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 #define __KERNEL_SYSCALLS__
  13
  14 #include <linux/config.h>
  15 #include <linux/types.h>
  16 #include <linux/module.h>
  17 #include <linux/proc_fs.h>
  18 #include <linux/devfs_fs_kernel.h>
  19 #include <linux/kernel.h>
  20 #include <linux/syscalls.h>
  21 #include <linux/string.h>
  22 #include <linux/ctype.h>
  23 #include <linux/delay.h>
  24 #include <linux/utsname.h>
  25 #include <linux/ioport.h>
  26 #include <linux/init.h>
  27 #include <linux/smp_lock.h>
  28 #include <linux/initrd.h>
  29 #include <linux/hdreg.h>
  30 #include <linux/bootmem.h>
  31 #include <linux/tty.h>
  32 #include <linux/gfp.h>
  33 #include <linux/percpu.h>
  34 #include <linux/kmod.h>
  35 #include <linux/kernel_stat.h>
  36 #include <linux/security.h>
  37 #include <linux/workqueue.h>
  38 #include <linux/profile.h>
  39 #include <linux/rcupdate.h>
  40 #include <linux/moduleparam.h>
  41 #include <linux/kallsyms.h>
  42 #include <linux/writeback.h>
  43 #include <linux/cpu.h>
  44 #include <linux/efi.h>
  45 #include <linux/unistd.h>
  46 #include <linux/rmap.h>
  47 #include <linux/mempolicy.h>
  48
  49 #include <asm/io.h>
  50 #include <asm/bugs.h>
  51 #include <asm/setup.h>
  52
  53 /*
  54  * This is one of the first .c files built. Error out early
  55  * if we have compiler trouble..
  56  */
  57 #if __GNUC__ == 2 && __GNUC_MINOR__ == 96
  58 #ifdef CONFIG_FRAME_POINTER
  59 #error This compiler cannot compile correctly with frame pointers enabled
  60 #endif
  61 #endif
  62
  63 #ifdef CONFIG_X86_LOCAL_APIC
  64 #include <asm/smp.h>
  65 #endif
  66
  67 /*
  68  * Versions of gcc older than that listed below may actually compile
  69  * and link okay, but the end product can have subtle run time bugs.
  70  * To avoid associated bogus bug reports, we flatly refuse to compile
  71  * with a gcc that is known to be too old from the very beginning.
  72  */
  73 #if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 95)
  74 #error Sorry, your GCC is too old. It builds incorrect kernels.
  75 #endif
  76
  77 extern char *linux_banner;
  78
  79 static int init(void *);
  80
  81 extern void init_IRQ(void);
  82 extern void sock_init(void);
  83 extern void fork_init(unsigned long);
  84 extern void mca_init(void);
  85 extern void sbus_init(void);
  86 extern void sysctl_init(void);
  87 extern void signals_init(void);
  88 extern void buffer_init(void);
  89 extern void pidhash_init(void);
  90 extern void pidmap_init(void);
  91 extern void prio_tree_init(void);
  92 extern void radix_tree_init(void);
  93 extern void free_initmem(void);
  94 extern void populate_rootfs(void);
  95 extern void driver_init(void);
  96 extern void prepare_namespace(void);
  97 #ifdef  CONFIG_ACPI
  98 extern void acpi_early_init(void);
  99 #else
 100 static inline void acpi_early_init(void) { }
 101 #endif
 102
 103 #ifdef CONFIG_TC
 104 extern void tc_init(void);
 105 #endif
 106
 107 enum system_states system_state;
 108 EXPORT_SYMBOL(system_state);
 109
 110 /*
 111  * Boot command-line arguments
 112  */
 113 #define MAX_INIT_ARGS 32
 114 #define MAX_INIT_ENVS 32
 115
 116 extern void time_init(void);
 117 /* Default late time init is NULL. archs can override this later. */
 118 void (*late_time_init)(void);
 119 extern void softirq_init(void);
 120
 121 /* Untouched command line (eg. for /proc) saved by arch-specific code. */
 122 char saved_command_line[COMMAND_LINE_SIZE];
 123
 124 static char *execute_command;
 125
 126 /* Setup configured maximum number of CPUs to activate */
 127 static unsigned int max_cpus = NR_CPUS;
 128
 129 /*
 130  * Setup routine for controlling SMP activation
 131  *
 132  * Command-line option of "nosmp" or "maxcpus=0" will disable SMP
 133  * activation entirely (the MPS table probe still happens, though).
