Commit | Line | Data |
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1da177e4 LT |
1 | /* |
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 | ||
12 | #define __KERNEL_SYSCALLS__ | |
13 | ||
14 | #include <linux/config.h> | |
15 | #include <linux/types.h> | |
16 | #include <linux/module.h> | |
17 | #include <linux/proc_fs.h> | |
18 | #include <linux/devfs_fs_kernel.h> | |
19 | #include <linux/kernel.h> | |
20 | #include <linux/syscalls.h> | |
21 | #include <linux/string.h> | |
22 | #include <linux/ctype.h> | |
23 | #include <linux/delay.h> | |
24 | #include <linux/utsname.h> | |
25 | #include <linux/ioport.h> | |
26 | #include <linux/init.h> | |
27 | #include <linux/smp_lock.h> | |
28 | #include <linux/initrd.h> | |
29 | #include <linux/hdreg.h> | |
30 | #include <linux/bootmem.h> | |
31 | #include <linux/tty.h> | |
32 | #include <linux/gfp.h> | |
33 | #include <linux/percpu.h> | |
34 | #include <linux/kmod.h> | |
35 | #include <linux/kernel_stat.h> | |
36 | #include <linux/security.h> | |
37 | #include <linux/workqueue.h> | |
38 | #include <linux/profile.h> | |
39 | #include <linux/rcupdate.h> | |
40 | #include <linux/moduleparam.h> | |
41 | #include <linux/kallsyms.h> | |
42 | #include <linux/writeback.h> | |
43 | #include <linux/cpu.h> | |
44 | #include <linux/cpuset.h> | |
45 | #include <linux/efi.h> | |
46 | #include <linux/unistd.h> | |
47 | #include <linux/rmap.h> | |
48 | #include <linux/mempolicy.h> | |
49 | #include <linux/key.h> | |
50 | ||
51 | #include <asm/io.h> | |
52 | #include <asm/bugs.h> | |
53 | #include <asm/setup.h> | |
54 | ||
55 | /* | |
56 | * This is one of the first .c files built. Error out early | |
57 | * if we have compiler trouble.. | |
58 | */ | |
59 | #if __GNUC__ == 2 && __GNUC_MINOR__ == 96 | |
60 | #ifdef CONFIG_FRAME_POINTER | |
61 | #error This compiler cannot compile correctly with frame pointers enabled | |
62 | #endif | |
63 | #endif | |
64 | ||
65 | #ifdef CONFIG_X86_LOCAL_APIC | |
66 | #include <asm/smp.h> | |
67 | #endif | |
68 | ||
69 | /* | |
70 | * Versions of gcc older than that listed below may actually compile | |
71 | * and link okay, but the end product can have subtle run time bugs. | |
72 | * To avoid associated bogus bug reports, we flatly refuse to compile | |
73 | * with a gcc that is known to be too old from the very beginning. | |
74 | */ | |
75 | #if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 95) | |
76 | #error Sorry, your GCC is too old. It builds incorrect kernels. | |
77 | #endif | |
78 | ||
79 | static int init(void *); | |
80 | ||
81 | extern void init_IRQ(void); | |
82 | extern void sock_init(void); | |
83 | extern void fork_init(unsigned long); | |
84 | extern void mca_init(void); | |
85 | extern void sbus_init(void); | |
86 | extern void sysctl_init(void); | |
87 | extern void signals_init(void); | |
88 | extern void buffer_init(void); | |
89 | extern void pidhash_init(void); | |
90 | extern void pidmap_init(void); | |
91 | extern void prio_tree_init(void); | |
92 | extern void radix_tree_init(void); | |
93 | extern void free_initmem(void); | |
94 | extern void populate_rootfs(void); | |
95 | extern void driver_init(void); | |
96 | extern void prepare_namespace(void); | |
97 | #ifdef CONFIG_ACPI | |
98 | extern void acpi_early_init(void); | |
99 | #else | |
100 | static inline void acpi_early_init(void) { } | |
101 | #endif | |
102 | ||
103 | #ifdef CONFIG_TC | |
104 | extern void tc_init(void); | |
105 | #endif | |
106 | ||
107 | enum system_states system_state; | |
108 | EXPORT_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 | ||
116 | extern void time_init(void); | |
117 | /* Default late time init is NULL. archs can override this later. */ | |
118 | void (*late_time_init)(void); | |
