blob: 2a78932f6c075abd36b331db09191b785d3156bc [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>
Paul Menageddbcc7e2007-10-18 23:39:30 -070042#include <linux/cgroup.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070043#include <linux/efi.h>
Thomas Gleixner906568c2007-02-16 01:28:01 -080044#include <linux/tick.h>
Andrew Morton6168a702007-02-17 21:22:39 -080045#include <linux/interrupt.h>
Shailabh Nagarc7572492006-07-14 00:24:40 -070046#include <linux/taskstats_kern.h>
Shailabh Nagarca74e922006-07-14 00:24:36 -070047#include <linux/delayacct.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070048#include <linux/unistd.h>
49#include <linux/rmap.h>
50#include <linux/mempolicy.h>
51#include <linux/key.h>
Jan Beulich4552d5d2006-06-26 13:57:28 +020052#include <linux/unwind.h>
Adrian Bunkb6cd0b72006-06-27 02:53:54 -070053#include <linux/buffer_head.h>
Ingo Molnar9a11b49a2006-07-03 00:24:33 -070054#include <linux/debug_locks.h>
Ingo Molnarfbb9ce952006-07-03 00:24:50 -070055#include <linux/lockdep.h>
Sukadev Bhattiprolu84d73782006-12-08 02:38:01 -080056#include <linux/pid_namespace.h>
Adrian Bunk1f217822006-12-19 13:01:28 -080057#include <linux/device.h>
Eric W. Biederman73c27992007-05-09 02:34:32 -070058#include <linux/kthread.h>
Adrian Bunke6fe6642007-11-09 22:39:39 +010059#include <linux/sched.h>
Adrian Bunka1c9eea2008-02-06 01:36:44 -080060#include <linux/signal.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070061
62#include <asm/io.h>
63#include <asm/bugs.h>
64#include <asm/setup.h>
Andi Kleena9401992005-07-28 21:15:30 -070065#include <asm/sections.h>
Arjan van de Ven37b73c82006-01-06 00:12:01 -080066#include <asm/cacheflush.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070067
Linus Torvalds1da177e2005-04-16 15:20:36 -070068#ifdef CONFIG_X86_LOCAL_APIC
69#include <asm/smp.h>
70#endif
71
72/*
Coywolf Qi Hunt69c99ac2006-01-14 13:21:11 -080073 * This is one of the first .c files built. Error out early if we have compiler
74 * trouble.
Linus Torvalds1da177e2005-04-16 15:20:36 -070075 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070076
Andrew Mortonf1a60db2006-12-06 20:39:59 -080077#if __GNUC__ == 4 && __GNUC_MINOR__ == 1 && __GNUC_PATCHLEVEL__ == 0
78#warning gcc-4.1.0 is known to miscompile the kernel. A different compiler version is recommended.
79#endif
80
Sam Ravnborgaae5f662007-02-26 16:45:41 +010081static int kernel_init(void *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070082
83extern void init_IRQ(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070084extern void fork_init(unsigned long);
85extern void mca_init(void);
86extern void sbus_init(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070087extern void pidhash_init(void);
88extern void pidmap_init(void);
89extern void prio_tree_init(void);
90extern void radix_tree_init(void);
91extern void free_initmem(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070092#ifdef CONFIG_ACPI
93extern void acpi_early_init(void);
94#else
95static inline void acpi_early_init(void) { }
96#endif
Arjan van de Ven37b73c82006-01-06 00:12:01 -080097#ifndef CONFIG_DEBUG_RODATA
98static inline void mark_rodata_ro(void) { }
99#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100
101#ifdef CONFIG_TC
102extern void tc_init(void);
103#endif
104
Markus Gaugusch71fc47a2008-02-05 00:04:06 +0100105#ifdef CONFIG_ACPI_CUSTOM_DSDT_INITRD
106extern int populate_rootfs(void);
107#else
108static inline void populate_rootfs(void) {}
109#endif
110
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111enum system_states system_state;
112EXPORT_SYMBOL(system_state);
113
114/*
115 * Boot command-line arguments
116 */
117#define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
118#define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
119
120extern void time_init(void);
121/* Default late time init is NULL. archs can override this later. */
122void (*late_time_init)(void);
123extern void softirq_init(void);
124
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800125/* Untouched command line saved by arch-specific code. */
126char __initdata boot_command_line[COMMAND_LINE_SIZE];
127/* Untouched saved command line (eg. for /proc) */
128char *saved_command_line;
129/* Command line for parameter parsing */
130static char *static_command_line;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131
132static char *execute_command;
Olof Johanssonffdfc402005-09-06 15:17:19 -0700133static char *ramdisk_execute_command;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134
Jan Beulich8b3b2952007-07-15 23:41:07 -0700135#ifdef CONFIG_SMP
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136/* Setup configured maximum number of CPUs to activate */
Andi Kleenca74a6f2008-01-30 13:33:17 +0100137unsigned int __initdata setup_max_cpus = NR_CPUS;
Vivek Goyal7e962872006-09-27 01:50:44 -0700138
139/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140 * Setup routine for controlling SMP activation
141 *
142 * Command-line option of "nosmp" or "maxcpus=0" will disable SMP
143 * activation entirely (the MPS table probe still happens, though).
