blob: eb8bdbae4fc79026f8ee4664f34da66c82076c1e [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/init/main.c
3 *
4 * Copyright (C) 1991, 1992 Linus Torvalds
5 *
6 * GK 2/5/95 - Changed to support mounting root fs via NFS
7 * Added initrd & change_root: Werner Almesberger & Hans Lermen, Feb '96
8 * Moan early if gcc is old, avoiding bogus kernels - Paul Gortmaker, May '96
9 * Simplified starting of init: Michael A. Griffith <grif@acm.org>
10 */
11
Linus Torvalds1da177e2005-04-16 15:20:36 -070012#include <linux/types.h>
13#include <linux/module.h>
14#include <linux/proc_fs.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070015#include <linux/kernel.h>
16#include <linux/syscalls.h>
17#include <linux/string.h>
18#include <linux/ctype.h>
19#include <linux/delay.h>
20#include <linux/utsname.h>
21#include <linux/ioport.h>
22#include <linux/init.h>
23#include <linux/smp_lock.h>
24#include <linux/initrd.h>
25#include <linux/hdreg.h>
26#include <linux/bootmem.h>
27#include <linux/tty.h>
28#include <linux/gfp.h>
29#include <linux/percpu.h>
30#include <linux/kmod.h>
31#include <linux/kernel_stat.h>
Rusty Russelld7cd5612006-12-07 02:14:08 +010032#include <linux/start_kernel.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070033#include <linux/security.h>
34#include <linux/workqueue.h>
35#include <linux/profile.h>
36#include <linux/rcupdate.h>
37#include <linux/moduleparam.h>
38#include <linux/kallsyms.h>
39#include <linux/writeback.h>
40#include <linux/cpu.h>
41#include <linux/cpuset.h>
42#include <linux/efi.h>
Thomas Gleixner906568c2007-02-16 01:28:01 -080043#include <linux/tick.h>
Andrew Morton6168a702007-02-17 21:22:39 -080044#include <linux/interrupt.h>
Shailabh Nagarc7572492006-07-14 00:24:40 -070045#include <linux/taskstats_kern.h>
Shailabh Nagarca74e922006-07-14 00:24:36 -070046#include <linux/delayacct.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070047#include <linux/unistd.h>
48#include <linux/rmap.h>
49#include <linux/mempolicy.h>
50#include <linux/key.h>
Jan Beulich4552d5d2006-06-26 13:57:28 +020051#include <linux/unwind.h>
Adrian Bunkb6cd0b72006-06-27 02:53:54 -070052#include <linux/buffer_head.h>
Ingo Molnar9a11b49a2006-07-03 00:24:33 -070053#include <linux/debug_locks.h>
Ingo Molnarfbb9ce952006-07-03 00:24:50 -070054#include <linux/lockdep.h>
Sukadev Bhattiprolu84d73782006-12-08 02:38:01 -080055#include <linux/pid_namespace.h>
Adrian Bunk1f217822006-12-19 13:01:28 -080056#include <linux/device.h>
Eric W. Biederman73c27992007-05-09 02:34:32 -070057#include <linux/kthread.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070058
59#include <asm/io.h>
60#include <asm/bugs.h>
61#include <asm/setup.h>
Andi Kleena9401992005-07-28 21:15:30 -070062#include <asm/sections.h>
Arjan van de Ven37b73c82006-01-06 00:12:01 -080063#include <asm/cacheflush.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070064
Linus Torvalds1da177e2005-04-16 15:20:36 -070065#ifdef CONFIG_X86_LOCAL_APIC
66#include <asm/smp.h>
67#endif
68
69/*
Coywolf Qi Hunt69c99ac2006-01-14 13:21:11 -080070 * This is one of the first .c files built. Error out early if we have compiler
71 * trouble.
72 *
73 * Versions of gcc older than that listed below may actually compile and link
74 * okay, but the end product can have subtle run time bugs. To avoid associated
75 * bogus bug reports, we flatly refuse to compile with a gcc that is known to be
76 * too old from the very beginning.