119 | extern void softirq_init(void); | |
120 | ||
121 | /* Untouched command line (eg. for /proc) saved by arch-specific code. */ | |
122 | char saved_command_line[COMMAND_LINE_SIZE]; | |
123 | ||
124 | static char *execute_command; | |
125 | ||
126 | /* Setup configured maximum number of CPUs to activate */ | |
127 | static unsigned int max_cpus = NR_CPUS; | |
128 | ||
129 | /* | |
130 | * Setup routine for controlling SMP activation | |
131 | * | |
132 | * Command-line option of "nosmp" or "maxcpus=0" will disable SMP | |
133 | * activation entirely (the MPS table probe still happens, though). | |
134 | * | |
135 | * Command-line option of "maxcpus=<NUM>", where <NUM> is an integer | |
136 | * greater than 0, limits the maximum number of CPUs activated in | |
137 | * SMP mode to <NUM>. | |
138 | */ | |
139 | static int __init nosmp(char *str) | |
140 | { | |
141 | max_cpus = 0; | |
142 | return 1; | |
143 | } | |
144 | ||
145 | __setup("nosmp", nosmp); | |
146 | ||
147 | static int __init maxcpus(char *str) | |
148 | { | |
149 | get_option(&str, &max_cpus); | |
150 | return 1; | |
151 | } | |
152 | ||
153 | __setup("maxcpus=", maxcpus); | |
154 | ||
155 | static char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, }; | |
156 | char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, }; | |
157 | static const char *panic_later, *panic_param; | |
158 | ||
159 | extern struct obs_kernel_param __setup_start[], __setup_end[]; | |
160 | ||
161 | static int __init obsolete_checksetup(char *line) | |
162 | { | |
163 | struct obs_kernel_param *p; | |
164 | ||
165 | p = __setup_start; | |
166 | do { | |
167 | int n = strlen(p->str); | |
168 | if (!strncmp(line, p->str, n)) { | |
169 | if (p->early) { | |
170 | /* Already done in parse_early_param? (Needs | |
171 | * exact match on param part) */ | |
172 | if (line[n] == '\0' || line[n] == '=') | |
173 | return 1; | |
174 | } else if (!p->setup_func) { | |
175 | printk(KERN_WARNING "Parameter %s is obsolete," | |
176 | " ignored\n", p->str); | |
177 | return 1; | |
178 | } else if (p->setup_func(line + n)) | |
179 | return 1; | |
180 | } | |
181 | p++; | |
182 | } while (p < __setup_end); | |
183 | return 0; | |
184 | } | |
185 | ||
186 | /* | |
187 | * This should be approx 2 Bo*oMips to start (note initial shift), and will | |
188 | * still work even if initially too large, it will just take slightly longer | |
189 | */ | |
190 | unsigned long loops_per_jiffy = (1<<12); | |
191 | ||
192 | EXPORT_SYMBOL(loops_per_jiffy); | |
193 | ||
194 | static int __init debug_kernel(char *str) | |
195 | { | |
196 | if (*str) | |
197 | return 0; | |
198 | console_loglevel = 10; | |
199 | return 1; | |
200 | } | |
201 | ||
202 | static int __init quiet_kernel(char *str) | |
203 | { | |
204 | if (*str) | |
205 | return 0; | |
206 | console_loglevel = 4; | |
207 | return 1; | |
208 | } | |
209 | ||
210 | __setup("debug", debug_kernel); | |
211 | __setup("quiet", quiet_kernel); | |
212 | ||
213 | static int __init loglevel(char *str) | |
214 | { | |
215 | get_option(&str, &console_loglevel); | |
216 | return 1; | |
217 | } | |
218 | ||
219 | __setup("loglevel=", loglevel); | |
220 | ||
221 | /* | |
222 | * Unknown boot options get handed to init, unless they look like | |
223 | * failed parameters | |
224 | */ | |
225 | static int __init unknown_bootoption(char *param, char *val) | |
226 | { | |
227 | /* Change NUL term back to "=", to make "param" the whole string. */ | |
228 | if (val) { | |
229 | /* param=val or param="val"? */ | |
230 | if (val == param+strlen(param)+1) | |
231 | val[-1] = '='; | |
232 | else if (val == param+strlen(param)+2) { | |
233 | val[-2] = '='; | |
234 | memmove(val-1, val, strlen(val)+1); | |
235 | val--; | |