 134  *
 135  * Command-line option of "maxcpus=<NUM>", where <NUM> is an integer
 136  * greater than 0, limits the maximum number of CPUs activated in
 137  * SMP mode to <NUM>.
 138  */
 139 static int __init nosmp(char *str)
 140 {
 141         max_cpus = 0;
 142         return 1;
 143 }
 144
 145 __setup("nosmp", nosmp);
 146
 147 static int __init maxcpus(char *str)
 148 {
 149         get_option(&str, &max_cpus);
 150         return 1;
 151 }
 152
 153 __setup("maxcpus=", maxcpus);
 154
 155 static char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
 156 char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
 157 static const char *panic_later, *panic_param;
 158
 159 static int __init obsolete_checksetup(char *line)
 160 {
 161         struct obs_kernel_param *p;
 162         extern struct obs_kernel_param __setup_start, __setup_end;
 163
 164         p = &__setup_start;
 165         do {
 166                 int n = strlen(p->str);
 167                 if (!strncmp(line, p->str, n)) {
 168                         if (p->early) {
 169                                 /* Already done in parse_early_param?  (Needs
 170                                  * exact match on param part) */
 171                                 if (line[n] == '\0' || line[n] == '=')
 172                                         return 1;
 173                         } else if (!p->setup_func) {
 174                                 printk(KERN_WARNING "Parameter %s is obsolete,"
 175                                        " ignored\n", p->str);
 176                                 return 1;
 177                         } else if (p->setup_func(line + n))
 178                                 return 1;
 179                 }
 180                 p++;
 181         } while (p < &__setup_end);
 182         return 0;
 183 }
 184
 185 static unsigned long preset_lpj;
 186 static int __init lpj_setup(char *str)
 187 {
 188         preset_lpj = simple_strtoul(str,NULL,0);
 189         return 1;
 190 }
 191
 192 __setup("lpj=", lpj_setup);
 193
 194 /*
 195  * This should be approx 2 Bo*oMips to start (note initial shift), and will
 196  * still work even if initially too large, it will just take slightly longer
 197  */
 198 unsigned long loops_per_jiffy = (1<<12);
 199
 200 EXPORT_SYMBOL(loops_per_jiffy);
 201
 202 /*
 203  * This is the number of bits of precision for the loops_per_jiffy.  Each
 204  * bit takes on average 1.5/HZ seconds.  This (like the original) is a little
 205  * better than 1%
 206  */
 207 #define LPS_PREC 8
 208
 209 void __devinit calibrate_delay(void)
 210 {
 211         unsigned long ticks, loopbit;
 212         int lps_precision = LPS_PREC;
 213
 214         if (preset_lpj) {
 215                 loops_per_jiffy = preset_lpj;
 216                 printk("Calibrating delay loop (skipped)... "
 217                         "%lu.%02lu BogoMIPS preset\n",
 218                         loops_per_jiffy/(500000/HZ),
 219                         (loops_per_jiffy/(5000/HZ)) % 100);
 220         } else {
 221                 loops_per_jiffy = (1<<12);
 222
 223 #if 0   // mask by Victor Yu. 06-02-2005
 224                 printk(KERN_DEBUG "Calibrating delay loop... ");
 225 #else   // add by Victor Yu. 06-02-2005
 226                 printk("Calibrating delay loop... ");
 227 #endif
 228                 while ((loops_per_jiffy <<= 1) != 0) {
 229                         /* wait for "start of" clock tick */
 230                         ticks = jiffies;
 231                         while (ticks == jiffies)
 232                                 /* nothing */;
 233                         /* Go .. */
 234                         ticks = jiffies;
 235                         __delay(loops_per_jiffy);
 236                         ticks = jiffies - ticks;
 237                         if (ticks)
 238                                 break;
 239                 }
 240
 241                 /*
 242                  * Do a binary approximation to get loops_per_jiffy set to
 243                  * equal one clock (up to lps_precision bits)
 244                  */
 245                 loops_per_jiffy >>= 1;
 246                 loopbit = loops_per_jiffy;
 247                 while (lps_precision-- && (loopbit >>= 1)) {
 248                         loops_per_jiffy |= loopbit;
 249                         ticks = jiffies;
 250                         while (ticks == jiffies)
 251                                 /* nothing */;
 252                         ticks = jiffies;
 253                         __delay(loops_per_jiffy);
 254                         if (jiffies != ticks)   /* longer than 1 tick */
 255                                 loops_per_jiffy &= ~loopbit;
 256                 }