Linus Torvalds1da177e2005-04-16 15:20:36 -070077 */
Andrew Mortonfd285bb2006-01-08 01:04:07 -080078#if (__GNUC__ < 3) || (__GNUC__ == 3 && __GNUC_MINOR__ < 2)
Linus Torvalds1da177e2005-04-16 15:20:36 -070079#error Sorry, your GCC is too old. It builds incorrect kernels.
80#endif
81
Andrew Mortonf1a60db2006-12-06 20:39:59 -080082#if __GNUC__ == 4 && __GNUC_MINOR__ == 1 && __GNUC_PATCHLEVEL__ == 0
83#warning gcc-4.1.0 is known to miscompile the kernel. A different compiler version is recommended.
84#endif
85
Sam Ravnborgaae5f662007-02-26 16:45:41 +010086static int kernel_init(void *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070087
88extern void init_IRQ(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070089extern void fork_init(unsigned long);
90extern void mca_init(void);
91extern void sbus_init(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070092extern void signals_init(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070093extern void pidhash_init(void);
94extern void pidmap_init(void);
95extern void prio_tree_init(void);
96extern void radix_tree_init(void);
97extern void free_initmem(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070098#ifdef CONFIG_ACPI
99extern void acpi_early_init(void);
100#else
101static inline void acpi_early_init(void) { }
102#endif
Arjan van de Ven37b73c82006-01-06 00:12:01 -0800103#ifndef CONFIG_DEBUG_RODATA
104static inline void mark_rodata_ro(void) { }
105#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106
107#ifdef CONFIG_TC
108extern void tc_init(void);
109#endif
110
111enum system_states system_state;
112EXPORT_SYMBOL(system_state);
113
114/*
115 * Boot command-line arguments
116 */
117#define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
118#define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
119
120extern void time_init(void);
121/* Default late time init is NULL. archs can override this later. */
122void (*late_time_init)(void);
123extern void softirq_init(void);
124
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800125/* Untouched command line saved by arch-specific code. */
126char __initdata boot_command_line[COMMAND_LINE_SIZE];
127/* Untouched saved command line (eg. for /proc) */
128char *saved_command_line;
129/* Command line for parameter parsing */
130static char *static_command_line;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131
132static char *execute_command;
Olof Johanssonffdfc402005-09-06 15:17:19 -0700133static char *ramdisk_execute_command;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134
135/* Setup configured maximum number of CPUs to activate */
136static unsigned int max_cpus = NR_CPUS;
137
138/*
Vivek Goyal7e962872006-09-27 01:50:44 -0700139 * If set, this is an indication to the drivers that reset the underlying
140 * device before going ahead with the initialization otherwise driver might
141 * rely on the BIOS and skip the reset operation.
142 *
143 * This is useful if kernel is booting in an unreliable environment.
144 * For ex. kdump situaiton where previous kernel has crashed, BIOS has been
145 * skipped and devices will be in unknown state.
146 */
147unsigned int reset_devices;
148EXPORT_SYMBOL(reset_devices);
149
150/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151 * Setup routine for controlling SMP activation
152 *
153 * Command-line option of "nosmp" or "maxcpus=0" will disable SMP
154 * activation entirely (the MPS table probe still happens, though).
155 *
156 * Command-line option of "maxcpus=<NUM>", where <NUM> is an integer
157 * greater than 0, limits the maximum number of CPUs activated in
158 * SMP mode to <NUM>.
