blob: 507c9fba03bb16d8c4d3f37699364a881741acd7 [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
105enum system_states system_state;
106EXPORT_SYMBOL(system_state);
107
108/*
109 * Boot command-line arguments
110 */
111#define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
112#define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
113
114extern void time_init(void);
115/* Default late time init is NULL. archs can override this later. */
116void (*late_time_init)(void);
117extern void softirq_init(void);
118
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800119/* Untouched command line saved by arch-specific code. */
120char __initdata boot_command_line[COMMAND_LINE_SIZE];
121/* Untouched saved command line (eg. for /proc) */
122char *saved_command_line;
123/* Command line for parameter parsing */
124static char *static_command_line;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125
126static char *execute_command;
Olof Johanssonffdfc402005-09-06 15:17:19 -0700127static char *ramdisk_execute_command;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128
Jan Beulich8b3b2952007-07-15 23:41:07 -0700129#ifdef CONFIG_SMP
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130/* Setup configured maximum number of CPUs to activate */
Andi Kleenca74a6f2008-01-30 13:33:17 +0100131unsigned int __initdata setup_max_cpus = NR_CPUS;
Vivek Goyal7e962872006-09-27 01:50:44 -0700132
133/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134 * Setup routine for controlling SMP activation
135 *
136 * Command-line option of "nosmp" or "maxcpus=0" will disable SMP
137 * activation entirely (the MPS table probe still happens, though).
138 *
139 * Command-line option of "maxcpus=<NUM>", where <NUM> is an integer
140 * greater than 0, limits the maximum number of CPUs activated in
141 * SMP mode to <NUM>.
142 */
Len Brown61ec7562007-08-16 03:34:22 -0400143#ifndef CONFIG_X86_IO_APIC
144static inline void disable_ioapic_setup(void) {};
145#endif
146
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147static int __init nosmp(char *str)
148{
Andi Kleenca74a6f2008-01-30 13:33:17 +0100149 setup_max_cpus = 0;
Len Brown61ec7562007-08-16 03:34:22 -0400150 disable_ioapic_setup();
Jan Beulich8b3b2952007-07-15 23:41:07 -0700151 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152}
153
Jan Beulich8b3b2952007-07-15 23:41:07 -0700154early_param("nosmp", nosmp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155
156static int __init maxcpus(char *str)
157{
Andi Kleenca74a6f2008-01-30 13:33:17 +0100158 get_option(&str, &setup_max_cpus);
159 if (setup_max_cpus == 0)
Len Brown61ec7562007-08-16 03:34:22 -0400160 disable_ioapic_setup();
161
162 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163}
164
Hugh Dickins81340972007-08-27 16:02:12 +0100165early_param("maxcpus", maxcpus);
Jan Beulich8b3b2952007-07-15 23:41:07 -0700166#else
Andi Kleenca74a6f2008-01-30 13:33:17 +0100167#define setup_max_cpus NR_CPUS
Jan Beulich8b3b2952007-07-15 23:41:07 -0700168#endif
169
170/*
171 * If set, this is an indication to the drivers that reset the underlying
172 * device before going ahead with the initialization otherwise driver might
173 * rely on the BIOS and skip the reset operation.
174 *
175 * This is useful if kernel is booting in an unreliable environment.
176 * For ex. kdump situaiton where previous kernel has crashed, BIOS has been
177 * skipped and devices will be in unknown state.
178 */
179unsigned int reset_devices;
180EXPORT_SYMBOL(reset_devices);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181
Vivek Goyal7e962872006-09-27 01:50:44 -0700182static int __init set_reset_devices(char *str)
183{
184 reset_devices = 1;
185 return 1;
186}
187
188__setup("reset_devices", set_reset_devices);
189
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190static char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
191char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
192static const char *panic_later, *panic_param;
193
194extern struct obs_kernel_param __setup_start[], __setup_end[];
195
196static int __init obsolete_checksetup(char *line)
197{
198 struct obs_kernel_param *p;
Rusty Russell33df0d12006-09-26 10:52:32 +0200199 int had_early_param = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200
201 p = __setup_start;
202 do {
203 int n = strlen(p->str);
204 if (!strncmp(line, p->str, n)) {
205 if (p->early) {
Rusty Russell33df0d12006-09-26 10:52:32 +0200206 /* Already done in parse_early_param?
207 * (Needs exact match on param part).
