blob: 8e7c83c5e5c1715ab1227a7b168d0fe00dbfe33d [file] [log] [blame]
lh9ed821d2023-04-07 01:36:19 -07001/*
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#include <linux/perf_event.h>
71#include <linux/posix-timers.h>
72#include <linux/random.h>
73
74#include <asm/io.h>
75#include <asm/bugs.h>
76#include <asm/setup.h>
77#include <asm/sections.h>
78#include <asm/cacheflush.h>
79
80#ifdef CONFIG_X86_LOCAL_APIC
81#include <asm/smp.h>
82#endif
83
xf.lie31de8b2023-12-26 23:38:58 -080084#ifdef CONFIG_FLAGS_UTILS
85#include <linux/reboot.h>
86#include "pub_flags.h"
87#endif
88
lh9ed821d2023-04-07 01:36:19 -070089static int kernel_init(void *);
90
91extern void init_IRQ(void);
92extern void fork_init(unsigned long);
93extern void mca_init(void);
94extern void sbus_init(void);
95extern void prio_tree_init(void);
96extern void radix_tree_init(void);
97#ifndef CONFIG_DEBUG_RODATA
98static inline void mark_rodata_ro(void) { }
99#endif
100
101#ifdef CONFIG_TC
102extern void tc_init(void);
103#endif
104
105#ifdef CONFIG_SLOB
106extern void slob_sizes_init(void);
107#endif
108
109/*
110 * Debug helper: via this flag we know that we are in 'early bootup code'
111 * where only the boot processor is running with IRQ disabled. This means
112 * two things - IRQ must not be enabled before the flag is cleared and some
113 * operations which are not allowed with IRQ disabled are allowed while the
114 * flag is set.
115 */
116bool early_boot_irqs_disabled __read_mostly;
117
118enum system_states system_state __read_mostly;
119EXPORT_SYMBOL(system_state);
120int KERNEL_START_END=0;
121EXPORT_SYMBOL(KERNEL_START_END);
122
123/*
124 * Boot command-line arguments
125 */
126#define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
127#define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
128
129extern void time_init(void);
130/* Default late time init is NULL. archs can override this later. */
131void (*__initdata late_time_init)(void);
132extern void softirq_init(void);
133
134/* Untouched command line saved by arch-specific code. */
135char __initdata boot_command_line[COMMAND_LINE_SIZE];
136/* Untouched saved command line (eg. for /proc) */
137char *saved_command_line;
138/* Command line for parameter parsing */
139static char *static_command_line;
140
141static char *execute_command;
142static char *ramdisk_execute_command;
143
144/*
145 * If set, this is an indication to the drivers that reset the underlying
146 * device before going ahead with the initialization otherwise driver might
147 * rely on the BIOS and skip the reset operation.
148 *
149 * This is useful if kernel is booting in an unreliable environment.
150 * For ex. kdump situaiton where previous kernel has crashed, BIOS has been
151 * skipped and devices will be in unknown state.
152 */
153unsigned int reset_devices;
154EXPORT_SYMBOL(reset_devices);
155
156static int __init set_reset_devices(char *str)
157{
158 reset_devices = 1;
159 return 1;
160}
161
162__setup("reset_devices", set_reset_devices);
163
164static const char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
165const char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
166static const char *panic_later, *panic_param;
167
168extern const struct obs_kernel_param __setup_start[], __setup_end[];
169
170static int __init obsolete_checksetup(char *line)
171{
172 const struct obs_kernel_param *p;
173 int had_early_param = 0;
174
175 p = __setup_start;
176 do {
177 int n = strlen(p->str);
178 if (parameqn(line, p->str, n)) {
179 if (p->early) {
180 /* Already done in parse_early_param?
181 * (Needs exact match on param part).
