blob: ddada7acf363c9b4dda58913a3080da6462e4b09 [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>
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -070055#include <linux/debugobjects.h>
Ingo Molnarfbb9ce952006-07-03 00:24:50 -070056#include <linux/lockdep.h>
Sukadev Bhattiprolu84d73782006-12-08 02:38:01 -080057#include <linux/pid_namespace.h>
Adrian Bunk1f217822006-12-19 13:01:28 -080058#include <linux/device.h>
Eric W. Biederman73c27992007-05-09 02:34:32 -070059#include <linux/kthread.h>
Adrian Bunke6fe6642007-11-09 22:39:39 +010060#include <linux/sched.h>
Adrian Bunka1c9eea2008-02-06 01:36:44 -080061#include <linux/signal.h>
Akinobu Mita199f0ca2008-04-29 01:03:13 -070062#include <linux/idr.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070063
64#include <asm/io.h>
65#include <asm/bugs.h>
66#include <asm/setup.h>
Andi Kleena9401992005-07-28 21:15:30 -070067#include <asm/sections.h>
Arjan van de Ven37b73c82006-01-06 00:12:01 -080068#include <asm/cacheflush.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070069
Linus Torvalds1da177e2005-04-16 15:20:36 -070070#ifdef CONFIG_X86_LOCAL_APIC
71#include <asm/smp.h>
72#endif
73
74/*
Coywolf Qi Hunt69c99ac2006-01-14 13:21:11 -080075 * This is one of the first .c files built. Error out early if we have compiler
76 * trouble.
Linus Torvalds1da177e2005-04-16 15:20:36 -070077 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070078
Andrew Mortonf1a60db2006-12-06 20:39:59 -080079#if __GNUC__ == 4 && __GNUC_MINOR__ == 1 && __GNUC_PATCHLEVEL__ == 0
80#warning gcc-4.1.0 is known to miscompile the kernel. A different compiler version is recommended.
81#endif
82
Sam Ravnborgaae5f662007-02-26 16:45:41 +010083static int kernel_init(void *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070084
85extern void init_IRQ(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070086extern void fork_init(unsigned long);
87extern void mca_init(void);
88extern void sbus_init(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070089extern void pidhash_init(void);
90extern void pidmap_init(void);
91extern void prio_tree_init(void);
92extern void radix_tree_init(void);
93extern void free_initmem(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070094#ifdef CONFIG_ACPI
95extern void acpi_early_init(void);
96#else
97static inline void acpi_early_init(void) { }
98#endif
Arjan van de Ven37b73c82006-01-06 00:12:01 -080099#ifndef CONFIG_DEBUG_RODATA
100static inline void mark_rodata_ro(void) { }
101#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102
103#ifdef CONFIG_TC
104extern void tc_init(void);
105#endif
106
107enum system_states system_state;
108EXPORT_SYMBOL(system_state);
109
110/*
111 * Boot command-line arguments
112 */
113#define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
114#define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
115
116extern void time_init(void);
117/* Default late time init is NULL. archs can override this later. */
118void (*late_time_init)(void);
119extern void softirq_init(void);
120
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800121/* Untouched command line saved by arch-specific code. */
122char __initdata boot_command_line[COMMAND_LINE_SIZE];
123/* Untouched saved command line (eg. for /proc) */
124char *saved_command_line;
125/* Command line for parameter parsing */
126static char *static_command_line;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127
128static char *execute_command;
Olof Johanssonffdfc402005-09-06 15:17:19 -0700129static char *ramdisk_execute_command;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130
Jan Beulich8b3b2952007-07-15 23:41:07 -0700131#ifdef CONFIG_SMP
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132/* Setup configured maximum number of CPUs to activate */
Andi Kleenca74a6f2008-01-30 13:33:17 +0100133unsigned int __initdata setup_max_cpus = NR_CPUS;
Vivek Goyal7e962872006-09-27 01:50:44 -0700134
135/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136 * Setup routine for controlling SMP activation
137 *
138 * Command-line option of "nosmp" or "maxcpus=0" will disable SMP
139 * activation entirely (the MPS table probe still happens, though).
140 *
141 * Command-line option of "maxcpus=<NUM>", where <NUM> is an integer
142 * greater than 0, limits the maximum number of CPUs activated in
143 * SMP mode to <NUM>.
