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/proc_fs.h>
  16 #include <linux/devfs_fs_kernel.h>
  17 #include <linux/unistd.h>
  18 #include <linux/string.h>
  19 #include <linux/ctype.h>
  20 #include <linux/delay.h>
  21 #include <linux/utsname.h>
  22 #include <linux/ioport.h>
  23 #include <linux/init.h>
  24 #include <linux/raid/md.h>
  25 #include <linux/smp_lock.h>
  26 #include <linux/blk.h>
  27 #include <linux/hdreg.h>
  28 #include <linux/iobuf.h>
  29 #include <linux/bootmem.h>
  30
  31 #include <asm/io.h>
  32 #include <asm/bugs.h>
  33
  34 #ifdef CONFIG_PCI
  35 #include <linux/pci.h>
  36 #endif
  37
  38 #ifdef CONFIG_DIO
  39 #include <linux/dio.h>
  40 #endif
  41
  42 #ifdef CONFIG_ZORRO
  43 #include <linux/zorro.h>
  44 #endif
  45
  46 #ifdef CONFIG_MTRR
  47 #  include <asm/mtrr.h>
  48 #endif
  49
  50 #ifdef CONFIG_3215_CONSOLE
  51 extern int con3215_activate(void);
  52 #endif
  53
  54 #ifdef CONFIG_MAC
  55 extern void nubus_init(void);
  56 #endif
  57
  58 #ifdef CONFIG_ISAPNP
  59 #include <linux/isapnp.h>
  60 #endif
  61
  62 #ifdef CONFIG_IRDA
  63 #include <net/irda/irda_device.h>
  64 #endif
  65
  66 #ifdef CONFIG_X86_IO_APIC
  67 #include <asm/smp.h>
  68 #endif
  69
  70 /*
  71  * Versions of gcc older than that listed below may actually compile
  72  * and link okay, but the end product can have subtle run time bugs.
  73  * To avoid associated bogus bug reports, we flatly refuse to compile
  74  * with a gcc that is known to be too old from the very beginning.
  75  */
  76 #if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 7)
  77 #error sorry, your GCC is too old. It builds incorrect kernels.
  78 #endif
  79
  80 extern char _stext, _etext;
  81 extern char *linux_banner;
  82
  83 extern int console_loglevel;
  84
  85 static int init(void *);
  86
  87 extern void init_IRQ(void);
  88 extern void init_modules(void);
  89 extern void init_inventory(void);
  90 extern void sock_init(void);
  91 extern void fork_init(unsigned long);
  92 extern void mca_init(void);
  93 extern void sbus_init(void);
  94 extern void ppc_init(void);
  95 extern void sysctl_init(void);
  96 extern void filescache_init(void);
  97 extern void signals_init(void);
  98 extern void bdev_init(void);
  99 extern int init_pcmcia_ds(void);
 100 extern int usb_init(void);
 101
 102 extern void free_initmem(void);
 103 extern void filesystem_setup(void);
 104
 105 #ifdef CONFIG_TC
 106 extern void tc_init(void);
 107 #endif
 108
 109 extern void ecard_init(void);
 110
 111 #if defined(CONFIG_SYSVIPC)
 112 extern void ipc_init(void);
 113 #endif
 114 #if defined(CONFIG_QUOTA)
 115 extern void dquot_init_hash(void);
 116 #endif
 117
 118 /*
 119  * Boot command-line arguments
 120  */
 121 #define MAX_INIT_ARGS 8
 122 #define MAX_INIT_ENVS 8
 123
 124 extern void time_init(void);
 125 extern void softirq_init(void);
 126
 127 int rows, cols;
 128
 129 #ifdef CONFIG_BLK_DEV_INITRD
 130 kdev_t real_root_dev;
 131 #endif
 132
 133 int root_mountflags = MS_RDONLY;
 134 char *execute_command;
 135 char root_device_name[64];
 136
 137
 138 static char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
 139 static char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
 140
 141 static int __init profile_setup(char *str)
 142 {
 143     int par;
 144     if (get_option(&str,&par)) prof_shift = par;
 145         return 1;
 146 }
 147
 148 __setup("profile=", profile_setup);
 149
 150
 151 static struct dev_name_struct {
 152         const char *name;
 153         const int num;
 154 } root_dev_names[] __initdata = {
