 14:03:06 +0300645 kmem_cache_init_late();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700646
647 /*
648 * HACK ALERT! This is early. We're enabling the console before
649 * we've done PCI setups etc, and console_init() must be aware of
650 * this. But we do want output early, in case something goes wrong.
651 */
652 console_init();
653 if (panic_later)
654 panic(panic_later, panic_param);
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700655
656 lockdep_info();
657
Ingo Molnar9a11b49a2006-07-03 00:24:33 -0700658 /*
659 * Need to run this when irqs are enabled, because it wants
660 * to self-test [hard/soft]-irqs on/off lock inversion bugs
661 * too:
662 */
663 locking_selftest();
664
Linus Torvalds1da177e2005-04-16 15:20:36 -0700665#ifdef CONFIG_BLK_DEV_INITRD
666 if (initrd_start && !initrd_below_start_ok &&
Geert Uytterhoevenbd673c72008-07-29 22:33:36 -0700667 page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700668 printk(KERN_CRIT "initrd overwritten (0x%08lx < 0x%08lx) - "
Geert Uytterhoevenfb6624e2008-07-17 21:16:36 +0200669 "disabling it.\n",
Geert Uytterhoevenbd673c72008-07-29 22:33:36 -0700670 page_to_pfn(virt_to_page((void *)initrd_start)),
671 min_low_pfn);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700672 initrd_start = 0;
673 }
674#endif
KAMEZAWA Hiroyuki94b6da52008-10-22 14:15:05 -0700675 page_cgroup_init();
Thomas Gleixnera03c2a42008-02-09 23:24:09 +0100676 enable_debug_pagealloc();
Eduard - Gabriel Munteanub9ce08c2008-08-10 20:14:03 +0300677 kmemtrace_init();
Catalin Marinas3c7b4e62009-06-11 13:22:39 +0100678 kmemleak_init();
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700679 debug_objects_mem_init();
Akinobu Mita199f0ca2008-04-29 01:03:13 -0700680 idr_init_cache();
Christoph Lametere7c8d5c2005-06-21 17:14:47 -0700681 setup_per_cpu_pageset();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700682 numa_policy_init();
683 if (late_time_init)
684 late_time_init();
685 calibrate_delay();
686 pidmap_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700687 anon_vma_init();
688#ifdef CONFIG_X86
689 if (efi_enabled)
690 efi_enter_virtual_mode();
691#endif
Benjamin Herrenschmidt8c9843e2008-04-18 16:56:15 +1000692 thread_info_cache_init();
David Howellsd84f4f92008-11-14 10:39:23 +1100693 cred_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700694 fork_init(num_physpages);
695 proc_caches_init();
696 buffer_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700697 key_init();
698 security_init();
699 vfs_caches_init(num_physpages);
700 radix_tree_init();
701 signals_init();
702 /* rootfs populating might need page-writeback */
703 page_writeback_init();
704#ifdef CONFIG_PROC_FS
705 proc_root_init();
706#endif
Paul Menageddbcc7e2007-10-18 23:39:30 -0700707 cgroup_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700708 cpuset_init();
Shailabh Nagarc7572492006-07-14 00:24:40 -0700709 taskstats_init_early();
Shailabh Nagarca74e922006-07-14 00:24:36 -0700710 delayacct_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700711
712 check_bugs();
713
714 acpi_early_init(); /* before LAPIC and SMP init */
715
Steven Rostedt68bf21a2008-08-14 15:45:08 -0400716 ftrace_init();
717
Linus Torvalds1da177e2005-04-16 15:20:36 -0700718 /* Do the rest non-__init'ed, we're now alive */
719 rest_init();
720}
721
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700722/* Call all constructor functions linked into the kernel. */
723static void __init do_ctors(void)
724{
725#ifdef CONFIG_CONSTRUCTORS
726 ctor_fn_t *call = (ctor_fn_t *) __ctors_start;
727
728 for (; call < (ctor_fn_t *) __ctors_end; call++)
729 (*call)();
730#endif
731}
732
Arjan van de Ven22a9d642009-01-07 08:45:46 -0800733int initcall_debug;
