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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 | #include <asm/sections.h> | |
55 | #include <asm/cacheflush.h> | |
56 | ||
57 | /* | |
58 | * This is one of the first .c files built. Error out early | |
59 | * if we have compiler trouble.. | |
60 | */ | |
61 | #if __GNUC__ == 2 && __GNUC_MINOR__ == 96 | |
62 | #ifdef CONFIG_FRAME_POINTER | |
63 | #error This compiler cannot compile correctly with frame pointers enabled | |
64 | #endif | |
65 | #endif | |
66 | ||
67 | #ifdef CONFIG_X86_LOCAL_APIC | |
68 | #include <asm/smp.h> | |
69 | #endif | |
70 | ||
71 | /* | |
72 | * Versions of gcc older than that listed below may actually compile | |
73 | * and link okay, but the end product can have subtle run time bugs. | |
74 | * To avoid associated bogus bug reports, we flatly refuse to compile | |
75 | * with a gcc that is known to be too old from the very beginning. | |
76 | */ | |
77 | #if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 95) | |
78 | #error Sorry, your GCC is too old. It builds incorrect kernels. | |
79 | #endif | |
80 | ||
81 | static int init(void *); | |
82 | ||
83 | extern void init_IRQ(void); | |
84 | extern void fork_init(unsigned long); | |
85 | extern void mca_init(void); | |
86 | extern void sbus_init(void); | |
87 | extern void sysctl_init(void); | |
88 | extern void signals_init(void); | |
89 | extern void buffer_init(void); | |
90 | extern void pidhash_init(void); | |
91 | extern void pidmap_init(void); | |
92 | extern void prio_tree_init(void); | |
93 | extern void radix_tree_init(void); | |
94 | extern void free_initmem(void); | |
95 | extern void populate_rootfs(void); | |
96 | extern void driver_init(void); | |
97 | extern void prepare_namespace(void); | |
98 | #ifdef CONFIG_ACPI | |
99 | extern void acpi_early_init(void); | |
100 | #else | |
101 | static inline void acpi_early_init(void) { } | |
102 | #endif | |
103 | #ifndef CONFIG_DEBUG_RODATA | |
104 | static inline void mark_rodata_ro(void) { } | |
105 | #endif | |
106 | ||
107 | #ifdef CONFIG_TC | |
108 | extern void tc_init(void); | |
109 | #endif | |
110 | ||
111 | enum system_states system_state; | |
112 | EXPORT_SYMBOL(system_state); | |
113 | ||
114 | /* | |
115 | * Boot command-line arguments | |
116 | */ | |
117 | #define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT | |
118 | #define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT | |
119 | ||
120 | extern void time_init(void); | |
121 | /* Default late time init is NULL. archs can override this later. */ | |
122 | void (*late_time_init)(void); | |
123 | extern void softirq_init(void); | |
124 | ||
125 | /* Untouched command line (eg. for /proc) saved by arch-specific code. */ | |
126 | char saved_command_line[COMMAND_LINE_SIZE]; | |
127 | ||
128 | static char *execute_command; | |
129 | static char *ramdisk_execute_command; | |
130 | ||
131 | /* Setup configured maximum number of CPUs to activate */ | |
132 | static unsigned int max_cpus = NR_CPUS; | |
133 | ||
134 | /* | |
135 | * Setup routine for controlling SMP activation | |
136 | * | |
137 | * Command-line option of "nosmp" or "maxcpus=0" will disable SMP | |
138 | * activation entirely (the MPS table probe still happens, though). | |
139 | * | |
140 | * Command-line option of "maxcpus=<NUM>", where <NUM> is an integer | |
141 | * greater than 0, limits the maximum number of CPUs activated in | |
142 | * SMP mode to <NUM>. | |
143 | */ | |
144 | static int __init nosmp(char *str) | |
145 | { | |
146 | max_cpus = 0; | |
147 | return 1; | |
148 | } | |
149 | ||
150 | __setup("nosmp", nosmp); | |
151 | ||
152 | static int __init maxcpus(char *str) | |
153 | { | |