159 */
160static int __init nosmp(char *str)
161{
162 max_cpus = 0;
163 return 1;
164}
165
166__setup("nosmp", nosmp);
167
168static int __init maxcpus(char *str)
169{
170 get_option(&str, &max_cpus);
171 return 1;
172}
173
174__setup("maxcpus=", maxcpus);
175
Vivek Goyal7e962872006-09-27 01:50:44 -0700176static int __init set_reset_devices(char *str)
177{
178 reset_devices = 1;
179 return 1;
180}
181
182__setup("reset_devices", set_reset_devices);
183
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184static char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
185char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
186static const char *panic_later, *panic_param;
187
188extern struct obs_kernel_param __setup_start[], __setup_end[];
189
190static int __init obsolete_checksetup(char *line)
191{
192 struct obs_kernel_param *p;
Rusty Russell33df0d12006-09-26 10:52:32 +0200193 int had_early_param = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194
195 p = __setup_start;
196 do {
197 int n = strlen(p->str);
198 if (!strncmp(line, p->str, n)) {
199 if (p->early) {
Rusty Russell33df0d12006-09-26 10:52:32 +0200200 /* Already done in parse_early_param?
201 * (Needs exact match on param part).
202 * Keep iterating, as we can have early
203 * params and __setups of same names 8( */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204 if (line[n] == '\0' || line[n] == '=')
Rusty Russell33df0d12006-09-26 10:52:32 +0200205 had_early_param = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206 } else if (!p->setup_func) {
207 printk(KERN_WARNING "Parameter %s is obsolete,"
208 " ignored\n", p->str);
209 return 1;
210 } else if (p->setup_func(line + n))
211 return 1;
212 }
213 p++;
214 } while (p < __setup_end);
Rusty Russell33df0d12006-09-26 10:52:32 +0200215
216 return had_early_param;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217}
218
219/*
220 * This should be approx 2 Bo*oMips to start (note initial shift), and will
221 * still work even if initially too large, it will just take slightly longer
222 */
223unsigned long loops_per_jiffy = (1<<12);
224
225EXPORT_SYMBOL(loops_per_jiffy);
226
227static int __init debug_kernel(char *str)
228{
229 if (*str)
230 return 0;
231 console_loglevel = 10;
232 return 1;
233}
234
235static int __init quiet_kernel(char *str)
236{
237 if (*str)
238 return 0;
239 console_loglevel = 4;
240 return 1;
241}
242
243__setup("debug", debug_kernel);
244__setup("quiet", quiet_kernel);
245
246static int __init loglevel(char *str)
247{
248 get_option(&str, &console_loglevel);
249 return 1;
250}
251
252__setup("loglevel=", loglevel);
253
254/*
255 * Unknown boot options get handed to init, unless they look like
256 * failed parameters
257 */
258static int __init unknown_bootoption(char *param, char *val)
259{
260 /* Change NUL term back to "=", to make "param" the whole string. */
261 if (val) {
262 /* param=val or param="val"? */
263 if (val == param+strlen(param)+1)
264 val[-1] = '=';
265 else if (val == param+strlen(param)+2) {
266 val[-2] = '=';
267 memmove(val-1, val, strlen(val)+1);
268 val--;
269 } else
270 BUG();
271 }
272
273 /* Handle obsolete-style parameters */
274 if (obsolete_checksetup(param))
275 return 0;
276
277 /*
278 * Preemptive maintenance for "why didn't my mispelled command
279 * line work?"
280 */
281 if (strchr(param, '.') && (!val || strchr(param, '.') < val)) {
282 printk(KERN_ERR "Unknown boot option `%s': ignoring\n", param);
283 return 0;
284 }
285
286 if (panic_later)
287 return 0;
288
289 if (val) {
290 /* Environment option */
291 unsigned int i;
292 for (i = 0; envp_init[i]; i++) {
293 if (i == MAX_INIT_ENVS) {
294 panic_later = "Too many boot env vars at `%s'";
295 panic_param = param;
296 }
297 if (!strncmp(param, envp_init[i], val - param))
298 break;
299 }
300 envp_init[i] = param;
301 } else {
302 /* Command line option */
303 unsigned int i;
304 for (i = 0; argv_init[i]; i++) {
305 if (i == MAX_INIT_ARGS) {
306 panic_later = "Too many boot init vars at `%s'";
307 panic_param = param;
308 }
309 }
310 argv_init[i] = param;
311 }
312 return 0;
313}
314
315static int __init init_setup(char *str)
316{
317 unsigned int i;
318
319 execute_command = str;
320 /*
321 * In case LILO is going to boot us with default command line,
322 * it prepends "auto" before the whole cmdline which makes
323 * the shell think it should execute a script with such name.