208 * Keep iterating, as we can have early
209 * params and __setups of same names 8( */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210 if (line[n] == '\0' || line[n] == '=')
Rusty Russell33df0d12006-09-26 10:52:32 +0200211 had_early_param = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212 } else if (!p->setup_func) {
213 printk(KERN_WARNING "Parameter %s is obsolete,"
214 " ignored\n", p->str);
215 return 1;
216 } else if (p->setup_func(line + n))
217 return 1;
218 }
219 p++;
220 } while (p < __setup_end);
Rusty Russell33df0d12006-09-26 10:52:32 +0200221
222 return had_early_param;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223}
224
225/*
226 * This should be approx 2 Bo*oMips to start (note initial shift), and will
227 * still work even if initially too large, it will just take slightly longer
228 */
229unsigned long loops_per_jiffy = (1<<12);
230
231EXPORT_SYMBOL(loops_per_jiffy);
232
233static int __init debug_kernel(char *str)
234{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235 console_loglevel = 10;
Yinghai Luf6f21c812008-02-08 04:21:58 -0800236 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237}
238
239static int __init quiet_kernel(char *str)
240{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241 console_loglevel = 4;
Yinghai Luf6f21c812008-02-08 04:21:58 -0800242 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243}
244
Yinghai Luf6f21c812008-02-08 04:21:58 -0800245early_param("debug", debug_kernel);
246early_param("quiet", quiet_kernel);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247
248static int __init loglevel(char *str)
249{
250 get_option(&str, &console_loglevel);
Alex Riesend9d4fcf2008-03-04 14:28:31 -0800251 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252}
253
Yinghai Luf6f21c812008-02-08 04:21:58 -0800254early_param("loglevel", loglevel);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255
256/*
257 * Unknown boot options get handed to init, unless they look like
258 * failed parameters
259 */
260static int __init unknown_bootoption(char *param, char *val)
261{
262 /* Change NUL term back to "=", to make "param" the whole string. */
263 if (val) {
264 /* param=val or param="val"? */
265 if (val == param+strlen(param)+1)
266 val[-1] = '=';
267 else if (val == param+strlen(param)+2) {
268 val[-2] = '=';
269 memmove(val-1, val, strlen(val)+1);
270 val--;
271 } else
272 BUG();
273 }
274
275 /* Handle obsolete-style parameters */
276 if (obsolete_checksetup(param))
277 return 0;
278
279 /*
Simon Arlott211fee82007-10-20 01:28:29 +0200280 * Preemptive maintenance for "why didn't my misspelled command
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281 * line work?"
282 */
283 if (strchr(param, '.') && (!val || strchr(param, '.') < val)) {
284 printk(KERN_ERR "Unknown boot option `%s': ignoring\n", param);
285 return 0;
286 }
287
288 if (panic_later)
289 return 0;
290
291 if (val) {
292 /* Environment option */
293 unsigned int i;
294 for (i = 0; envp_init[i]; i++) {
295 if (i == MAX_INIT_ENVS) {
296 panic_later = "Too many boot env vars at `%s'";
297 panic_param = param;
298 }
299 if (!strncmp(param, envp_init[i], val - param))
300 break;
301 }
302 envp_init[i] = param;
303 } else {
304 /* Command line option */
305 unsigned int i;
306 for (i = 0; argv_init[i]; i++) {
307 if (i == MAX_INIT_ARGS) {
308 panic_later = "Too many boot init vars at `%s'";
309 panic_param = param;
310 }
311 }
312 argv_init[i] = param;
313 }
314 return 0;
315}
316
Ingo Molnar12d6f212008-01-30 13:33:58 +0100317#ifdef CONFIG_DEBUG_PAGEALLOC
318int __read_mostly debug_pagealloc_enabled = 0;
319#endif
320
Linus Torvalds1da177e2005-04-16 15:20:36 -0700321static int __init init_setup(char *str)
322{
323 unsigned int i;
324
325 execute_command = str;
326 /*
327 * In case LILO is going to boot us with default command line,
328 * it prepends "auto" before the whole cmdline which makes
329 * the shell think it should execute a script with such name.
