i2c: Convert the pcf8575 driver to a new-style i2c driver
[linux-2.6/mini2440.git] / init / main.c
blobedeace036fd96b08de9f5b57fffcb04cf8f7c44c
1 /*
2 * linux/init/main.c
4 * Copyright (C) 1991, 1992 Linus Torvalds
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>
12 #include <linux/types.h>
13 #include <linux/module.h>
14 #include <linux/proc_fs.h>
15 #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>
32 #include <linux/start_kernel.h>
33 #include <linux/security.h>
34 #include <linux/smp.h>
35 #include <linux/workqueue.h>
36 #include <linux/profile.h>
37 #include <linux/rcupdate.h>
38 #include <linux/moduleparam.h>
39 #include <linux/kallsyms.h>
40 #include <linux/writeback.h>
41 #include <linux/cpu.h>
42 #include <linux/cpuset.h>
43 #include <linux/cgroup.h>
44 #include <linux/efi.h>
45 #include <linux/tick.h>
46 #include <linux/interrupt.h>
47 #include <linux/taskstats_kern.h>
48 #include <linux/delayacct.h>
49 #include <linux/unistd.h>
50 #include <linux/rmap.h>
51 #include <linux/mempolicy.h>
52 #include <linux/key.h>
53 #include <linux/unwind.h>
54 #include <linux/buffer_head.h>
55 #include <linux/debug_locks.h>
56 #include <linux/debugobjects.h>
57 #include <linux/lockdep.h>
58 #include <linux/pid_namespace.h>
59 #include <linux/device.h>
60 #include <linux/kthread.h>
61 #include <linux/sched.h>
62 #include <linux/signal.h>
63 #include <linux/idr.h>
65 #include <asm/io.h>
66 #include <asm/bugs.h>
67 #include <asm/setup.h>
68 #include <asm/sections.h>
69 #include <asm/cacheflush.h>
71 #ifdef CONFIG_X86_LOCAL_APIC
72 #include <asm/smp.h>
73 #endif
76 * This is one of the first .c files built. Error out early if we have compiler
77 * trouble.
80 #if __GNUC__ == 4 && __GNUC_MINOR__ == 1 && __GNUC_PATCHLEVEL__ == 0
81 #warning gcc-4.1.0 is known to miscompile the kernel. A different compiler version is recommended.
82 #endif
84 static int kernel_init(void *);
86 extern void init_IRQ(void);
87 extern void fork_init(unsigned long);
88 extern void mca_init(void);
89 extern void sbus_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 #ifdef CONFIG_ACPI
96 extern void acpi_early_init(void);
97 #else
98 static inline void acpi_early_init(void) { }
99 #endif
100 #ifndef CONFIG_DEBUG_RODATA
101 static inline void mark_rodata_ro(void) { }
102 #endif
104 #ifdef CONFIG_TC
105 extern void tc_init(void);
106 #endif
108 enum system_states system_state;
109 EXPORT_SYMBOL(system_state);
112 * Boot command-line arguments
114 #define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
115 #define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
117 extern void time_init(void);
118 /* Default late time init is NULL. archs can override this later. */
119 void (*late_time_init)(void);
120 extern void softirq_init(void);
122 /* Untouched command line saved by arch-specific code. */
123 char __initdata boot_command_line[COMMAND_LINE_SIZE];
124 /* Untouched saved command line (eg. for /proc) */
125 char *saved_command_line;
126 /* Command line for parameter parsing */
127 static char *static_command_line;
129 static char *execute_command;
130 static char *ramdisk_execute_command;
132 #ifdef CONFIG_SMP
133 /* Setup configured maximum number of CPUs to activate */
134 unsigned int __initdata setup_max_cpus = NR_CPUS;
137 * Setup routine for controlling SMP activation
139 * Command-line option of "nosmp" or "maxcpus=0" will disable SMP
140 * activation entirely (the MPS table probe still happens, though).
142 * Command-line option of "maxcpus=<NUM>", where <NUM> is an integer
143 * greater than 0, limits the maximum number of CPUs activated in
144 * SMP mode to <NUM>.