324 * So we ignore all arguments entered _before_ init=... [MJ]
325 */
326 for (i = 1; i < MAX_INIT_ARGS; i++)
327 argv_init[i] = NULL;
328 return 1;
329}
330__setup("init=", init_setup);
331
Olof Johanssonffdfc402005-09-06 15:17:19 -0700332static int __init rdinit_setup(char *str)
333{
334 unsigned int i;
335
336 ramdisk_execute_command = str;
337 /* See "auto" comment in init_setup */
338 for (i = 1; i < MAX_INIT_ARGS; i++)
339 argv_init[i] = NULL;
340 return 1;
341}
342__setup("rdinit=", rdinit_setup);
343
Linus Torvalds1da177e2005-04-16 15:20:36 -0700344#ifndef CONFIG_SMP
345
346#ifdef CONFIG_X86_LOCAL_APIC
347static void __init smp_init(void)
348{
349 APIC_init_uniprocessor();
350}
351#else
352#define smp_init() do { } while (0)
353#endif
354
355static inline void setup_per_cpu_areas(void) { }
356static inline void smp_prepare_cpus(unsigned int maxcpus) { }
357
358#else
359
360#ifdef __GENERIC_PER_CPU
Eric Dumazetb73b4592006-03-23 03:01:07 -0800361unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700362
363EXPORT_SYMBOL(__per_cpu_offset);
364
365static void __init setup_per_cpu_areas(void)
366{
367 unsigned long size, i;
368 char *ptr;
Eric Dumazet63872f82006-03-23 03:01:04 -0800369 unsigned long nr_possible_cpus = num_possible_cpus();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700370
371 /* Copy section for each CPU (we discard the original) */
Jeremy Fitzhardingeb6e35902007-05-02 19:27:12 +0200372 size = ALIGN(PERCPU_ENOUGH_ROOM, PAGE_SIZE);
373 ptr = alloc_bootmem_pages(size * nr_possible_cpus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700374
KAMEZAWA Hiroyuki0a945022006-03-28 01:56:37 -0800375 for_each_possible_cpu(i) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700376 __per_cpu_offset[i] = ptr - __per_cpu_start;
377 memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start);
Eric Dumazet63872f82006-03-23 03:01:04 -0800378 ptr += size;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700379 }
380}
381#endif /* !__GENERIC_PER_CPU */
382
383/* Called by boot processor to activate the rest. */
384static void __init smp_init(void)
385{
Christoph Lameter53b8a312007-02-20 13:57:51 -0800386 unsigned int cpu;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387
388 /* FIXME: This should be done in userspace --RR */
Christoph Lameter53b8a312007-02-20 13:57:51 -0800389 for_each_present_cpu(cpu) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700390 if (num_online_cpus() >= max_cpus)
391 break;
Christoph Lameter53b8a312007-02-20 13:57:51 -0800392 if (!cpu_online(cpu))
393 cpu_up(cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394 }
395
396 /* Any cleanup work */
397 printk(KERN_INFO "Brought up %ld CPUs\n", (long)num_online_cpus());
398 smp_cpus_done(max_cpus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700399}
400
401#endif
402
403/*
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800404 * We need to store the untouched command line for future reference.
405 * We also need to store the touched command line since the parameter
406 * parsing is performed in place, and we should allow a component to
407 * store reference of name/value for future reference.
408 */
409static void __init setup_command_line(char *command_line)
410{
411 saved_command_line = alloc_bootmem(strlen (boot_command_line)+1);
412 static_command_line = alloc_bootmem(strlen (command_line)+1);
413 strcpy (saved_command_line, boot_command_line);
414 strcpy (static_command_line, command_line);
415}
416
417/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700418 * We need to finalize in a non-__init function or else race conditions
419 * between the root thread and the init thread may cause start_kernel to
420 * be reaped by free_initmem before the root thread has proceeded to
421 * cpu_idle.