330 * So we ignore all arguments entered _before_ init=... [MJ]
331 */
332 for (i = 1; i < MAX_INIT_ARGS; i++)
333 argv_init[i] = NULL;
334 return 1;
335}
336__setup("init=", init_setup);
337
Olof Johanssonffdfc402005-09-06 15:17:19 -0700338static int __init rdinit_setup(char *str)
339{
340 unsigned int i;
341
342 ramdisk_execute_command = str;
343 /* See "auto" comment in init_setup */
344 for (i = 1; i < MAX_INIT_ARGS; i++)
345 argv_init[i] = NULL;
346 return 1;
347}
348__setup("rdinit=", rdinit_setup);
349
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350#ifndef CONFIG_SMP
351
352#ifdef CONFIG_X86_LOCAL_APIC
353static void __init smp_init(void)
354{
355 APIC_init_uniprocessor();
356}
357#else
358#define smp_init() do { } while (0)
359#endif
360
361static inline void setup_per_cpu_areas(void) { }
Mike Travise0982e92008-03-26 14:23:48 -0700362static inline void setup_nr_cpu_ids(void) { }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700363static inline void smp_prepare_cpus(unsigned int maxcpus) { }
364
365#else
366
Mike Travis321a8e92008-04-04 18:11:02 -0700367#if NR_CPUS > BITS_PER_LONG
368cpumask_t cpu_mask_all __read_mostly = CPU_MASK_ALL;
369EXPORT_SYMBOL(cpu_mask_all);
370#endif
371
Mike Travise0982e92008-03-26 14:23:48 -0700372/* Setup number of possible processor ids */
373int nr_cpu_ids __read_mostly = NR_CPUS;
374EXPORT_SYMBOL(nr_cpu_ids);
375
376/* An arch may set nr_cpu_ids earlier if needed, so this would be redundant */
377static void __init setup_nr_cpu_ids(void)
378{
379 int cpu, highest_cpu = 0;
380
381 for_each_possible_cpu(cpu)
382 highest_cpu = cpu;
383
384 nr_cpu_ids = highest_cpu + 1;
385}
386
Mike Travisdd5af902008-01-30 13:33:32 +0100387#ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA
Eric Dumazetb73b4592006-03-23 03:01:07 -0800388unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389
390EXPORT_SYMBOL(__per_cpu_offset);
391
392static void __init setup_per_cpu_areas(void)
393{
394 unsigned long size, i;
395 char *ptr;
Eric Dumazet63872f82006-03-23 03:01:04 -0800396 unsigned long nr_possible_cpus = num_possible_cpus();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700397
398 /* Copy section for each CPU (we discard the original) */
Jeremy Fitzhardingeb6e35902007-05-02 19:27:12 +0200399 size = ALIGN(PERCPU_ENOUGH_ROOM, PAGE_SIZE);
400 ptr = alloc_bootmem_pages(size * nr_possible_cpus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700401
KAMEZAWA Hiroyuki0a945022006-03-28 01:56:37 -0800402 for_each_possible_cpu(i) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700403 __per_cpu_offset[i] = ptr - __per_cpu_start;
404 memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start);
Eric Dumazet63872f82006-03-23 03:01:04 -0800405 ptr += size;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700406 }
407}
Mike Travisdd5af902008-01-30 13:33:32 +0100408#endif /* CONFIG_HAVE_SETUP_PER_CPU_AREA */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700409
410/* Called by boot processor to activate the rest. */
411static void __init smp_init(void)
412{
Christoph Lameter53b8a312007-02-20 13:57:51 -0800413 unsigned int cpu;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700414
415 /* FIXME: This should be done in userspace --RR */
Christoph Lameter53b8a312007-02-20 13:57:51 -0800416 for_each_present_cpu(cpu) {
Andi Kleenca74a6f2008-01-30 13:33:17 +0100417 if (num_online_cpus() >= setup_max_cpus)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700418 break;
Christoph Lameter53b8a312007-02-20 13:57:51 -0800419 if (!cpu_online(cpu))
420 cpu_up(cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700421 }
422
423 /* Any cleanup work */
424 printk(KERN_INFO "Brought up %ld CPUs\n", (long)num_online_cpus());
Andi Kleenca74a6f2008-01-30 13:33:17 +0100425 smp_cpus_done(setup_max_cpus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700426}
427
428#endif
429
430/*
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800431 * We need to store the untouched command line for future reference.
432 * We also need to store the touched command line since the parameter
433 * parsing is performed in place, and we should allow a component to
434 * store reference of name/value for future reference.