144 */
Len Brown61ec7562007-08-16 03:34:22 -0400145#ifndef CONFIG_X86_IO_APIC
146static inline void disable_ioapic_setup(void) {};
147#endif
148
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149static int __init nosmp(char *str)
150{
Andi Kleenca74a6f2008-01-30 13:33:17 +0100151 setup_max_cpus = 0;
Len Brown61ec7562007-08-16 03:34:22 -0400152 disable_ioapic_setup();
Jan Beulich8b3b2952007-07-15 23:41:07 -0700153 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154}
155
Jan Beulich8b3b2952007-07-15 23:41:07 -0700156early_param("nosmp", nosmp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157
158static int __init maxcpus(char *str)
159{
Andi Kleenca74a6f2008-01-30 13:33:17 +0100160 get_option(&str, &setup_max_cpus);
161 if (setup_max_cpus == 0)
Len Brown61ec7562007-08-16 03:34:22 -0400162 disable_ioapic_setup();
163
164 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165}
166
Hugh Dickins81340972007-08-27 16:02:12 +0100167early_param("maxcpus", maxcpus);
Jan Beulich8b3b2952007-07-15 23:41:07 -0700168#else
Andi Kleenca74a6f2008-01-30 13:33:17 +0100169#define setup_max_cpus NR_CPUS
Jan Beulich8b3b2952007-07-15 23:41:07 -0700170#endif
171
172/*
173 * If set, this is an indication to the drivers that reset the underlying
174 * device before going ahead with the initialization otherwise driver might
175 * rely on the BIOS and skip the reset operation.
176 *
177 * This is useful if kernel is booting in an unreliable environment.
178 * For ex. kdump situaiton where previous kernel has crashed, BIOS has been
179 * skipped and devices will be in unknown state.
180 */
181unsigned int reset_devices;
182EXPORT_SYMBOL(reset_devices);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183
Vivek Goyal7e962872006-09-27 01:50:44 -0700184static int __init set_reset_devices(char *str)
185{
186 reset_devices = 1;
187 return 1;
188}
189
190__setup("reset_devices", set_reset_devices);
191
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192static char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
193char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
194static const char *panic_later, *panic_param;
195
196extern struct obs_kernel_param __setup_start[], __setup_end[];
197
198static int __init obsolete_checksetup(char *line)
199{
200 struct obs_kernel_param *p;
Rusty Russell33df0d12006-09-26 10:52:32 +0200201 int had_early_param = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202
203 p = __setup_start;
204 do {
205 int n = strlen(p->str);
206 if (!strncmp(line, p->str, n)) {
207 if (p->early) {
Rusty Russell33df0d12006-09-26 10:52:32 +0200208 /* Already done in parse_early_param?
209 * (Needs exact match on param part).
210 * Keep iterating, as we can have early
211 * params and __setups of same names 8( */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212 if (line[n] == '\0' || line[n] == '=')
Rusty Russell33df0d12006-09-26 10:52:32 +0200213 had_early_param = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214 } else if (!p->setup_func) {
215 printk(KERN_WARNING "Parameter %s is obsolete,"
216 " ignored\n", p->str);
217 return 1;
218 } else if (p->setup_func(line + n))
219 return 1;
220 }
221 p++;
222 } while (p < __setup_end);
Rusty Russell33df0d12006-09-26 10:52:32 +0200223
224 return had_early_param;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225}
226
227/*
228 * This should be approx 2 Bo*oMips to start (note initial shift), and will
229 * still work even if initially too large, it will just take slightly longer
230 */
231unsigned long loops_per_jiffy = (1<<12);
232
233EXPORT_SYMBOL(loops_per_jiffy);
234
235static int __init debug_kernel(char *str)
236{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237 console_loglevel = 10;
Yinghai Luf6f21c812008-02-08 04:21:58 -0800238 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239}
240
241static int __init quiet_kernel(char *str)
242{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243 console_loglevel = 4;
Yinghai Luf6f21c812008-02-08 04:21:58 -0800244 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245}
246
Yinghai Luf6f21c812008-02-08 04:21:58 -0800247early_param("debug", debug_kernel);
248early_param("quiet", quiet_kernel);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249
250static int __init loglevel(char *str)
251{
252 get_option(&str, &console_loglevel);
Alex Riesend9d4fcf2008-03-04 14:28:31 -0800253 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254}
255
Yinghai Luf6f21c812008-02-08 04:21:58 -0800256early_param("loglevel", loglevel);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257
258/*
259 * Unknown boot options get handed to init, unless they look like
260 * failed parameters
261 */
262static int __init unknown_bootoption(char *param, char *val)
263{
264 /* Change NUL term back to "=", to make "param" the whole string. */
265 if (val) {
266 /* param=val or param="val"? */
267 if (val == param+strlen(param)+1)
268 val[-1] = '=';
269 else if (val == param+strlen(param)+2) {
270 val[-2] = '=';
271 memmove(val-1, val, strlen(val)+1);
272 val--;
273 } else
274 BUG();
275 }
276
277 /* Handle obsolete-style parameters */
278 if (obsolete_checksetup(param))
279 return 0;
280
281 /*
Simon Arlott211fee82007-10-20 01:28:29 +0200282 * Preemptive maintenance for "why didn't my misspelled command
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283 * line work?"
