Root/init/main.c

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#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/stackprotector.h>
18#include <linux/string.h>
19#include <linux/ctype.h>
20#include <linux/delay.h>
21#include <linux/ioport.h>
22#include <linux/init.h>
23#include <linux/initrd.h>
24#include <linux/bootmem.h>
25#include <linux/acpi.h>
26#include <linux/tty.h>
27#include <linux/percpu.h>
28#include <linux/kmod.h>
29#include <linux/vmalloc.h>
30#include <linux/kernel_stat.h>
31#include <linux/start_kernel.h>
32#include <linux/security.h>
33#include <linux/smp.h>
34#include <linux/profile.h>
35#include <linux/rcupdate.h>
36#include <linux/moduleparam.h>
37#include <linux/kallsyms.h>
38#include <linux/writeback.h>
39#include <linux/cpu.h>
40#include <linux/cpuset.h>
41#include <linux/cgroup.h>
42#include <linux/efi.h>
43#include <linux/tick.h>
44#include <linux/interrupt.h>
45#include <linux/taskstats_kern.h>
46#include <linux/delayacct.h>
47#include <linux/unistd.h>
48#include <linux/rmap.h>
49#include <linux/mempolicy.h>
50#include <linux/key.h>
51#include <linux/buffer_head.h>
52#include <linux/page_cgroup.h>
53#include <linux/debug_locks.h>
54#include <linux/debugobjects.h>
55#include <linux/lockdep.h>
56#include <linux/kmemleak.h>
57#include <linux/pid_namespace.h>
58#include <linux/device.h>
59#include <linux/kthread.h>
60#include <linux/sched.h>
61#include <linux/signal.h>
62#include <linux/idr.h>
63#include <linux/kgdb.h>
64#include <linux/ftrace.h>
65#include <linux/async.h>
66#include <linux/kmemcheck.h>
67#include <linux/sfi.h>
68#include <linux/shmem_fs.h>
69#include <linux/slab.h>
70
71#include <asm/io.h>
72#include <asm/bugs.h>
73#include <asm/setup.h>
74#include <asm/sections.h>
75#include <asm/cacheflush.h>
76
77#ifdef CONFIG_X86_LOCAL_APIC
78#include <asm/smp.h>
79#endif
80
81static int kernel_init(void *);
82
83extern void init_IRQ(void);
84extern void fork_init(unsigned long);
85extern void mca_init(void);
86extern void sbus_init(void);
87extern void prio_tree_init(void);
88extern void radix_tree_init(void);
89extern void free_initmem(void);
90#ifndef CONFIG_DEBUG_RODATA
91static inline void mark_rodata_ro(void) { }
92#endif
93
94#ifdef CONFIG_TC
95extern void tc_init(void);
96#endif
97
98enum system_states system_state __read_mostly;
99EXPORT_SYMBOL(system_state);
100
101/*
102 * Boot command-line arguments
103 */
104#define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
105#define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
106
107extern void time_init(void);
108/* Default late time init is NULL. archs can override this later. */
109void (*__initdata late_time_init)(void);
110extern void softirq_init(void);
111
112/* Untouched command line saved by arch-specific code. */
113char __initdata boot_command_line[COMMAND_LINE_SIZE];
114/* Untouched saved command line (eg. for /proc) */
115char *saved_command_line;
116/* Command line for parameter parsing */
117static char *static_command_line;
118
119static char *execute_command;
120static char *ramdisk_execute_command;
121
122#ifdef CONFIG_SMP
123/* Setup configured maximum number of CPUs to activate */
124unsigned int setup_max_cpus = NR_CPUS;
125EXPORT_SYMBOL(setup_max_cpus);
126
127
128/*
129 * Setup routine for controlling SMP activation
130 *
131 * Command-line option of "nosmp" or "maxcpus=0" will disable SMP
132 * activation entirely (the MPS table probe still happens, though).