Rusty Russelld0ea3d72008-10-22 10:00:23 -0500734core_param(initcall_debug, initcall_debug, bool, 0644);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700735
Arjan van de Ven59f94152008-07-30 12:49:02 -0700736int do_one_initcall(initcall_t fn)
Linus Torvaldse0df1542008-05-15 18:14:01 -0700737{
738 int count = preempt_count();
Frederic Weisbecker74239072008-11-11 23:24:42 +0100739 ktime_t calltime, delta, rettime;
Cyrill Gorcunova76bfd02008-05-15 13:52:41 -0700740 char msgbuf[64];
Frederic Weisbecker74239072008-11-11 23:24:42 +0100741 struct boot_trace_call call;
742 struct boot_trace_ret ret;
Linus Torvaldse0df1542008-05-15 18:14:01 -0700743
744 if (initcall_debug) {
Frederic Weisbecker74239072008-11-11 23:24:42 +0100745 call.caller = task_pid_nr(current);
746 printk("calling %pF @ %i\n", fn, call.caller);
747 calltime = ktime_get();
748 trace_boot_call(&call, fn);
Frederic Weisbecker71566a02008-10-31 12:57:20 +0100749 enable_boot_trace();
Linus Torvaldse0df1542008-05-15 18:14:01 -0700750 }
751
Frederic Weisbecker74239072008-11-11 23:24:42 +0100752 ret.result = fn();
Linus Torvaldse0df1542008-05-15 18:14:01 -0700753
754 if (initcall_debug) {
Frederic Weisbecker71566a02008-10-31 12:57:20 +0100755 disable_boot_trace();
Frederic Weisbecker74239072008-11-11 23:24:42 +0100756 rettime = ktime_get();
757 delta = ktime_sub(rettime, calltime);
Will Newton1d926f22008-11-21 14:08:59 -0800758 ret.duration = (unsigned long long) ktime_to_ns(delta) >> 10;
Frederic Weisbecker74239072008-11-11 23:24:42 +0100759 trace_boot_ret(&ret, fn);
Tim Birdca538f62008-10-09 15:23:05 -0700760 printk("initcall %pF returned %d after %Ld usecs\n", fn,
Frederic Weisbecker74239072008-11-11 23:24:42 +0100761 ret.result, ret.duration);
Linus Torvaldse0df1542008-05-15 18:14:01 -0700762 }
763
764 msgbuf[0] = 0;
765
Frederic Weisbecker74239072008-11-11 23:24:42 +0100766 if (ret.result && ret.result != -ENODEV && initcall_debug)
767 sprintf(msgbuf, "error code %d ", ret.result);
Linus Torvaldse0df1542008-05-15 18:14:01 -0700768
769 if (preempt_count() != count) {
Cyrill Gorcunova76bfd02008-05-15 13:52:41 -0700770 strlcat(msgbuf, "preemption imbalance ", sizeof(msgbuf));
Linus Torvaldse0df1542008-05-15 18:14:01 -0700771 preempt_count() = count;
772 }
773 if (irqs_disabled()) {
Cyrill Gorcunova76bfd02008-05-15 13:52:41 -0700774 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
Linus Torvaldse0df1542008-05-15 18:14:01 -0700775 local_irq_enable();
776 }
777 if (msgbuf[0]) {
Linus Torvalds96d746c2008-10-03 13:38:07 -0700778 printk("initcall %pF returned with %s\n", fn, msgbuf);
Linus Torvaldse0df1542008-05-15 18:14:01 -0700779 }
Arjan van de Ven59f94152008-07-30 12:49:02 -0700780
Frederic Weisbecker74239072008-11-11 23:24:42 +0100781 return ret.result;
Linus Torvaldse0df1542008-05-15 18:14:01 -0700782}
783
784
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700785extern initcall_t __initcall_start[], __initcall_end[], __early_initcall_end[];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700786
787static void __init do_initcalls(void)
788{
789 initcall_t *call;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700790
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700791 for (call = __early_initcall_end; call < __initcall_end; call++)
Linus Torvaldse0df1542008-05-15 18:14:01 -0700792 do_one_initcall(*call);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700793
794 /* Make sure there is no pending stuff from the initcall sequence */
795 flush_scheduled_work();
796}
797
798/*
799 * Ok, the machine is now initialized. None of the devices
800 * have been touched yet, but the CPU subsystem is up and
801 * running, and memory and process management works.
802 *
803 * Now we can finally start doing some real work..