284 */
285 if (strchr(param, '.') && (!val || strchr(param, '.') < val)) {
286 printk(KERN_ERR "Unknown boot option `%s': ignoring\n", param);
287 return 0;
288 }
289
290 if (panic_later)
291 return 0;
292
293 if (val) {
294 /* Environment option */
295 unsigned int i;
296 for (i = 0; envp_init[i]; i++) {
297 if (i == MAX_INIT_ENVS) {
298 panic_later = "Too many boot env vars at `%s'";
299 panic_param = param;
300 }
301 if (!strncmp(param, envp_init[i], val - param))
302 break;
303 }
304 envp_init[i] = param;
305 } else {
306 /* Command line option */
307 unsigned int i;
308 for (i = 0; argv_init[i]; i++) {
309 if (i == MAX_INIT_ARGS) {
310 panic_later = "Too many boot init vars at `%s'";
311 panic_param = param;
312 }
313 }
314 argv_init[i] = param;
315 }
316 return 0;
317}
318
Ingo Molnar12d6f212008-01-30 13:33:58 +0100319#ifdef CONFIG_DEBUG_PAGEALLOC
320int __read_mostly debug_pagealloc_enabled = 0;
321#endif
322
Linus Torvalds1da177e2005-04-16 15:20:36 -0700323static int __init init_setup(char *str)
324{
325 unsigned int i;
326
327 execute_command = str;
328 /*
329 * In case LILO is going to boot us with default command line,
330 * it prepends "auto" before the whole cmdline which makes
331 * the shell think it should execute a script with such name.
332 * So we ignore all arguments entered _before_ init=... [MJ]
333 */
334 for (i = 1; i < MAX_INIT_ARGS; i++)
335 argv_init[i] = NULL;
336 return 1;
337}
338__setup("init=", init_setup);
339
Olof Johanssonffdfc402005-09-06 15:17:19 -0700340static int __init rdinit_setup(char *str)
341{
342 unsigned int i;
343
344 ramdisk_execute_command = str;
345 /* See "auto" comment in init_setup */
346 for (i = 1; i < MAX_INIT_ARGS; i++)
347 argv_init[i] = NULL;
348 return 1;
349}
350__setup("rdinit=", rdinit_setup);
351
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352#ifndef CONFIG_SMP
353
354#ifdef CONFIG_X86_LOCAL_APIC
355static void __init smp_init(void)
356{
357 APIC_init_uniprocessor();
358}
359#else
360#define smp_init() do { } while (0)
361#endif
362
363static inline void setup_per_cpu_areas(void) { }
Mike Travise0982e92008-03-26 14:23:48 -0700364static inline void setup_nr_cpu_ids(void) { }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700365static inline void smp_prepare_cpus(unsigned int maxcpus) { }
366
367#else
368
Mike Travis321a8e92008-04-04 18:11:02 -0700369#if NR_CPUS > BITS_PER_LONG
370cpumask_t cpu_mask_all __read_mostly = CPU_MASK_ALL;
371EXPORT_SYMBOL(cpu_mask_all);
372#endif
373
Mike Travise0982e92008-03-26 14:23:48 -0700374/* Setup number of possible processor ids */
375int nr_cpu_ids __read_mostly = NR_CPUS;
376EXPORT_SYMBOL(nr_cpu_ids);
377
378/* An arch may set nr_cpu_ids earlier if needed, so this would be redundant */
379static void __init setup_nr_cpu_ids(void)
380{
381 int cpu, highest_cpu = 0;
382
383 for_each_possible_cpu(cpu)
384 highest_cpu = cpu;
385
386 nr_cpu_ids = highest_cpu + 1;
387}
388
Mike Travisdd5af902008-01-30 13:33:32 +0100389#ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA
Eric Dumazetb73b4592006-03-23 03:01:07 -0800390unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391