144 *
145 * Command-line option of "maxcpus=<NUM>", where <NUM> is an integer
146 * greater than 0, limits the maximum number of CPUs activated in
147 * SMP mode to <NUM>.
148 */
Len Brown61ec7562007-08-16 03:34:22 -0400149#ifndef CONFIG_X86_IO_APIC
150static inline void disable_ioapic_setup(void) {};
151#endif
152
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153static int __init nosmp(char *str)
154{
Andi Kleenca74a6f2008-01-30 13:33:17 +0100155 setup_max_cpus = 0;
Len Brown61ec7562007-08-16 03:34:22 -0400156 disable_ioapic_setup();
Jan Beulich8b3b2952007-07-15 23:41:07 -0700157 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158}
159
Jan Beulich8b3b2952007-07-15 23:41:07 -0700160early_param("nosmp", nosmp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161
162static int __init maxcpus(char *str)
163{
Andi Kleenca74a6f2008-01-30 13:33:17 +0100164 get_option(&str, &setup_max_cpus);
165 if (setup_max_cpus == 0)
Len Brown61ec7562007-08-16 03:34:22 -0400166 disable_ioapic_setup();
167
168 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169}
170
Hugh Dickins81340972007-08-27 16:02:12 +0100171early_param("maxcpus", maxcpus);
Jan Beulich8b3b2952007-07-15 23:41:07 -0700172#else
Andi Kleenca74a6f2008-01-30 13:33:17 +0100173#define setup_max_cpus NR_CPUS
Jan Beulich8b3b2952007-07-15 23:41:07 -0700174#endif
175
176/*
177 * If set, this is an indication to the drivers that reset the underlying
178 * device before going ahead with the initialization otherwise driver might
179 * rely on the BIOS and skip the reset operation.
180 *
181 * This is useful if kernel is booting in an unreliable environment.
182 * For ex. kdump situaiton where previous kernel has crashed, BIOS has been
183 * skipped and devices will be in unknown state.
184 */
185unsigned int reset_devices;
186EXPORT_SYMBOL(reset_devices);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187
Vivek Goyal7e962872006-09-27 01:50:44 -0700188static int __init set_reset_devices(char *str)
189{
190 reset_devices = 1;
191 return 1;
192}
193
194__setup("reset_devices", set_reset_devices);
195
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196static char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
197char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
198static const char *panic_later, *panic_param;
199
200extern struct obs_kernel_param __setup_start[], __setup_end[];
201
202static int __init obsolete_checksetup(char *line)
203{
204 struct obs_kernel_param *p;
Rusty Russell33df0d12006-09-26 10:52:32 +0200205 int had_early_param = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206
207 p = __setup_start;
208 do {
209 int n = strlen(p->str);
210 if (!strncmp(line, p->str, n)) {
211 if (p->early) {
Rusty Russell33df0d12006-09-26 10:52:32 +0200212 /* Already done in parse_early_param?
213 * (Needs exact match on param part).