 155         { "nfs",     0x00ff },
 156         { "hda",     0x0300 },
 157         { "hdb",     0x0340 },
 158         { "hdc",     0x1600 },
 159         { "hdd",     0x1640 },
 160         { "hde",     0x2100 },
 161         { "hdf",     0x2140 },
 162         { "hdg",     0x2200 },
 163         { "hdh",     0x2240 },
 164         { "hdi",     0x3800 },
 165         { "hdj",     0x3840 },
 166         { "hdk",     0x3900 },
 167         { "hdl",     0x3940 },
 168         { "hdm",     0x5800 },
 169         { "hdn",     0x5840 },
 170         { "hdo",     0x5900 },
 171         { "hdp",     0x5940 },
 172         { "hdq",     0x5A00 },
 173         { "hdr",     0x5A40 },
 174         { "hds",     0x5B00 },
 175         { "hdt",     0x5B40 },
 176         { "sda",     0x0800 },
 177         { "sdb",     0x0810 },
 178         { "sdc",     0x0820 },
 179         { "sdd",     0x0830 },
 180         { "sde",     0x0840 },
 181         { "sdf",     0x0850 },
 182         { "sdg",     0x0860 },
 183         { "sdh",     0x0870 },
 184         { "sdi",     0x0880 },
 185         { "sdj",     0x0890 },
 186         { "sdk",     0x08a0 },
 187         { "sdl",     0x08b0 },
 188         { "sdm",     0x08c0 },
 189         { "sdn",     0x08d0 },
 190         { "sdo",     0x08e0 },
 191         { "sdp",     0x08f0 },
 192         { "ada",     0x1c00 },
 193         { "adb",     0x1c10 },
 194         { "adc",     0x1c20 },
 195         { "add",     0x1c30 },
 196         { "ade",     0x1c40 },
 197         { "fd",      0x0200 },
 198         { "md",      0x0900 },
 199         { "xda",     0x0d00 },
 200         { "xdb",     0x0d40 },
 201         { "ram",     0x0100 },
 202         { "scd",     0x0b00 },
 203         { "mcd",     0x1700 },
 204         { "cdu535",  0x1800 },
 205         { "sonycd",  0x1800 },
 206         { "aztcd",   0x1d00 },
 207         { "cm206cd", 0x2000 },
 208         { "gscd",    0x1000 },
 209         { "sbpcd",   0x1900 },
 210         { "eda",     0x2400 },
 211         { "edb",     0x2440 },
 212         { "pda",        0x2d00 },
 213         { "pdb",        0x2d10 },
 214         { "pdc",        0x2d20 },
 215         { "pdd",        0x2d30 },
 216         { "pcd",        0x2e00 },
 217         { "pf",         0x2f00 },
 218         { "apblock", APBLOCK_MAJOR << 8},
 219         { "ddv", DDV_MAJOR << 8},
 220         { "jsfd",    JSFD_MAJOR << 8},
 221 #ifdef CONFIG_MDISK
 222         { "mnda", (MDISK_MAJOR << MINORBITS)},
 223         { "mndb", (MDISK_MAJOR << MINORBITS) + 1},
 224         { "mndc", (MDISK_MAJOR << MINORBITS) + 2},
 225         { "mndd", (MDISK_MAJOR << MINORBITS) + 3},
 226         { "mnde", (MDISK_MAJOR << MINORBITS) + 4},
 227         { "mndf", (MDISK_MAJOR << MINORBITS) + 5},
 228         { "mndg", (MDISK_MAJOR << MINORBITS) + 6},
 229         { "mndh", (MDISK_MAJOR << MINORBITS) + 7},
 230 #endif
 231 #ifdef CONFIG_DASD
 232         { "dasda", (DASD_MAJOR << MINORBITS) },
 233         { "dasdb", (DASD_MAJOR << MINORBITS) + (1 << 2) },
 234         { "dasdc", (DASD_MAJOR << MINORBITS) + (2 << 2) },
 235         { "dasdd", (DASD_MAJOR << MINORBITS) + (3 << 2) },
 236         { "dasde", (DASD_MAJOR << MINORBITS) + (4 << 2) },
 237         { "dasdf", (DASD_MAJOR << MINORBITS) + (5 << 2) },
 238         { "dasdg", (DASD_MAJOR << MINORBITS) + (6 << 2) },
 239         { "dasdh", (DASD_MAJOR << MINORBITS) + (7 << 2) },
 240 #endif
 241 #if defined(CONFIG_BLK_CPQ_DA) || defined(CONFIG_BLK_CPQ_DA_MODULE)
 242         { "ida/c0d0p",0x4800 },
 243         { "ida/c0d1p",0x4810 },
 244         { "ida/c0d2p",0x4820 },