154 | get_option(&str, &max_cpus); | |
155 | return 1; | |
156 | } | |
157 | ||
158 | __setup("maxcpus=", maxcpus); | |
159 | ||
160 | static char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, }; | |
161 | char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, }; | |
162 | static const char *panic_later, *panic_param; | |
163 | ||
164 | extern struct obs_kernel_param __setup_start[], __setup_end[]; | |
165 | ||
166 | static int __init obsolete_checksetup(char *line) | |
167 | { | |
168 | struct obs_kernel_param *p; | |
169 | ||
170 | p = __setup_start; | |
171 | do { | |
172 | int n = strlen(p->str); | |
173 | if (!strncmp(line, p->str, n)) { | |
174 | if (p->early) { | |
175 | /* Already done in parse_early_param? (Needs | |
176 | * exact match on param part) */ | |
177 | if (line[n] == '\0' || line[n] == '=') | |
178 | return 1; | |
179 | } else if (!p->setup_func) { | |
180 | printk(KERN_WARNING "Parameter %s is obsolete," | |
181 | " ignored\n", p->str); | |
182 | return 1; | |
183 | } else if (p->setup_func(line + n)) | |
184 | return 1; | |
185 | } | |
186 | p++; | |
187 | } while (p < __setup_end); | |
188 | return 0; | |
189 | } | |
190 | ||
191 | /* | |
192 | * This should be approx 2 Bo*oMips to start (note initial shift), and will | |
193 | * still work even if initially too large, it will just take slightly longer | |
194 | */ | |
195 | unsigned long loops_per_jiffy = (1<<12); | |
196 | ||
197 | EXPORT_SYMBOL(loops_per_jiffy); | |
198 | ||
199 | static int __init debug_kernel(char *str) | |
200 | { | |
201 | if (*str) | |
202 | return 0; | |
203 | console_loglevel = 10; | |
204 | return 1; | |
205 | } | |
206 | ||
207 | static int __init quiet_kernel(char *str) | |
208 | { | |
209 | if (*str) | |
210 | return 0; | |
211 | console_loglevel = 4; | |
212 | return 1; | |
213 | } | |
214 | ||
215 | __setup("debug", debug_kernel); | |
216 | __setup("quiet", quiet_kernel); | |
217 | ||
218 | static int __init loglevel(char *str) | |
219 | { | |
220 | get_option(&str, &console_loglevel); | |
221 | return 1; | |
222 | } | |
223 | ||
224 | __setup("loglevel=", loglevel); | |
225 | ||
226 | /* | |
227 | * Unknown boot options get handed to init, unless they look like | |
228 | * failed parameters | |
229 | */ | |
230 | static int __init unknown_bootoption(char *param, char *val) | |
231 | { | |
232 | /* Change NUL term back to "=", to make "param" the whole string. */ | |
233 | if (val) { | |
234 | /* param=val or param="val"? */ | |
235 | if (val == param+strlen(param)+1) | |
236 | val[-1] = '='; | |
237 | else if (val == param+strlen(param)+2) { | |
238 | val[-2] = '='; | |
239 | memmove(val-1, val, strlen(val)+1); | |
240 | val--; | |
241 | } else | |
242 | BUG(); | |
243 | } | |
244 | ||
245 | /* Handle obsolete-style parameters */ | |
246 | if (obsolete_checksetup(param)) | |
247 | return 0; | |
248 | ||
249 | /* | |
250 | * Preemptive maintenance for "why didn't my mispelled command | |
251 | * line work?" | |
252 | */ | |
253 | if (strchr(param, '.') && (!val || strchr(param, '.') < val)) { | |
254 | printk(KERN_ERR "Unknown boot option `%s': ignoring\n", param); | |
255 | return 0; | |
256 | } | |
257 | ||
258 | if (panic_later) | |
259 | return 0; | |
260 | ||
261 | if (val) { | |
262 | /* Environment option */ | |
263 | unsigned int i; | |
264 | for (i = 0; envp_init[i]; i++) { | |
265 | if (i == MAX_INIT_ENVS) { | |
266 | panic_later = "Too many boot env vars at `%s'"; | |
267 | panic_param = param; | |
268 | } | |
269 | if (!strncmp(param, envp_init[i], val - param)) | |
270 | break; | |
271 | } | |
272 | envp_init[i] = param; | |
273 | } else { | |
274 | /* Command line option */ | |
275 | unsigned int i; | |
276 | for (i = 0; argv_init[i]; i++) { | |