214 * Keep iterating, as we can have early
215 * params and __setups of same names 8( */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216 if (line[n] == '\0' || line[n] == '=')
Rusty Russell33df0d12006-09-26 10:52:32 +0200217 had_early_param = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218 } else if (!p->setup_func) {
219 printk(KERN_WARNING "Parameter %s is obsolete,"
220 " ignored\n", p->str);
221 return 1;
222 } else if (p->setup_func(line + n))
223 return 1;
224 }
225 p++;
226 } while (p < __setup_end);
Rusty Russell33df0d12006-09-26 10:52:32 +0200227
228 return had_early_param;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229}
230
231/*
232 * This should be approx 2 Bo*oMips to start (note initial shift), and will
233 * still work even if initially too large, it will just take slightly longer
234 */
235unsigned long loops_per_jiffy = (1<<12);
236
237EXPORT_SYMBOL(loops_per_jiffy);
238
239static int __init debug_kernel(char *str)
240{
241 if (*str)
242 return 0;
243 console_loglevel = 10;
244 return 1;
245}
246
247static int __init quiet_kernel(char *str)
248{
249 if (*str)
250 return 0;
251 console_loglevel = 4;
252 return 1;
253}
254
255__setup("debug", debug_kernel);
256__setup("quiet", quiet_kernel);
257
258static int __init loglevel(char *str)
259{
260 get_option(&str, &console_loglevel);
261 return 1;
262}
263
264__setup("loglevel=", loglevel);
265
266/*
267 * Unknown boot options get handed to init, unless they look like
268 * failed parameters
269 */
270static int __init unknown_bootoption(char *param, char *val)
271{
272 /* Change NUL term back to "=", to make "param" the whole string. */
273 if (val) {
274 /* param=val or param="val"? */
275 if (val == param+strlen(param)+1)
276 val[-1] = '=';
277 else if (val == param+strlen(param)+2) {
278 val[-2] = '=';
279 memmove(val-1, val, strlen(val)+1);
280 val--;
281 } else
282 BUG();
283 }
284
285 /* Handle obsolete-style parameters */
286 if (obsolete_checksetup(param))
287 return 0;
288
289 /*
Simon Arlott211fee82007-10-20 01:28:29 +0200290 * Preemptive maintenance for "why didn't my misspelled command
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291 * line work?"
292 */
293 if (strchr(param, '.') && (!val || strchr(param, '.') < val)) {
294 printk(KERN_ERR "Unknown boot option `%s': ignoring\n", param);
295 return 0;
296 }
297
298 if (panic_later)
299 return 0;
300
301 if (val) {
302 /* Environment option */
303 unsigned int i;
304 for (i = 0; envp_init[i]; i++) {
305 if (i == MAX_INIT_ENVS) {
306 panic_later = "Too many boot env vars at `%s'";
307 panic_param = param;
308 }
309 if (!strncmp(param, envp_init[i], val - param))
310 break;
311 }
312 envp_init[i] = param;
313 } else {
314 /* Command line option */
315 unsigned int i;
316 for (i = 0; argv_init[i]; i++) {
317 if (i == MAX_INIT_ARGS) {
318 panic_later = "Too many boot init vars at `%s'";
319 panic_param = param;
320 }
321 }
322 argv_init[i] = param;
323 }
324 return 0;
325}
326
Ingo Molnar12d6f212008-01-30 13:33:58 +0100327#ifdef CONFIG_DEBUG_PAGEALLOC
328int __read_mostly debug_pagealloc_enabled = 0;
329#endif
330
Linus Torvalds1da177e2005-04-16 15:20:36 -0700331static int __init init_setup(char *str)
332{
333 unsigned int i;
334
335 execute_command = str;
336 /*
337 * In case LILO is going to boot us with default command line,
338 * it prepends "auto" before the whole cmdline which makes
339 * the shell think it should execute a script with such name.