392EXPORT_SYMBOL(__per_cpu_offset);
393
394static void __init setup_per_cpu_areas(void)
395{
396 unsigned long size, i;
397 char *ptr;
Eric Dumazet63872f82006-03-23 03:01:04 -0800398 unsigned long nr_possible_cpus = num_possible_cpus();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700399
400 /* Copy section for each CPU (we discard the original) */
Jeremy Fitzhardingeb6e35902007-05-02 19:27:12 +0200401 size = ALIGN(PERCPU_ENOUGH_ROOM, PAGE_SIZE);
402 ptr = alloc_bootmem_pages(size * nr_possible_cpus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700403
KAMEZAWA Hiroyuki0a945022006-03-28 01:56:37 -0800404 for_each_possible_cpu(i) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700405 __per_cpu_offset[i] = ptr - __per_cpu_start;
406 memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start);
Eric Dumazet63872f82006-03-23 03:01:04 -0800407 ptr += size;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700408 }
409}
Mike Travisdd5af902008-01-30 13:33:32 +0100410#endif /* CONFIG_HAVE_SETUP_PER_CPU_AREA */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700411
412/* Called by boot processor to activate the rest. */
413static void __init smp_init(void)
414{
Christoph Lameter53b8a312007-02-20 13:57:51 -0800415 unsigned int cpu;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700416
417 /* FIXME: This should be done in userspace --RR */
Christoph Lameter53b8a312007-02-20 13:57:51 -0800418 for_each_present_cpu(cpu) {
Andi Kleenca74a6f2008-01-30 13:33:17 +0100419 if (num_online_cpus() >= setup_max_cpus)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700420 break;
Christoph Lameter53b8a312007-02-20 13:57:51 -0800421 if (!cpu_online(cpu))
422 cpu_up(cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700423 }
424
425 /* Any cleanup work */
426 printk(KERN_INFO "Brought up %ld CPUs\n", (long)num_online_cpus());
Andi Kleenca74a6f2008-01-30 13:33:17 +0100427 smp_cpus_done(setup_max_cpus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700428}
429
430#endif
431
432/*
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800433 * We need to store the untouched command line for future reference.
434 * We also need to store the touched command line since the parameter
435 * parsing is performed in place, and we should allow a component to
436 * store reference of name/value for future reference.
437 */
438static void __init setup_command_line(char *command_line)
439{
440 saved_command_line = alloc_bootmem(strlen (boot_command_line)+1);
441 static_command_line = alloc_bootmem(strlen (command_line)+1);
442 strcpy (saved_command_line, boot_command_line);
443 strcpy (static_command_line, command_line);
444}
445
446/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700447 * We need to finalize in a non-__init function or else race conditions
448 * between the root thread and the init thread may cause start_kernel to
449 * be reaped by free_initmem before the root thread has proceeded to
450 * cpu_idle.
451 *
452 * gcc-3.4 accidentally inlines this function, so use noinline.