133 *
134 * Command-line option of "maxcpus=<NUM>", where <NUM> is an integer
135 * greater than 0, limits the maximum number of CPUs activated in
136 * SMP mode to <NUM>.
137 */
138
139void __weak arch_disable_smp_support(void) { }
140
141static int __init nosmp(char *str)
142{
143    setup_max_cpus = 0;
144    arch_disable_smp_support();
145
146    return 0;
147}
148
149early_param("nosmp", nosmp);
150
151/* this is hard limit */
152static int __init nrcpus(char *str)
153{
154    int nr_cpus;
155
156    get_option(&str, &nr_cpus);
157    if (nr_cpus > 0 && nr_cpus < nr_cpu_ids)
158        nr_cpu_ids = nr_cpus;
159
160    return 0;
161}
162
163early_param("nr_cpus", nrcpus);
164
165static int __init maxcpus(char *str)
166{
167    get_option(&str, &setup_max_cpus);
168    if (setup_max_cpus == 0)
169        arch_disable_smp_support();
170
171    return 0;
172}
173
174early_param("maxcpus", maxcpus);
175#else
176static const unsigned int setup_max_cpus = NR_CPUS;
177#endif
178
179/*
180 * If set, this is an indication to the drivers that reset the underlying
181 * device before going ahead with the initialization otherwise driver might
182 * rely on the BIOS and skip the reset operation.
183 *
184 * This is useful if kernel is booting in an unreliable environment.
185 * For ex. kdump situaiton where previous kernel has crashed, BIOS has been
186 * skipped and devices will be in unknown state.
187 */
188unsigned int reset_devices;
189EXPORT_SYMBOL(reset_devices);
190
191static int __init set_reset_devices(char *str)
192{
193    reset_devices = 1;
194    return 1;
195}
196
197__setup("reset_devices", set_reset_devices);
198
199static const char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
200const char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
201static const char *panic_later, *panic_param;
202
203extern const struct obs_kernel_param __setup_start[], __setup_end[];
204
205static int __init obsolete_checksetup(char *line)
206{
207    const struct obs_kernel_param *p;
208    int had_early_param = 0;
209
210    p = __setup_start;
211    do {
212        int n = strlen(p->str);
213        if (!strncmp(line, p->str, n)) {
214            if (p->early) {
215                /* Already done in parse_early_param?
216                 * (Needs exact match on param part).
217                 * Keep iterating, as we can have early
218                 * params and __setups of same names 8( */
219                if (line[n] == '\0' || line[n] == '=')
220                    had_early_param = 1;
221            } else if (!p->setup_func) {
222                printk(KERN_WARNING "Parameter %s is obsolete,"
223                       " ignored\n", p->str);
224                return 1;
225            } else if (p->setup_func(line + n))
226                return 1;
227        }
228        p++;
229    } while (p < __setup_end);
230
231    return had_early_param;
232}
233
234/*
235 * This should be approx 2 Bo*oMips to start (note initial shift), and will
236 * still work even if initially too large, it will just take slightly longer
237 */
238unsigned long loops_per_jiffy = (1<<12);
239
240EXPORT_SYMBOL(loops_per_jiffy);
241
242static int __init debug_kernel(char *str)
243{
244    console_loglevel = 10;
245    return 0;
246}
247
248static int __init quiet_kernel(char *str)
249{
250    console_loglevel = 4;
251    return 0;
252}
253
254early_param("debug", debug_kernel);
255early_param("quiet", quiet_kernel);
256
257static int __init loglevel(char *str)
258{
259    get_option(&str, &console_loglevel);
260    return 0;
261}
262
263early_param("loglevel", loglevel);
264
265/*
266 * Unknown boot options get handed to init, unless they look like
267 * unused parameters (modprobe will find them in /proc/cmdline).