 245         { "ida/c0d3p",0x4830 },
 246         { "ida/c0d4p",0x4840 },
 247         { "ida/c0d5p",0x4850 },
 248         { "ida/c0d6p",0x4860 },
 249         { "ida/c0d7p",0x4870 },
 250         { "ida/c0d8p",0x4880 },
 251         { "ida/c0d9p",0x4890 },
 252         { "ida/c0d10p",0x48A0 },
 253         { "ida/c0d11p",0x48B0 },
 254         { "ida/c0d12p",0x48C0 },
 255         { "ida/c0d13p",0x48D0 },
 256         { "ida/c0d14p",0x48E0 },
 257         { "ida/c0d15p",0x48F0 },
 258 #endif
 259
 260         { NULL, 0 }
 261 };
 262
 263 kdev_t __init name_to_kdev_t(char *line)
 264 {
 265         int base = 0;
 266
 267         if (strncmp(line,"/dev/",5) == 0) {
 268                 struct dev_name_struct *dev = root_dev_names;
 269                 line += 5;
 270                 do {
 271                         int len = strlen(dev->name);
 272                         if (strncmp(line,dev->name,len) == 0) {
 273                                 line += len;
 274                                 base = dev->num;
 275                                 break;
 276                         }
 277                         dev++;
 278                 } while (dev->name);
 279         }
 280         return to_kdev_t(base + simple_strtoul(line,NULL,base?10:16));
 281 }
 282
 283 static int __init root_dev_setup(char *line)
 284 {
 285         int i;
 286         char ch;
 287
 288         ROOT_DEV = name_to_kdev_t(line);
 289         memset (root_device_name, 0, sizeof root_device_name);
 290         if (strncmp (line, "/dev/", 5) == 0) line += 5;
 291         for (i = 0; i < sizeof root_device_name - 1; ++i)
 292         {
 293             ch = line[i];
 294             if ( isspace (ch) || (ch == ',') || (ch == '\0') ) break;
 295             root_device_name[i] = ch;
 296         }
 297         return 1;
 298 }
 299
 300 __setup("root=", root_dev_setup);
 301
 302 static int __init checksetup(char *line)
 303 {
 304         struct kernel_param *p;
 305
 306         p = &__setup_start;
 307         do {
 308                 int n = strlen(p->str);
 309                 if (!strncmp(line,p->str,n)) {
 310                         if (p->setup_func(line+n))
 311                                 return 1;
 312                 }
 313                 p++;
 314         } while (p < &__setup_end);
 315         return 0;
 316 }
 317
 318 /* this should be approx 2 Bo*oMips to start (note initial shift), and will
 319    still work even if initially too large, it will just take slightly longer */
 320 unsigned long loops_per_sec = (1<<12);
 321
 322 /* This is the number of bits of precision for the loops_per_second.  Each
 323    bit takes on average 1.5/HZ seconds.  This (like the original) is a little
 324    better than 1% */
 325 #define LPS_PREC 8
 326
 327 void __init calibrate_delay(void)
 328 {
 329         unsigned long ticks, loopbit;
 330         int lps_precision = LPS_PREC;
 331
 332         loops_per_sec = (1<<12);
 333
 334         printk("Calibrating delay loop... ");
 335         while (loops_per_sec <<= 1) {
 336                 /* wait for "start of" clock tick */
 337                 ticks = jiffies;
 338                 while (ticks == jiffies)
 339                         /* nothing */;
 340                 /* Go .. */
 341                 ticks = jiffies;
 342                 __delay(loops_per_sec);
 343                 ticks = jiffies - ticks;
 344                 if (ticks)
 345                         break;
 346         }
 347
 348 /* Do a binary approximation to get loops_per_second set to equal one clock
 349    (up to lps_precision bits) */