146 #ifndef CONFIG_X86_IO_APIC
147 static inline void disable_ioapic_setup(void) {};
148 #endif
150 static int __init nosmp(char *str)
152 setup_max_cpus = 0;
153 disable_ioapic_setup();
154 return 0;
157 early_param("nosmp", nosmp);
159 static int __init maxcpus(char *str)
161 get_option(&str, &setup_max_cpus);
162 if (setup_max_cpus == 0)
163 disable_ioapic_setup();
165 return 0;
168 early_param("maxcpus", maxcpus);
169 #else
170 #define setup_max_cpus NR_CPUS
171 #endif
174 * If set, this is an indication to the drivers that reset the underlying
175 * device before going ahead with the initialization otherwise driver might
176 * rely on the BIOS and skip the reset operation.
178 * This is useful if kernel is booting in an unreliable environment.
179 * For ex. kdump situaiton where previous kernel has crashed, BIOS has been
180 * skipped and devices will be in unknown state.
182 unsigned int reset_devices;
183 EXPORT_SYMBOL(reset_devices);
185 static int __init set_reset_devices(char *str)
187 reset_devices = 1;
188 return 1;
191 __setup("reset_devices", set_reset_devices);
193 static char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
194 char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
195 static const char *panic_later, *panic_param;
197 extern struct obs_kernel_param __setup_start[], __setup_end[];
199 static int __init obsolete_checksetup(char *line)
201 struct obs_kernel_param *p;
202 int had_early_param = 0;
204 p = __setup_start;
205 do {
206 int n = strlen(p->str);
207 if (!strncmp(line, p->str, n)) {
208 if (p->early) {
209 /* Already done in parse_early_param?
210 * (Needs exact match on param part).
211 * Keep iterating, as we can have early
212 * params and __setups of same names 8( */
213 if (line[n] == '\0' || line[n] == '=')
214 had_early_param = 1;
215 } else if (!p->setup_func) {
216 printk(KERN_WARNING "Parameter %s is obsolete,"
217 " ignored\n", p->str);
218 return 1;
219 } else if (p->setup_func(line + n))
220 return 1;
222 p++;
223 } while (p < __setup_end);
225 return had_early_param;
229 * This should be approx 2 Bo*oMips to start (note initial shift), and will
230 * still work even if initially too large, it will just take slightly longer
232 unsigned long loops_per_jiffy = (1<<12);
234 EXPORT_SYMBOL(loops_per_jiffy);
236 static int __init debug_kernel(char *str)
238 console_loglevel = 10;
239 return 0;
242 static int __init quiet_kernel(char *str)
244 console_loglevel = 4;
245 return 0;
248 early_param("debug", debug_kernel);
249 early_param("quiet", quiet_kernel);
251 static int __init loglevel(char *str)
253 get_option(&str, &console_loglevel);
254 return 0;
257 early_param("loglevel", loglevel);
260 * Unknown boot options get handed to init, unless they look like
261 * failed parameters
263 static int __init unknown_bootoption(char *param, char *val)
265 /* Change NUL term back to "=", to make "param" the whole string. */
266 if (val) {
267 /* param=val or param="val"? */
268 if (val == param+strlen(param)+1)
269 val[-1] = '=';
270 else if (val == param+strlen(param)+2) {
271 val[-2] = '=';
272 memmove(val-1, val, strlen(val)+1);
273 val--;
274 } else
275 BUG();
278 /* Handle obsolete-style parameters */
279 if (obsolete_checksetup(param))
280 return 0;
283 * Preemptive maintenance for "why didn't my misspelled command
284 * line work?"