277 | if (i == MAX_INIT_ARGS) { | |
278 | panic_later = "Too many boot init vars at `%s'"; | |
279 | panic_param = param; | |
280 | } | |
281 | } | |
282 | argv_init[i] = param; | |
283 | } | |
284 | return 0; | |
285 | } | |
286 | ||
287 | static int __init init_setup(char *str) | |
288 | { | |
289 | unsigned int i; | |
290 | ||
291 | execute_command = str; | |
292 | /* | |
293 | * In case LILO is going to boot us with default command line, | |
294 | * it prepends "auto" before the whole cmdline which makes | |
295 | * the shell think it should execute a script with such name. | |
296 | * So we ignore all arguments entered _before_ init=... [MJ] | |
297 | */ | |
298 | for (i = 1; i < MAX_INIT_ARGS; i++) | |
299 | argv_init[i] = NULL; | |
300 | return 1; | |
301 | } | |
302 | __setup("init=", init_setup); | |
303 | ||
304 | static int __init rdinit_setup(char *str) | |
305 | { | |
306 | unsigned int i; | |
307 | ||
308 | ramdisk_execute_command = str; | |
309 | /* See "auto" comment in init_setup */ | |
310 | for (i = 1; i < MAX_INIT_ARGS; i++) | |
311 | argv_init[i] = NULL; | |
312 | return 1; | |
313 | } | |
314 | __setup("rdinit=", rdinit_setup); | |
315 | ||
316 | extern void setup_arch(char **); | |
317 | ||
318 | #ifndef CONFIG_SMP | |
319 | ||
320 | #ifdef CONFIG_X86_LOCAL_APIC | |
321 | static void __init smp_init(void) | |
322 | { | |
323 | APIC_init_uniprocessor(); | |
324 | } | |
325 | #else | |
326 | #define smp_init() do { } while (0) | |
327 | #endif | |
328 | ||
329 | static inline void setup_per_cpu_areas(void) { } | |
330 | static inline void smp_prepare_cpus(unsigned int maxcpus) { } | |
331 | ||
332 | #else | |
333 | ||
334 | #ifdef __GENERIC_PER_CPU | |
335 | unsigned long __per_cpu_offset[NR_CPUS]; | |
336 | ||
337 | EXPORT_SYMBOL(__per_cpu_offset); | |
338 | ||
339 | static void __init setup_per_cpu_areas(void) | |
340 | { | |
341 | unsigned long size, i; | |
342 | char *ptr; | |
343 | ||
344 | /* Copy section for each CPU (we discard the original) */ | |
345 | size = ALIGN(__per_cpu_end - __per_cpu_start, SMP_CACHE_BYTES); | |
346 | #ifdef CONFIG_MODULES | |
347 | if (size < PERCPU_ENOUGH_ROOM) | |
348 | size = PERCPU_ENOUGH_ROOM; | |
349 | #endif | |
350 | ||
351 | ptr = alloc_bootmem(size * NR_CPUS); | |
352 | ||
353 | for (i = 0; i < NR_CPUS; i++, ptr += size) { | |
354 | __per_cpu_offset[i] = ptr - __per_cpu_start; | |
355 | memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start); | |
356 | } | |
357 | } | |
358 | #endif /* !__GENERIC_PER_CPU */ | |
359 | ||
360 | /* Called by boot processor to activate the rest. */ | |
361 | static void __init smp_init(void) | |
362 | { | |
363 | unsigned int i; | |
364 | ||
365 | /* FIXME: This should be done in userspace --RR */ | |
366 | for_each_present_cpu(i) { | |
367 | if (num_online_cpus() >= max_cpus) | |
368 | break; | |
369 | if (!cpu_online(i)) | |
370 | cpu_up(i); | |
371 | } | |
372 | ||
373 | /* Any cleanup work */ | |
374 | printk(KERN_INFO "Brought up %ld CPUs\n", (long)num_online_cpus()); | |
375 | smp_cpus_done(max_cpus); | |
376 | #if 0 | |
377 | /* Get other processors into their bootup holding patterns. */ | |
378 | ||
379 | smp_commence(); | |
380 | #endif | |
381 | } | |
382 | ||
383 | #endif | |
384 | ||
385 | /* | |
386 | * We need to finalize in a non-__init function or else race conditions | |
387 | * between the root thread and the init thread may cause start_kernel to | |
388 | * be reaped by free_initmem before the root thread has proceeded to | |
389 | * cpu_idle. | |
390 | * | |
391 | * gcc-3.4 accidentally inlines this function, so use noinline. | |
392 | */ | |
393 | ||
394 | static void noinline rest_init(void) | |