422 *
423 * gcc-3.4 accidentally inlines this function, so use noinline.
424 */
425
Sam Ravnborg92080302007-05-17 20:43:54 +0200426static void noinline __init_refok rest_init(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700427 __releases(kernel_lock)
428{
Eric W. Biederman73c27992007-05-09 02:34:32 -0700429 int pid;
430
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);
434 kthreadd_task = find_task_by_pid(pid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700435 unlock_kernel();
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200436
437 /*
438 * The boot idle thread must execute schedule()
439 * at least one to get things moving:
440 */
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800441 preempt_enable_no_resched();
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200442 schedule();
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800443 preempt_disable();
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200444
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800445 /* Call into cpu_idle with preempt disabled */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700446 cpu_idle();
447}
448
449/* Check for early params. */
450static int __init do_early_param(char *param, char *val)
451{
452 struct obs_kernel_param *p;
453
454 for (p = __setup_start; p < __setup_end; p++) {
455 if (p->early && strcmp(param, p->str) == 0) {
456 if (p->setup_func(val) != 0)
457 printk(KERN_WARNING
458 "Malformed early option '%s'\n", param);
459 }
460 }
461 /* We accept everything at this stage. */
462 return 0;
463}
464
465/* Arch code calls this early on, or if not, just before other parsing. */
466void __init parse_early_param(void)
467{
468 static __initdata int done = 0;
469 static __initdata char tmp_cmdline[COMMAND_LINE_SIZE];
470
471 if (done)
472 return;
473
474 /* All fall through to do_early_param. */
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800475 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700476 parse_args("early options", tmp_cmdline, NULL, 0, do_early_param);
477 done = 1;
478}
479
480/*
481 * Activate the first processor.
482 */
483
Stas Sergeev44fd2292006-03-23 02:59:44 -0800484static void __init boot_cpu_init(void)
485{
486 int cpu = smp_processor_id();
487 /* Mark the boot cpu "present", "online" etc for SMP and UP case */
488 cpu_set(cpu, cpu_online_map);
489 cpu_set(cpu, cpu_present_map);
490 cpu_set(cpu, cpu_possible_map);
491}
492
Andrew Morton033ab7f2006-06-30 01:55:50 -0700493void __init __attribute__((weak)) smp_setup_processor_id(void)
494{
495}
496
Linus Torvalds1da177e2005-04-16 15:20:36 -0700497asmlinkage void __init start_kernel(void)
498{
499 char * command_line;
500 extern struct kernel_param __start___param[], __stop___param[];
Andrew Morton033ab7f2006-06-30 01:55:50 -0700501
502 smp_setup_processor_id();
503
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700504 /*
505 * Need to run as early as possible, to initialize the
506 * lockdep hash:
507 */
Andi Kleenc9538ed2006-09-26 10:52:34 +0200508 unwind_init();
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700509 lockdep_init();
510
511 local_irq_disable();
512 early_boot_irqs_off();
Ingo Molnar243c7622006-07-03 00:25:06 -0700513 early_init_irq_lock_class();
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700514
Linus Torvalds1da177e2005-04-16 15:20:36 -0700515/*
516 * Interrupts are still disabled. Do necessary setups, then
517 * enable them
518 */
519 lock_kernel();
Thomas Gleixner906568c2007-02-16 01:28:01 -0800520 tick_init();
Stas Sergeev44fd2292006-03-23 02:59:44 -0800521 boot_cpu_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700522 page_address_init();
523 printk(KERN_NOTICE);
Linus Torvalds89937802006-12-11 09:28:46 -0800524 printk(linux_banner);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700525 setup_arch(&command_line);
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800526 setup_command_line(command_line);
Jan Beulich690a9732006-10-21 18:37:01 +0200527 unwind_setup();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700528 setup_per_cpu_areas();
Stas Sergeev44fd2292006-03-23 02:59:44 -0800529 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700530
531 /*
532 * Set up the scheduler prior starting any interrupts (such as the
533 * timer interrupt). Full topology setup happens at smp_init()
534 * time - but meanwhile we still have a functioning scheduler.