286 if (strchr(param, '.') && (!val || strchr(param, '.') < val)) {
287 printk(KERN_ERR "Unknown boot option `%s': ignoring\n", param);
288 return 0;
291 if (panic_later)
292 return 0;
294 if (val) {
295 /* Environment option */
296 unsigned int i;
297 for (i = 0; envp_init[i]; i++) {
298 if (i == MAX_INIT_ENVS) {
299 panic_later = "Too many boot env vars at `%s'";
300 panic_param = param;
302 if (!strncmp(param, envp_init[i], val - param))
303 break;
305 envp_init[i] = param;
306 } else {
307 /* Command line option */
308 unsigned int i;
309 for (i = 0; argv_init[i]; i++) {
310 if (i == MAX_INIT_ARGS) {
311 panic_later = "Too many boot init vars at `%s'";
312 panic_param = param;
315 argv_init[i] = param;
317 return 0;
320 #ifdef CONFIG_DEBUG_PAGEALLOC
321 int __read_mostly debug_pagealloc_enabled = 0;
322 #endif
324 static int __init init_setup(char *str)
326 unsigned int i;
328 execute_command = str;
330 * In case LILO is going to boot us with default command line,
331 * it prepends "auto" before the whole cmdline which makes
332 * the shell think it should execute a script with such name.
333 * So we ignore all arguments entered _before_ init=... [MJ]
335 for (i = 1; i < MAX_INIT_ARGS; i++)
336 argv_init[i] = NULL;
337 return 1;
339 __setup("init=", init_setup);
341 static int __init rdinit_setup(char *str)
343 unsigned int i;
345 ramdisk_execute_command = str;
346 /* See "auto" comment in init_setup */
347 for (i = 1; i < MAX_INIT_ARGS; i++)
348 argv_init[i] = NULL;
349 return 1;
351 __setup("rdinit=", rdinit_setup);
353 #ifndef CONFIG_SMP
355 #ifdef CONFIG_X86_LOCAL_APIC
356 static void __init smp_init(void)
358 APIC_init_uniprocessor();
360 #else
361 #define smp_init() do { } while (0)
362 #endif
364 static inline void setup_per_cpu_areas(void) { }
365 static inline void setup_nr_cpu_ids(void) { }
366 static inline void smp_prepare_cpus(unsigned int maxcpus) { }
368 #else
370 #if NR_CPUS > BITS_PER_LONG
371 cpumask_t cpu_mask_all __read_mostly = CPU_MASK_ALL;
372 EXPORT_SYMBOL(cpu_mask_all);
373 #endif
375 /* Setup number of possible processor ids */
376 int nr_cpu_ids __read_mostly = NR_CPUS;
377 EXPORT_SYMBOL(nr_cpu_ids);
379 /* An arch may set nr_cpu_ids earlier if needed, so this would be redundant */
380 static void __init setup_nr_cpu_ids(void)
382 int cpu, highest_cpu = 0;
384 for_each_possible_cpu(cpu)
385 highest_cpu = cpu;
387 nr_cpu_ids = highest_cpu + 1;
390 #ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA
391 unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
393 EXPORT_SYMBOL(__per_cpu_offset);
395 static void __init setup_per_cpu_areas(void)
397 unsigned long size, i;
398 char *ptr;
399 unsigned long nr_possible_cpus = num_possible_cpus();
401 /* Copy section for each CPU (we discard the original) */
402 size = ALIGN(PERCPU_ENOUGH_ROOM, PAGE_SIZE);
403 ptr = alloc_bootmem_pages(size * nr_possible_cpus);
405 for_each_possible_cpu(i) {
406 __per_cpu_offset[i] = ptr - __per_cpu_start;
407 memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start);
408 ptr += size;
411 #endif /* CONFIG_HAVE_SETUP_PER_CPU_AREA */
413 /* Called by boot processor to activate the rest. */
414 static void __init smp_init(void)
416 unsigned int cpu;
418 /* FIXME: This should be done in userspace --RR */
419 for_each_present_cpu(cpu) {
420 if (num_online_cpus() >= setup_max_cpus)
421 break;
422 if (!cpu_online(cpu))
423 cpu_up(cpu);
426 /* Any cleanup work */
427 printk(KERN_INFO "Brought up %ld CPUs\n", (long)num_online_cpus());
428 smp_cpus_done(setup_max_cpus);
431 #endif
434 * We need to store the untouched command line for future reference.
435 * We also need to store the touched command line since the parameter
436 * parsing is performed in place, and we should allow a component to
437 * store reference of name/value for future reference.