340 * So we ignore all arguments entered _before_ init=... [MJ]
341 */
342 for (i = 1; i < MAX_INIT_ARGS; i++)
343 argv_init[i] = NULL;
344 return 1;
345}
346__setup("init=", init_setup);
347
Olof Johanssonffdfc402005-09-06 15:17:19 -0700348static int __init rdinit_setup(char *str)
349{
350 unsigned int i;
351
352 ramdisk_execute_command = str;
353 /* See "auto" comment in init_setup */
354 for (i = 1; i < MAX_INIT_ARGS; i++)
355 argv_init[i] = NULL;
356 return 1;
357}
358__setup("rdinit=", rdinit_setup);
359
Linus Torvalds1da177e2005-04-16 15:20:36 -0700360#ifndef CONFIG_SMP
361
362#ifdef CONFIG_X86_LOCAL_APIC
363static void __init smp_init(void)
364{
365 APIC_init_uniprocessor();
366}
367#else
368#define smp_init() do { } while (0)
369#endif
370
371static inline void setup_per_cpu_areas(void) { }
372static inline void smp_prepare_cpus(unsigned int maxcpus) { }
373
374#else
375
Mike Travisdd5af902008-01-30 13:33:32 +0100376#ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA
Eric Dumazetb73b4592006-03-23 03:01:07 -0800377unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378
379EXPORT_SYMBOL(__per_cpu_offset);
380
381static void __init setup_per_cpu_areas(void)
382{
383 unsigned long size, i;
384 char *ptr;
Eric Dumazet63872f82006-03-23 03:01:04 -0800385 unsigned long nr_possible_cpus = num_possible_cpus();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700386
387 /* Copy section for each CPU (we discard the original) */
Jeremy Fitzhardingeb6e35902007-05-02 19:27:12 +0200388 size = ALIGN(PERCPU_ENOUGH_ROOM, PAGE_SIZE);
389 ptr = alloc_bootmem_pages(size * nr_possible_cpus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700390
KAMEZAWA Hiroyuki0a945022006-03-28 01:56:37 -0800391 for_each_possible_cpu(i) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700392 __per_cpu_offset[i] = ptr - __per_cpu_start;
393 memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start);
Eric Dumazet63872f82006-03-23 03:01:04 -0800394 ptr += size;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700395 }
396}
Mike Travisdd5af902008-01-30 13:33:32 +0100397#endif /* CONFIG_HAVE_SETUP_PER_CPU_AREA */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700398
399/* Called by boot processor to activate the rest. */
400static void __init smp_init(void)
401{
Christoph Lameter53b8a312007-02-20 13:57:51 -0800402 unsigned int cpu;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700403
404 /* FIXME: This should be done in userspace --RR */
Christoph Lameter53b8a312007-02-20 13:57:51 -0800405 for_each_present_cpu(cpu) {
Andi Kleenca74a6f2008-01-30 13:33:17 +0100406 if (num_online_cpus() >= setup_max_cpus)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700407 break;
Christoph Lameter53b8a312007-02-20 13:57:51 -0800408 if (!cpu_online(cpu))
409 cpu_up(cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700410 }
411
412 /* Any cleanup work */
413 printk(KERN_INFO "Brought up %ld CPUs\n", (long)num_online_cpus());
Andi Kleenca74a6f2008-01-30 13:33:17 +0100414 smp_cpus_done(setup_max_cpus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700415}
416
417#endif
418
419/*
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800420 * We need to store the untouched command line for future reference.
421 * We also need to store the touched command line since the parameter
422 * parsing is performed in place, and we should allow a component to
423 * store reference of name/value for future reference.
424 */
425static void __init setup_command_line(char *command_line)
426{
427 saved_command_line = alloc_bootmem(strlen (boot_command_line)+1);
428 static_command_line = alloc_bootmem(strlen (command_line)+1);
429 strcpy (saved_command_line, boot_command_line);
430 strcpy (static_command_line, command_line);
431}
432
433/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700434 * We need to finalize in a non-__init function or else race conditions
435 * between the root thread and the init thread may cause start_kernel to
436 * be reaped by free_initmem before the root thread has proceeded to
437 * cpu_idle.
438 *
439 * gcc-3.4 accidentally inlines this function, so use noinline.