395 | __releases(kernel_lock) | |
396 | { | |
397 | kernel_thread(init, NULL, CLONE_FS | CLONE_SIGHAND); | |
398 | numa_default_policy(); | |
399 | unlock_kernel(); | |
400 | ||
401 | /* | |
402 | * The boot idle thread must execute schedule() | |
403 | * at least one to get things moving: | |
404 | */ | |
405 | preempt_enable_no_resched(); | |
406 | schedule(); | |
407 | preempt_disable(); | |
408 | ||
409 | /* Call into cpu_idle with preempt disabled */ | |
410 | cpu_idle(); | |
411 | } | |
412 | ||
413 | /* Check for early params. */ | |
414 | static int __init do_early_param(char *param, char *val) | |
415 | { | |
416 | struct obs_kernel_param *p; | |
417 | ||
418 | for (p = __setup_start; p < __setup_end; p++) { | |
419 | if (p->early && strcmp(param, p->str) == 0) { | |
420 | if (p->setup_func(val) != 0) | |
421 | printk(KERN_WARNING | |
422 | "Malformed early option '%s'\n", param); | |
423 | } | |
424 | } | |
425 | /* We accept everything at this stage. */ | |
426 | return 0; | |
427 | } | |
428 | ||
429 | /* Arch code calls this early on, or if not, just before other parsing. */ | |
430 | void __init parse_early_param(void) | |
431 | { | |
432 | static __initdata int done = 0; | |
433 | static __initdata char tmp_cmdline[COMMAND_LINE_SIZE]; | |
434 | ||
435 | if (done) | |
436 | return; | |
437 | ||
438 | /* All fall through to do_early_param. */ | |
439 | strlcpy(tmp_cmdline, saved_command_line, COMMAND_LINE_SIZE); | |
440 | parse_args("early options", tmp_cmdline, NULL, 0, do_early_param); | |
441 | done = 1; | |
442 | } | |
443 | ||
444 | /* | |
445 | * Activate the first processor. | |
446 | */ | |
447 | ||
448 | asmlinkage void __init start_kernel(void) | |
449 | { | |
450 | char * command_line; | |
451 | extern struct kernel_param __start___param[], __stop___param[]; | |
452 | /* | |
453 | * Interrupts are still disabled. Do necessary setups, then | |
454 | * enable them | |
455 | */ | |
456 | lock_kernel(); | |
457 | page_address_init(); | |
458 | printk(KERN_NOTICE); | |
459 | printk(linux_banner); | |
460 | setup_arch(&command_line); | |
461 | setup_per_cpu_areas(); | |
462 | ||
463 | /* | |
464 | * Mark the boot cpu "online" so that it can call console drivers in | |
465 | * printk() and can access its per-cpu storage. | |
466 | */ | |
467 | smp_prepare_boot_cpu(); | |
468 | ||
469 | /* | |
470 | * Set up the scheduler prior starting any interrupts (such as the | |
471 | * timer interrupt). Full topology setup happens at smp_init() | |
472 | * time - but meanwhile we still have a functioning scheduler. | |
473 | */ | |
474 | sched_init(); | |
475 | /* | |
476 | * Disable preemption - early bootup scheduling is extremely | |
477 | * fragile until we cpu_idle() for the first time. | |
478 | */ | |
479 | preempt_disable(); | |
480 | build_all_zonelists(); | |
481 | page_alloc_init(); | |
482 | printk(KERN_NOTICE "Kernel command line: %s\n", saved_command_line); | |
483 | parse_early_param(); | |
484 | parse_args("Booting kernel", command_line, __start___param, | |
485 | __stop___param - __start___param, | |
486 | &unknown_bootoption); | |
487 | sort_main_extable(); | |
488 | trap_init(); | |
489 | rcu_init(); | |
490 | init_IRQ(); | |
491 | pidhash_init(); | |
492 | init_timers(); | |
493 | softirq_init(); | |
494 | time_init(); | |
495 | ||
496 | /* | |
497 | * HACK ALERT! This is early. We're enabling the console before | |
498 | * we've done PCI setups etc, and console_init() must be aware of | |
499 | * this. But we do want output early, in case something goes wrong. | |
500 | */ | |
501 | console_init(); | |
502 | if (panic_later) | |
503 | panic(panic_later, panic_param); | |
504 | profile_init(); | |
505 | local_irq_enable(); | |