435 */
436static void __init setup_command_line(char *command_line)
437{
438 saved_command_line = alloc_bootmem(strlen (boot_command_line)+1);
439 static_command_line = alloc_bootmem(strlen (command_line)+1);
440 strcpy (saved_command_line, boot_command_line);
441 strcpy (static_command_line, command_line);
442}
443
444/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445 * We need to finalize in a non-__init function or else race conditions
446 * between the root thread and the init thread may cause start_kernel to
447 * be reaped by free_initmem before the root thread has proceeded to
448 * cpu_idle.
449 *
450 * gcc-3.4 accidentally inlines this function, so use noinline.
451 */
452
Sam Ravnborg92080302007-05-17 20:43:54 +0200453static void noinline __init_refok rest_init(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700454 __releases(kernel_lock)
455{
Eric W. Biederman73c27992007-05-09 02:34:32 -0700456 int pid;
457
Sam Ravnborgaae5f662007-02-26 16:45:41 +0100458 kernel_thread(kernel_init, NULL, CLONE_FS | CLONE_SIGHAND);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700459 numa_default_policy();
Eric W. Biederman73c27992007-05-09 02:34:32 -0700460 pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
461 kthreadd_task = find_task_by_pid(pid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700462 unlock_kernel();
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200463
464 /*
465 * The boot idle thread must execute schedule()
Ingo Molnar1df21052007-07-09 18:51:58 +0200466 * at least once to get things moving:
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200467 */
Ingo Molnar1df21052007-07-09 18:51:58 +0200468 init_idle_bootup_task(current);
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800469 preempt_enable_no_resched();
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200470 schedule();
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800471 preempt_disable();
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200472
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800473 /* Call into cpu_idle with preempt disabled */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700474 cpu_idle();
Ingo Molnar1df21052007-07-09 18:51:58 +0200475}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700476
477/* Check for early params. */
478static int __init do_early_param(char *param, char *val)
479{
480 struct obs_kernel_param *p;
481
482 for (p = __setup_start; p < __setup_end; p++) {
Yinghai Lu18a8bd92007-07-15 23:37:59 -0700483 if ((p->early && strcmp(param, p->str) == 0) ||
484 (strcmp(param, "console") == 0 &&
485 strcmp(p->str, "earlycon") == 0)
486 ) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700487 if (p->setup_func(val) != 0)
488 printk(KERN_WARNING
489 "Malformed early option '%s'\n", param);
490 }
491 }
492 /* We accept everything at this stage. */
493 return 0;
494}
495
496/* Arch code calls this early on, or if not, just before other parsing. */
497void __init parse_early_param(void)
498{
499 static __initdata int done = 0;
500 static __initdata char tmp_cmdline[COMMAND_LINE_SIZE];
501
502 if (done)
503 return;
504
505 /* All fall through to do_early_param. */
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800506 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700507 parse_args("early options", tmp_cmdline, NULL, 0, do_early_param);
508 done = 1;
509}
510
511/*
512 * Activate the first processor.
513 */
514
Stas Sergeev44fd2292006-03-23 02:59:44 -0800515static void __init boot_cpu_init(void)
516{
517 int cpu = smp_processor_id();
518 /* Mark the boot cpu "present", "online" etc for SMP and UP case */
519 cpu_set(cpu, cpu_online_map);
520 cpu_set(cpu, cpu_present_map);
521 cpu_set(cpu, cpu_possible_map);
522}
523
Andrew Morton033ab7f2006-06-30 01:55:50 -0700524void __init __attribute__((weak)) smp_setup_processor_id(void)
525{
526}
527
Benjamin Herrenschmidt8c9843e2008-04-18 16:56:15 +1000528void __init __weak thread_info_cache_init(void)
529{
530}
531
Linus Torvalds1da177e2005-04-16 15:20:36 -0700532asmlinkage void __init start_kernel(void)
533{
534 char * command_line;
535 extern struct kernel_param __start___param[], __stop___param[];
Andrew Morton033ab7f2006-06-30 01:55:50 -0700536
537 smp_setup_processor_id();
538
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700539 /*
540 * Need to run as early as possible, to initialize the
541 * lockdep hash:
542 */
Andi Kleenc9538ed2006-09-26 10:52:34 +0200543 unwind_init();
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700544 lockdep_init();
Paul Menageddbcc7e2007-10-18 23:39:30 -0700545 cgroup_init_early();
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700546
547 local_irq_disable();
548 early_boot_irqs_off();
Ingo Molnar243c7622006-07-03 00:25:06 -0700549 early_init_irq_lock_class();
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700550
Linus Torvalds1da177e2005-04-16 15:20:36 -0700551/*
552 * Interrupts are still disabled. Do necessary setups, then
553 * enable them
554 */
555 lock_kernel();
Thomas Gleixner906568c2007-02-16 01:28:01 -0800556 tick_init();
Stas Sergeev44fd2292006-03-23 02:59:44 -0800557 boot_cpu_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700558 page_address_init();
559 printk(KERN_NOTICE);
Linus Torvalds89937802006-12-11 09:28:46 -0800560 printk(linux_banner);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700561 setup_arch(&command_line);
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800562 setup_command_line(command_line);
Jan Beulich690a9732006-10-21 18:37:01 +0200563 unwind_setup();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700564 setup_per_cpu_areas();
Mike Travise0982e92008-03-26 14:23:48 -0700565 setup_nr_cpu_ids();
Stas Sergeev44fd2292006-03-23 02:59:44 -0800566 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700567
568 /*
569 * Set up the scheduler prior starting any interrupts (such as the
570 * timer interrupt). Full topology setup happens at smp_init()
571 * time - but meanwhile we still have a functioning scheduler.