439 static void __init setup_command_line(char *command_line)
441 saved_command_line = alloc_bootmem(strlen (boot_command_line)+1);
442 static_command_line = alloc_bootmem(strlen (command_line)+1);
443 strcpy (saved_command_line, boot_command_line);
444 strcpy (static_command_line, command_line);
448 * We need to finalize in a non-__init function or else race conditions
449 * between the root thread and the init thread may cause start_kernel to
450 * be reaped by free_initmem before the root thread has proceeded to
451 * cpu_idle.
453 * gcc-3.4 accidentally inlines this function, so use noinline.
456 static void noinline __init_refok rest_init(void)
457 __releases(kernel_lock)
459 int pid;
461 kernel_thread(kernel_init, NULL, CLONE_FS | CLONE_SIGHAND);
462 numa_default_policy();
463 pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
464 kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
465 unlock_kernel();
468 * The boot idle thread must execute schedule()
469 * at least once to get things moving:
471 init_idle_bootup_task(current);
472 preempt_enable_no_resched();
473 schedule();
474 preempt_disable();
476 /* Call into cpu_idle with preempt disabled */
477 cpu_idle();
480 /* Check for early params. */
481 static int __init do_early_param(char *param, char *val)
483 struct obs_kernel_param *p;
485 for (p = __setup_start; p < __setup_end; p++) {
486 if ((p->early && strcmp(param, p->str) == 0) ||
487 (strcmp(param, "console") == 0 &&
488 strcmp(p->str, "earlycon") == 0)
490 if (p->setup_func(val) != 0)
491 printk(KERN_WARNING
492 "Malformed early option '%s'\n", param);
495 /* We accept everything at this stage. */
496 return 0;
499 /* Arch code calls this early on, or if not, just before other parsing. */
500 void __init parse_early_param(void)
502 static __initdata int done = 0;
503 static __initdata char tmp_cmdline[COMMAND_LINE_SIZE];
505 if (done)
506 return;
508 /* All fall through to do_early_param. */
509 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
510 parse_args("early options", tmp_cmdline, NULL, 0, do_early_param);
511 done = 1;
515 * Activate the first processor.
518 static void __init boot_cpu_init(void)
520 int cpu = smp_processor_id();
521 /* Mark the boot cpu "present", "online" etc for SMP and UP case */
522 cpu_set(cpu, cpu_online_map);
523 cpu_set(cpu, cpu_present_map);
524 cpu_set(cpu, cpu_possible_map);
527 void __init __weak smp_setup_processor_id(void)
531 void __init __weak thread_info_cache_init(void)
535 asmlinkage void __init start_kernel(void)
537 char * command_line;
538 extern struct kernel_param __start___param[], __stop___param[];
540 smp_setup_processor_id();
543 * Need to run as early as possible, to initialize the
544 * lockdep hash:
546 unwind_init();
547 lockdep_init();
548 debug_objects_early_init();
549 cgroup_init_early();
551 local_irq_disable();
552 early_boot_irqs_off();
553 early_init_irq_lock_class();
556 * Interrupts are still disabled. Do necessary setups, then
557 * enable them
559 lock_kernel();
560 tick_init();
561 boot_cpu_init();
562 page_address_init();
563 printk(KERN_NOTICE);
564 printk(linux_banner);
565 setup_arch(&command_line);
566 mm_init_owner(&init_mm, &init_task);
567 setup_command_line(command_line);
568 unwind_setup();
569 setup_per_cpu_areas();
570 setup_nr_cpu_ids();
571 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
574 * Set up the scheduler prior starting any interrupts (such as the
575 * timer interrupt). Full topology setup happens at smp_init()
576 * time - but meanwhile we still have a functioning scheduler.
578 sched_init();
580 * Disable preemption - early bootup scheduling is extremely
581 * fragile until we cpu_idle() for the first time.