506 | #ifdef CONFIG_BLK_DEV_INITRD | |
507 | if (initrd_start && !initrd_below_start_ok && | |
508 | initrd_start < min_low_pfn << PAGE_SHIFT) { | |
509 | printk(KERN_CRIT "initrd overwritten (0x%08lx < 0x%08lx) - " | |
510 | "disabling it.\n",initrd_start,min_low_pfn << PAGE_SHIFT); | |
511 | initrd_start = 0; | |
512 | } | |
513 | #endif | |
514 | vfs_caches_init_early(); | |
515 | mem_init(); | |
516 | kmem_cache_init(); | |
517 | setup_per_cpu_pageset(); | |
518 | numa_policy_init(); | |
519 | if (late_time_init) | |
520 | late_time_init(); | |
521 | calibrate_delay(); | |
522 | pidmap_init(); | |
523 | pgtable_cache_init(); | |
524 | prio_tree_init(); | |
525 | anon_vma_init(); | |
526 | #ifdef CONFIG_X86 | |
527 | if (efi_enabled) | |
528 | efi_enter_virtual_mode(); | |
529 | #endif | |
530 | fork_init(num_physpages); | |
531 | proc_caches_init(); | |
532 | buffer_init(); | |
533 | unnamed_dev_init(); | |
534 | key_init(); | |
535 | security_init(); | |
536 | vfs_caches_init(num_physpages); | |
537 | radix_tree_init(); | |
538 | signals_init(); | |
539 | /* rootfs populating might need page-writeback */ | |
540 | page_writeback_init(); | |
541 | #ifdef CONFIG_PROC_FS | |
542 | proc_root_init(); | |
543 | #endif | |
544 | cpuset_init(); | |
545 | ||
546 | check_bugs(); | |
547 | ||
548 | acpi_early_init(); /* before LAPIC and SMP init */ | |
549 | ||
550 | /* Do the rest non-__init'ed, we're now alive */ | |
551 | rest_init(); | |
552 | } | |
553 | ||
554 | static int __initdata initcall_debug; | |
555 | ||
556 | static int __init initcall_debug_setup(char *str) | |
557 | { | |
558 | initcall_debug = 1; | |
559 | return 1; | |
560 | } | |
561 | __setup("initcall_debug", initcall_debug_setup); | |
562 | ||
563 | struct task_struct *child_reaper = &init_task; | |
564 | ||
565 | extern initcall_t __initcall_start[], __initcall_end[]; | |
566 | ||
567 | static void __init do_initcalls(void) | |
568 | { | |
569 | initcall_t *call; | |
570 | int count = preempt_count(); | |
571 | ||
572 | for (call = __initcall_start; call < __initcall_end; call++) { | |
573 | char *msg; | |
574 | ||
575 | if (initcall_debug) { | |
576 | printk(KERN_DEBUG "Calling initcall 0x%p", *call); | |
577 | print_fn_descriptor_symbol(": %s()", (unsigned long) *call); | |
578 | printk("\n"); | |
579 | } | |
580 | ||
581 | (*call)(); | |
582 | ||
583 | msg = NULL; | |
584 | if (preempt_count() != count) { | |
585 | msg = "preemption imbalance"; | |
586 | preempt_count() = count; | |
587 | } | |
588 | if (irqs_disabled()) { | |
589 | msg = "disabled interrupts"; | |
590 | local_irq_enable(); | |
591 | } | |
592 | if (msg) { | |
593 | printk(KERN_WARNING "error in initcall at 0x%p: " | |
594 | "returned with %s\n", *call, msg); | |
595 | } | |
596 | } | |
597 | ||
598 | /* Make sure there is no pending stuff from the initcall sequence */ | |
599 | flush_scheduled_work(); | |
600 | } | |
601 | ||
602 | /* | |
603 | * Ok, the machine is now initialized. None of the devices | |
604 | * have been touched yet, but the CPU subsystem is up and | |
605 | * running, and memory and process management works. | |
606 | * | |
607 | * Now we can finally start doing some real work.. | |
608 | */ | |
609 | static void __init do_basic_setup(void) | |
610 | { | |
611 | /* drivers will send hotplug events */ | |
612 | init_workqueues(); | |
613 | usermodehelper_init(); | |
614 | driver_init(); | |
615 | ||
616 | #ifdef CONFIG_SYSCTL | |
617 | sysctl_init(); | |
618 | #endif | |
619 | ||
620 | do_initcalls(); | |
621 | } | |
622 | ||
623 | static void do_pre_smp_initcalls(void) | |
624 | { | |
625 | extern int spawn_ksoftirqd(void); | |
626 | #ifdef CONFIG_SMP | |
627 | extern int migration_init(void); | |
628 | ||