182 * Keep iterating, as we can have early
183 * params and __setups of same names 8( */
184 if (line[n] == '\0' || line[n] == '=')
185 had_early_param = 1;
186 } else if (!p->setup_func) {
187 printk(KERN_WARNING "Parameter %s is obsolete,"
188 " ignored\n", p->str);
189 return 1;
190 } else if (p->setup_func(line + n))
191 return 1;
192 }
193 p++;
194 } while (p < __setup_end);
195
196 return had_early_param;
197}
198
199/*
200 * This should be approx 2 Bo*oMips to start (note initial shift), and will
201 * still work even if initially too large, it will just take slightly longer
202 */
203unsigned long loops_per_jiffy = (1<<12);
204
205EXPORT_SYMBOL(loops_per_jiffy);
206
207static int __init debug_kernel(char *str)
208{
209 console_loglevel = 10;
210 return 0;
211}
212
213static int __init quiet_kernel(char *str)
214{
215 console_loglevel = 4;
216 return 0;
217}
218
219early_param("debug", debug_kernel);
220early_param("quiet", quiet_kernel);
221
222static int __init loglevel(char *str)
223{
224 int newlevel;
225
226 /*
227 * Only update loglevel value when a correct setting was passed,
228 * to prevent blind crashes (when loglevel being set to 0) that
229 * are quite hard to debug
230 */
231 if (get_option(&str, &newlevel)) {
232 console_loglevel = newlevel;
233 return 0;
234 }
235
236 return -EINVAL;
237}
238
239early_param("loglevel", loglevel);
240
241/* Change NUL term back to "=", to make "param" the whole string. */
242static int __init repair_env_string(char *param, char *val)
243{
244 if (val) {
245 /* param=val or param="val"? */
246 if (val == param+strlen(param)+1)
247 val[-1] = '=';
248 else if (val == param+strlen(param)+2) {
249 val[-2] = '=';
250 memmove(val-1, val, strlen(val)+1);
251 val--;
252 } else
253 BUG();
254 }
255 return 0;
256}
257
258/*
259 * Unknown boot options get handed to init, unless they look like
260 * unused parameters (modprobe will find them in /proc/cmdline).
261 */
262static int __init unknown_bootoption(char *param, char *val)
263{
264 repair_env_string(param, val);
265
266 /* Handle obsolete-style parameters */
267 if (obsolete_checksetup(param))
268 return 0;
269
270 /* Unused module parameter. */
271 if (strchr(param, '.') && (!val || strchr(param, '.') < val))
272 return 0;
273
274 if (panic_later)
275 return 0;
276
277 if (val) {
278 /* Environment option */
279 unsigned int i;
280 for (i = 0; envp_init[i]; i++) {
281 if (i == MAX_INIT_ENVS) {
282 panic_later = "Too many boot env vars at `%s'";
283 panic_param = param;
284 }
285 if (!strncmp(param, envp_init[i], val - param))
286 break;
287 }
288 envp_init[i] = param;
289 } else {
290 /* Command line option */
291 unsigned int i;
292 for (i = 0; argv_init[i]; i++) {
293 if (i == MAX_INIT_ARGS) {
294 panic_later = "Too many boot init vars at `%s'";
295 panic_param = param;
296 }
297 }
298 argv_init[i] = param;
299 }
300 return 0;
301}
302
303static int __init init_setup(char *str)
304{
305 unsigned int i;
306
307 execute_command = str;
308 /*
309 * In case LILO is going to boot us with default command line,
310 * it prepends "auto" before the whole cmdline which makes
311 * the shell think it should execute a script with such name.
312 * So we ignore all arguments entered _before_ init=... [MJ]
313 */
314 for (i = 1; i < MAX_INIT_ARGS; i++)
315 argv_init[i] = NULL;
316 return 1;
317}
318__setup("init=", init_setup);
319
320static int __init rdinit_setup(char *str)
321{
322 unsigned int i;
323
324 ramdisk_execute_command = str;
325 /* See "auto" comment in init_setup */
326 for (i = 1; i < MAX_INIT_ARGS; i++)
327 argv_init[i] = NULL;
328 return 1;
329}
330__setup("rdinit=", rdinit_setup);
331
332#ifndef CONFIG_SMP
333static const unsigned int setup_max_cpus = NR_CPUS;
334#ifdef CONFIG_X86_LOCAL_APIC
335static void __init smp_init(void)
336{
337 APIC_init_uniprocessor();
338}
339#else
340#define smp_init() do { } while (0)
341#endif
342
343static inline void setup_nr_cpu_ids(void) { }
344static inline void smp_prepare_cpus(unsigned int maxcpus) { }
345#endif
346
347/*
348 * We need to store the untouched command line for future reference.