583 preempt_disable();
584 build_all_zonelists();
585 page_alloc_init();
586 printk(KERN_NOTICE "Kernel command line: %s\n", boot_command_line);
587 parse_early_param();
588 parse_args("Booting kernel", static_command_line, __start___param,
589 __stop___param - __start___param,
590 &unknown_bootoption);
591 if (!irqs_disabled()) {
592 printk(KERN_WARNING "start_kernel(): bug: interrupts were "
593 "enabled *very* early, fixing it\n");
594 local_irq_disable();
596 sort_main_extable();
597 trap_init();
598 rcu_init();
599 init_IRQ();
600 pidhash_init();
601 init_timers();
602 hrtimers_init();
603 softirq_init();
604 timekeeping_init();
605 time_init();
606 sched_clock_init();
607 profile_init();
608 if (!irqs_disabled())
609 printk("start_kernel(): bug: interrupts were enabled early\n");
610 early_boot_irqs_on();
611 local_irq_enable();
614 * HACK ALERT! This is early. We're enabling the console before
615 * we've done PCI setups etc, and console_init() must be aware of
616 * this. But we do want output early, in case something goes wrong.
618 console_init();
619 if (panic_later)
620 panic(panic_later, panic_param);
622 lockdep_info();
625 * Need to run this when irqs are enabled, because it wants
626 * to self-test [hard/soft]-irqs on/off lock inversion bugs
627 * too:
629 locking_selftest();
631 #ifdef CONFIG_BLK_DEV_INITRD
632 if (initrd_start && !initrd_below_start_ok &&
633 initrd_start < min_low_pfn << PAGE_SHIFT) {
634 printk(KERN_CRIT "initrd overwritten (0x%08lx < 0x%08lx) - "
635 "disabling it.\n",initrd_start,min_low_pfn << PAGE_SHIFT);
636 initrd_start = 0;
638 #endif
639 vfs_caches_init_early();
640 cpuset_init_early();
641 mem_init();
642 enable_debug_pagealloc();
643 cpu_hotplug_init();
644 kmem_cache_init();
645 debug_objects_mem_init();
646 idr_init_cache();
647 setup_per_cpu_pageset();
648 numa_policy_init();
649 if (late_time_init)
650 late_time_init();
651 calibrate_delay();
652 pidmap_init();
653 pgtable_cache_init();
654 prio_tree_init();
655 anon_vma_init();
656 #ifdef CONFIG_X86
657 if (efi_enabled)
658 efi_enter_virtual_mode();
659 #endif
660 thread_info_cache_init();
661 fork_init(num_physpages);
662 proc_caches_init();
663 buffer_init();
664 unnamed_dev_init();
665 key_init();
666 security_init();
667 vfs_caches_init(num_physpages);
668 radix_tree_init();
669 signals_init();
670 /* rootfs populating might need page-writeback */
671 page_writeback_init();
672 #ifdef CONFIG_PROC_FS
673 proc_root_init();
674 #endif
675 cgroup_init();
676 cpuset_init();
677 taskstats_init_early();
678 delayacct_init();
680 check_bugs();
682 acpi_early_init(); /* before LAPIC and SMP init */
684 /* Do the rest non-__init'ed, we're now alive */
685 rest_init();
688 static int __initdata initcall_debug;
690 static int __init initcall_debug_setup(char *str)
692 initcall_debug = 1;
693 return 1;
695 __setup("initcall_debug", initcall_debug_setup);
697 static void __init do_one_initcall(initcall_t fn)
699 int count = preempt_count();
700 ktime_t t0, t1, delta;
701 char msgbuf[64];
702 int result;
704 if (initcall_debug) {
705 print_fn_descriptor_symbol("calling %s\n", fn);
706 t0 = ktime_get();
709 result = fn();
711 if (initcall_debug) {
712 t1 = ktime_get();
713 delta = ktime_sub(t1, t0);
715 print_fn_descriptor_symbol("initcall %s", fn);
716 printk(" returned %d after %Ld msecs\n", result,
717 (unsigned long long) delta.tv64 >> 20);
720 msgbuf[0] = 0;
722 if (result && result != -ENODEV && initcall_debug)
723 sprintf(msgbuf, "error code %d ", result);
725 if (preempt_count() != count) {
726 strlcat(msgbuf, "preemption imbalance ", sizeof(msgbuf));
727 preempt_count() = count;
729 if (irqs_disabled()) {
730 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
731 local_irq_enable();
733 if (msgbuf[0]) {
734 print_fn_descriptor_symbol(KERN_WARNING "initcall %s", fn);
735 printk(" returned with %s\n", msgbuf);
740 extern initcall_t __initcall_start[], __initcall_end[];
742 static void __init do_initcalls(void)
744 initcall_t *call;
746 for (call = __initcall_start; call < __initcall_end; call++)
747 do_one_initcall(*call);
749 /* Make sure there is no pending stuff from the initcall sequence */
750 flush_scheduled_work();
754 * Ok, the machine is now initialized. None of the devices
755 * have been touched yet, but the CPU subsystem is up and
756 * running, and memory and process management works.