629 | migration_init(); | |
630 | #endif | |
631 | spawn_ksoftirqd(); | |
632 | spawn_softlockup_task(); | |
633 | } | |
634 | ||
635 | static void run_init_process(char *init_filename) | |
636 | { | |
637 | argv_init[0] = init_filename; | |
638 | execve(init_filename, argv_init, envp_init); | |
639 | } | |
640 | ||
641 | static inline void fixup_cpu_present_map(void) | |
642 | { | |
643 | #ifdef CONFIG_SMP | |
644 | int i; | |
645 | ||
646 | /* | |
647 | * If arch is not hotplug ready and did not populate | |
648 | * cpu_present_map, just make cpu_present_map same as cpu_possible_map | |
649 | * for other cpu bringup code to function as normal. e.g smp_init() etc. | |
650 | */ | |
651 | if (cpus_empty(cpu_present_map)) { | |
652 | for_each_cpu(i) { | |
653 | cpu_set(i, cpu_present_map); | |
654 | } | |
655 | } | |
656 | #endif | |
657 | } | |
658 | ||
659 | static int init(void * unused) | |
660 | { | |
661 | lock_kernel(); | |
662 | /* | |
663 | * init can run on any cpu. | |
664 | */ | |
665 | set_cpus_allowed(current, CPU_MASK_ALL); | |
666 | /* | |
667 | * Tell the world that we're going to be the grim | |
668 | * reaper of innocent orphaned children. | |
669 | * | |
670 | * We don't want people to have to make incorrect | |
671 | * assumptions about where in the task array this | |
672 | * can be found. | |
673 | */ | |
674 | child_reaper = current; | |
675 | ||
676 | /* Sets up cpus_possible() */ | |
677 | smp_prepare_cpus(max_cpus); | |
678 | ||
679 | do_pre_smp_initcalls(); | |
680 | ||
681 | fixup_cpu_present_map(); | |
682 | smp_init(); | |
683 | sched_init_smp(); | |
684 | ||
685 | cpuset_init_smp(); | |
686 | ||
687 | /* | |
688 | * Do this before initcalls, because some drivers want to access | |
689 | * firmware files. | |
690 | */ | |
691 | populate_rootfs(); | |
692 | ||
693 | do_basic_setup(); | |
694 | ||
695 | /* | |
696 | * check if there is an early userspace init. If yes, let it do all | |
697 | * the work | |
698 | */ | |
699 | ||
700 | if (!ramdisk_execute_command) | |
701 | ramdisk_execute_command = "/init"; | |
702 | ||
703 | if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) { | |
704 | ramdisk_execute_command = NULL; | |
705 | prepare_namespace(); | |
706 | } | |
707 | ||
708 | /* | |
709 | * Ok, we have completed the initial bootup, and | |
710 | * we're essentially up and running. Get rid of the | |
711 | * initmem segments and start the user-mode stuff.. | |
712 | */ | |
713 | free_initmem(); | |
714 | unlock_kernel(); | |
715 | mark_rodata_ro(); | |
716 | system_state = SYSTEM_RUNNING; | |
717 | numa_default_policy(); | |
718 | ||
719 | if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0) | |
720 | printk(KERN_WARNING "Warning: unable to open an initial console.\n"); | |
721 | ||
722 | (void) sys_dup(0); | |
723 | (void) sys_dup(0); | |
724 | ||
725 | if (ramdisk_execute_command) { | |
726 | run_init_process(ramdisk_execute_command); | |
727 | printk(KERN_WARNING "Failed to execute %s\n", | |
728 | ramdisk_execute_command); | |
729 | } | |
730 | ||
731 | /* | |
732 | * We try each of these until one succeeds. | |
733 | * | |
734 | * The Bourne shell can be used instead of init if we are | |
735 | * trying to recover a really broken machine. | |
736 | */ | |
737 | if (execute_command) { | |
738 | run_init_process(execute_command); | |
739 | printk(KERN_WARNING "Failed to execute %s. Attempting " | |
740 | "defaults...\n", execute_command); | |
741 | } | |
742 | run_init_process("/sbin/init"); | |
743 | run_init_process("/etc/init"); | |
744 | run_init_process("/bin/init"); | |
745 | run_init_process("/bin/sh"); | |
746 | ||
747 | panic("No init found. Try passing init= option to kernel."); | |
748 | } |