236 | } else | |
237 | BUG(); | |
238 | } | |
239 | ||
240 | /* Handle obsolete-style parameters */ | |
241 | if (obsolete_checksetup(param)) | |
242 | return 0; | |
243 | ||
244 | /* | |
245 | * Preemptive maintenance for "why didn't my mispelled command | |
246 | * line work?" | |
247 | */ | |
248 | if (strchr(param, '.') && (!val || strchr(param, '.') < val)) { | |
249 | printk(KERN_ERR "Unknown boot option `%s': ignoring\n", param); | |
250 | return 0; | |
251 | } | |
252 | ||
253 | if (panic_later) | |
254 | return 0; | |
255 | ||
256 | if (val) { | |
257 | /* Environment option */ | |
258 | unsigned int i; | |
259 | for (i = 0; envp_init[i]; i++) { | |
260 | if (i == MAX_INIT_ENVS) { | |
261 | panic_later = "Too many boot env vars at `%s'"; | |
262 | panic_param = param; | |
263 | } | |
264 | if (!strncmp(param, envp_init[i], val - param)) | |
265 | break; | |
266 | } | |
267 | envp_init[i] = param; | |
268 | } else { | |
269 | /* Command line option */ | |
270 | unsigned int i; | |
271 | for (i = 0; argv_init[i]; i++) { | |
272 | if (i == MAX_INIT_ARGS) { | |
273 | panic_later = "Too many boot init vars at `%s'"; | |
274 | panic_param = param; | |
275 | } | |
276 | } | |
277 | argv_init[i] = param; | |
278 | } | |
279 | return 0; | |
280 | } | |
281 | ||
282 | static int __init init_setup(char *str) | |
283 | { | |
284 | unsigned int i; | |
285 | ||
286 | execute_command = str; | |
287 | /* | |
288 | * In case LILO is going to boot us with default command line, | |
289 | * it prepends "auto" before the whole cmdline which makes | |
290 | * the shell think it should execute a script with such name. | |
291 | * So we ignore all arguments entered _before_ init=... [MJ] | |
292 | */ | |
293 | for (i = 1; i < MAX_INIT_ARGS; i++) | |
294 | argv_init[i] = NULL; | |
295 | return 1; | |
296 | } | |
297 | __setup("init=", init_setup); | |
298 | ||
299 | extern void setup_arch(char **); | |
300 | ||
301 | #ifndef CONFIG_SMP | |
302 | ||
303 | #ifdef CONFIG_X86_LOCAL_APIC | |
304 | static void __init smp_init(void) | |
305 | { | |
306 | APIC_init_uniprocessor(); | |
307 | } | |
308 | #else | |
309 | #define smp_init() do { } while (0) | |
310 | #endif | |
311 | ||
312 | static inline void setup_per_cpu_areas(void) { } | |
313 | static inline void smp_prepare_cpus(unsigned int maxcpus) { } | |
314 | ||
315 | #else | |
316 | ||
317 | #ifdef __GENERIC_PER_CPU | |
318 | unsigned long __per_cpu_offset[NR_CPUS]; | |
319 | ||
320 | EXPORT_SYMBOL(__per_cpu_offset); | |
321 | ||
322 | static void __init setup_per_cpu_areas(void) | |
323 | { | |
324 | unsigned long size, i; | |
325 | char *ptr; | |
326 | /* Created by linker magic */ | |
327 | extern char __per_cpu_start[], __per_cpu_end[]; | |
328 | ||
329 | /* Copy section for each CPU (we discard the original) */ | |
330 | size = ALIGN(__per_cpu_end - __per_cpu_start, SMP_CACHE_BYTES); | |
331 | #ifdef CONFIG_MODULES | |
332 | if (size < PERCPU_ENOUGH_ROOM) | |
333 | size = PERCPU_ENOUGH_ROOM; | |
334 | #endif | |
335 | ||
336 | ptr = alloc_bootmem(size * NR_CPUS); | |
337 | ||
338 | for (i = 0; i < NR_CPUS; i++, ptr += size) { | |
339 | __per_cpu_offset[i] = ptr - __per_cpu_start; | |
340 | memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start); | |
341 | } | |
342 | } | |
343 | #endif /* !__GENERIC_PER_CPU */ | |
344 | ||
345 | /* Called by boot processor to activate the rest. */ | |
346 | static void __init smp_init(void) | |
347 | { | |
348 | unsigned int i; | |
349 | ||
350 | /* FIXME: This should be done in userspace --RR */ | |
351 | for_each_present_cpu(i) { | |
352 | if (num_online_cpus() >= max_cpus) | |
353 | break; | |
354 | if (!cpu_online(i)) | |
355 | cpu_up(i); | |
356 | } | |
357 | ||
358 | /* Any cleanup work */ | |