268 */
269static int __init unknown_bootoption(char *param, char *val)
270{
271    /* Change NUL term back to "=", to make "param" the whole string. */
272    if (val) {
273        /* param=val or param="val"? */
274        if (val == param+strlen(param)+1)
275            val[-1] = '=';
276        else if (val == param+strlen(param)+2) {
277            val[-2] = '=';
278            memmove(val-1, val, strlen(val)+1);
279            val--;
280        } else
281            BUG();
282    }
283
284    /* Handle obsolete-style parameters */
285    if (obsolete_checksetup(param))
286        return 0;
287
288    /* Unused module parameter. */
289    if (strchr(param, '.') && (!val || strchr(param, '.') < val))
290        return 0;
291
292    if (panic_later)
293        return 0;
294
295    if (val) {
296        /* Environment option */
297        unsigned int i;
298        for (i = 0; envp_init[i]; i++) {
299            if (i == MAX_INIT_ENVS) {
300                panic_later = "Too many boot env vars at `%s'";
301                panic_param = param;
302            }
303            if (!strncmp(param, envp_init[i], val - param))
304                break;
305        }
306        envp_init[i] = param;
307    } else {
308        /* Command line option */
309        unsigned int i;
310        for (i = 0; argv_init[i]; i++) {
311            if (i == MAX_INIT_ARGS) {
312                panic_later = "Too many boot init vars at `%s'";
313                panic_param = param;
314            }
315        }
316        argv_init[i] = param;
317    }
318    return 0;
319}
320
321#ifdef CONFIG_DEBUG_PAGEALLOC
322int __read_mostly debug_pagealloc_enabled = 0;
323#endif
324
325static int __init init_setup(char *str)
326{
327    unsigned int i;
328
329    execute_command = str;
330    /*
331     * In case LILO is going to boot us with default command line,
332     * it prepends "auto" before the whole cmdline which makes
333     * the shell think it should execute a script with such name.
334     * So we ignore all arguments entered _before_ init=... [MJ]
335     */
336    for (i = 1; i < MAX_INIT_ARGS; i++)
337        argv_init[i] = NULL;
338    return 1;
339}
340__setup("init=", init_setup);
341
342static int __init rdinit_setup(char *str)
343{
344    unsigned int i;
345
346    ramdisk_execute_command = str;
347    /* See "auto" comment in init_setup */
348    for (i = 1; i < MAX_INIT_ARGS; i++)
349        argv_init[i] = NULL;
350    return 1;
351}
352__setup("rdinit=", rdinit_setup);
353
354#ifndef CONFIG_SMP
355
356#ifdef CONFIG_X86_LOCAL_APIC
357static void __init smp_init(void)
358{
359    APIC_init_uniprocessor();
360}
361#else
362#define smp_init() do { } while (0)
363#endif
364
365static inline void setup_nr_cpu_ids(void) { }
366static inline void smp_prepare_cpus(unsigned int maxcpus) { }
367
368#else
369
370/* Setup number of possible processor ids */
371int nr_cpu_ids __read_mostly = NR_CPUS;
372EXPORT_SYMBOL(nr_cpu_ids);
373
374/* An arch may set nr_cpu_ids earlier if needed, so this would be redundant */
375static void __init setup_nr_cpu_ids(void)
376{
377    nr_cpu_ids = find_last_bit(cpumask_bits(cpu_possible_mask),NR_CPUS) + 1;
378}
379
380/* Called by boot processor to activate the rest. */
381static void __init smp_init(void)
382{
383    unsigned int cpu;
384
385    /* FIXME: This should be done in userspace --RR */
386    for_each_present_cpu(cpu) {
387        if (num_online_cpus() >= setup_max_cpus)
388            break;
389        if (!cpu_online(cpu))
390            cpu_up(cpu);
391    }
392
393    /* Any cleanup work */
394    printk(KERN_INFO "Brought up %ld CPUs\n", (long)num_online_cpus());
395    smp_cpus_done(setup_max_cpus);
396}
397
398#endif
399
400/*
401 * We need to store the untouched command line for future reference.