758 * Now we can finally start doing some real work..
760 static void __init do_basic_setup(void)
762 rcu_init_sched(); /* needed by module_init stage. */
763 /* drivers will send hotplug events */
764 init_workqueues();
765 usermodehelper_init();
766 driver_init();
767 init_irq_proc();
768 do_initcalls();
771 static int __initdata nosoftlockup;
773 static int __init nosoftlockup_setup(char *str)
775 nosoftlockup = 1;
776 return 1;
778 __setup("nosoftlockup", nosoftlockup_setup);
780 static void __init do_pre_smp_initcalls(void)
782 extern int spawn_ksoftirqd(void);
784 init_call_single_data();
785 migration_init();
786 spawn_ksoftirqd();
787 if (!nosoftlockup)
788 spawn_softlockup_task();
791 static void run_init_process(char *init_filename)
793 argv_init[0] = init_filename;
794 kernel_execve(init_filename, argv_init, envp_init);
797 /* This is a non __init function. Force it to be noinline otherwise gcc
798 * makes it inline to init() and it becomes part of init.text section
800 static int noinline init_post(void)
802 free_initmem();
803 unlock_kernel();
804 mark_rodata_ro();
805 system_state = SYSTEM_RUNNING;
806 numa_default_policy();
808 if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
809 printk(KERN_WARNING "Warning: unable to open an initial console.\n");
811 (void) sys_dup(0);
812 (void) sys_dup(0);
814 current->signal->flags |= SIGNAL_UNKILLABLE;
816 if (ramdisk_execute_command) {
817 run_init_process(ramdisk_execute_command);
818 printk(KERN_WARNING "Failed to execute %s\n",
819 ramdisk_execute_command);
823 * We try each of these until one succeeds.
825 * The Bourne shell can be used instead of init if we are
826 * trying to recover a really broken machine.
828 if (execute_command) {
829 run_init_process(execute_command);
830 printk(KERN_WARNING "Failed to execute %s. Attempting "
831 "defaults...\n", execute_command);
833 run_init_process("/sbin/init");
834 run_init_process("/etc/init");
835 run_init_process("/bin/init");
836 run_init_process("/bin/sh");
838 panic("No init found. Try passing init= option to kernel.");
841 static int __init kernel_init(void * unused)
843 lock_kernel();
845 * init can run on any cpu.
847 set_cpus_allowed_ptr(current, CPU_MASK_ALL_PTR);
849 * Tell the world that we're going to be the grim
850 * reaper of innocent orphaned children.
852 * We don't want people to have to make incorrect
853 * assumptions about where in the task array this
854 * can be found.
856 init_pid_ns.child_reaper = current;
858 cad_pid = task_pid(current);
860 smp_prepare_cpus(setup_max_cpus);
862 do_pre_smp_initcalls();
864 smp_init();
865 sched_init_smp();
867 cpuset_init_smp();
869 do_basic_setup();
872 * check if there is an early userspace init. If yes, let it do all
873 * the work
876 if (!ramdisk_execute_command)
877 ramdisk_execute_command = "/init";
879 if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
880 ramdisk_execute_command = NULL;
881 prepare_namespace();
885 * Ok, we have completed the initial bootup, and
886 * we're essentially up and running. Get rid of the
887 * initmem segments and start the user-mode stuff..
889 init_post();
890 return 0;