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main.c
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1 /*
2  * linux/init/main.c
3  *
4  * Copyright (C) 1991, 1992 Linus Torvalds
5  *
6  * GK 2/5/95 - Changed to support mounting root fs via NFS
7  * Added initrd & change_root: Werner Almesberger & Hans Lermen, Feb '96
8  * Moan early if gcc is old, avoiding bogus kernels - Paul Gortmaker, May '96
9  * Simplified starting of init: Michael A. Griffith <[email protected]>
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/file.h>
72 #include <linux/ptrace.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 
84 static int kernel_init(void *);
85 
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 radix_tree_init(void);
91 #ifndef CONFIG_DEBUG_RODATA
92 static inline void mark_rodata_ro(void) { }
93 #endif
94 
95 #ifdef CONFIG_TC
96 extern void tc_init(void);
97 #endif
98 
99 /*
100  * Debug helper: via this flag we know that we are in 'early bootup code'
101  * where only the boot processor is running with IRQ disabled. This means
102  * two things - IRQ must not be enabled before the flag is cleared and some
103  * operations which are not allowed with IRQ disabled are allowed while the
104  * flag is set.
105  */
107 
110 
111 /*
112  * Boot command-line arguments
113  */
114 #define MAX_INIT_ARGS CONFIG_INIT_ENV_ARG_LIMIT
115 #define MAX_INIT_ENVS CONFIG_INIT_ENV_ARG_LIMIT
116 
117 extern void time_init(void);
118 /* Default late time init is NULL. archs can override this later. */
119 void (*__initdata late_time_init)(void);
120 extern void softirq_init(void);
121 
122 /* Untouched command line saved by arch-specific code. */
124 /* Untouched saved command line (eg. for /proc) */
126 /* Command line for parameter parsing */
127 static char *static_command_line;
128 
129 static char *execute_command;
130 static char *ramdisk_execute_command;
131 
132 /*
133  * If set, this is an indication to the drivers that reset the underlying
134  * device before going ahead with the initialization otherwise driver might
135  * rely on the BIOS and skip the reset operation.
136  *
137  * This is useful if kernel is booting in an unreliable environment.
138  * For ex. kdump situaiton where previous kernel has crashed, BIOS has been
139  * skipped and devices will be in unknown state.
140  */
141 unsigned int reset_devices;
143 
144 static int __init set_reset_devices(char *str)
145 {
146  reset_devices = 1;
147  return 1;
148 }
149 
150 __setup("reset_devices", set_reset_devices);
151 
152 static const char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
153 const char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
154 static const char *panic_later, *panic_param;
155 
156 extern const struct obs_kernel_param __setup_start[], __setup_end[];
157 
158 static int __init obsolete_checksetup(char *line)
159 {
160  const struct obs_kernel_param *p;
161  int had_early_param = 0;
162 
163  p = __setup_start;
164  do {
165  int n = strlen(p->str);
166  if (parameqn(line, p->str, n)) {
167  if (p->early) {
168  /* Already done in parse_early_param?
169  * (Needs exact match on param part).
170  * Keep iterating, as we can have early
171  * params and __setups of same names 8( */
172  if (line[n] == '\0' || line[n] == '=')
173  had_early_param = 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 
184  return had_early_param;
185 }
186 
187 /*
188  * This should be approx 2 Bo*oMips to start (note initial shift), and will
189  * still work even if initially too large, it will just take slightly longer
190  */
191 unsigned long loops_per_jiffy = (1<<12);
192 
193 EXPORT_SYMBOL(loops_per_jiffy);
194 
195 static int __init debug_kernel(char *str)
196 {
197  console_loglevel = 10;
198  return 0;
199 }
200 
201 static int __init quiet_kernel(char *str)
202 {
203  console_loglevel = 4;
204  return 0;
205 }
206 
207 early_param("debug", debug_kernel);
208 early_param("quiet", quiet_kernel);
209 
210 static int __init loglevel(char *str)
211 {
212  int newlevel;
213 
214  /*
215  * Only update loglevel value when a correct setting was passed,
216  * to prevent blind crashes (when loglevel being set to 0) that
217  * are quite hard to debug
218  */
219  if (get_option(&str, &newlevel)) {
220  console_loglevel = newlevel;
221  return 0;
222  }
223 
224  return -EINVAL;
225 }
226 
227 early_param("loglevel", loglevel);
228 
229 /* Change NUL term back to "=", to make "param" the whole string. */
230 static int __init repair_env_string(char *param, char *val, const char *unused)
231 {
232  if (val) {
233  /* param=val or param="val"? */
234  if (val == param+strlen(param)+1)
235  val[-1] = '=';
236  else if (val == param+strlen(param)+2) {
237  val[-2] = '=';
238  memmove(val-1, val, strlen(val)+1);
239  val--;
240  } else
241  BUG();
242  }
243  return 0;
244 }
245 
246 /*
247  * Unknown boot options get handed to init, unless they look like
248  * unused parameters (modprobe will find them in /proc/cmdline).