402 * We also need to store the touched command line since the parameter
403 * parsing is performed in place, and we should allow a component to
404 * store reference of name/value for future reference.
405 */
406static void __init setup_command_line(char *command_line)
407{
408    saved_command_line = alloc_bootmem(strlen (boot_command_line)+1);
409    static_command_line = alloc_bootmem(strlen (command_line)+1);
410    strcpy (saved_command_line, boot_command_line);
411    strcpy (static_command_line, command_line);
412}
413
414/*
415 * We need to finalize in a non-__init function or else race conditions
416 * between the root thread and the init thread may cause start_kernel to
417 * be reaped by free_initmem before the root thread has proceeded to
418 * cpu_idle.
419 *
420 * gcc-3.4 accidentally inlines this function, so use noinline.
421 */
422
423static __initdata DECLARE_COMPLETION(kthreadd_done);
424
425static noinline void __init_refok rest_init(void)
426{
427    int pid;
428
429    rcu_scheduler_starting();
430    /*
431     * We need to spawn init first so that it obtains pid 1, however
432     * the init task will end up wanting to create kthreads, which, if
433     * we schedule it before we create kthreadd, will OOPS.
434     */
435    kernel_thread(kernel_init, NULL, CLONE_FS | CLONE_SIGHAND);
436    numa_default_policy();
437    pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
438    rcu_read_lock();
439    kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
440    rcu_read_unlock();
441    complete(&kthreadd_done);
442
443    /*
444     * The boot idle thread must execute schedule()
445     * at least once to get things moving:
446     */
447    init_idle_bootup_task(current);
448    preempt_enable_no_resched();
449    schedule();
450    preempt_disable();
451
452    /* Call into cpu_idle with preempt disabled */
453    cpu_idle();
454}
455
456/* Check for early params. */
457static int __init do_early_param(char *param, char *val)
458{
459    const struct obs_kernel_param *p;
460
461    for (p = __setup_start; p < __setup_end; p++) {
462        if ((p->early && strcmp(param, p->str) == 0) ||
463            (strcmp(param, "console") == 0 &&
464             strcmp(p->str, "earlycon") == 0)
465        ) {
466            if (p->setup_func(val) != 0)
467                printk(KERN_WARNING
468                       "Malformed early option '%s'\n", param);
469        }
470    }
471    /* We accept everything at this stage. */
472    return 0;
473}
474
475void __init parse_early_options(char *cmdline)
476{
477    parse_args("early options", cmdline, NULL, 0, do_early_param);
478}
479
480/* Arch code calls this early on, or if not, just before other parsing. */
481void __init parse_early_param(void)
482{
483    static __initdata int done = 0;
484    static __initdata char tmp_cmdline[COMMAND_LINE_SIZE];
485
486    if (done)
487        return;
488
489    /* All fall through to do_early_param. */
490    strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
491    parse_early_options(tmp_cmdline);
492    done = 1;
493}
494
495/*
496 * Activate the first processor.
497 */
498
499static void __init boot_cpu_init(void)
500{
501    int cpu = smp_processor_id();
502    /* Mark the boot cpu "present", "online" etc for SMP and UP case */
503    set_cpu_online(cpu, true);
504    set_cpu_active(cpu, true);
505    set_cpu_present(cpu, true);
506    set_cpu_possible(cpu, true);
507}
508
509void __init __weak smp_setup_processor_id(void)
510{
511}
512
513void __init __weak thread_info_cache_init(void)
514{
515}
516
517/*
518 * Set up kernel memory allocators
519 */
520static void __init mm_init(void)
521{
522    /*
523     * page_cgroup requires countinous pages as memmap
524     * and it's bigger than MAX_ORDER unless SPARSEMEM.