359 | printk(KERN_INFO "Brought up %ld CPUs\n", (long)num_online_cpus()); | |
360 | smp_cpus_done(max_cpus); | |
361 | #if 0 | |
362 | /* Get other processors into their bootup holding patterns. */ | |
363 | ||
364 | smp_commence(); | |
365 | #endif | |
366 | } | |
367 | ||
368 | #endif | |
369 | ||
370 | /* | |
371 | * We need to finalize in a non-__init function or else race conditions | |
372 | * between the root thread and the init thread may cause start_kernel to | |
373 | * be reaped by free_initmem before the root thread has proceeded to | |
374 | * cpu_idle. | |
375 | * | |
376 | * gcc-3.4 accidentally inlines this function, so use noinline. | |
377 | */ | |
378 | ||
379 | static void noinline rest_init(void) | |
380 | __releases(kernel_lock) | |
381 | { | |
382 | kernel_thread(init, NULL, CLONE_FS | CLONE_SIGHAND); | |
383 | numa_default_policy(); | |
384 | unlock_kernel(); | |
385 | preempt_enable_no_resched(); | |
386 | cpu_idle(); | |
387 | } | |
388 | ||
389 | /* Check for early params. */ | |
390 | static int __init do_early_param(char *param, char *val) | |
391 | { | |
392 | struct obs_kernel_param *p; | |
393 | ||
394 | for (p = __setup_start; p < __setup_end; p++) { | |
395 | if (p->early && strcmp(param, p->str) == 0) { | |
396 | if (p->setup_func(val) != 0) | |
397 | printk(KERN_WARNING | |
398 | "Malformed early option '%s'\n", param); | |
399 | } | |
400 | } | |
401 | /* We accept everything at this stage. */ | |
402 | return 0; | |
403 | } | |
404 | ||
405 | /* Arch code calls this early on, or if not, just before other parsing. */ | |
406 | void __init parse_early_param(void) | |
407 | { | |
408 | static __initdata int done = 0; | |
409 | static __initdata char tmp_cmdline[COMMAND_LINE_SIZE]; | |
410 | ||
411 | if (done) | |
412 | return; | |
413 | ||
414 | /* All fall through to do_early_param. */ | |
415 | strlcpy(tmp_cmdline, saved_command_line, COMMAND_LINE_SIZE); | |
416 | parse_args("early options", tmp_cmdline, NULL, 0, do_early_param); | |
417 | done = 1; | |
418 | } | |
419 | ||
420 | /* | |
421 | * Activate the first processor. | |
422 | */ | |
423 | ||
424 | asmlinkage void __init start_kernel(void) | |
425 | { | |
426 | char * command_line; | |
427 | extern struct kernel_param __start___param[], __stop___param[]; | |
428 | /* | |
429 | * Interrupts are still disabled. Do necessary setups, then | |
430 | * enable them | |
431 | */ | |
432 | lock_kernel(); | |
433 | page_address_init(); | |
434 | printk(KERN_NOTICE); | |
435 | printk(linux_banner); | |
436 | setup_arch(&command_line); | |
437 | setup_per_cpu_areas(); | |
438 | ||
439 | /* | |
440 | * Mark the boot cpu "online" so that it can call console drivers in | |
441 | * printk() and can access its per-cpu storage. | |
442 | */ | |
443 | smp_prepare_boot_cpu(); | |
444 | ||
445 | /* | |
446 | * Set up the scheduler prior starting any interrupts (such as the | |
447 | * timer interrupt). Full topology setup happens at smp_init() | |
448 | * time - but meanwhile we still have a functioning scheduler. | |
449 | */ | |
450 | sched_init(); | |
451 | /* | |
452 | * Disable preemption - early bootup scheduling is extremely | |
453 | * fragile until we cpu_idle() for the first time. | |
454 | */ | |
455 | preempt_disable(); | |
456 | build_all_zonelists(); | |
457 | page_alloc_init(); | |
458 | printk(KERN_NOTICE "Kernel command line: %s\n", saved_command_line); | |
459 | parse_early_param(); | |
460 | parse_args("Booting kernel", command_line, __start___param, | |
461 | __stop___param - __start___param, | |
462 | &unknown_bootoption); | |
463 | sort_main_extable(); | |
464 | trap_init(); | |
465 | rcu_init(); | |
466 | init_IRQ(); | |
467 | pidhash_init(); | |
468 | init_timers(); | |