 350         loops_per_sec >>= 1;
 351         loopbit = loops_per_sec;
 352         while ( lps_precision-- && (loopbit >>= 1) ) {
 353                 loops_per_sec |= loopbit;
 354                 ticks = jiffies;
 355                 while (ticks == jiffies);
 356                 ticks = jiffies;
 357                 __delay(loops_per_sec);
 358                 if (jiffies != ticks)   /* longer than 1 tick */
 359                         loops_per_sec &= ~loopbit;
 360         }
 361
 362 /* finally, adjust loops per second in terms of seconds instead of clocks */
 363         loops_per_sec *= HZ;
 364 /* Round the value and print it */
 365         printk("%lu.%02lu BogoMIPS\n",
 366                 (loops_per_sec+2500)/500000,
 367                 ((loops_per_sec+2500)/5000) % 100);
 368 }
 369
 370 static int __init readonly(char *str)
 371 {
 372         if (*str)
 373                 return 0;
 374         root_mountflags |= MS_RDONLY;
 375         return 1;
 376 }
 377
 378 static int __init readwrite(char *str)
 379 {
 380         if (*str)
 381                 return 0;
 382         root_mountflags &= ~MS_RDONLY;
 383         return 1;
 384 }
 385
 386 static int __init debug_kernel(char *str)
 387 {
 388         if (*str)
 389                 return 0;
 390         console_loglevel = 10;
 391         return 1;
 392 }
 393
 394 static int __init quiet_kernel(char *str)
 395 {
 396         if (*str)
 397                 return 0;
 398         console_loglevel = 4;
 399         return 1;
 400 }
 401
 402 __setup("ro", readonly);
 403 __setup("rw", readwrite);
 404 __setup("debug", debug_kernel);
 405 __setup("quiet", quiet_kernel);
 406
 407 /*
 408  * This is a simple kernel command line parsing function: it parses
 409  * the command line, and fills in the arguments/environment to init
 410  * as appropriate. Any cmd-line option is taken to be an environment
 411  * variable if it contains the character '='.
 412  *
 413  * This routine also checks for options meant for the kernel.
 414  * These options are not given to init - they are for internal kernel use only.
 415  */
 416 static void __init parse_options(char *line)
 417 {
 418         char *next,*quote;
 419         int args, envs;
 420
 421         if (!*line)
 422                 return;
 423         args = 0;
 424         envs = 1;       /* TERM is set to 'linux' by default */
 425         next = line;
 426         while ((line = next) != NULL) {
 427                 quote = strchr(line,'"');
 428                 next = strchr(line, ' ');
 429                 while (next != NULL && quote != NULL && quote < next) {
 430                         /* we found a left quote before the next blank
 431                          * now we have to find the matching right quote
 432                          */
 433                         next = strchr(quote+1, '"');
 434                         if (next != NULL) {
 435                                 quote = strchr(next+1, '"');
 436                                 next = strchr(next+1, ' ');
 437                         }
 438                 }
 439                 if (next != NULL)
 440                         *next++ = 0;
 441                 if (!strncmp(line,"init=",5)) {
 442                         line += 5;
 443                         execute_command = line;
 444                         /* In case LILO is going to boot us with default command line,
 445                          * it prepends "auto" before the whole cmdline which makes
 446                          * the shell think it should execute a script with such name.