453 */
454
Sam Ravnborg92080302007-05-17 20:43:54 +0200455static void noinline __init_refok rest_init(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700456 __releases(kernel_lock)
457{
Eric W. Biederman73c27992007-05-09 02:34:32 -0700458 int pid;
459
Sam Ravnborgaae5f662007-02-26 16:45:41 +0100460 kernel_thread(kernel_init, NULL, CLONE_FS | CLONE_SIGHAND);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700461 numa_default_policy();
Eric W. Biederman73c27992007-05-09 02:34:32 -0700462 pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
Pavel Emelyanov5cd20452008-04-30 00:54:24 -0700463 kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700464 unlock_kernel();
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200465
466 /*
467 * The boot idle thread must execute schedule()
Ingo Molnar1df21052007-07-09 18:51:58 +0200468 * at least once to get things moving:
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200469 */
Ingo Molnar1df21052007-07-09 18:51:58 +0200470 init_idle_bootup_task(current);
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800471 preempt_enable_no_resched();
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200472 schedule();
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800473 preempt_disable();
Ingo Molnarf340c0d2005-06-28 16:40:42 +0200474
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800475 /* Call into cpu_idle with preempt disabled */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700476 cpu_idle();
Ingo Molnar1df21052007-07-09 18:51:58 +0200477}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700478
479/* Check for early params. */
480static int __init do_early_param(char *param, char *val)
481{
482 struct obs_kernel_param *p;
483
484 for (p = __setup_start; p < __setup_end; p++) {
Yinghai Lu18a8bd92007-07-15 23:37:59 -0700485 if ((p->early && strcmp(param, p->str) == 0) ||
486 (strcmp(param, "console") == 0 &&
487 strcmp(p->str, "earlycon") == 0)
488 ) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700489 if (p->setup_func(val) != 0)
490 printk(KERN_WARNING
491 "Malformed early option '%s'\n", param);
492 }
493 }
494 /* We accept everything at this stage. */
495 return 0;
496}
497
498/* Arch code calls this early on, or if not, just before other parsing. */
499void __init parse_early_param(void)
500{
501 static __initdata int done = 0;
502 static __initdata char tmp_cmdline[COMMAND_LINE_SIZE];
503
504 if (done)
505 return;
506
507 /* All fall through to do_early_param. */
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800508 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700509 parse_args("early options", tmp_cmdline, NULL, 0, do_early_param);
510 done = 1;
511}
512
513/*
514 * Activate the first processor.
515 */
516
Stas Sergeev44fd2292006-03-23 02:59:44 -0800517static void __init boot_cpu_init(void)
518{
519 int cpu = smp_processor_id();
520 /* Mark the boot cpu "present", "online" etc for SMP and UP case */
521 cpu_set(cpu, cpu_online_map);
522 cpu_set(cpu, cpu_present_map);
523 cpu_set(cpu, cpu_possible_map);
524}
525
Benjamin Herrenschmidt839ad622008-04-18 16:56:18 +1000526void __init __weak smp_setup_processor_id(void)
Andrew Morton033ab7f2006-06-30 01:55:50 -0700527{
528}
529
Benjamin Herrenschmidt8c9843e2008-04-18 16:56:15 +1000530void __init __weak thread_info_cache_init(void)
531{
532}
533
Linus Torvalds1da177e2005-04-16 15:20:36 -0700534asmlinkage void __init start_kernel(void)
535{
536 char * command_line;
537 extern struct kernel_param __start___param[], __stop___param[];
Andrew Morton033ab7f2006-06-30 01:55:50 -0700538
539 smp_setup_processor_id();
540
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700541 /*
542 * Need to run as early as possible, to initialize the
543 * lockdep hash:
544 */
Andi Kleenc9538ed2006-09-26 10:52:34 +0200545 unwind_init();
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700546 lockdep_init();
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700547 debug_objects_early_init();
Paul Menageddbcc7e2007-10-18 23:39:30 -0700548 cgroup_init_early();
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700549
550 local_irq_disable();
551 early_boot_irqs_off();
Ingo Molnar243c7622006-07-03 00:25:06 -0700552 early_init_irq_lock_class();
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700553
Linus Torvalds1da177e2005-04-16 15:20:36 -0700554/*
555 * Interrupts are still disabled. Do necessary setups, then
556 * enable them
557 */
558 lock_kernel();
Thomas Gleixner906568c2007-02-16 01:28:01 -0800559 tick_init();
Stas Sergeev44fd2292006-03-23 02:59:44 -0800560 boot_cpu_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700561 page_address_init();
562 printk(KERN_NOTICE);
Linus Torvalds89937802006-12-11 09:28:46 -0800563 printk(linux_banner);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700564 setup_arch(&command_line);
Balbir Singhcf475ad2008-04-29 01:00:16 -0700565 mm_init_owner(&init_mm, &init_task);
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800566 setup_command_line(command_line);
Jan Beulich690a9732006-10-21 18:37:01 +0200567 unwind_setup();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700568 setup_per_cpu_areas();
Mike Travise0982e92008-03-26 14:23:48 -0700569 setup_nr_cpu_ids();
Stas Sergeev44fd2292006-03-23 02:59:44 -0800570 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700571
572 /*
573 * Set up the scheduler prior starting any interrupts (such as the
574 * timer interrupt). Full topology setup happens at smp_init()
575 * time - but meanwhile we still have a functioning scheduler.