249  */
250 static int __init unknown_bootoption(char *param, char *val, const char *unused)
251 {
252  repair_env_string(param, val, unused);
253 
254  /* Handle obsolete-style parameters */
255  if (obsolete_checksetup(param))
256  return 0;
257 
258  /* Unused module parameter. */
259  if (strchr(param, '.') && (!val || strchr(param, '.') < val))
260  return 0;
261 
262  if (panic_later)
263  return 0;
264 
265  if (val) {
266  /* Environment option */
267  unsigned int i;
268  for (i = 0; envp_init[i]; i++) {
269  if (i == MAX_INIT_ENVS) {
270  panic_later = "Too many boot env vars at `%s'";
271  panic_param = param;
272  }
273  if (!strncmp(param, envp_init[i], val - param))
274  break;
275  }
276  envp_init[i] = param;
277  } else {
278  /* Command line option */
279  unsigned int i;
280  for (i = 0; argv_init[i]; i++) {
281  if (i == MAX_INIT_ARGS) {
282  panic_later = "Too many boot init vars at `%s'";
283  panic_param = param;
284  }
285  }
286  argv_init[i] = param;
287  }
288  return 0;
289 }
290 
291 static int __init init_setup(char *str)
292 {
293  unsigned int i;
294 
295  execute_command = str;
296  /*
297  * In case LILO is going to boot us with default command line,
298  * it prepends "auto" before the whole cmdline which makes
299  * the shell think it should execute a script with such name.
300  * So we ignore all arguments entered _before_ init=... [MJ]
301  */
302  for (i = 1; i < MAX_INIT_ARGS; i++)
303  argv_init[i] = NULL;
304  return 1;
305 }
306 __setup("init=", init_setup);
307 
308 static int __init rdinit_setup(char *str)
309 {
310  unsigned int i;
311 
312  ramdisk_execute_command = str;
313  /* See "auto" comment in init_setup */
314  for (i = 1; i < MAX_INIT_ARGS; i++)
315  argv_init[i] = NULL;
316  return 1;
317 }
318 __setup("rdinit=", rdinit_setup);
319 
320 #ifndef CONFIG_SMP
321 static const unsigned int setup_max_cpus = NR_CPUS;
322 #ifdef CONFIG_X86_LOCAL_APIC
323 static void __init smp_init(void)
324 {
326 }
327 #else
328 #define smp_init() do { } while (0)
329 #endif
330 
331 static inline void setup_nr_cpu_ids(void) { }
332 static inline void smp_prepare_cpus(unsigned int maxcpus) { }
333 #endif
334 
335 /*
336  * We need to store the untouched command line for future reference.
337  * We also need to store the touched command line since the parameter
338  * parsing is performed in place, and we should allow a component to
339  * store reference of name/value for future reference.
340  */
341 static void __init setup_command_line(char *command_line)
342 {
344  static_command_line = alloc_bootmem(strlen (command_line)+1);
346  strcpy (static_command_line, command_line);
347 }
348 
349 /*
350  * We need to finalize in a non-__init function or else race conditions
351  * between the root thread and the init thread may cause start_kernel to
352  * be reaped by free_initmem before the root thread has proceeded to
353  * cpu_idle.
354  *
355  * gcc-3.4 accidentally inlines this function, so use noinline.
356  */
357 
358 static __initdata DECLARE_COMPLETION(kthreadd_done);
359 
360 static noinline void __init_refok rest_init(void)
361 {
362  int pid;
363 
365  /*
366  * We need to spawn init first so that it obtains pid 1, however
367  * the init task will end up wanting to create kthreads, which, if
368  * we schedule it before we create kthreadd, will OOPS.