469 | softirq_init(); | |
470 | time_init(); | |
471 | ||
472 | /* | |
473 | * HACK ALERT! This is early. We're enabling the console before | |
474 | * we've done PCI setups etc, and console_init() must be aware of | |
475 | * this. But we do want output early, in case something goes wrong. | |
476 | */ | |
477 | console_init(); | |
478 | if (panic_later) | |
479 | panic(panic_later, panic_param); | |
480 | profile_init(); | |
481 | local_irq_enable(); | |
482 | #ifdef CONFIG_BLK_DEV_INITRD | |
483 | if (initrd_start && !initrd_below_start_ok && | |
484 | initrd_start < min_low_pfn << PAGE_SHIFT) { | |
485 | printk(KERN_CRIT "initrd overwritten (0x%08lx < 0x%08lx) - " | |
486 | "disabling it.\n",initrd_start,min_low_pfn << PAGE_SHIFT); | |
487 | initrd_start = 0; | |
488 | } | |
489 | #endif | |
490 | vfs_caches_init_early(); | |
491 | mem_init(); | |
492 | kmem_cache_init(); | |
493 | numa_policy_init(); | |
494 | if (late_time_init) | |
495 | late_time_init(); | |
496 | calibrate_delay(); | |
497 | pidmap_init(); | |
498 | pgtable_cache_init(); | |
499 | prio_tree_init(); | |
500 | anon_vma_init(); | |
501 | #ifdef CONFIG_X86 | |
502 | if (efi_enabled) | |
503 | efi_enter_virtual_mode(); | |
504 | #endif | |
505 | fork_init(num_physpages); | |
506 | proc_caches_init(); | |
507 | buffer_init(); | |
508 | unnamed_dev_init(); | |
509 | key_init(); | |
510 | security_init(); | |
511 | vfs_caches_init(num_physpages); | |
512 | radix_tree_init(); | |
513 | signals_init(); | |
514 | /* rootfs populating might need page-writeback */ | |
515 | page_writeback_init(); | |
516 | #ifdef CONFIG_PROC_FS | |
517 | proc_root_init(); | |
518 | #endif | |
519 | cpuset_init(); | |
520 | ||
521 | check_bugs(); | |
522 | ||
523 | acpi_early_init(); /* before LAPIC and SMP init */ | |
524 | ||
525 | /* Do the rest non-__init'ed, we're now alive */ | |
526 | rest_init(); | |
527 | } | |
528 | ||
529 | static int __initdata initcall_debug; | |
530 | ||
531 | static int __init initcall_debug_setup(char *str) | |
532 | { | |
533 | initcall_debug = 1; | |
534 | return 1; | |
535 | } | |
536 | __setup("initcall_debug", initcall_debug_setup); | |
537 | ||
538 | struct task_struct *child_reaper = &init_task; | |
539 | ||
540 | extern initcall_t __initcall_start[], __initcall_end[]; | |
541 | ||
542 | static void __init do_initcalls(void) | |
543 | { | |
544 | initcall_t *call; | |
545 | int count = preempt_count(); | |
546 | ||
547 | for (call = __initcall_start; call < __initcall_end; call++) { | |
548 | char *msg; | |
549 | ||
550 | if (initcall_debug) { | |
551 | printk(KERN_DEBUG "Calling initcall 0x%p", *call); | |
552 | print_fn_descriptor_symbol(": %s()", (unsigned long) *call); | |
553 | printk("\n"); | |
554 | } | |
555 | ||
556 | (*call)(); | |
557 | ||
558 | msg = NULL; | |
559 | if (preempt_count() != count) { | |
560 | msg = "preemption imbalance"; | |
561 | preempt_count() = count; | |
562 | } | |
563 | if (irqs_disabled()) { | |
564 | msg = "disabled interrupts"; | |
565 | local_irq_enable(); | |
566 | } | |
567 | if (msg) { | |
568 | printk(KERN_WARNING "error in initcall at 0x%p: " | |
569 | "returned with %s\n", *call, msg); | |
570 | } | |
571 | } | |
572 | ||
573 | /* Make sure there is no pending stuff from the initcall sequence */ | |
574 | flush_scheduled_work(); | |
575 | } | |
576 | ||
577 | /* | |
578 | * Ok, the machine is now initialized. None of the devices | |
579 | * have been touched yet, but the CPU subsystem is up and | |
580 | * running, and memory and process management works. | |
581 | * | |
582 | * Now we can finally start doing some real work.. | |
583 | */ | |
584 | static void __init do_basic_setup(void) | |
585 | { | |
586 | /* drivers will send hotplug events */ | |