804 */
805static void __init do_basic_setup(void)
806{
Paul E. McKenney4446a362008-05-12 21:21:05 +0200807 rcu_init_sched(); /* needed by module_init stage. */
Linus Torvalds4403b402008-10-25 19:53:38 -0700808 init_workqueues();
Lai Jiangshan759ee092009-03-25 17:06:30 +0800809 cpuset_init_smp();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700810 usermodehelper_init();
811 driver_init();
Eric W. Biedermanb04c3af2007-02-14 00:33:57 -0800812 init_irq_proc();
Peter Oberparleiterb99b87f2009-06-17 16:28:03 -0700813 do_ctors();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700814 do_initcalls();
815}
816
Eduard - Gabriel Munteanu7babe8d2008-07-25 19:45:11 -0700817static void __init do_pre_smp_initcalls(void)
Eduard - Gabriel Munteanuc2147a52008-07-25 19:45:11 -0700818{
819 initcall_t *call;
820
821 for (call = __initcall_start; call < __early_initcall_end; call++)
822 do_one_initcall(*call);
823}
824
Linus Torvalds1da177e2005-04-16 15:20:36 -0700825static void run_init_process(char *init_filename)
826{
827 argv_init[0] = init_filename;
Arnd Bergmann67608562006-10-02 02:18:26 -0700828 kernel_execve(init_filename, argv_init, envp_init);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700829}
830
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100831/* This is a non __init function. Force it to be noinline otherwise gcc
832 * makes it inline to init() and it becomes part of init.text section
833 */
Rakib Mullickf99ebf02009-01-06 14:40:38 -0800834static noinline int init_post(void)
Hannes Ederacdd0522009-03-31 15:23:50 -0700835 __releases(kernel_lock)
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100836{
Arjan van de Ven22a9d642009-01-07 08:45:46 -0800837 /* need to finish all async __init code before freeing the memory */
838 async_synchronize_full();
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100839 free_initmem();
840 unlock_kernel();
841 mark_rodata_ro();
842 system_state = SYSTEM_RUNNING;
843 numa_default_policy();
844
845 if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
846 printk(KERN_WARNING "Warning: unable to open an initial console.\n");
847
848 (void) sys_dup(0);
849 (void) sys_dup(0);
850
Oleg Nesterovfae5fa42008-04-30 00:53:03 -0700851 current->signal->flags |= SIGNAL_UNKILLABLE;
852
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100853 if (ramdisk_execute_command) {
854 run_init_process(ramdisk_execute_command);
855 printk(KERN_WARNING "Failed to execute %s\n",
856 ramdisk_execute_command);
857 }
858
859 /*
860 * We try each of these until one succeeds.
861 *
862 * The Bourne shell can be used instead of init if we are
863 * trying to recover a really broken machine.
864 */
865 if (execute_command) {
866 run_init_process(execute_command);
867 printk(KERN_WARNING "Failed to execute %s. Attempting "
868 "defaults...\n", execute_command);
869 }
870 run_init_process("/sbin/init");
871 run_init_process("/etc/init");
872 run_init_process("/bin/init");
873 run_init_process("/bin/sh");
874
875 panic("No init found. Try passing init= option to kernel.");
876}
877
Sam Ravnborgaae5f662007-02-26 16:45:41 +0100878static int __init kernel_init(void * unused)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700879{
880 lock_kernel();
Miao Xie58568d22009-06-16 15:31:49 -0700881
882 /*
883 * init can allocate pages on any node
884 */
885 set_mems_allowed(node_possible_map);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700886 /*
887 * init can run on any cpu.
888 */
Rusty Russell1a2142a2009-03-30 22:05:10 -0600889 set_cpus_allowed_ptr(current, cpu_all_mask);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700890 /*
891 * Tell the world that we're going to be the grim
892 * reaper of innocent orphaned children.
893 *
894 * We don't want people to have to make incorrect
895 * assumptions about where in the task array this
896 * can be found.
897 */
Sukadev Bhattiprolu84d73782006-12-08 02:38:01 -0800898 init_pid_ns.child_reaper = current;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700899
Cedric Le Goater9ec52092006-10-02 02:19:00 -0700900 cad_pid = task_pid(current);
901
Andi Kleenca74a6f2008-01-30 13:33:17 +0100902 smp_prepare_cpus(setup_max_cpus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700903
904 do_pre_smp_initcalls();
Frédéric Weisbecker3bf77af2008-09-23 11:38:18 +0100905 start_boot_trace();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700906
Linus Torvalds1da177e2005-04-16 15:20:36 -0700907 smp_init();
908 sched_init_smp();
909
Linus Torvalds1da177e2005-04-16 15:20:36 -0700910 do_basic_setup();
911
912 /*
913 * check if there is an early userspace init. If yes, let it do all
914 * the work
915 */
Olof Johanssonffdfc402005-09-06 15:17:19 -0700916
917 if (!ramdisk_execute_command)
918 ramdisk_execute_command = "/init";
919
920 if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
921 ramdisk_execute_command = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700922 prepare_namespace();
Olof Johanssonffdfc402005-09-06 15:17:19 -0700923 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700924
925 /*
926 * Ok, we have completed the initial bootup, and
927 * we're essentially up and running. Get rid of the
928 * initmem segments and start the user-mode stuff..
929 */
Frederic Weisbecker71566a02008-10-31 12:57:20 +0100930
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100931 init_post();
932 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700933}