572 */
573 sched_init();
574 /*
575 * Disable preemption - early bootup scheduling is extremely
576 * fragile until we cpu_idle() for the first time.
577 */
578 preempt_disable();
579 build_all_zonelists();
580 page_alloc_init();
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800581 printk(KERN_NOTICE "Kernel command line: %s\n", boot_command_line);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700582 parse_early_param();
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800583 parse_args("Booting kernel", static_command_line, __start___param,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700584 __stop___param - __start___param,
585 &unknown_bootoption);
Ard van Breemenc4a68302007-01-05 16:36:19 -0800586 if (!irqs_disabled()) {
587 printk(KERN_WARNING "start_kernel(): bug: interrupts were "
588 "enabled *very* early, fixing it\n");
589 local_irq_disable();
590 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700591 sort_main_extable();
592 trap_init();
593 rcu_init();
594 init_IRQ();
595 pidhash_init();
596 init_timers();
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800597 hrtimers_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700598 softirq_init();
john stultzad596172006-06-26 00:25:06 -0700599 timekeeping_init();
john stultz88fecaa2006-07-03 00:24:04 -0700600 time_init();
Heiko Carstens93e02812006-07-03 00:24:24 -0700601 profile_init();
602 if (!irqs_disabled())
603 printk("start_kernel(): bug: interrupts were enabled early\n");
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700604 early_boot_irqs_on();
Heiko Carstens93e02812006-07-03 00:24:24 -0700605 local_irq_enable();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700606
607 /*
608 * HACK ALERT! This is early. We're enabling the console before
609 * we've done PCI setups etc, and console_init() must be aware of
610 * this. But we do want output early, in case something goes wrong.
611 */
612 console_init();
613 if (panic_later)
614 panic(panic_later, panic_param);
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700615
616 lockdep_info();
617
Ingo Molnar9a11b49a2006-07-03 00:24:33 -0700618 /*
619 * Need to run this when irqs are enabled, because it wants
620 * to self-test [hard/soft]-irqs on/off lock inversion bugs
621 * too:
622 */
623 locking_selftest();
624
Linus Torvalds1da177e2005-04-16 15:20:36 -0700625#ifdef CONFIG_BLK_DEV_INITRD
626 if (initrd_start && !initrd_below_start_ok &&
627 initrd_start < min_low_pfn << PAGE_SHIFT) {
628 printk(KERN_CRIT "initrd overwritten (0x%08lx < 0x%08lx) - "
629 "disabling it.\n",initrd_start,min_low_pfn << PAGE_SHIFT);
630 initrd_start = 0;
631 }
632#endif
633 vfs_caches_init_early();
Paul Jacksonc417f022006-01-08 01:02:01 -0800634 cpuset_init_early();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700635 mem_init();
Thomas Gleixnera03c2a42008-02-09 23:24:09 +0100636 enable_debug_pagealloc();
Gautham R Shenoyd2219382008-01-25 21:08:01 +0100637 cpu_hotplug_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700638 kmem_cache_init();
Christoph Lametere7c8d5c2005-06-21 17:14:47 -0700639 setup_per_cpu_pageset();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700640 numa_policy_init();
641 if (late_time_init)
642 late_time_init();
643 calibrate_delay();
644 pidmap_init();
645 pgtable_cache_init();
646 prio_tree_init();
647 anon_vma_init();
648#ifdef CONFIG_X86
649 if (efi_enabled)
650 efi_enter_virtual_mode();
651#endif
Benjamin Herrenschmidt8c9843e2008-04-18 16:56:15 +1000652 thread_info_cache_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700653 fork_init(num_physpages);