440 */
441
Sam Ravnborg92080302007-05-17 20:43:54 +0200442static void noinline __init_refok rest_init(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700443 __releases(kernel_lock)
444{
Eric W. Biederman73c27992007-05-09 02:34:32 -0700445 int pid;
446
Sam Ravnborgaae5f662007-02-26 16:45:41 +0100447 kernel_thread(kernel_init, NULL, CLONE_FS | CLONE_SIGHAND);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700448 numa_default_policy();
Eric W. Biederman73c27992007-05-09 02:34:32 -0700449 pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
450 kthreadd_task = find_task_by_pid(pid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700451 unlock_kernel();
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200452
453 /*
454 * The boot idle thread must execute schedule()
Ingo Molnar1df21052007-07-09 18:51:58 +0200455 * at least once to get things moving:
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200456 */
Ingo Molnar1df21052007-07-09 18:51:58 +0200457 init_idle_bootup_task(current);
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800458 preempt_enable_no_resched();
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200459 schedule();
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800460 preempt_disable();
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200461
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800462 /* Call into cpu_idle with preempt disabled */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700463 cpu_idle();
Ingo Molnar1df21052007-07-09 18:51:58 +0200464}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465
466/* Check for early params. */
467static int __init do_early_param(char *param, char *val)
468{
469 struct obs_kernel_param *p;
470
471 for (p = __setup_start; p < __setup_end; p++) {
Yinghai Lu18a8bd92007-07-15 23:37:59 -0700472 if ((p->early && strcmp(param, p->str) == 0) ||
473 (strcmp(param, "console") == 0 &&
474 strcmp(p->str, "earlycon") == 0)
475 ) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700476 if (p->setup_func(val) != 0)
477 printk(KERN_WARNING
478 "Malformed early option '%s'\n", param);
479 }
480 }
481 /* We accept everything at this stage. */
482 return 0;
483}
484
485/* Arch code calls this early on, or if not, just before other parsing. */
486void __init parse_early_param(void)
487{
488 static __initdata int done = 0;
489 static __initdata char tmp_cmdline[COMMAND_LINE_SIZE];
490
491 if (done)
492 return;
493
494 /* All fall through to do_early_param. */
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800495 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700496 parse_args("early options", tmp_cmdline, NULL, 0, do_early_param);
497 done = 1;
498}
499
500/*
501 * Activate the first processor.
502 */
503
Stas Sergeev44fd2292006-03-23 02:59:44 -0800504static void __init boot_cpu_init(void)
505{
506 int cpu = smp_processor_id();
507 /* Mark the boot cpu "present", "online" etc for SMP and UP case */
508 cpu_set(cpu, cpu_online_map);
509 cpu_set(cpu, cpu_present_map);
510 cpu_set(cpu, cpu_possible_map);
511}
512
Andrew Morton033ab7f2006-06-30 01:55:50 -0700513void __init __attribute__((weak)) smp_setup_processor_id(void)
514{
515}
516
Linus Torvalds1da177e2005-04-16 15:20:36 -0700517asmlinkage void __init start_kernel(void)
518{
519 char * command_line;
520 extern struct kernel_param __start___param[], __stop___param[];
Andrew Morton033ab7f2006-06-30 01:55:50 -0700521
522 smp_setup_processor_id();
523
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700524 /*
525 * Need to run as early as possible, to initialize the
526 * lockdep hash:
527 */
Andi Kleenc9538ed2006-09-26 10:52:34 +0200528 unwind_init();
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700529 lockdep_init();
Paul Menageddbcc7e2007-10-18 23:39:30 -0700530 cgroup_init_early();
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700531
532 local_irq_disable();
533 early_boot_irqs_off();
Ingo Molnar243c7622006-07-03 00:25:06 -0700534 early_init_irq_lock_class();
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700535
Linus Torvalds1da177e2005-04-16 15:20:36 -0700536/*
537 * Interrupts are still disabled. Do necessary setups, then
538 * enable them
539 */
540 lock_kernel();
Thomas Gleixner906568c2007-02-16 01:28:01 -0800541 tick_init();
Stas Sergeev44fd2292006-03-23 02:59:44 -0800542 boot_cpu_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700543 page_address_init();
544 printk(KERN_NOTICE);
Linus Torvalds89937802006-12-11 09:28:46 -0800545 printk(linux_banner);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700546 setup_arch(&command_line);
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800547 setup_command_line(command_line);
Jan Beulich690a9732006-10-21 18:37:01 +0200548 unwind_setup();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700549 setup_per_cpu_areas();
Stas Sergeev44fd2292006-03-23 02:59:44 -0800550 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700551
552 /*
553 * Set up the scheduler prior starting any interrupts (such as the
554 * timer interrupt). Full topology setup happens at smp_init()
555 * time - but meanwhile we still have a functioning scheduler.