 447                          * So we ignore all arguments entered _before_ init=... [MJ]
 448                          */
 449                         args = 0;
 450                         continue;
 451                 }
 452                 if (checksetup(line))
 453                         continue;
 454
 455                 /*
 456                  * Then check if it's an environment variable or
 457                  * an option.
 458                  */
 459                 if (strchr(line,'=')) {
 460                         if (envs >= MAX_INIT_ENVS)
 461                                 break;
 462                         envp_init[++envs] = line;
 463                 } else {
 464                         if (args >= MAX_INIT_ARGS)
 465                                 break;
 466                         if(*line)
 467                         argv_init[++args] = line;
 468                 }
 469         }
 470         argv_init[args+1] = NULL;
 471         envp_init[envs+1] = NULL;
 472 }
 473
 474
 475 extern void setup_arch(char **);
 476 extern void cpu_idle(void);
 477
 478 #ifndef CONFIG_SMP
 479
 480 #ifdef CONFIG_X86_IO_APIC
 481 static void __init smp_init(void)
 482 {
 483         IO_APIC_init_uniprocessor();
 484 }
 485 #else
 486 #define smp_init()      do { } while (0)
 487 #endif
 488
 489 #else
 490
 491 /* Called by boot processor to activate the rest. */
 492 static void __init smp_init(void)
 493 {
 494         /* Get other processors into their bootup holding patterns. */
 495         smp_boot_cpus();
 496         smp_threads_ready=1;
 497         smp_commence();
 498 }
 499
 500 #endif
 501
 502 /*
 503  *      Activate the first processor.
 504  */
 505
 506 asmlinkage void __init start_kernel(void)
 507 {
 508         char * command_line;
 509         unsigned long mempages;
 510         extern char saved_command_line[];
 511 /*
 512  * Interrupts are still disabled. Do necessary setups, then
 513  * enable them
 514  */
 515         lock_kernel();
 516         printk(linux_banner);
 517         setup_arch(&command_line);
 518         printk("Kernel command line: %s\n", saved_command_line);
 519         parse_options(command_line);
 520         trap_init();
 521         init_IRQ();
 522         sched_init();
 523         time_init();
 524         softirq_init();
 525
 526         /*
 527          * HACK ALERT! This is early. We're enabling the console before
 528          * we've done PCI setups etc, and console_init() must be aware of
 529          * this. But we do want output early, in case something goes wrong.