369  */
370  kernel_thread(kernel_init, NULL, CLONE_FS | CLONE_SIGHAND);
373  rcu_read_lock();
375  rcu_read_unlock();
376  complete(&kthreadd_done);
377 
378  /*
379  * The boot idle thread must execute schedule()
380  * at least once to get things moving:
381  */
384  /* Call into cpu_idle with preempt disabled */
385  cpu_idle();
386 }
387 
388 /* Check for early params. */
389 static int __init do_early_param(char *param, char *val, const char *unused)
390 {
391  const struct obs_kernel_param *p;
392 
393  for (p = __setup_start; p < __setup_end; p++) {
394  if ((p->early && parameq(param, p->str)) ||
395  (strcmp(param, "console") == 0 &&
396  strcmp(p->str, "earlycon") == 0)
397  ) {
398  if (p->setup_func(val) != 0)
400  "Malformed early option '%s'\n", param);
401  }
402  }
403  /* We accept everything at this stage. */
404  return 0;
405 }
406 
408 {
409  parse_args("early options", cmdline, NULL, 0, 0, 0, do_early_param);
410 }
411 
412 /* Arch code calls this early on, or if not, just before other parsing. */
414 {
415  static __initdata int done = 0;
416  static __initdata char tmp_cmdline[COMMAND_LINE_SIZE];
417 
418  if (done)
419  return;
420 
421  /* All fall through to do_early_param. */
423  parse_early_options(tmp_cmdline);
424  done = 1;
425 }
426 
427 /*
428  * Activate the first processor.
429  */
430 
431 static void __init boot_cpu_init(void)
432 {
433  int cpu = smp_processor_id();
434  /* Mark the boot cpu "present", "online" etc for SMP and UP case */
435  set_cpu_online(cpu, true);
436  set_cpu_active(cpu, true);
437  set_cpu_present(cpu, true);
438  set_cpu_possible(cpu, true);
439 }
440 
442 {
443 }
444 
445 # if THREAD_SIZE >= PAGE_SIZE
447 {
448 }
449 #endif
450 
451 /*
452  * Set up kernel memory allocators
453  */
454 static void __init mm_init(void)
455 {
456  /*
457  * page_cgroup requires contiguous pages,
458  * bigger than MAX_ORDER unless SPARSEMEM.
459  */
461  mem_init();
462  kmem_cache_init();
465  vmalloc_init();
466 }
467 
469 {
470  char * command_line;
471  extern const struct kernel_param __start___param[], __stop___param[];
472 
473  /*
474  * Need to run as early as possible, to initialize the
475  * lockdep hash:
476  */
477  lockdep_init();
480 
481  /*
482  * Set up the the initial canary ASAP:
483  */
484  boot_init_stack_canary();
485 
487 
490 
491 /*
492  * Interrupts are still disabled. Do necessary setups, then
493  * enable them
494  */
495  tick_init();
496  boot_cpu_init();
497  page_address_init();
499  setup_arch(&command_line);
500  mm_init_owner(&init_mm, &init_task);
501  mm_init_cpumask(&init_mm);
502  setup_command_line(command_line);
505  smp_prepare_boot_cpu(); /* arch-specific boot-cpu hooks */
506 
508  page_alloc_init();
509 
510  printk(KERN_NOTICE "Kernel command line: %s\n", boot_command_line);
512  parse_args("Booting kernel", static_command_line, __start___param,
513  __stop___param - __start___param,
514  -1, -1, &unknown_bootoption);
515 
516  jump_label_init();
517 
518  /*
519  * These use large bootmem allocations and must precede
520  * kmem_cache_init()
521  */
522  setup_log_buf(0);
523  pidhash_init();
526  trap_init();
527  mm_init();
528 
529  /*
530  * Set up the scheduler prior starting any interrupts (such as the
531  * timer interrupt). Full topology setup happens at smp_init()
532  * time - but meanwhile we still have a functioning scheduler.
533  */
534  sched_init();
535  /*
536  * Disable preemption - early bootup scheduling is extremely
537  * fragile until we cpu_idle() for the first time.
538  */
539  preempt_disable();
540  if (!irqs_disabled()) {
541  printk(KERN_WARNING "start_kernel(): bug: interrupts were "
542  "enabled *very* early, fixing it\n");
544  }
545  idr_init_cache();
546  perf_event_init();
547  rcu_init();
548  radix_tree_init();
549  /* init some links before init_ISA_irqs() */
550  early_irq_init();
551  init_IRQ();
552  init_timers();
553  hrtimers_init();
554  softirq_init();
556  time_init();
557  profile_init();
558  call_function_init();
559  if (!irqs_disabled())
560  printk(KERN_CRIT "start_kernel(): bug: interrupts were "
561  "enabled early\n");
562  early_boot_irqs_disabled = false;
564 
566 
567  /*
568  * HACK ALERT! This is early. We're enabling the console before
569  * we've done PCI setups etc, and console_init() must be aware of
570  * this. But we do want output early, in case something goes wrong.