535 */
536 sched_init();
537 /*
538 * Disable preemption - early bootup scheduling is extremely
539 * fragile until we cpu_idle() for the first time.
540 */
541 preempt_disable();
542 build_all_zonelists();
543 page_alloc_init();
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800544 printk(KERN_NOTICE "Kernel command line: %s\n", boot_command_line);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700545 parse_early_param();
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800546 parse_args("Booting kernel", static_command_line, __start___param,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700547 __stop___param - __start___param,
548 &unknown_bootoption);
Ard van Breemenc4a68302007-01-05 16:36:19 -0800549 if (!irqs_disabled()) {
550 printk(KERN_WARNING "start_kernel(): bug: interrupts were "
551 "enabled *very* early, fixing it\n");
552 local_irq_disable();
553 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700554 sort_main_extable();
555 trap_init();
556 rcu_init();
557 init_IRQ();
558 pidhash_init();
559 init_timers();
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800560 hrtimers_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700561 softirq_init();
john stultzad596172006-06-26 00:25:06 -0700562 timekeeping_init();
john stultz88fecaa2006-07-03 00:24:04 -0700563 time_init();
Heiko Carstens93e02812006-07-03 00:24:24 -0700564 profile_init();
565 if (!irqs_disabled())
566 printk("start_kernel(): bug: interrupts were enabled early\n");
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700567 early_boot_irqs_on();
Heiko Carstens93e02812006-07-03 00:24:24 -0700568 local_irq_enable();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700569
570 /*
571 * HACK ALERT! This is early. We're enabling the console before
572 * we've done PCI setups etc, and console_init() must be aware of
573 * this. But we do want output early, in case something goes wrong.
574 */
575 console_init();
576 if (panic_later)
577 panic(panic_later, panic_param);
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700578
579 lockdep_info();
580
Ingo Molnar9a11b49a2006-07-03 00:24:33 -0700581 /*
582 * Need to run this when irqs are enabled, because it wants
583 * to self-test [hard/soft]-irqs on/off lock inversion bugs
584 * too:
585 */
586 locking_selftest();
587
Linus Torvalds1da177e2005-04-16 15:20:36 -0700588#ifdef CONFIG_BLK_DEV_INITRD
589 if (initrd_start && !initrd_below_start_ok &&
590 initrd_start < min_low_pfn << PAGE_SHIFT) {
591 printk(KERN_CRIT "initrd overwritten (0x%08lx < 0x%08lx) - "
592 "disabling it.\n",initrd_start,min_low_pfn << PAGE_SHIFT);
593 initrd_start = 0;
594 }
595#endif
596 vfs_caches_init_early();
Paul Jacksonc417f022006-01-08 01:02:01 -0800597 cpuset_init_early();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700598 mem_init();
599 kmem_cache_init();
Christoph Lametere7c8d5c2005-06-21 17:14:47 -0700600 setup_per_cpu_pageset();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700601 numa_policy_init();
602 if (late_time_init)
603 late_time_init();
604 calibrate_delay();
605 pidmap_init();
606 pgtable_cache_init();
607 prio_tree_init();
608 anon_vma_init();
609#ifdef CONFIG_X86
610 if (efi_enabled)
611 efi_enter_virtual_mode();
612#endif
613 fork_init(num_physpages);
614 proc_caches_init();
615 buffer_init();
616 unnamed_dev_init();
617 key_init();
618 security_init();