654 proc_caches_init();
655 buffer_init();
656 unnamed_dev_init();
657 key_init();
658 security_init();
659 vfs_caches_init(num_physpages);
660 radix_tree_init();
661 signals_init();
662 /* rootfs populating might need page-writeback */
663 page_writeback_init();
664#ifdef CONFIG_PROC_FS
665 proc_root_init();
666#endif
Paul Menageddbcc7e2007-10-18 23:39:30 -0700667 cgroup_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700668 cpuset_init();
Shailabh Nagarc7572492006-07-14 00:24:40 -0700669 taskstats_init_early();
Shailabh Nagarca74e922006-07-14 00:24:36 -0700670 delayacct_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700671
672 check_bugs();
673
674 acpi_early_init(); /* before LAPIC and SMP init */
675
676 /* Do the rest non-__init'ed, we're now alive */
677 rest_init();
678}
679
680static int __initdata initcall_debug;
681
682static int __init initcall_debug_setup(char *str)
683{
684 initcall_debug = 1;
685 return 1;
686}
687__setup("initcall_debug", initcall_debug_setup);
688
Linus Torvalds1da177e2005-04-16 15:20:36 -0700689extern initcall_t __initcall_start[], __initcall_end[];
690
691static void __init do_initcalls(void)
692{
693 initcall_t *call;
694 int count = preempt_count();
695
696 for (call = __initcall_start; call < __initcall_end; call++) {
Ingo Molnar8f0c45c2007-05-08 00:28:26 -0700697 ktime_t t0, t1, delta;
Andrew Mortonc1cda482006-03-25 03:07:15 -0800698 char *msg = NULL;
699 char msgbuf[40];
700 int result;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700701
702 if (initcall_debug) {
Andrew Mortonc1cda482006-03-25 03:07:15 -0800703 printk("Calling initcall 0x%p", *call);
704 print_fn_descriptor_symbol(": %s()",
705 (unsigned long) *call);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700706 printk("\n");
Ingo Molnar8f0c45c2007-05-08 00:28:26 -0700707 t0 = ktime_get();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700708 }
709
Andrew Mortonc1cda482006-03-25 03:07:15 -0800710 result = (*call)();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700711
Ingo Molnar8f0c45c2007-05-08 00:28:26 -0700712 if (initcall_debug) {
713 t1 = ktime_get();
714 delta = ktime_sub(t1, t0);
715
716 printk("initcall 0x%p", *call);
717 print_fn_descriptor_symbol(": %s()",
718 (unsigned long) *call);
719 printk(" returned %d.\n", result);
720
721 printk("initcall 0x%p ran for %Ld msecs: ",
722 *call, (unsigned long long)delta.tv64 >> 20);
723 print_fn_descriptor_symbol("%s()\n",
724 (unsigned long) *call);
725 }
726
Andrew Mortonf3a19cb2006-05-01 12:15:52 -0700727 if (result && result != -ENODEV && initcall_debug) {
Andrew Mortonc1cda482006-03-25 03:07:15 -0800728 sprintf(msgbuf, "error code %d", result);
729 msg = msgbuf;
730 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700731 if (preempt_count() != count) {
732 msg = "preemption imbalance";
733 preempt_count() = count;
734 }
735 if (irqs_disabled()) {
736 msg = "disabled interrupts";
737 local_irq_enable();
738 }
739 if (msg) {
Andrew Mortonc1cda482006-03-25 03:07:15 -0800740 printk(KERN_WARNING "initcall at 0x%p", *call);
741 print_fn_descriptor_symbol(": %s()",
742 (unsigned long) *call);
743 printk(": returned with %s\n", msg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700744 }
745 }
746
747 /* Make sure there is no pending stuff from the initcall sequence */
748 flush_scheduled_work();
749}
750
751/*
752 * Ok, the machine is now initialized. None of the devices
753 * have been touched yet, but the CPU subsystem is up and
754 * running, and memory and process management works.
755 *
756 * Now we can finally start doing some real work..