349 * We also need to store the touched command line since the parameter
350 * parsing is performed in place, and we should allow a component to
351 * store reference of name/value for future reference.
352 */
353static void __init setup_command_line(char *command_line)
354{
355 saved_command_line = alloc_bootmem(strlen (boot_command_line)+1);
356 static_command_line = alloc_bootmem(strlen (command_line)+1);
357 strcpy (saved_command_line, boot_command_line);
358 strcpy (static_command_line, command_line);
359}
360
361/*
362 * We need to finalize in a non-__init function or else race conditions
363 * between the root thread and the init thread may cause start_kernel to
364 * be reaped by free_initmem before the root thread has proceeded to
365 * cpu_idle.
366 *
367 * gcc-3.4 accidentally inlines this function, so use noinline.
368 */
369
370static __initdata DECLARE_COMPLETION(kthreadd_done);
371
372static noinline void __init_refok rest_init(void)
373{
374 int pid;
375
376 rcu_scheduler_starting();
377 /*
378 * We need to spawn init first so that it obtains pid 1, however
379 * the init task will end up wanting to create kthreads, which, if
380 * we schedule it before we create kthreadd, will OOPS.
381 */
382 kernel_thread(kernel_init, NULL, CLONE_FS | CLONE_SIGHAND);
383 numa_default_policy();
384 pid = kernel_thread(kthreadd, NULL, CLONE_FS | CLONE_FILES);
385 rcu_read_lock();
386 kthreadd_task = find_task_by_pid_ns(pid, &init_pid_ns);
387 rcu_read_unlock();
388 complete(&kthreadd_done);
389
390 /*
391 * The boot idle thread must execute schedule()
392 * at least once to get things moving:
393 */
394 init_idle_bootup_task(current);
395 schedule_preempt_disabled();
396 /* Call into cpu_idle with preempt disabled */
397 cpu_idle();
398}
399
400/* Check for early params. */
401static int __init do_early_param(char *param, char *val)
402{
403 const struct obs_kernel_param *p;
404
405 for (p = __setup_start; p < __setup_end; p++) {
406 if ((p->early && parameq(param, p->str)) ||
407 (strcmp(param, "console") == 0 &&
408 strcmp(p->str, "earlycon") == 0)
409 ) {
410 if (p->setup_func(val) != 0)
411 printk(KERN_WARNING
412 "Malformed early option '%s'\n", param);
413 }
414 }
415 /* We accept everything at this stage. */
416 return 0;
417}
418
419void __init parse_early_options(char *cmdline)
420{
421 parse_args("early options", cmdline, NULL, 0, 0, 0, do_early_param);
422}
423
424/* Arch code calls this early on, or if not, just before other parsing. */
425void __init parse_early_param(void)
426{
427 static __initdata int done = 0;
428 static __initdata char tmp_cmdline[COMMAND_LINE_SIZE];
429
430 if (done)
431 return;
432
433 /* All fall through to do_early_param. */
434 strlcpy(tmp_cmdline, boot_command_line, COMMAND_LINE_SIZE);
435 parse_early_options(tmp_cmdline);
436 done = 1;
437}
438
439/*
440 * Activate the first processor.