525     */
526    page_cgroup_init_flatmem();
527    mem_init();
528    kmem_cache_init();
529    percpu_init_late();
530    pgtable_cache_init();
531    vmalloc_init();
532}
533
534asmlinkage void __init start_kernel(void)
535{
536    char * command_line;
537    extern const struct kernel_param __start___param[], __stop___param[];
538
539    smp_setup_processor_id();
540
541    /*
542     * Need to run as early as possible, to initialize the
543     * lockdep hash:
544     */
545    lockdep_init();
546    debug_objects_early_init();
547
548    /*
549     * Set up the the initial canary ASAP:
550     */
551    boot_init_stack_canary();
552
553    cgroup_init_early();
554
555    local_irq_disable();
556    early_boot_irqs_off();
557
558/*
559 * Interrupts are still disabled. Do necessary setups, then
560 * enable them
561 */
562    tick_init();
563    boot_cpu_init();
564    page_address_init();
565    printk(KERN_NOTICE "%s", linux_banner);
566    setup_arch(&command_line);
567    mm_init_owner(&init_mm, &init_task);
568    setup_command_line(command_line);
569    setup_nr_cpu_ids();
570    setup_per_cpu_areas();
571    smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
572
573    build_all_zonelists(NULL);
574    page_alloc_init();
575
576    printk(KERN_NOTICE "Kernel command line: %s\n", boot_command_line);
577    parse_early_param();
578    parse_args("Booting kernel", static_command_line, __start___param,
579           __stop___param - __start___param,
580           &unknown_bootoption);
581    /*
582     * These use large bootmem allocations and must precede
583     * kmem_cache_init()
584     */
585    pidhash_init();
586    vfs_caches_init_early();
587    sort_main_extable();
588    trap_init();
589    mm_init();
590    /*
591     * Set up the scheduler prior starting any interrupts (such as the
592     * timer interrupt). Full topology setup happens at smp_init()
593     * time - but meanwhile we still have a functioning scheduler.
594     */
595    sched_init();
596    /*
597     * Disable preemption - early bootup scheduling is extremely
598     * fragile until we cpu_idle() for the first time.
599     */
600    preempt_disable();
601    if (!irqs_disabled()) {
602        printk(KERN_WARNING "start_kernel(): bug: interrupts were "
603                "enabled *very* early, fixing it\n");
604        local_irq_disable();
605    }
606    rcu_init();
607    radix_tree_init();
608    /* init some links before init_ISA_irqs() */
609    early_irq_init();
610    init_IRQ();
611    prio_tree_init();
612    init_timers();
613    hrtimers_init();
614    softirq_init();
615    timekeeping_init();
616    time_init();
617    profile_init();
618    if (!irqs_disabled())
619        printk(KERN_CRIT "start_kernel(): bug: interrupts were "
620                 "enabled early\n");
621    early_boot_irqs_on();
622    local_irq_enable();
623
624    /* Interrupts are enabled now so all GFP allocations are safe. */
625    gfp_allowed_mask = __GFP_BITS_MASK;
626
627    kmem_cache_init_late();
628
629    /*
630     * HACK ALERT! This is early. We're enabling the console before
631     * we've done PCI setups etc, and console_init() must be aware of
632     * this. But we do want output early, in case something goes wrong.