576 */
577 sched_init();
578 /*
579 * Disable preemption - early bootup scheduling is extremely
580 * fragile until we cpu_idle() for the first time.
581 */
582 preempt_disable();
583 build_all_zonelists();
584 page_alloc_init();
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800585 printk(KERN_NOTICE "Kernel command line: %s\n", boot_command_line);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700586 parse_early_param();
Alon Bar-Lev30d7e0d2007-02-12 00:53:52 -0800587 parse_args("Booting kernel", static_command_line, __start___param,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700588 __stop___param - __start___param,
589 &unknown_bootoption);
Ard van Breemenc4a68302007-01-05 16:36:19 -0800590 if (!irqs_disabled()) {
591 printk(KERN_WARNING "start_kernel(): bug: interrupts were "
592 "enabled *very* early, fixing it\n");
593 local_irq_disable();
594 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700595 sort_main_extable();
596 trap_init();
597 rcu_init();
598 init_IRQ();
599 pidhash_init();
600 init_timers();
Thomas Gleixnerc0a31322006-01-09 20:52:32 -0800601 hrtimers_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700602 softirq_init();
john stultzad596172006-06-26 00:25:06 -0700603 timekeeping_init();
john stultz88fecaa2006-07-03 00:24:04 -0700604 time_init();
Peter Zijlstra3e51f332008-05-03 18:29:28 +0200605 sched_clock_init();
Heiko Carstens93e02812006-07-03 00:24:24 -0700606 profile_init();
607 if (!irqs_disabled())
608 printk("start_kernel(): bug: interrupts were enabled early\n");
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700609 early_boot_irqs_on();
Heiko Carstens93e02812006-07-03 00:24:24 -0700610 local_irq_enable();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700611
612 /*
613 * HACK ALERT! This is early. We're enabling the console before
614 * we've done PCI setups etc, and console_init() must be aware of
615 * this. But we do want output early, in case something goes wrong.
616 */
617 console_init();
618 if (panic_later)
619 panic(panic_later, panic_param);
Ingo Molnarfbb9ce952006-07-03 00:24:50 -0700620
621 lockdep_info();
622
Ingo Molnar9a11b49a2006-07-03 00:24:33 -0700623 /*
624 * Need to run this when irqs are enabled, because it wants
625 * to self-test [hard/soft]-irqs on/off lock inversion bugs
626 * too:
627 */
628 locking_selftest();
629
Linus Torvalds1da177e2005-04-16 15:20:36 -0700630#ifdef CONFIG_BLK_DEV_INITRD
631 if (initrd_start && !initrd_below_start_ok &&
632 initrd_start < min_low_pfn << PAGE_SHIFT) {
633 printk(KERN_CRIT "initrd overwritten (0x%08lx < 0x%08lx) - "
634 "disabling it.\n",initrd_start,min_low_pfn << PAGE_SHIFT);
635 initrd_start = 0;
636 }
637#endif
638 vfs_caches_init_early();
Paul Jacksonc417f022006-01-08 01:02:01 -0800639 cpuset_init_early();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700640 mem_init();
Thomas Gleixnera03c2a42008-02-09 23:24:09 +0100641 enable_debug_pagealloc();
Gautham R Shenoyd2219382008-01-25 21:08:01 +0100642 cpu_hotplug_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700643 kmem_cache_init();
Thomas Gleixner3ac7fe52008-04-30 00:55:01 -0700644 debug_objects_mem_init();
Akinobu Mita199f0ca2008-04-29 01:03:13 -0700645 idr_init_cache();
Christoph Lametere7c8d5c2005-06-21 17:14:47 -0700646 setup_per_cpu_pageset();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700647 numa_policy_init();
648 if (late_time_init)
649 late_time_init();
650 calibrate_delay();
651 pidmap_init();
652 pgtable_cache_init();