 257
 258                 /* Round the value and print it */
 259                 printk("%lu.%02lu BogoMIPS (lpj=%lu)\n",
 260                         loops_per_jiffy/(500000/HZ),
 261                         (loops_per_jiffy/(5000/HZ)) % 100,
 262                         loops_per_jiffy);
 263         }
 264 }
 265
 266 static int __init debug_kernel(char *str)
 267 {
 268         if (*str)
 269                 return 0;
 270         console_loglevel = 10;
 271         return 1;
 272 }
 273
 274 static int __init quiet_kernel(char *str)
 275 {
 276         if (*str)
 277                 return 0;
 278         console_loglevel = 4;
 279         return 1;
 280 }
 281
 282 __setup("debug", debug_kernel);
 283 __setup("quiet", quiet_kernel);
 284
 285 /*
 286  * Unknown boot options get handed to init, unless they look like
 287  * failed parameters
 288  */
 289 static int __init unknown_bootoption(char *param, char *val)
 290 {
 291         /* Change NUL term back to "=", to make "param" the whole string. */
 292         if (val) {
 293                 if (val[-1] == '"') val[-2] = '=';
 294                 else val[-1] = '=';
 295         }
 296
 297         /* Handle obsolete-style parameters */
 298         if (obsolete_checksetup(param))
 299                 return 0;
 300
 301         /*
 302          * Preemptive maintenance for "why didn't my mispelled command
 303          * line work?"
 304          */
 305         if (strchr(param, '.') && (!val || strchr(param, '.') < val)) {
 306                 printk(KERN_ERR "Unknown boot option `%s': ignoring\n", param);
 307                 return 0;
 308         }
 309
 310         if (panic_later)
 311                 return 0;
 312
 313         if (val) {
 314                 /* Environment option */
 315                 unsigned int i;
 316                 for (i = 0; envp_init[i]; i++) {
 317                         if (i == MAX_INIT_ENVS) {
 318                                 panic_later = "Too many boot env vars at `%s'";
 319                                 panic_param = param;
 320                         }
 321                         if (!strncmp(param, envp_init[i], val - param))
 322                                 break;
 323                 }
 324                 envp_init[i] = param;
 325         } else {
 326                 /* Command line option */
 327                 unsigned int i;
 328                 for (i = 0; argv_init[i]; i++) {
 329                         if (i == MAX_INIT_ARGS) {
 330                                 panic_later = "Too many boot init vars at `%s'";
 331                                 panic_param = param;
 332                         }
 333                 }
 334                 argv_init[i] = param;
 335         }
 336         return 0;
 337 }
 338
 339 static int __init init_setup(char *str)
 340 {
 341         unsigned int i;
 342
 343         execute_command = str;
 344         /*
 345          * In case LILO is going to boot us with default command line,
 346          * it prepends "auto" before the whole cmdline which makes
 347          * the shell think it should execute a script with such name.
 348          * So we ignore all arguments entered _before_ init=... [MJ]
 349          */
 350         for (i = 1; i < MAX_INIT_ARGS; i++)
 351                 argv_init[i] = NULL;
 352         return 1;
 353 }
 354 __setup("init=", init_setup);
 355
 356 extern void setup_arch(char **);
 357 extern void cpu_idle(void);
 358
 359 #ifndef CONFIG_SMP
 360
 361 #ifdef CONFIG_X86_LOCAL_APIC
 362 static void __init smp_init(void)
 363 {
 364         APIC_init_uniprocessor();
 365 }
 366 #else
 367 #define smp_init()      do { } while (0)
 368 #endif
 369
 370 static inline void setup_per_cpu_areas(void) { }
 371 static inline void smp_prepare_cpus(unsigned int maxcpus) { }
 372
 373 #else
 374
 375 #ifdef __GENERIC_PER_CPU
 376 unsigned long __per_cpu_offset[NR_CPUS];
 377
 378 EXPORT_SYMBOL(__per_cpu_offset);
 379
 380 static void __init setup_per_cpu_areas(void)
 381 {
 382         unsigned long size, i;
 383         char *ptr;
 384         /* Created by linker magic */
 385         extern char __per_cpu_start[], __per_cpu_end[];
 386
 387         /* Copy section for each CPU (we discard the original) */
 388         size = ALIGN(__per_cpu_end - __per_cpu_start, SMP_CACHE_BYTES);
 389 #ifdef CONFIG_MODULES
 390         if (size < PERCPU_ENOUGH_ROOM)
 391                 size = PERCPU_ENOUGH_ROOM;
 392 #endif
 393
 394         ptr = alloc_bootmem(size * NR_CPUS);
 395
 396         for (i = 0; i < NR_CPUS; i++, ptr += size) {
 397                 __per_cpu_offset[i] = ptr - __per_cpu_start;
 398                 memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start);