587 | init_workqueues(); | |
588 | usermodehelper_init(); | |
589 | driver_init(); | |
590 | ||
591 | #ifdef CONFIG_SYSCTL | |
592 | sysctl_init(); | |
593 | #endif | |
594 | ||
595 | /* Networking initialization needs a process context */ | |
596 | sock_init(); | |
597 | ||
598 | do_initcalls(); | |
599 | } | |
600 | ||
601 | static void do_pre_smp_initcalls(void) | |
602 | { | |
603 | extern int spawn_ksoftirqd(void); | |
604 | #ifdef CONFIG_SMP | |
605 | extern int migration_init(void); | |
606 | ||
607 | migration_init(); | |
608 | #endif | |
609 | spawn_ksoftirqd(); | |
610 | } | |
611 | ||
612 | static void run_init_process(char *init_filename) | |
613 | { | |
614 | argv_init[0] = init_filename; | |
615 | execve(init_filename, argv_init, envp_init); | |
616 | } | |
617 | ||
618 | static inline void fixup_cpu_present_map(void) | |
619 | { | |
620 | #ifdef CONFIG_SMP | |
621 | int i; | |
622 | ||
623 | /* | |
624 | * If arch is not hotplug ready and did not populate | |
625 | * cpu_present_map, just make cpu_present_map same as cpu_possible_map | |
626 | * for other cpu bringup code to function as normal. e.g smp_init() etc. | |
627 | */ | |
628 | if (cpus_empty(cpu_present_map)) { | |
629 | for_each_cpu(i) { | |
630 | cpu_set(i, cpu_present_map); | |
631 | } | |
632 | } | |
633 | #endif | |
634 | } | |
635 | ||
636 | static int init(void * unused) | |
637 | { | |
638 | lock_kernel(); | |
639 | /* | |
640 | * init can run on any cpu. | |
641 | */ | |
642 | set_cpus_allowed(current, CPU_MASK_ALL); | |
643 | /* | |
644 | * Tell the world that we're going to be the grim | |
645 | * reaper of innocent orphaned children. | |
646 | * | |
647 | * We don't want people to have to make incorrect | |
648 | * assumptions about where in the task array this | |
649 | * can be found. | |
650 | */ | |
651 | child_reaper = current; | |
652 | ||
653 | /* Sets up cpus_possible() */ | |
654 | smp_prepare_cpus(max_cpus); | |
655 | ||
656 | do_pre_smp_initcalls(); | |
657 | ||
658 | fixup_cpu_present_map(); | |
659 | smp_init(); | |
660 | sched_init_smp(); | |
661 | ||
662 | cpuset_init_smp(); | |
663 | ||
664 | /* | |
665 | * Do this before initcalls, because some drivers want to access | |
666 | * firmware files. | |
667 | */ | |
668 | populate_rootfs(); | |
669 | ||
670 | do_basic_setup(); | |
671 | ||
672 | /* | |
673 | * check if there is an early userspace init. If yes, let it do all | |
674 | * the work | |
675 | */ | |
676 | if (sys_access((const char __user *) "/init", 0) == 0) | |
677 | execute_command = "/init"; | |
678 | else | |
679 | prepare_namespace(); | |
680 | ||
681 | /* | |
682 | * Ok, we have completed the initial bootup, and | |
683 | * we're essentially up and running. Get rid of the | |
684 | * initmem segments and start the user-mode stuff.. | |
685 | */ | |
686 | free_initmem(); | |
687 | unlock_kernel(); | |
688 | system_state = SYSTEM_RUNNING; | |
689 | numa_default_policy(); | |
690 | ||
691 | if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0) | |
692 | printk(KERN_WARNING "Warning: unable to open an initial console.\n"); | |
693 | ||
694 | (void) sys_dup(0); | |
695 | (void) sys_dup(0); | |
696 | ||
697 | /* | |
698 | * We try each of these until one succeeds. | |
699 | * | |
700 | * The Bourne shell can be used instead of init if we are | |
701 | * trying to recover a really broken machine. | |
702 | */ | |
703 | ||
704 | if (execute_command) | |
705 | run_init_process(execute_command); | |
706 | ||
707 | run_init_process("/sbin/init"); | |
708 | run_init_process("/etc/init"); | |
709 | run_init_process("/bin/init"); | |
710 | run_init_process("/bin/sh"); | |
711 | ||
712 | panic("No init found. Try passing init= option to kernel."); | |
713 | } |