diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /init/main.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'init/main.c')
-rw-r--r-- | init/main.c | 713 |
1 files changed, 713 insertions, 0 deletions
diff --git a/init/main.c b/init/main.c new file mode 100644 index 000000000000..40bf367ffdf1 --- /dev/null +++ b/init/main.c | |||
@@ -0,0 +1,713 @@ | |||
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 | } | ||