 399         }
 400 }
 401 #endif /* !__GENERIC_PER_CPU */
 402
 403 /* Called by boot processor to activate the rest. */
 404 static void __init smp_init(void)
 405 {
 406         unsigned int i;
 407
 408         /* FIXME: This should be done in userspace --RR */
 409         for_each_present_cpu(i) {
 410                 if (num_online_cpus() >= max_cpus)
 411                         break;
 412                 if (!cpu_online(i))
 413                         cpu_up(i);
 414         }
 415
 416         /* Any cleanup work */
 417         printk("Brought up %ld CPUs\n", (long)num_online_cpus());
 418         smp_cpus_done(max_cpus);
 419 #if 0
 420         /* Get other processors into their bootup holding patterns. */
 421
 422         smp_threads_ready=1;
 423         smp_commence();
 424 #endif
 425 }
 426
 427 #endif
 428
 429 /*
 430  * We need to finalize in a non-__init function or else race conditions
 431  * between the root thread and the init thread may cause start_kernel to
 432  * be reaped by free_initmem before the root thread has proceeded to
 433  * cpu_idle.
 434  *
 435  * gcc-3.4 accidentally inlines this function, so use noinline.
 436  */
 437
 438 static void noinline rest_init(void)
 439 {
 440         kernel_thread(init, NULL, CLONE_FS | CLONE_SIGHAND);
 441         numa_default_policy();
 442         unlock_kernel();
 443         cpu_idle();
 444 }
 445
 446 /* Check for early params. */
 447 static int __init do_early_param(char *param, char *val)
 448 {
 449         struct obs_kernel_param *p;
 450         extern struct obs_kernel_param __setup_start, __setup_end;
 451
 452         for (p = &__setup_start; p < &__setup_end; p++) {
 453                 if (p->early && strcmp(param, p->str) == 0) {
 454                         if (p->setup_func(val) != 0)
 455                                 printk(KERN_WARNING
 456                                        "Malformed early option '%s'\n", param);
 457                 }
 458         }
 459         /* We accept everything at this stage. */
 460         return 0;
 461 }
 462
 463 /* Arch code calls this early on, or if not, just before other parsing. */
 464 void __init parse_early_param(void)
 465 {
 466         static __initdata int done = 0;
 467         static __initdata char tmp_cmdline[COMMAND_LINE_SIZE];
 468
 469         if (done)
 470                 return;
 471
 472         /* All fall through to do_early_param. */
 473         strlcpy(tmp_cmdline, saved_command_line, COMMAND_LINE_SIZE);
 474         parse_args("early options", tmp_cmdline, NULL, 0, do_early_param);
 475         done = 1;
 476 }
 477
 478 /*
 479  *      Activate the first processor.
 480  */
 481
 482 asmlinkage void __init start_kernel(void)
 483 {
 484         char * command_line;
 485         extern struct kernel_param __start___param[], __stop___param[];
 486 #if 1  // add by Victor Yu. for debug using 07-27-2007, Fraddy tell me this issue
 487                 int     tlb, entry, way, rd, index;
 488 #endif
 489 /*
 490  * Interrupts are still disabled. Do necessary setups, then
 491  * enable them
 492  */
 493         lock_kernel();
 494         page_address_init();
 495         printk(linux_banner);
 496         setup_arch(&command_line);
 497         setup_per_cpu_areas();
 498 #if 1   // add by Victor Yu. for debug using 07-27-2007, Fraddy tell me this issue
 499         //printk("start_kernel: lock TLB\n");
 500         rd = 0xF9400003;        // garbage address for lock
 501         for ( tlb=0; tlb<2; tlb++ ) {
 502                 for (way=0; way<4; way++ ) {
 503                         for (entry=0; entry<16/*32*/; entry++ ) {
 504                                 /*
 505                                 if ( ((tlb == 0) && (entry == 0)) ||
 506                                      ((tlb == 0) && (entry == 1)) ) {
 507                                      */
 508                                         index = ((tlb << 24) | (way << 22) | (entry << 18)) & 0x1FC0000;
 509                                         //printk("index = 0x%x\n", index);
 510                                         asm("mcr p15, 4, %0, c15, c0, 1"
 511                                             :
 512                                             : "r" (index));
 513                                         asm("mcr p15, 4, %0, c15, c6, 0"
 514                                             :
 515                                             : "r" (rd));
 516                                 //}
 517                         }
 518                 }
 519         }
 520 #endif
 521
 522         /*
 523          * Mark the boot cpu "online" so that it can call console drivers in
 524          * printk() and can access its per-cpu storage.