653 prio_tree_init();
654 anon_vma_init();
655#ifdef CONFIG_X86
656 if (efi_enabled)
657 efi_enter_virtual_mode();
658#endif
Benjamin Herrenschmidt8c9843e2008-04-18 16:56:15 +1000659 thread_info_cache_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700660 fork_init(num_physpages);
661 proc_caches_init();
662 buffer_init();
663 unnamed_dev_init();
664 key_init();
665 security_init();
666 vfs_caches_init(num_physpages);
667 radix_tree_init();
668 signals_init();
669 /* rootfs populating might need page-writeback */
670 page_writeback_init();
671#ifdef CONFIG_PROC_FS
672 proc_root_init();
673#endif
Paul Menageddbcc7e2007-10-18 23:39:30 -0700674 cgroup_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700675 cpuset_init();
Shailabh Nagarc7572492006-07-14 00:24:40 -0700676 taskstats_init_early();
Shailabh Nagarca74e922006-07-14 00:24:36 -0700677 delayacct_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700678
679 check_bugs();
680
681 acpi_early_init(); /* before LAPIC and SMP init */
682
683 /* Do the rest non-__init'ed, we're now alive */
684 rest_init();
685}
686
687static int __initdata initcall_debug;
688
689static int __init initcall_debug_setup(char *str)
690{
691 initcall_debug = 1;
692 return 1;
693}
694__setup("initcall_debug", initcall_debug_setup);
695
Linus Torvalds1da177e2005-04-16 15:20:36 -0700696extern initcall_t __initcall_start[], __initcall_end[];
697
698static void __init do_initcalls(void)
699{
700 initcall_t *call;
701 int count = preempt_count();
702
703 for (call = __initcall_start; call < __initcall_end; call++) {
Ingo Molnar8f0c45c2007-05-08 00:28:26 -0700704 ktime_t t0, t1, delta;
Andrew Mortonc1cda482006-03-25 03:07:15 -0800705 char *msg = NULL;
706 char msgbuf[40];
707 int result;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700708
709 if (initcall_debug) {
Bjorn Helgaas626adeb2008-04-29 00:59:10 -0700710 print_fn_descriptor_symbol("calling %s()\n",
Andrew Mortonc1cda482006-03-25 03:07:15 -0800711 (unsigned long) *call);
Ingo Molnar8f0c45c2007-05-08 00:28:26 -0700712 t0 = ktime_get();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700713 }
714
Andrew Mortonc1cda482006-03-25 03:07:15 -0800715 result = (*call)();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700716
Ingo Molnar8f0c45c2007-05-08 00:28:26 -0700717 if (initcall_debug) {
718 t1 = ktime_get();
719 delta = ktime_sub(t1, t0);
720
Bjorn Helgaas626adeb2008-04-29 00:59:10 -0700721 print_fn_descriptor_symbol("initcall %s()",
Ingo Molnar8f0c45c2007-05-08 00:28:26 -0700722 (unsigned long) *call);
Bjorn Helgaas626adeb2008-04-29 00:59:10 -0700723 printk(" returned %d after %Ld msecs\n", result,
724 (unsigned long long) delta.tv64 >> 20);
Ingo Molnar8f0c45c2007-05-08 00:28:26 -0700725 }
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) {
Bjorn Helgaas626adeb2008-04-29 00:59:10 -0700740 print_fn_descriptor_symbol(KERN_WARNING "initcall %s()",
Andrew Mortonc1cda482006-03-25 03:07:15 -0800741 (unsigned long) *call);
Bjorn Helgaas626adeb2008-04-29 00:59:10 -0700742 printk(" returned with %s\n", msg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700743 }
744 }
745
746 /* Make sure there is no pending stuff from the initcall sequence */
747 flush_scheduled_work();
748}
749
750/*
751 * Ok, the machine is now initialized. None of the devices
752 * have been touched yet, but the CPU subsystem is up and
753 * running, and memory and process management works.
754 *
755 * Now we can finally start doing some real work..