556 */
557 sched_init();
558 /*
559 * Disable preemption - early bootup scheduling is extremely
560 * fragile until we cpu_idle() for the first time.
561 */
562 preempt_disable();
563 build_all_zonelists();
564 page_alloc_init();
Ingo Molnar12d6f212008-01-30 13:33:58 +0100565 enable_debug_pagealloc();
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800566 printk(KERN_NOTICE "Kernel command line: %s\n", boot_command_line);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700567 parse_early_param();
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800568 parse_args("Booting kernel", static_command_line, __start___param,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700569 __stop___param - __start___param,
570 &unknown_bootoption);
Ard van Breemenc4a68302007-01-05 16:36:19 -0800571 if (!irqs_disabled()) {
572 printk(KERN_WARNING "start_kernel(): bug: interrupts were "
573 "enabled *very* early, fixing it\n");
574 local_irq_disable();
575 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700576 sort_main_extable();
577 trap_init();
578 rcu_init();
579 init_IRQ();
580 pidhash_init();
581 init_timers();
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800582 hrtimers_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700583 softirq_init();
john stultzad596172006-06-26 00:25:06 -0700584 timekeeping_init();
john stultz88fecaa2006-07-03 00:24:04 -0700585 time_init();
Heiko Carstens93e02812006-07-03 00:24:24 -0700586 profile_init();
587 if (!irqs_disabled())
588 printk("start_kernel(): bug: interrupts were enabled early\n");
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700589 early_boot_irqs_on();
Heiko Carstens93e02812006-07-03 00:24:24 -0700590 local_irq_enable();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700591
592 /*
593 * HACK ALERT! This is early. We're enabling the console before
594 * we've done PCI setups etc, and console_init() must be aware of
595 * this. But we do want output early, in case something goes wrong.
596 */
597 console_init();
598 if (panic_later)
599 panic(panic_later, panic_param);
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700600
601 lockdep_info();
602
Ingo Molnar9a11b49a2006-07-03 00:24:33 -0700603 /*
604 * Need to run this when irqs are enabled, because it wants
605 * to self-test [hard/soft]-irqs on/off lock inversion bugs
606 * too:
607 */
608 locking_selftest();
609
Linus Torvalds1da177e2005-04-16 15:20:36 -0700610#ifdef CONFIG_BLK_DEV_INITRD
611 if (initrd_start && !initrd_below_start_ok &&
612 initrd_start < min_low_pfn << PAGE_SHIFT) {
613 printk(KERN_CRIT "initrd overwritten (0x%08lx < 0x%08lx) - "
614 "disabling it.\n",initrd_start,min_low_pfn << PAGE_SHIFT);
615 initrd_start = 0;
616 }
617#endif
618 vfs_caches_init_early();
Paul Jacksonc417f022006-01-08 01:02:01 -0800619 cpuset_init_early();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700620 mem_init();
Gautham R Shenoyd2219382008-01-25 21:08:01 +0100621 cpu_hotplug_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700622 kmem_cache_init();
Christoph Lametere7c8d5c2005-06-21 17:14:47 -0700623 setup_per_cpu_pageset();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700624 numa_policy_init();
625 if (late_time_init)
626 late_time_init();
627 calibrate_delay();
628 pidmap_init();
629 pgtable_cache_init();
630 prio_tree_init();
631 anon_vma_init();
632#ifdef CONFIG_X86
633 if (efi_enabled)
634 efi_enter_virtual_mode();
635#endif
636 fork_init(num_physpages);
637 proc_caches_init();
638 buffer_init();
639 unnamed_dev_init();
640 key_init();
641 security_init();
642 vfs_caches_init(num_physpages);