 525          */
 526         smp_prepare_boot_cpu();
 527
 528         /*
 529          * Set up the scheduler prior starting any interrupts (such as the
 530          * timer interrupt). Full topology setup happens at smp_init()
 531          * time - but meanwhile we still have a functioning scheduler.
 532          */
 533         sched_init();
 534         build_all_zonelists();
 535         page_alloc_init();
 536         printk("Kernel command line: %s\n", saved_command_line);
 537         parse_early_param();
 538         parse_args("Booting kernel", command_line, __start___param,
 539                    __stop___param - __start___param,
 540                    &unknown_bootoption);
 541         sort_main_extable();
 542         trap_init();
 543         rcu_init();
 544         init_IRQ();
 545         pidhash_init();
 546         init_timers();
 547         softirq_init();
 548         time_init();
 549
 550         /*
 551          * HACK ALERT! This is early. We're enabling the console before
 552          * we've done PCI setups etc, and console_init() must be aware of
 553          * this. But we do want output early, in case something goes wrong.
 554          */
 555         console_init();
 556         if (panic_later)
 557                 panic(panic_later, panic_param);
 558         profile_init();
 559         local_irq_enable();
 560 #ifdef CONFIG_BLK_DEV_INITRD
 561         if (initrd_start && !initrd_below_start_ok &&
 562                         initrd_start < min_low_pfn << PAGE_SHIFT) {
 563                 printk(KERN_CRIT "initrd overwritten (0x%08lx < 0x%08lx) - "
 564                     "disabling it.\n",initrd_start,min_low_pfn << PAGE_SHIFT);
 565                 initrd_start = 0;
 566         }
 567 #endif
 568         vfs_caches_init_early();
 569         mem_init();
 570         kmem_cache_init();
 571         numa_policy_init();
 572         if (late_time_init)
 573                 late_time_init();
 574         calibrate_delay();
 575         pidmap_init();
 576         pgtable_cache_init();
 577         prio_tree_init();
 578         anon_vma_init();
 579 #ifdef CONFIG_X86
 580         if (efi_enabled)
 581                 efi_enter_virtual_mode();
 582 #endif
 583         fork_init(num_physpages);
 584         proc_caches_init();
 585         buffer_init();
 586         unnamed_dev_init();
 587         security_scaffolding_startup();
 588         vfs_caches_init(num_physpages);
 589         radix_tree_init();
 590         signals_init();
 591         /* rootfs populating might need page-writeback */
 592         page_writeback_init();
 593 #ifdef CONFIG_PROC_FS
 594         proc_root_init();
 595 #endif
 596         check_bugs();
 597
 598         acpi_early_init(); /* before LAPIC and SMP init */
 599
 600         /* Do the rest non-__init'ed, we're now alive */
 601         rest_init();
 602 }
 603
 604 static int __initdata initcall_debug;
 605
 606 static int __init initcall_debug_setup(char *str)
 607 {
 608         initcall_debug = 1;
 609         return 1;
 610 }
 611 __setup("initcall_debug", initcall_debug_setup);
 612
 613 struct task_struct *child_reaper = &init_task;
 614
 615 extern initcall_t __initcall_start, __initcall_end;
 616
 617 static void __init do_initcalls(void)
 618 {
 619         initcall_t *call;
 620         int count = preempt_count();
 621
 622         for (call = &__initcall_start; call < &__initcall_end; call++) {
 623                 char *msg;
 624
 625                 if (initcall_debug) {
 626                         printk(KERN_DEBUG "Calling initcall 0x%p", *call);
 627                         print_symbol(": %s()", (unsigned long) *call);
 628                         printk("\n");
 629                 }
 630
 631                 (*call)();
 632
 633                 msg = NULL;
 634                 if (preempt_count() != count) {
 635                         msg = "preemption imbalance";
 636                         preempt_count() = count;
 637                 }
 638                 if (irqs_disabled()) {
 639                         msg = "disabled interrupts";
 640                         local_irq_enable();
 641                 }
 642                 if (msg) {
 643                         printk("error in initcall at 0x%p: "
 644                                 "returned with %s\n", *call, msg);
 645                 }
 646         }
 647
 648         /* Make sure there is no pending stuff from the initcall sequence */
 649         flush_scheduled_work();
 650 }
 651
 652 /*
 653  * Ok, the machine is now initialized. None of the devices
 654  * have been touched yet, but the CPU subsystem is up and
 655  * running, and memory and process management works.