441 */
442
443static void __init boot_cpu_init(void)
444{
445 int cpu = smp_processor_id();
446 /* Mark the boot cpu "present", "online" etc for SMP and UP case */
447 set_cpu_online(cpu, true);
448 set_cpu_active(cpu, true);
449 set_cpu_present(cpu, true);
450 set_cpu_possible(cpu, true);
451}
452
453void __init __weak smp_setup_processor_id(void)
454{
455}
456
457void __init __weak thread_info_cache_init(void)
458{
459}
460
461/*
462 * Set up kernel memory allocators
463 */
464static void __init mm_init(void)
465{
466 /*
467 * page_cgroup requires contiguous pages,
468 * bigger than MAX_ORDER unless SPARSEMEM.
469 */
470 page_cgroup_init_flatmem();
471 mem_init();
472 kmem_cache_init();
473 percpu_init_late();
474 pgtable_cache_init();
475 vmalloc_init();
476}
477
478static void current_kernel_init(void)
479{
480#ifdef CONFIG_STACK_SIZE
481 current_kernel_thread = &init_thread_info;
482#endif
483}
xf.lidf7f8ba2024-09-12 23:53:34 -0700484void __weak early_debug_info_init(void){}
lh9ed821d2023-04-07 01:36:19 -0700485
486asmlinkage void __init start_kernel(void)
487{
488
489 char * command_line;
490 extern const struct kernel_param __start___param[], __stop___param[];
491
492#ifdef CONFIG_SLOB
493 slob_sizes_init();
494#endif
495
496 /*
497 * Need to run as early as possible, to initialize the
498 * lockdep hash:
499 */
500 current_kernel_init();
501
502 lockdep_init();
503 smp_setup_processor_id();
504 debug_objects_early_init();
505
506 /*
507 * Set up the the initial canary ASAP:
508 */
509 boot_init_stack_canary();
510
511 cgroup_init_early();
512
513 local_irq_disable();
514 early_boot_irqs_disabled = true;
515
516
517
518/*
519 * Interrupts are still disabled. Do necessary setups, then
520 * enable them
521 */
522 tick_init();
523 boot_cpu_init();
524 page_address_init();
525 /* printk(KERN_NOTICE "%s", linux_banner); */
526 setup_arch(&command_line);
527 mm_init_owner(&init_mm, &init_task);
528 mm_init_cpumask(&init_mm);
529 setup_command_line(command_line);
530 setup_nr_cpu_ids();
531 setup_per_cpu_areas();
532 softirq_early_init();
533 smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
534
535 build_all_zonelists(NULL);
536 page_alloc_init();
537
538 /* printk(KERN_NOTICE "Kernel command line: %s\n", boot_command_line); */
539 parse_early_param();
540 parse_args("Booting kernel", static_command_line, __start___param,
541 __stop___param - __start___param,
542 -1, -1, &unknown_bootoption);
543
544 jump_label_init();
545
546 /*
547 * These use large bootmem allocations and must precede
548 * kmem_cache_init()
549 */
550 setup_log_buf(0);
551 pidhash_init();
552 vfs_caches_init_early();
553 sort_main_extable();
554 trap_init();
555 mm_init();
556
557 /*
558 * Set up the scheduler prior starting any interrupts (such as the
559 * timer interrupt). Full topology setup happens at smp_init()
560 * time - but meanwhile we still have a functioning scheduler.
561 */
562 sched_init();
563 /*
564 * Disable preemption - early bootup scheduling is extremely
565 * fragile until we cpu_idle() for the first time.
566 */
567 preempt_disable();
568 if (!irqs_disabled()) {
569 printk(KERN_WARNING "start_kernel(): bug: interrupts were "
570 "enabled *very* early, fixing it\n");
571 local_irq_disable();
572 }
573 idr_init_cache();
574 perf_event_init();
575 rcu_init();
576 radix_tree_init();
577 /* init some links before init_ISA_irqs() */
xf.lidf7f8ba2024-09-12 23:53:34 -0700578 early_debug_info_init();
lh9ed821d2023-04-07 01:36:19 -0700579 early_irq_init();
580 init_IRQ();
581 prio_tree_init();
582 init_timers();
583 hrtimers_init();
584 softirq_init();
585 timekeeping_init();
586 time_init();
587 profile_init();
588 call_function_init();
589 if (!irqs_disabled())
590 printk(KERN_CRIT "start_kernel(): bug: interrupts were "
591 "enabled early\n");
592 early_boot_irqs_disabled = false;
593 local_irq_enable();
594
595 kmem_cache_init_late();
596
597 /*
598 * HACK ALERT! This is early. We're enabling the console before
599 * we've done PCI setups etc, and console_init() must be aware of
600 * this. But we do want output early, in case something goes wrong.