643 radix_tree_init();
644 signals_init();
645 /* rootfs populating might need page-writeback */
646 page_writeback_init();
647#ifdef CONFIG_PROC_FS
648 proc_root_init();
649#endif
Paul Menageddbcc7e2007-10-18 23:39:30 -0700650 cgroup_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700651 cpuset_init();
Shailabh Nagarc7572492006-07-14 00:24:40 -0700652 taskstats_init_early();
Shailabh Nagarca74e922006-07-14 00:24:36 -0700653 delayacct_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700654
655 check_bugs();
656
Markus Gaugusch71fc47a2008-02-05 00:04:06 +0100657 populate_rootfs(); /* For DSDT override from initramfs */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700658 acpi_early_init(); /* before LAPIC and SMP init */
659
660 /* Do the rest non-__init'ed, we're now alive */
661 rest_init();
662}
663
664static int __initdata initcall_debug;
665
666static int __init initcall_debug_setup(char *str)
667{
668 initcall_debug = 1;
669 return 1;
670}
671__setup("initcall_debug", initcall_debug_setup);
672
Linus Torvalds1da177e2005-04-16 15:20:36 -0700673extern initcall_t __initcall_start[], __initcall_end[];
674
675static void __init do_initcalls(void)
676{
677 initcall_t *call;
678 int count = preempt_count();
679
680 for (call = __initcall_start; call < __initcall_end; call++) {
Ingo Molnar8f0c45c2007-05-08 00:28:26 -0700681 ktime_t t0, t1, delta;
Andrew Mortonc1cda482006-03-25 03:07:15 -0800682 char *msg = NULL;
683 char msgbuf[40];
684 int result;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700685
686 if (initcall_debug) {
Andrew Mortonc1cda482006-03-25 03:07:15 -0800687 printk("Calling initcall 0x%p", *call);
688 print_fn_descriptor_symbol(": %s()",
689 (unsigned long) *call);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700690 printk("\n");
Ingo Molnar8f0c45c2007-05-08 00:28:26 -0700691 t0 = ktime_get();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700692 }
693
Andrew Mortonc1cda482006-03-25 03:07:15 -0800694 result = (*call)();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700695
Ingo Molnar8f0c45c2007-05-08 00:28:26 -0700696 if (initcall_debug) {
697 t1 = ktime_get();
698 delta = ktime_sub(t1, t0);
699
700 printk("initcall 0x%p", *call);
701 print_fn_descriptor_symbol(": %s()",
702 (unsigned long) *call);
703 printk(" returned %d.\n", result);
704
705 printk("initcall 0x%p ran for %Ld msecs: ",
706 *call, (unsigned long long)delta.tv64 >> 20);
707 print_fn_descriptor_symbol("%s()\n",
708 (unsigned long) *call);
709 }
710
Andrew Mortonf3a19cb2006-05-01 12:15:52 -0700711 if (result && result != -ENODEV && initcall_debug) {
Andrew Mortonc1cda482006-03-25 03:07:15 -0800712 sprintf(msgbuf, "error code %d", result);
713 msg = msgbuf;
714 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700715 if (preempt_count() != count) {
716 msg = "preemption imbalance";
717 preempt_count() = count;
718 }
719 if (irqs_disabled()) {
720 msg = "disabled interrupts";
721 local_irq_enable();
722 }
723 if (msg) {
Andrew Mortonc1cda482006-03-25 03:07:15 -0800724 printk(KERN_WARNING "initcall at 0x%p", *call);
725 print_fn_descriptor_symbol(": %s()",
726 (unsigned long) *call);
727 printk(": returned with %s\n", msg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700728 }
729 }
730
731 /* Make sure there is no pending stuff from the initcall sequence */
732 flush_scheduled_work();
733}
734
735/*
736 * Ok, the machine is now initialized. None of the devices
737 * have been touched yet, but the CPU subsystem is up and
738 * running, and memory and process management works.
739 *
740 * Now we can finally start doing some real work..