619 vfs_caches_init(num_physpages);
620 radix_tree_init();
621 signals_init();
622 /* rootfs populating might need page-writeback */
623 page_writeback_init();
624#ifdef CONFIG_PROC_FS
625 proc_root_init();
626#endif
627 cpuset_init();
Shailabh Nagarc7572492006-07-14 00:24:40 -0700628 taskstats_init_early();
Shailabh Nagarca74e922006-07-14 00:24:36 -0700629 delayacct_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700630
631 check_bugs();
632
633 acpi_early_init(); /* before LAPIC and SMP init */
634
635 /* Do the rest non-__init'ed, we're now alive */
636 rest_init();
637}
638
639static int __initdata initcall_debug;
640
641static int __init initcall_debug_setup(char *str)
642{
643 initcall_debug = 1;
644 return 1;
645}
646__setup("initcall_debug", initcall_debug_setup);
647
Linus Torvalds1da177e2005-04-16 15:20:36 -0700648extern initcall_t __initcall_start[], __initcall_end[];
649
650static void __init do_initcalls(void)
651{
652 initcall_t *call;
653 int count = preempt_count();
654
655 for (call = __initcall_start; call < __initcall_end; call++) {
Ingo Molnar8f0c45c2007-05-08 00:28:26 -0700656 ktime_t t0, t1, delta;
Andrew Mortonc1cda482006-03-25 03:07:15 -0800657 char *msg = NULL;
658 char msgbuf[40];
659 int result;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700660
661 if (initcall_debug) {
Andrew Mortonc1cda482006-03-25 03:07:15 -0800662 printk("Calling initcall 0x%p", *call);
663 print_fn_descriptor_symbol(": %s()",
664 (unsigned long) *call);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700665 printk("\n");
Ingo Molnar8f0c45c2007-05-08 00:28:26 -0700666 t0 = ktime_get();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700667 }
668
Andrew Mortonc1cda482006-03-25 03:07:15 -0800669 result = (*call)();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700670
Ingo Molnar8f0c45c2007-05-08 00:28:26 -0700671 if (initcall_debug) {
672 t1 = ktime_get();
673 delta = ktime_sub(t1, t0);
674
675 printk("initcall 0x%p", *call);
676 print_fn_descriptor_symbol(": %s()",
677 (unsigned long) *call);
678 printk(" returned %d.\n", result);
679
680 printk("initcall 0x%p ran for %Ld msecs: ",
681 *call, (unsigned long long)delta.tv64 >> 20);
682 print_fn_descriptor_symbol("%s()\n",
683 (unsigned long) *call);
684 }
685
Andrew Mortonf3a19cb2006-05-01 12:15:52 -0700686 if (result && result != -ENODEV && initcall_debug) {
Andrew Mortonc1cda482006-03-25 03:07:15 -0800687 sprintf(msgbuf, "error code %d", result);
688 msg = msgbuf;
689 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700690 if (preempt_count() != count) {
691 msg = "preemption imbalance";
692 preempt_count() = count;
693 }
694 if (irqs_disabled()) {
695 msg = "disabled interrupts";
696 local_irq_enable();
697 }
698 if (msg) {
Andrew Mortonc1cda482006-03-25 03:07:15 -0800699 printk(KERN_WARNING "initcall at 0x%p", *call);
700 print_fn_descriptor_symbol(": %s()",
701 (unsigned long) *call);
702 printk(": returned with %s\n", msg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700703 }
704 }
705
706 /* Make sure there is no pending stuff from the initcall sequence */
707 flush_scheduled_work();
708}
709
710/*
711 * Ok, the machine is now initialized. None of the devices
712 * have been touched yet, but the CPU subsystem is up and
713 * running, and memory and process management works.
714 *
715 * Now we can finally start doing some real work..