571  */
572  console_init();
573  if (panic_later)
574  panic(panic_later, panic_param);
575 
576  lockdep_info();
577 
578  /*
579  * Need to run this when irqs are enabled, because it wants
580  * to self-test [hard/soft]-irqs on/off lock inversion bugs
581  * too:
582  */
584 
585 #ifdef CONFIG_BLK_DEV_INITRD
588  printk(KERN_CRIT "initrd overwritten (0x%08lx < 0x%08lx) - "
589  "disabling it.\n",
591  min_low_pfn);
592  initrd_start = 0;
593  }
594 #endif
595  page_cgroup_init();
597  kmemleak_init();
600  if (late_time_init)
601  late_time_init();
603  calibrate_delay();
604  pidmap_init();
605  anon_vma_init();
606 #ifdef CONFIG_X86
607  if (efi_enabled)
609 #endif
611  cred_init();
612  fork_init(totalram_pages);
614  buffer_init();
615  key_init();
616  security_init();
617  dbg_late_init();
618  vfs_caches_init(totalram_pages);
619  signals_init();
620  /* rootfs populating might need page-writeback */
622 #ifdef CONFIG_PROC_FS
623  proc_root_init();
624 #endif
625  cgroup_init();
626  cpuset_init();
628  delayacct_init();
629 
630  check_bugs();
631 
632  acpi_early_init(); /* before LAPIC and SMP init */
633  sfi_init_late();
634 
635  if (efi_enabled) {
636  efi_late_init();
638  }
639 
640  ftrace_init();
641 
642  /* Do the rest non-__init'ed, we're now alive */
643  rest_init();
644 }
645 
646 /* Call all constructor functions linked into the kernel. */
647 static void __init do_ctors(void)
648 {
649 #ifdef CONFIG_CONSTRUCTORS
650  ctor_fn_t *fn = (ctor_fn_t *) __ctors_start;
651 
652  for (; fn < (ctor_fn_t *) __ctors_end; fn++)
653  (*fn)();
654 #endif
655 }
656 
658 core_param(initcall_debug, initcall_debug, bool, 0644);
659 
660 static char msgbuf[64];
661 
662 static int __init_or_module do_one_initcall_debug(initcall_t fn)
663 {
664  ktime_t calltime, delta, rettime;
665  unsigned long long duration;
666  int ret;
667 
668  printk(KERN_DEBUG "calling %pF @ %i\n", fn, task_pid_nr(current));
669  calltime = ktime_get();
670  ret = fn();
671  rettime = ktime_get();
672  delta = ktime_sub(rettime, calltime);
673  duration = (unsigned long long) ktime_to_ns(delta) >> 10;
674  printk(KERN_DEBUG "initcall %pF returned %d after %lld usecs\n", fn,
675  ret, duration);
676 
677  return ret;
678 }
679 
681 {
682  int count = preempt_count();
683  int ret;
684 
685  if (initcall_debug)
686  ret = do_one_initcall_debug(fn);
687  else
688  ret = fn();
689 
690  msgbuf[0] = 0;
691 
692  if (ret && ret != -ENODEV && initcall_debug)
693  sprintf(msgbuf, "error code %d ", ret);
694 
695  if (preempt_count() != count) {
696  strlcat(msgbuf, "preemption imbalance ", sizeof(msgbuf));
697  preempt_count() = count;
698  }
699  if (irqs_disabled()) {
700  strlcat(msgbuf, "disabled interrupts ", sizeof(msgbuf));
702  }
703  if (msgbuf[0]) {
704  printk("initcall %pF returned with %s\n", fn, msgbuf);
705  }
706 
707  return ret;
708 }
709 
710 
720 extern initcall_t __initcall_end[];
721 
722 static initcall_t *initcall_levels[] __initdata = {
723  __initcall0_start,
724  __initcall1_start,
725  __initcall2_start,
726  __initcall3_start,
727  __initcall4_start,
728  __initcall5_start,
729  __initcall6_start,
730  __initcall7_start,
731  __initcall_end,
732 };
733 
734 /* Keep these in sync with initcalls in include/linux/init.h */
735 static char *initcall_level_names[] __initdata = {
736  "early",
737  "core",
738  "postcore",
739  "arch",
740  "subsys",
741  "fs",
742  "device",
743  "late",
744 };
745 
746 static void __init do_initcall_level(int level)
747 {
748  extern const struct kernel_param __start___param[], __stop___param[];
749  initcall_t *fn;
750 
751  strcpy(static_command_line, saved_command_line);
752  parse_args(initcall_level_names[level],
753  static_command_line, __start___param,
754  __stop___param - __start___param,
755  level, level,
756  &repair_env_string);
757 
758  for (fn = initcall_levels[level]; fn < initcall_levels[level+1]; fn++)
759  do_one_initcall(*fn);
760 }
761 
762 static void __init do_initcalls(void)
763 {
764  int level;
765 
766  for (level = 0; level < ARRAY_SIZE(initcall_levels) - 1; level++)
767  do_initcall_level(level);
768 }
769 
770 /*
771  * Ok, the machine is now initialized. None of the devices
772  * have been touched yet, but the CPU subsystem is up and
773  * running, and memory and process management works.