 530          */
 531         console_init();
 532 #ifdef CONFIG_MODULES
 533         init_modules();
 534 #endif
 535         if (prof_shift) {
 536                 unsigned int size;
 537                 /* only text is profiled */
 538                 prof_len = (unsigned long) &_etext - (unsigned long) &_stext;
 539                 prof_len >>= prof_shift;
 540
 541                 size = prof_len * sizeof(unsigned int) + PAGE_SIZE-1;
 542                 prof_buffer = (unsigned int *) alloc_bootmem(size);
 543         }
 544
 545         kmem_cache_init();
 546         sti();
 547         calibrate_delay();
 548 #ifdef CONFIG_BLK_DEV_INITRD
 549         if (initrd_start && !initrd_below_start_ok &&
 550                         initrd_start < min_low_pfn << PAGE_SHIFT) {
 551                 printk(KERN_CRIT "initrd overwritten (0x%08lx < 0x%08lx) - "
 552                     "disabling it.\n",initrd_start,min_low_pfn << PAGE_SHIFT);
 553                 initrd_start = 0;
 554         }
 555 #endif
 556 #ifdef CONFIG_BINFMT_IRIX
 557         init_inventory();
 558 #endif
 559         mem_init();
 560         kmem_cache_sizes_init();
 561 #ifdef CONFIG_3215_CONSOLE
 562         con3215_activate();
 563 #endif
 564 #ifdef CONFIG_PROC_FS
 565         proc_root_init();
 566 #endif
 567         mempages = num_physpages;
 568
 569         fork_init(mempages);
 570         filescache_init();
 571         dcache_init(mempages);
 572         vma_init();
 573         buffer_init(mempages);
 574         page_cache_init(mempages);
 575         kiobuf_setup();
 576         signals_init();
 577         bdev_init();
 578         inode_init(mempages);
 579         file_table_init();
 580 #if defined(CONFIG_SYSVIPC)
 581         ipc_init();
 582 #endif
 583 #if defined(CONFIG_QUOTA)
 584         dquot_init_hash();
 585 #endif
 586         check_bugs();
 587         printk("POSIX conformance testing by UNIFIX\n");
 588
 589         /*
 590          *      We count on the initial thread going ok
 591          *      Like idlers init is an unlocked kernel thread, which will
 592          *      make syscalls (and thus be locked).
 593          */
 594         smp_init();
 595         kmem_cpucache_init();
 596         kernel_thread(init, NULL, CLONE_FS | CLONE_FILES | CLONE_SIGHAND);
 597         unlock_kernel();
 598         current->need_resched = 1;
 599         cpu_idle();
 600 }
 601
 602 #ifdef CONFIG_BLK_DEV_INITRD
 603 static int do_linuxrc(void * shell)
 604 {
 605         static char *argv[] = { "linuxrc", NULL, };
 606
 607         close(0);close(1);close(2);
 608         setsid();
 609         (void) open("/dev/console",O_RDWR,0);
 610         (void) dup(0);
 611         (void) dup(0);
 612         return execve(shell, argv, envp_init);
 613 }
 614
 615 #endif
 616
 617 struct task_struct *child_reaper = &init_task;
 618
 619 static void __init do_initcalls(void)
 620 {
 621         initcall_t *call;
 622
 623         call = &__initcall_start;
 624         do {
 625                 (*call)();
 626                 call++;
 627         } while (call < &__initcall_end);
 628 }
 629
 630 /*
 631  * Ok, the machine is now initialized. None of the devices
 632  * have been touched yet, but the CPU subsystem is up and
 633  * running, and memory and process management works.
 634  *
 635  * Now we can finally start doing some real work..
 636  */
 637 static void __init do_basic_setup(void)
 638 {
 639 #ifdef CONFIG_BLK_DEV_INITRD
 640         int real_root_mountflags;
 641 #endif
 642
 643         /*
 644          * Tell the world that we're going to be the grim
 645          * reaper of innocent orphaned children.
 646          *
 647          * We don't want people to have to make incorrect
 648          * assumptions about where in the task array this
 649          * can be found.
 650          */
 651         child_reaper = current;
 652
 653 #if defined(CONFIG_MTRR)        /* Do this after SMP initialization */
 654 /*
 655  * We should probably create some architecture-dependent "fixup after
 656  * everything is up" style function where this would belong better
 657  * than in init/main.c..
 658  */
 659         mtrr_init();
 660 #endif
 661
 662 #ifdef CONFIG_SYSCTL
 663         sysctl_init();
 664 #endif
 665
 666         /*
 667          * Ok, at this point all CPU's should be initialized, so
 668          * we can start looking into devices..