756 */
757static void __init do_basic_setup(void)
758{
759 /* drivers will send hotplug events */
760 init_workqueues();
761 usermodehelper_init();
762 driver_init();
Eric W. Biedermanb04c3af2007-02-14 00:33:57 -0800763 init_irq_proc();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700764 do_initcalls();
765}
766
Dave Jones97842212007-07-15 23:41:05 -0700767static int __initdata nosoftlockup;
768
769static int __init nosoftlockup_setup(char *str)
770{
771 nosoftlockup = 1;
772 return 1;
773}
774__setup("nosoftlockup", nosoftlockup_setup);
775
Vivek Goyal88d20322007-01-11 01:52:44 +0100776static void __init do_pre_smp_initcalls(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700777{
778 extern int spawn_ksoftirqd(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700779
780 migration_init();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700781 spawn_ksoftirqd();
Dave Jones97842212007-07-15 23:41:05 -0700782 if (!nosoftlockup)
783 spawn_softlockup_task();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700784}
785
786static void run_init_process(char *init_filename)
787{
788 argv_init[0] = init_filename;
Arnd Bergmann67608562006-10-02 02:18:26 -0700789 kernel_execve(init_filename, argv_init, envp_init);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700790}
791
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100792/* This is a non __init function. Force it to be noinline otherwise gcc
793 * makes it inline to init() and it becomes part of init.text section
794 */
795static int noinline init_post(void)
796{
797 free_initmem();
798 unlock_kernel();
799 mark_rodata_ro();
800 system_state = SYSTEM_RUNNING;
801 numa_default_policy();
802
803 if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
804 printk(KERN_WARNING "Warning: unable to open an initial console.\n");
805
806 (void) sys_dup(0);
807 (void) sys_dup(0);
808
Oleg Nesterovfae5fa42008-04-30 00:53:03 -0700809 current->signal->flags |= SIGNAL_UNKILLABLE;
810
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100811 if (ramdisk_execute_command) {
812 run_init_process(ramdisk_execute_command);
813 printk(KERN_WARNING "Failed to execute %s\n",
814 ramdisk_execute_command);
815 }
816
817 /*
818 * We try each of these until one succeeds.
819 *
820 * The Bourne shell can be used instead of init if we are
821 * trying to recover a really broken machine.
822 */
823 if (execute_command) {
824 run_init_process(execute_command);
825 printk(KERN_WARNING "Failed to execute %s. Attempting "
826 "defaults...\n", execute_command);
827 }
828 run_init_process("/sbin/init");
829 run_init_process("/etc/init");
830 run_init_process("/bin/init");
831 run_init_process("/bin/sh");
832
833 panic("No init found. Try passing init= option to kernel.");
834}
835
Sam Ravnborgaae5f662007-02-26 16:45:41 +0100836static int __init kernel_init(void * unused)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700837{
838 lock_kernel();
839 /*
840 * init can run on any cpu.
841 */
Mike Travis321a8e92008-04-04 18:11:02 -0700842 set_cpus_allowed_ptr(current, CPU_MASK_ALL_PTR);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700843 /*
844 * Tell the world that we're going to be the grim
845 * reaper of innocent orphaned children.
846 *
847 * We don't want people to have to make incorrect
848 * assumptions about where in the task array this
849 * can be found.
850 */
Sukadev Bhattiprolu84d73782006-12-08 02:38:01 -0800851 init_pid_ns.child_reaper = current;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700852
Cedric Le Goater9ec52092006-10-02 02:19:00 -0700853 cad_pid = task_pid(current);
854
Andi Kleenca74a6f2008-01-30 13:33:17 +0100855 smp_prepare_cpus(setup_max_cpus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700856
857 do_pre_smp_initcalls();
858
Linus Torvalds1da177e2005-04-16 15:20:36 -0700859 smp_init();
860 sched_init_smp();
861
862 cpuset_init_smp();
863
Linus Torvalds1da177e2005-04-16 15:20:36 -0700864 do_basic_setup();
865
866 /*
867 * check if there is an early userspace init. If yes, let it do all
868 * the work
869 */
Olof Johanssonffdfc402005-09-06 15:17:19 -0700870
871 if (!ramdisk_execute_command)
872 ramdisk_execute_command = "/init";
873
874 if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
875 ramdisk_execute_command = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700876 prepare_namespace();
Olof Johanssonffdfc402005-09-06 15:17:19 -0700877 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700878
879 /*
880 * Ok, we have completed the initial bootup, and
881 * we're essentially up and running. Get rid of the
882 * initmem segments and start the user-mode stuff..
883 */
Vivek Goyalee5bfa62007-02-13 13:26:22 +0100884 init_post();
885 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700886}