757 */
758static void __init do_basic_setup(void)
759{
760 /* drivers will send hotplug events */
761 init_workqueues();
762 usermodehelper_init();
763 driver_init();
Eric W. Biedermanb04c3af2007-02-14 00:33:57 -0800764 init_irq_proc();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700765 do_initcalls();
766}
767
Dave Jones97842212007-07-15 23:41:05 -0700768static int __initdata nosoftlockup;
769
770static int __init nosoftlockup_setup(char *str)
771{
772 nosoftlockup = 1;
773 return 1;
774}
775__setup("nosoftlockup", nosoftlockup_setup);
776
Vivek Goyal88d20322007-01-11 01:52:44 +0100777static void __init do_pre_smp_initcalls(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700778{
779 extern int spawn_ksoftirqd(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700780
781 migration_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700782 spawn_ksoftirqd();
Dave Jones97842212007-07-15 23:41:05 -0700783 if (!nosoftlockup)
784 spawn_softlockup_task();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700785}
786
787static void run_init_process(char *init_filename)
788{
789 argv_init[0] = init_filename;
Arnd Bergmann67608562006-10-02 02:18:26 -0700790 kernel_execve(init_filename, argv_init, envp_init);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700791}
792
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100793/* This is a non __init function. Force it to be noinline otherwise gcc
794 * makes it inline to init() and it becomes part of init.text section
795 */
796static int noinline init_post(void)
797{
798 free_initmem();
799 unlock_kernel();
800 mark_rodata_ro();
801 system_state = SYSTEM_RUNNING;
802 numa_default_policy();
803
804 if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
805 printk(KERN_WARNING "Warning: unable to open an initial console.\n");
806
807 (void) sys_dup(0);
808 (void) sys_dup(0);
809
810 if (ramdisk_execute_command) {
811 run_init_process(ramdisk_execute_command);
812 printk(KERN_WARNING "Failed to execute %s\n",
813 ramdisk_execute_command);
814 }
815
816 /*
817 * We try each of these until one succeeds.
818 *
819 * The Bourne shell can be used instead of init if we are
820 * trying to recover a really broken machine.
821 */
822 if (execute_command) {
823 run_init_process(execute_command);
824 printk(KERN_WARNING "Failed to execute %s. Attempting "
825 "defaults...\n", execute_command);
826 }
827 run_init_process("/sbin/init");
828 run_init_process("/etc/init");
829 run_init_process("/bin/init");
830 run_init_process("/bin/sh");
831
832 panic("No init found. Try passing init= option to kernel.");
833}
834
Sam Ravnborgaae5f662007-02-26 16:45:41 +0100835static int __init kernel_init(void * unused)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700836{
837 lock_kernel();
838 /*
839 * init can run on any cpu.
840 */
Mike Travis321a8e92008-04-04 18:11:02 -0700841 set_cpus_allowed_ptr(current, CPU_MASK_ALL_PTR);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700842 /*
843 * Tell the world that we're going to be the grim
844 * reaper of innocent orphaned children.
845 *
846 * We don't want people to have to make incorrect
847 * assumptions about where in the task array this
848 * can be found.
849 */
Sukadev Bhattiprolu84d73782006-12-08 02:38:01 -0800850 init_pid_ns.child_reaper = current;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700851
Cedric Le Goater9ec52092006-10-02 02:19:00 -0700852 cad_pid = task_pid(current);
853
Andi Kleenca74a6f2008-01-30 13:33:17 +0100854 smp_prepare_cpus(setup_max_cpus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700855
856 do_pre_smp_initcalls();
857
Linus Torvalds1da177e2005-04-16 15:20:36 -0700858 smp_init();
859 sched_init_smp();
860
861 cpuset_init_smp();
862
Linus Torvalds1da177e2005-04-16 15:20:36 -0700863 do_basic_setup();
864
865 /*
866 * check if there is an early userspace init. If yes, let it do all
867 * the work
868 */
Olof Johanssonffdfc402005-09-06 15:17:19 -0700869
870 if (!ramdisk_execute_command)
871 ramdisk_execute_command = "/init";
872
873 if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
874 ramdisk_execute_command = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700875 prepare_namespace();
Olof Johanssonffdfc402005-09-06 15:17:19 -0700876 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700877
878 /*
879 * Ok, we have completed the initial bootup, and
880 * we're essentially up and running. Get rid of the
881 * initmem segments and start the user-mode stuff..
882 */
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100883 init_post();
884 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700885}