601 */
602 console_init();
603 if (panic_later)
604 panic(panic_later, panic_param);
605
606 lockdep_info();
607
608 /*
609 * Need to run this when irqs are enabled, because it wants
610 * to self-test [hard/soft]-irqs on/off lock inversion bugs
611 * too:
612 */
613 locking_selftest();
614
615#ifdef CONFIG_BLK_DEV_INITRD
616 if (initrd_start && !initrd_below_start_ok &&
617 page_to_pfn(virt_to_page((void *)initrd_start)) < min_low_pfn) {
618 printk(KERN_CRIT "initrd overwritten (0x%08lx < 0x%08lx) - "
619 "disabling it.\n",
620 page_to_pfn(virt_to_page((void *)initrd_start)),
621 min_low_pfn);
622 initrd_start = 0;
623 }
624#endif
625 page_cgroup_init();
626 debug_objects_mem_init();
627 kmemleak_init();
628 setup_per_cpu_pageset();
629 numa_policy_init();
630 if (late_time_init)
631 late_time_init();
632 sched_clock_init();
633 calibrate_delay();
634 pidmap_init();
635 anon_vma_init();
636#ifdef CONFIG_X86
637 if (efi_enabled(EFI_RUNTIME_SERVICES))
638 efi_enter_virtual_mode();
639#endif
640#ifdef CONFIG_X86_ESPFIX64
641 /* Should be run before the first non-init thread is created */
642 init_espfix_bsp();
643#endif
644 thread_info_cache_init();
645 cred_init();
646 fork_init(totalram_pages);
647 proc_caches_init();
648 buffer_init();
649 key_init();
650 security_init();
651 dbg_late_init();
652 vfs_caches_init(totalram_pages);
653 signals_init();
654 /* rootfs populating might need page-writeback */
655 page_writeback_init();
656#ifdef CONFIG_PROC_FS
657 proc_root_init();
658#endif
659 cgroup_init();
660 cpuset_init();
661 taskstats_init_early();
662 delayacct_init();
663
664 check_bugs();
665
666 acpi_early_init(); /* before LAPIC and SMP init */
667 sfi_init_late();
668
669 if (efi_enabled(EFI_RUNTIME_SERVICES))
670 efi_free_boot_services();
671
672 ftrace_init();
673
674 /* Do the rest non-__init'ed, we're now alive */
675 rest_init();
676}
677
678/* Call all constructor functions linked into the kernel. */
679static void __init do_ctors(void)
680{
681#ifdef CONFIG_CONSTRUCTORS
682 ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;
683
684 for (; fn < (ctor_fn_t *) __ctors_end; fn++)
685 (*fn)();
686#endif
687}
688
689bool initcall_debug;
690core_param(initcall_debug, initcall_debug, bool, 0644);
691
692static char msgbuf[64];
693
694static int __init_or_module do_one_initcall_debug(initcall_t fn)
695{
696 ktime_t calltime, delta, rettime;
697 unsigned long long duration;
698 int ret;
699
700 printk(KERN_DEBUG "calling %pF @ %i\n", fn, task_pid_nr(current));
701 calltime = ktime_get();
702 ret = fn();
703 rettime = ktime_get();
704 delta = ktime_sub(rettime, calltime);
705 duration = (unsigned long long) ktime_to_ns(delta) >> 10;
706 printk(KERN_DEBUG "initcall %pF returned %d after %lld usecs\n", fn,
707 ret, duration);
708
709 return ret;
710}
711
712int __init_or_module do_one_initcall(initcall_t fn)
713{
714 int count = preempt_count();
715 int ret;
716
717 if (initcall_debug)
718 ret = do_one_initcall_debug(fn);
719 else
720 ret = fn();
721
722 msgbuf[0] = 0;
723
724 if (ret && ret != -ENODEV && initcall_debug)
725 sprintf(msgbuf, "error code %d ", ret);
726
727 if (preempt_count() != count) {
728 strlcat(msgbuf, "preemption imbalance ", sizeof(msgbuf));
729 preempt_count() = count;
730 }
731 if (irqs_disabled()) {
732 strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