741 */
742static void __init do_basic_setup(void)
743{
744 /* drivers will send hotplug events */
745 init_workqueues();
746 usermodehelper_init();
747 driver_init();
Eric W. Biedermanb04c3af2007-02-14 00:33:57 -0800748 init_irq_proc();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700749 do_initcalls();
750}
751
Dave Jones97842212007-07-15 23:41:05 -0700752static int __initdata nosoftlockup;
753
754static int __init nosoftlockup_setup(char *str)
755{
756 nosoftlockup = 1;
757 return 1;
758}
759__setup("nosoftlockup", nosoftlockup_setup);
760
Vivek Goyal88d20322007-01-11 01:52:44 +0100761static void __init do_pre_smp_initcalls(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700762{
763 extern int spawn_ksoftirqd(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700764
765 migration_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700766 spawn_ksoftirqd();
Dave Jones97842212007-07-15 23:41:05 -0700767 if (!nosoftlockup)
768 spawn_softlockup_task();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700769}
770
771static void run_init_process(char *init_filename)
772{
773 argv_init[0] = init_filename;
Arnd Bergmann67608562006-10-02 02:18:26 -0700774 kernel_execve(init_filename, argv_init, envp_init);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700775}
776
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100777/* This is a non __init function. Force it to be noinline otherwise gcc
778 * makes it inline to init() and it becomes part of init.text section
779 */
780static int noinline init_post(void)
781{
782 free_initmem();
783 unlock_kernel();
784 mark_rodata_ro();
785 system_state = SYSTEM_RUNNING;
786 numa_default_policy();
787
788 if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
789 printk(KERN_WARNING "Warning: unable to open an initial console.\n");
790
791 (void) sys_dup(0);
792 (void) sys_dup(0);
793
794 if (ramdisk_execute_command) {
795 run_init_process(ramdisk_execute_command);
796 printk(KERN_WARNING "Failed to execute %s\n",
797 ramdisk_execute_command);
798 }
799
800 /*
801 * We try each of these until one succeeds.
802 *
803 * The Bourne shell can be used instead of init if we are
804 * trying to recover a really broken machine.
805 */
806 if (execute_command) {
807 run_init_process(execute_command);
808 printk(KERN_WARNING "Failed to execute %s. Attempting "
809 "defaults...\n", execute_command);
810 }
811 run_init_process("/sbin/init");
812 run_init_process("/etc/init");
813 run_init_process("/bin/init");
814 run_init_process("/bin/sh");
815
816 panic("No init found. Try passing init= option to kernel.");
817}
818
Sam Ravnborgaae5f662007-02-26 16:45:41 +0100819static int __init kernel_init(void * unused)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700820{
821 lock_kernel();
822 /*
823 * init can run on any cpu.
824 */
825 set_cpus_allowed(current, CPU_MASK_ALL);
826 /*
827 * Tell the world that we're going to be the grim
828 * reaper of innocent orphaned children.
829 *
830 * We don't want people to have to make incorrect
831 * assumptions about where in the task array this
832 * can be found.
833 */
Sukadev Bhattiprolu84d73782006-12-08 02:38:01 -0800834 init_pid_ns.child_reaper = current;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700835
Sukadev Bhattiprolu0e29b242007-05-10 22:23:01 -0700836 __set_special_pids(1, 1);
Cedric Le Goater9ec52092006-10-02 02:19:00 -0700837 cad_pid = task_pid(current);
838
Andi Kleenca74a6f2008-01-30 13:33:17 +0100839 smp_prepare_cpus(setup_max_cpus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700840
841 do_pre_smp_initcalls();
842
Linus Torvalds1da177e2005-04-16 15:20:36 -0700843 smp_init();
844 sched_init_smp();
845
846 cpuset_init_smp();
847
Linus Torvalds1da177e2005-04-16 15:20:36 -0700848 do_basic_setup();
849
850 /*
851 * check if there is an early userspace init. If yes, let it do all
852 * the work
853 */
Olof Johanssonffdfc402005-09-06 15:17:19 -0700854
855 if (!ramdisk_execute_command)
856 ramdisk_execute_command = "/init";
857
858 if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
859 ramdisk_execute_command = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700860 prepare_namespace();
Olof Johanssonffdfc402005-09-06 15:17:19 -0700861 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700862
863 /*
864 * Ok, we have completed the initial bootup, and
865 * we're essentially up and running. Get rid of the
866 * initmem segments and start the user-mode stuff..
867 */
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100868 init_post();
869 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700870}