633     */
634    console_init();
635    if (panic_later)
636        panic(panic_later, panic_param);
637
638    lockdep_info();
639
640    /*
641     * Need to run this when irqs are enabled, because it wants
642     * to self-test [hard/soft]-irqs on/off lock inversion bugs
643     * too:
644     */
645    locking_selftest();
646
647#ifdef CONFIG_BLK_DEV_INITRD
648    if (initrd_start && !initrd_below_start_ok &&
649        page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
650        printk(KERN_CRIT "initrd overwritten (0x%08lx < 0x%08lx) - "
651            "disabling it.\n",
652            page_to_pfn(virt_to_page((void *)initrd_start)),
653            min_low_pfn);
654        initrd_start = 0;
655    }
656#endif
657    page_cgroup_init();
658    enable_debug_pagealloc();
659    kmemleak_init();
660    debug_objects_mem_init();
661    idr_init_cache();
662    setup_per_cpu_pageset();
663    numa_policy_init();
664    if (late_time_init)
665        late_time_init();
666    sched_clock_init();
667    calibrate_delay();
668    pidmap_init();
669    anon_vma_init();
670#ifdef CONFIG_X86
671    if (efi_enabled)
672        efi_enter_virtual_mode();
673#endif
674    thread_info_cache_init();
675    cred_init();
676    fork_init(totalram_pages);
677    proc_caches_init();
678    buffer_init();
679    key_init();
680    security_init();
681    dbg_late_init();
682    vfs_caches_init(totalram_pages);
683    signals_init();
684    /* rootfs populating might need page-writeback */
685    page_writeback_init();
686#ifdef CONFIG_PROC_FS
687    proc_root_init();
688#endif
689    cgroup_init();
690    cpuset_init();
691    taskstats_init_early();
692    delayacct_init();
693
694    check_bugs();
695
696    acpi_early_init(); /* before LAPIC and SMP init */
697    sfi_init_late();
698
699    ftrace_init();
700
701    /* Do the rest non-__init'ed, we're now alive */
702    rest_init();
703}
704
705/* Call all constructor functions linked into the kernel. */
706static void __init do_ctors(void)
707{
708#ifdef CONFIG_CONSTRUCTORS
709    ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;
710
711    for (; fn < (ctor_fn_t *) __ctors_end; fn++)
712        (*fn)();
713#endif
714}
715
716int initcall_debug;
717core_param(initcall_debug, initcall_debug, bool, 0644);
718
719static char msgbuf[64];
720
721static int __init_or_module do_one_initcall_debug(initcall_t fn)
722{
723    ktime_t calltime, delta, rettime;
724    unsigned long long duration;
725    int ret;
726
727    printk(KERN_DEBUG "calling %pF @ %i\n", fn, task_pid_nr(current));
728    calltime = ktime_get();
729    ret = fn();
730    rettime = ktime_get();
731    delta = ktime_sub(rettime, calltime);
732    duration = (unsigned long long) ktime_to_ns(delta) >> 10;
733    printk(KERN_DEBUG "initcall %pF returned %d after %lld usecs\n", fn,
734        ret, duration);
735
736    return ret;
737}
738
739int __init_or_module do_one_initcall(initcall_t fn)
740{
741    int count = preempt_count();
742    int ret;
743
744    if (initcall_debug)
745        ret = do_one_initcall_debug(fn);
746    else
747        ret = fn();
748
749    msgbuf[0] = 0;
750
751    if (ret && ret != -ENODEV && initcall_debug)
752        sprintf(msgbuf, "error code %d ", ret);
753
754    if (preempt_count() != count) {
755        strlcat(msgbuf, "preemption imbalance ", sizeof(msgbuf));
756        preempt_count() = count;
757    }
758    if (irqs_disabled()) {
759        strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
760        local_irq_enable();
761    }
762    if (msgbuf[0]) {
763        printk("initcall %pF returned with %s\n", fn, msgbuf);
764    }
765
766    return ret;
767}
768
769
770extern initcall_t __initcall_start[], __initcall_end[], __early_initcall_end[];
771
772static void __init do_initcalls(void)
773{
774    initcall_t *fn;
775
776    for (fn = __early_initcall_end; fn < __initcall_end; fn++)
777        do_one_initcall(*fn);
778
779    /* Make sure there is no pending stuff from the initcall sequence */
780    flush_scheduled_work();
781}
782
783/*
784 * Ok, the machine is now initialized. None of the devices
785 * have been touched yet, but the CPU subsystem is up and
786 * running, and memory and process management works.
787 *
788 * Now we can finally start doing some real work..