733 local_irq_enable();
734 }
735 if (msgbuf[0]) {
736 printk("initcall %pF returned with %s\n", fn, msgbuf);
737 }
738
739 return ret;
740}
741
742
743extern initcall_t __initcall_start[];
744extern initcall_t __initcall0_start[];
745extern initcall_t __initcall1_start[];
746extern initcall_t __initcall2_start[];
747extern initcall_t __initcall3_start[];
748extern initcall_t __initcall4_start[];
749extern initcall_t __initcall5_start[];
750extern initcall_t __initcall6_start[];
751extern initcall_t __initcall7_start[];
752extern initcall_t __initcall_end[];
753
754static initcall_t *initcall_levels[] __initdata = {
755 __initcall0_start,
756 __initcall1_start,
757 __initcall2_start,
758 __initcall3_start,
759 __initcall4_start,
760 __initcall5_start,
761 __initcall6_start,
762 __initcall7_start,
763 __initcall_end,
764};
765
766static char *initcall_level_names[] __initdata = {
767 "early parameters",
768 "core parameters",
769 "postcore parameters",
770 "arch parameters",
771 "subsys parameters",
772 "fs parameters",
773 "device parameters",
774 "late parameters",
775};
776
777static void __init do_initcall_level(int level)
778{
779 extern const struct kernel_param __start___param[], __stop___param[];
780 initcall_t *fn;
781
782 strcpy(static_command_line, saved_command_line);
783 parse_args(initcall_level_names[level],
784 static_command_line, __start___param,
785 __stop___param - __start___param,
786 level, level,
787 repair_env_string);
788
789 for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++)
790 do_one_initcall(*fn);
791}
792
793static void __init do_initcalls(void)
794{
795 int level;
796
797 for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++)
798 do_initcall_level(level);
799}
800
801/*
802 * Ok, the machine is now initialized. None of the devices
803 * have been touched yet, but the CPU subsystem is up and
804 * running, and memory and process management works.
805 *
806 * Now we can finally start doing some real work..
807 */
808static void __init do_basic_setup(void)
809{
810 cpuset_init_smp();
811 usermodehelper_init();
812 shmem_init();
813 driver_init();
814 init_irq_proc();
815 do_ctors();
816 usermodehelper_enable();
817 do_initcalls();
818 random_int_secret_init();
819}
820
821static void __init do_pre_smp_initcalls(void)
822{
823 initcall_t *fn;
824
825 for (fn = __initcall_start; fn < __initcall0_start; fn++)
826 do_one_initcall(*fn);
827}
828
829static void run_init_process(const char *init_filename)
830{
831 argv_init[0] = init_filename;
832 kernel_execve(init_filename, argv_init, envp_init);
833}
834
835/* This is a non __init function. Force it to be noinline otherwise gcc
836 * makes it inline to init() and it becomes part of init.text section
837 */
838static noinline int init_post(void)
839{
840 /* need to finish all async __init code before freeing the memory */
841 async_synchronize_full();
842 free_initmem();
843 mark_rodata_ro();
844 system_state = SYSTEM_RUNNING;
845 numa_default_policy();
846
847 KERNEL_START_END=1;
848
849
850 current->signal->flags |= SIGNAL_UNKILLABLE;
851
852 if (ramdisk_execute_command) {
853 run_init_process(ramdisk_execute_command);
854 printk(KERN_WARNING "Failed to execute %s\n",
855 ramdisk_execute_command);
856 }
857
858 /*
859 * We try each of these until one succeeds.