 656  *
 657  * Now we can finally start doing some real work..
 658  */
 659 static void __init do_basic_setup(void)
 660 {
 661         /* drivers will send hotplug events */
 662         init_workqueues();
 663         usermodehelper_init();
 664
 665         driver_init();
 666
 667 #ifdef CONFIG_SYSCTL
 668         sysctl_init();
 669 #endif
 670
 671         /* Networking initialization needs a process context */
 672         sock_init();
 673
 674         do_initcalls();
 675 }
 676
 677 static void do_pre_smp_initcalls(void)
 678 {
 679         extern int spawn_ksoftirqd(void);
 680 #ifdef CONFIG_SMP
 681         extern int migration_init(void);
 682
 683         migration_init();
 684 #endif
 685         spawn_ksoftirqd();
 686 }
 687
 688 static void run_init_process(char *init_filename)
 689 {
 690         argv_init[0] = init_filename;
 691         execve(init_filename, argv_init, envp_init);
 692 }
 693
 694 static inline void fixup_cpu_present_map(void)
 695 {
 696 #ifdef CONFIG_SMP
 697         int i;
 698
 699         /*
 700          * If arch is not hotplug ready and did not populate
 701          * cpu_present_map, just make cpu_present_map same as cpu_possible_map
 702          * for other cpu bringup code to function as normal. e.g smp_init() etc.
 703          */
 704         if (cpus_empty(cpu_present_map)) {
 705                 for_each_cpu(i) {
 706                         cpu_set(i, cpu_present_map);
 707                 }
 708         }
 709 #endif
 710 }
 711
 712 static int init(void * unused)
 713 {
 714         lock_kernel();
 715         /*
 716          * Tell the world that we're going to be the grim
 717          * reaper of innocent orphaned children.
 718          *
 719          * We don't want people to have to make incorrect
 720          * assumptions about where in the task array this
 721          * can be found.
 722          */
 723         child_reaper = current;
 724
 725         /* Sets up cpus_possible() */
 726         smp_prepare_cpus(max_cpus);
 727
 728         do_pre_smp_initcalls();
 729
 730         fixup_cpu_present_map();
 731         smp_init();
 732         sched_init_smp();
 733
 734         /*
 735          * Do this before initcalls, because some drivers want to access
 736          * firmware files.
 737          */
 738         populate_rootfs();
 739
 740         do_basic_setup();
 741
 742         /*
 743          * check if there is an early userspace init.  If yes, let it do all
 744          * the work
 745          */
 746         if (sys_access((const char __user *) "/init", 0) == 0)
 747                 execute_command = "/init";
 748         else
 749                 prepare_namespace();
 750
 751         /*
 752          * Ok, we have completed the initial bootup, and
 753          * we're essentially up and running. Get rid of the
 754          * initmem segments and start the user-mode stuff..
 755          */
 756         free_initmem();
 757         unlock_kernel();
 758         system_state = SYSTEM_RUNNING;
 759         numa_default_policy();
 760
 761         if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
 762                 printk("Warning: unable to open an initial console.\n");
 763
 764         (void) sys_dup(0);
 765         (void) sys_dup(0);
 766
 767         /*
 768          * We try each of these until one succeeds.
 769          *
 770          * The Bourne shell can be used instead of init if we are
 771          * trying to recover a really broken machine.
 772          */
 773
 774         if (execute_command)
 775                 run_init_process(execute_command);
 776
 777         run_init_process("/sbin/init");
 778         run_init_process("/etc/init");
 779         run_init_process("/bin/init");
 780         run_init_process("/bin/sh");
 781
 782         panic("No init found.  Try passing init= option to kernel.");
 783 }
 784
 785 static int early_param_test(char *rest)
 786 {
 787         printk("early_parm_test: %s\n", rest ?: "(null)");
 788         return rest ? 0 : -EINVAL;
 789 }
 790 early_param("testsetup", early_param_test);
 791 static int early_setup_test(char *rest)
 792 {
 793         printk("early_setup_test: %s\n", rest ?: "(null)");
 794         return 0;
 795 }
 796 __setup("testsetup_long", early_setup_test);