 669          */
 670 #ifdef CONFIG_PCI
 671         pci_init();
 672 #endif
 673 #ifdef CONFIG_SBUS
 674         sbus_init();
 675 #endif
 676 #if defined(CONFIG_PPC)
 677         ppc_init();
 678 #endif
 679 #ifdef CONFIG_MCA
 680         mca_init();
 681 #endif
 682 #ifdef CONFIG_ARCH_ACORN
 683         ecard_init();
 684 #endif
 685 #ifdef CONFIG_ZORRO
 686         zorro_init();
 687 #endif
 688 #ifdef CONFIG_DIO
 689         dio_init();
 690 #endif
 691 #ifdef CONFIG_MAC
 692         nubus_init();
 693 #endif
 694 #ifdef CONFIG_ISAPNP
 695         isapnp_init();
 696 #endif
 697 #ifdef CONFIG_USB
 698         usb_init();     /* Do this before doing initcalls, so that we can make
 699                         usbcore initialize here, and all drivers initialize later */
 700 #endif
 701 #ifdef CONFIG_TC
 702         tc_init();
 703 #endif
 704
 705         /* Networking initialization needs a process context */
 706         sock_init();
 707
 708 #ifdef CONFIG_BLK_DEV_INITRD
 709         real_root_dev = ROOT_DEV;
 710         real_root_mountflags = root_mountflags;
 711         if (initrd_start && mount_initrd) root_mountflags &= ~MS_RDONLY;
 712         else mount_initrd =0;
 713 #endif
 714
 715         do_initcalls();
 716
 717         /* .. filesystems .. */
 718         filesystem_setup();
 719
 720 #ifdef CONFIG_IRDA
 721         irda_device_init(); /* Must be done after protocol initialization */
 722 #endif
 723 #ifdef CONFIG_PCMCIA
 724         init_pcmcia_ds();               /* Do this last */
 725 #endif
 726         /* Mount the root filesystem.. */
 727         mount_root();
 728
 729         mount_devfs_fs ();
 730
 731 #ifdef CONFIG_BLK_DEV_INITRD
 732         root_mountflags = real_root_mountflags;
 733         if (mount_initrd && ROOT_DEV != real_root_dev
 734             && MAJOR(ROOT_DEV) == RAMDISK_MAJOR && MINOR(ROOT_DEV) == 0) {
 735                 int error;
 736                 int i, pid;
 737
 738                 pid = kernel_thread(do_linuxrc, "/linuxrc", SIGCHLD);
 739                 if (pid>0)
 740                         while (pid != wait(&i));
 741                 if (MAJOR(real_root_dev) != RAMDISK_MAJOR
 742                      || MINOR(real_root_dev) != 0) {
 743 #ifdef CONFIG_BLK_DEV_MD
 744                         md_run_setup();
 745 #endif
 746                         error = change_root(real_root_dev,"/initrd");
 747                         if (error)
 748                                 printk(KERN_ERR "Change root to /initrd: "
 749                                     "error %d\n",error);
 750                 }
 751         }
 752 #endif
 753 }
 754
 755 static int init(void * unused)
 756 {
 757         lock_kernel();
 758         do_basic_setup();
 759
 760         /*
 761          * Ok, we have completed the initial bootup, and
 762          * we're essentially up and running. Get rid of the
 763          * initmem segments and start the user-mode stuff..
 764          */
 765         free_initmem();
 766         unlock_kernel();
 767
 768         if (open("/dev/console", O_RDWR, 0) < 0)
 769                 printk("Warning: unable to open an initial console.\n");
 770
 771         (void) dup(0);
 772         (void) dup(0);
 773
 774         /*
 775          * We try each of these until one succeeds.
 776          *
 777          * The Bourne shell can be used instead of init if we are
 778          * trying to recover a really broken machine.
 779          */
 780
 781         if (execute_command)
 782                 execve(execute_command,argv_init,envp_init);
 783         execve("/sbin/init",argv_init,envp_init);
 784         execve("/etc/init",argv_init,envp_init);
 785         execve("/bin/init",argv_init,envp_init);
 786         execve("/bin/sh",argv_init,envp_init);
 787         panic("No init found.  Try passing init= option to kernel.");
 788 }