860 *
861 * The Bourne shell can be used instead of init if we are
862 * trying to recover a really broken machine.
863 */
864 if (execute_command) {
865 run_init_process(execute_command);
866 printk(KERN_WARNING "Failed to execute %s. Attempting "
867 "defaults...\n", execute_command);
868 }
869#ifdef CONFIG_SYSTEM_RECOVERY
870 run_init_process("/recovery/sbin/init");
871#else
872 run_init_process("/sbin/init");
873 run_init_process("/etc/init");
874 run_init_process("/bin/init");
875 run_init_process("/bin/sh");
876#endif
xf.lie31de8b2023-12-26 23:38:58 -0800877#ifdef CONFIG_FLAGS_UTILS
878{
879 extern int flags_sys_switch(void);
880 printk(KERN_EMERG "No init found. Try passing init= option to kernel. "
881 "See Linux Documentation/init.txt for guidance.");
882 if (flags_sys_switch() < 0)
883 panic("init: flags_sys_switch fail");
884 else
885 kernel_restart("init: Switch to another system, please reset machine");
886}
887#endif
lh9ed821d2023-04-07 01:36:19 -0700888 panic("No init found. Try passing init= option to kernel. "
889 "See Linux Documentation/init.txt for guidance.");
890}
891
892
893/*/PSBUFµÄÐéÄâµØÖ·ÓëÎïÀíµØÖ·µÄÓ³Éä¹ØÏµ
894unsigned long virtaddr_to_phys(unsigned long virt)
895{
896 if(virt >= (unsigned long)vir_addr_ddrnet && virt <= ((unsigned long)vir_addr_ddrnet+10*1024*1024))
897 {
898 return 0x27400000 + (virt - (unsigned long)vir_addr_ddrnet);
899 }
900 return __pa(virt);
901}
902unsigned long physaddr_to_virt(unsigned long phys)
903{
904 if(phys >= 0x27400000 && phys <= (0x27400000 + 10*1024*1024))
905 return (unsigned long)vir_addr_ddrnet + (phys - 0x27400000);
906 return __va(phys);
907}
908*/
909static int __init kernel_init(void * unused)
910{
911 /*
912 * cp ps_buf mmap, for temp test.
913 * add by jkz,2016-01-07.
914 */
915 //int *vir_addr = NULL;
916
917 /*
918 * Wait until kthreadd is all set-up.
919 */
920 wait_for_completion(&kthreadd_done);
921
922 /* Now the scheduler is fully set up and can do blocking allocations */
923 gfp_allowed_mask = __GFP_BITS_MASK;
924
925 /*
926 * init can allocate pages on any node
927 */
928 set_mems_allowed(node_states[N_HIGH_MEMORY]);
929 /*
930 * init can run on any cpu.
931 */
932 set_cpus_allowed_ptr(current, cpu_all_mask);
933
934 cad_pid = task_pid(current);
935
936 smp_prepare_cpus(setup_max_cpus);
937
938 do_pre_smp_initcalls();
939 lockup_detector_init();
940
941 smp_init();
942 sched_init_smp();
943
944 do_basic_setup();
945
946 /*
947 * cp ps_buf mmap, for temp test.
948 * add by jkz,2016-01-07.
949 */
950
951 /* Open the /dev/console on the rootfs, this should never fail */
952 if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
953 printk(KERN_WARNING "Warning: unable to open an initial console.\n");
954
955 (void) sys_dup(0);
956 (void) sys_dup(0);
957 /*
958 * check if there is an early userspace init. If yes, let it do all
959 * the work
960 */
961
962 if (!ramdisk_execute_command)
963 ramdisk_execute_command = "/init";
964
965 if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
966 ramdisk_execute_command = NULL;
967 prepare_namespace();
968 }
969
970 /*
971 * Ok, we have completed the initial bootup, and
972 * we're essentially up and running. Get rid of the
973 * initmem segments and start the user-mode stuff..
974 */
975
976 init_post();
977 return 0;
978}