789 */
790static void __init do_basic_setup(void)
791{
792    cpuset_init_smp();
793    usermodehelper_init();
794    init_tmpfs();
795    driver_init();
796    init_irq_proc();
797    do_ctors();
798    do_initcalls();
799}
800
801static void __init do_pre_smp_initcalls(void)
802{
803    initcall_t *fn;
804
805    for (fn = __initcall_start; fn < __early_initcall_end; fn++)
806        do_one_initcall(*fn);
807}
808
809static void run_init_process(const char *init_filename)
810{
811    argv_init[0] = init_filename;
812    kernel_execve(init_filename, argv_init, envp_init);
813}
814
815/* This is a non __init function. Force it to be noinline otherwise gcc
816 * makes it inline to init() and it becomes part of init.text section
817 */
818static noinline int init_post(void)
819{
820    /* need to finish all async __init code before freeing the memory */
821    async_synchronize_full();
822    free_initmem();
823    mark_rodata_ro();
824    system_state = SYSTEM_RUNNING;
825    numa_default_policy();
826
827
828    current->signal->flags |= SIGNAL_UNKILLABLE;
829
830    if (ramdisk_execute_command) {
831        run_init_process(ramdisk_execute_command);
832        printk(KERN_WARNING "Failed to execute %s\n",
833                ramdisk_execute_command);
834    }
835
836    /*
837     * We try each of these until one succeeds.
838     *
839     * The Bourne shell can be used instead of init if we are
840     * trying to recover a really broken machine.
841     */
842    if (execute_command) {
843        run_init_process(execute_command);
844        printk(KERN_WARNING "Failed to execute %s. Attempting "
845                    "defaults...\n", execute_command);
846    }
847    run_init_process("/sbin/init");
848    run_init_process("/etc/init");
849    run_init_process("/bin/init");
850    run_init_process("/bin/sh");
851
852    panic("No init found. Try passing init= option to kernel. "
853          "See Linux Documentation/init.txt for guidance.");
854}
855
856static int __init kernel_init(void * unused)
857{
858    /*
859     * Wait until kthreadd is all set-up.
860     */
861    wait_for_completion(&kthreadd_done);
862    /*
863     * init can allocate pages on any node
864     */
865    set_mems_allowed(node_states[N_HIGH_MEMORY]);
866    /*
867     * init can run on any cpu.
868     */
869    set_cpus_allowed_ptr(current, cpu_all_mask);
870    /*
871     * Tell the world that we're going to be the grim
872     * reaper of innocent orphaned children.
873     *
874     * We don't want people to have to make incorrect
875     * assumptions about where in the task array this
876     * can be found.
877     */
878    init_pid_ns.child_reaper = current;
879
880    cad_pid = task_pid(current);
881
882    smp_prepare_cpus(setup_max_cpus);
883
884    do_pre_smp_initcalls();
885
886    smp_init();
887    sched_init_smp();
888
889    do_basic_setup();
890
891    /* Open the /dev/console on the rootfs, this should never fail */
892    if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
893        printk(KERN_WARNING "Warning: unable to open an initial console.\n");
894
895    (void) sys_dup(0);
896    (void) sys_dup(0);
897    /*
898     * check if there is an early userspace init. If yes, let it do all
899     * the work
900     */
901
902    if (!ramdisk_execute_command)
903        ramdisk_execute_command = "/init";
904
905    if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
906        ramdisk_execute_command = NULL;
907        prepare_namespace();
908    }
909
910    /*
911     * Ok, we have completed the initial bootup, and
912     * we're essentially up and running. Get rid of the
913     * initmem segments and start the user-mode stuff..
914     */
915
916    init_post();
917    return 0;
918}
919

Archive Download this file

Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
jz-2.6.34-rc7
jz-2.6.35
jz-2.6.36
jz-2.6.37
jz-2.6.38
jz-2.6.39
jz-3.0
jz-3.1
jz-3.11
jz-3.12
jz-3.13
jz-3.15
jz-3.16
jz-3.18-dt
jz-3.2
jz-3.3
jz-3.4
jz-3.5
jz-3.6
jz-3.6-rc2-pwm
jz-3.9
jz-3.9-clk
jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master

Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9



interactive