774  *
775  * Now we can finally start doing some real work..
776  */
777 static void __init do_basic_setup(void)
778 {
779  cpuset_init_smp();
781  shmem_init();
782  driver_init();
783  init_irq_proc();
784  do_ctors();
785  usermodehelper_enable();
786  do_initcalls();
787 }
788 
789 static void __init do_pre_smp_initcalls(void)
790 {
791  initcall_t *fn;
792 
793  for (fn = __initcall_start; fn < __initcall0_start; fn++)
794  do_one_initcall(*fn);
795 }
796 
797 static int run_init_process(const char *init_filename)
798 {
799  argv_init[0] = init_filename;
800  return kernel_execve(init_filename, argv_init, envp_init);
801 }
802 
803 static void __init kernel_init_freeable(void);
804 
805 static int __ref kernel_init(void *unused)
806 {
807  kernel_init_freeable();
808  /* need to finish all async __init code before freeing the memory */
810  free_initmem();
811  mark_rodata_ro();
814 
815  current->signal->flags |= SIGNAL_UNKILLABLE;
817 
818  if (ramdisk_execute_command) {
819  if (!run_init_process(ramdisk_execute_command))
820  return 0;
821  printk(KERN_WARNING "Failed to execute %s\n",
822  ramdisk_execute_command);
823  }
824 
825  /*
826  * We try each of these until one succeeds.
827  *
828  * The Bourne shell can be used instead of init if we are
829  * trying to recover a really broken machine.
830  */
831  if (execute_command) {
832  if (!run_init_process(execute_command))
833  return 0;
834  printk(KERN_WARNING "Failed to execute %s. Attempting "
835  "defaults...\n", execute_command);
836  }
837  if (!run_init_process("/sbin/init") ||
838  !run_init_process("/etc/init") ||
839  !run_init_process("/bin/init") ||
840  !run_init_process("/bin/sh"))
841  return 0;
842 
843  panic("No init found. Try passing init= option to kernel. "
844  "See Linux Documentation/init.txt for guidance.");
845 }
846 
847 static void __init kernel_init_freeable(void)
848 {
849  /*
850  * Wait until kthreadd is all set-up.
851  */
852  wait_for_completion(&kthreadd_done);
853 
854  /* Now the scheduler is fully set up and can do blocking allocations */
856 
857  /*
858  * init can allocate pages on any node
859  */
860  set_mems_allowed(node_states[N_HIGH_MEMORY]);
861  /*
862  * init can run on any cpu.
863  */
864  set_cpus_allowed_ptr(current, cpu_all_mask);
865 
866  cad_pid = task_pid(current);
867 
868  smp_prepare_cpus(setup_max_cpus);
869 
870  do_pre_smp_initcalls();
872 
873  smp_init();
874  sched_init_smp();
875 
876  do_basic_setup();
877 
878  /* Open the /dev/console on the rootfs, this should never fail */
879  if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
880  printk(KERN_WARNING "Warning: unable to open an initial console.\n");
881 
882  (void) sys_dup(0);
883  (void) sys_dup(0);
884  /*
885  * check if there is an early userspace init. If yes, let it do all
886  * the work
887  */
888 
889  if (!ramdisk_execute_command)
890  ramdisk_execute_command = "/init";
891 
892  if (sys_access((const char __user *) ramdisk_execute_command, 0) != 0) {
893  ramdisk_execute_command = NULL;
895  }
896 
897  /*
898  * Ok, we have completed the initial bootup, and
899  * we're essentially up and running. Get rid of the
900  * initmem segments and start the user-mode stuff..
901  */
902 }