716 */
717static void __init do_basic_setup(void)
718{
719 /* drivers will send hotplug events */
720 init_workqueues();
721 usermodehelper_init();
722 driver_init();
Eric W. Biedermanb04c3af2007-02-14 00:33:57 -0800723 init_irq_proc();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700724 do_initcalls();
725}
726
Vivek Goyal88d20322007-01-11 01:52:44 +0100727static void __init do_pre_smp_initcalls(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700728{
729 extern int spawn_ksoftirqd(void);
730#ifdef CONFIG_SMP
731 extern int migration_init(void);
732
733 migration_init();
734#endif
735 spawn_ksoftirqd();
Ingo Molnar8446f1d2005-09-06 15:16:27 -0700736 spawn_softlockup_task();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700737}
738
739static void run_init_process(char *init_filename)
740{
741 argv_init[0] = init_filename;
Arnd Bergmann67608562006-10-02 02:18:26 -0700742 kernel_execve(init_filename, argv_init, envp_init);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700743}
744
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100745/* This is a non __init function. Force it to be noinline otherwise gcc
746 * makes it inline to init() and it becomes part of init.text section
747 */
748static int noinline init_post(void)
749{
750 free_initmem();
751 unlock_kernel();
752 mark_rodata_ro();
753 system_state = SYSTEM_RUNNING;
754 numa_default_policy();
755
756 if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
757 printk(KERN_WARNING "Warning: unable to open an initial console.\n");
758
759 (void) sys_dup(0);
760 (void) sys_dup(0);
761
762 if (ramdisk_execute_command) {
763 run_init_process(ramdisk_execute_command);
764 printk(KERN_WARNING "Failed to execute %s\n",
765 ramdisk_execute_command);
766 }
767
768 /*
769 * We try each of these until one succeeds.
770 *
771 * The Bourne shell can be used instead of init if we are
772 * trying to recover a really broken machine.
773 */
774 if (execute_command) {
775 run_init_process(execute_command);
776 printk(KERN_WARNING "Failed to execute %s. Attempting "
777 "defaults...\n", execute_command);
778 }
779 run_init_process("/sbin/init");
780 run_init_process("/etc/init");
781 run_init_process("/bin/init");
782 run_init_process("/bin/sh");
783
784 panic("No init found. Try passing init= option to kernel.");
785}
786
Sam Ravnborgaae5f662007-02-26 16:45:41 +0100787static int __init kernel_init(void * unused)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700788{
789 lock_kernel();
790 /*
791 * init can run on any cpu.
792 */
793 set_cpus_allowed(current, CPU_MASK_ALL);
794 /*
795 * Tell the world that we're going to be the grim
796 * reaper of innocent orphaned children.
797 *
798 * We don't want people to have to make incorrect
799 * assumptions about where in the task array this
800 * can be found.
801 */
Sukadev Bhattiprolu84d73782006-12-08 02:38:01 -0800802 init_pid_ns.child_reaper = current;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700803
Sukadev Bhattiprolu0e29b242007-05-10 22:23:01 -0700804 __set_special_pids(1, 1);
Cedric Le Goater9ec52092006-10-02 02:19:00 -0700805 cad_pid = task_pid(current);
806
Linus Torvalds1da177e2005-04-16 15:20:36 -0700807 smp_prepare_cpus(max_cpus);
808
809 do_pre_smp_initcalls();
810
Linus Torvalds1da177e2005-04-16 15:20:36 -0700811 smp_init();
812 sched_init_smp();
813
814 cpuset_init_smp();
815
Linus Torvalds1da177e2005-04-16 15:20:36 -0700816 do_basic_setup();
817
818 /*
819 * check if there is an early userspace init. If yes, let it do all
820 * the work
821 */
Olof Johanssonffdfc402005-09-06 15:17:19 -0700822
823 if (!ramdisk_execute_command)
824 ramdisk_execute_command = "/init";
825
826 if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
827 ramdisk_execute_command = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700828 prepare_namespace();
Olof Johanssonffdfc402005-09-06 15:17:19 -0700829 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700830
831 /*
832 * Ok, we have completed the initial bootup, and
833 * we're essentially up and running. Get rid of the
834 * initmem segments and start the user-mode stuff..
835 */
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100836 init_post();
837 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700838}