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/unistd.h>
  17 #include <linux/string.h>
  18 #include <linux/ctype.h>
  19 #include <linux/delay.h>
  20 #include <linux/utsname.h>
  21 #include <linux/ioport.h>
  22 #include <linux/init.h>
  23 #include <linux/smp_lock.h>
  24 #include <linux/blk.h>
  25 #include <linux/hdreg.h>
  26 #include <linux/iobuf.h>
  27 #include <linux/bootmem.h>
  28
  29 #include <asm/io.h>
  30 #include <asm/bugs.h>
  31
  32 #ifdef CONFIG_PCI
  33 #include <linux/pci.h>
  34 #endif
  35
  36 #ifdef CONFIG_DIO
  37 #include <linux/dio.h>
  38 #endif
  39
  40 #ifdef CONFIG_ZORRO
  41 #include <linux/zorro.h>
  42 #endif
  43
  44 #ifdef CONFIG_MTRR
  45 #  include <asm/mtrr.h>
  46 #endif
  47
  48 #ifdef CONFIG_APM
  49 #include <linux/apm_bios.h>
  50 #endif
  51
  52 #ifdef CONFIG_MAC
  53 extern void nubus_init(void);
  54 #endif
  55
  56 #ifdef CONFIG_ISAPNP
  57 #include <linux/isapnp.h>
  58 #endif
  59
  60 #ifdef CONFIG_IRDA
  61 #include <net/irda/irda_device.h>
  62 #endif
  63
  64 /*
  65  * Versions of gcc older than that listed below may actually compile
  66  * and link okay, but the end product can have subtle run time bugs.
  67  * To avoid associated bogus bug reports, we flatly refuse to compile
  68  * with a gcc that is known to be too old from the very beginning.
  69  */
  70 #if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 6)
  71 #error sorry, your GCC is too old. It builds incorrect kernels.
  72 #endif
  73
  74 extern char _stext, _etext;
  75 extern char *linux_banner;
  76
  77 extern int console_loglevel;
  78
  79 static int init(void *);
  80
  81 extern void init_IRQ(void);
  82 extern void init_modules(void);
  83 extern void sock_init(void);
  84 extern void fork_init(unsigned long);
  85 extern void mca_init(void);
  86 extern void sbus_init(void);
  87 extern void ppc_init(void);
  88 extern void sysctl_init(void);
  89 extern void filescache_init(void);
  90 extern void signals_init(void);
  91 extern int init_pcmcia_ds(void);
  92
  93 extern void free_initmem(void);
  94 extern void filesystem_setup(void);
  95
  96 extern void ecard_init(void);
  97
  98 #if defined(CONFIG_SYSVIPC)
  99 extern void ipc_init(void);
 100 #endif
 101 #if defined(CONFIG_QUOTA)
 102 extern void dquot_init_hash(void);
 103 #endif
 104
 105 /*
 106  * Boot command-line arguments
 107  */
 108 #define MAX_INIT_ARGS 8
 109 #define MAX_INIT_ENVS 8
 110
 111 extern void time_init(void);
 112
 113 int rows, cols;
 114
 115 #ifdef CONFIG_BLK_DEV_INITRD
 116 kdev_t real_root_dev;
 117 #endif
 118
 119 int root_mountflags = MS_RDONLY;
 120 char *execute_command = NULL;
 121
 122 static char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
 123 static char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
 124
 125 /*
 126  * Read an int from an option string; if available accept a subsequent
 127  * comma as well.
 128  *
 129  * Return values:
 130  * 0 : no int in string
 131  * 1 : int found, no subsequent comma
 132  * 2 : int found including a subsequent comma
 133  */
 134 int get_option(char **str, int *pint)
 135 {
 136     char *cur = *str;
 137
 138     if (!cur || !(*cur)) return 0;
 139     *pint = simple_strtol(cur,str,0);
 140     if (cur==*str) return 0;
 141     if (**str==',') {
 142         (*str)++;
 143         return 2;
 144     }
 145
 146     return 1;
 147 }
 148
 149 char *get_options(char *str, int nints, int *ints)
 150 {
 151         int res,i=1;
 152
 153     while (i<nints) {
 154         res = get_option(&str, ints+i);
 155         if (res==0) break;
 156         i++;
 157         if (res==1) break;
 158     }
 159         ints[0] = i-1;
 160         return(str);
 161 }
 162
 163 static int __init profile_setup(char *str)
 164 {
 165     int par;
 166     if (get_option(&str,&par)) prof_shift = par;
 167         return 1;
 168 }
 169
 170 __setup("profile=", profile_setup);
 171
 172
 173 static struct dev_name_struct {
 174         const char *name;
 175         const int num;
 176 } root_dev_names[] __initdata = {
 177         { "nfs",     0x00ff },
 178         { "hda",     0x0300 },
 179         { "hdb",     0x0340 },
 180         { "hdc",     0x1600 },
 181         { "hdd",     0x1640 },
 182         { "hde",     0x2100 },
 183         { "hdf",     0x2140 },
 184         { "hdg",     0x2200 },
 185         { "hdh",     0x2240 },
 186         { "hdi",     0x3800 },
 187         { "hdj",     0x3840 },
 188         { "hdk",     0x3900 },
 189         { "hdl",     0x3940 },
 190         { "hdm",     0x5800 },
 191         { "hdn",     0x5840 },
 192         { "hdo",     0x5900 },
 193         { "hdp",     0x5940 },
 194         { "hdq",     0x5A00 },
 195         { "hdr",     0x5A40 },
 196         { "hds",     0x5B00 },
 197         { "hdt",     0x5B40 },
 198         { "sda",     0x0800 },
 199         { "sdb",     0x0810 },
 200         { "sdc",     0x0820 },
 201         { "sdd",     0x0830 },
 202         { "sde",     0x0840 },
 203         { "sdf",     0x0850 },
 204         { "sdg",     0x0860 },
 205         { "sdh",     0x0870 },
 206         { "sdi",     0x0880 },
 207         { "sdj",     0x0890 },
 208         { "sdk",     0x08a0 },
 209         { "sdl",     0x08b0 },
 210         { "sdm",     0x08c0 },
 211         { "sdn",     0x08d0 },
 212         { "sdo",     0x08e0 },
 213         { "sdp",     0x08f0 },
 214         { "ada",     0x1c00 },
 215         { "adb",     0x1c10 },
 216         { "adc",     0x1c20 },
 217         { "add",     0x1c30 },
 218         { "ade",     0x1c40 },
 219         { "fd",      0x0200 },
 220         { "md",      0x0900 },
 221         { "xda",     0x0d00 },
 222         { "xdb",     0x0d40 },
 223         { "ram",     0x0100 },
 224         { "scd",     0x0b00 },
 225         { "mcd",     0x1700 },
 226         { "cdu535",  0x1800 },
 227         { "sonycd",  0x1800 },
 228         { "aztcd",   0x1d00 },
 229         { "cm206cd", 0x2000 },
 230         { "gscd",    0x1000 },
 231         { "sbpcd",   0x1900 },
 232         { "eda",     0x2400 },
 233         { "edb",     0x2440 },
 234         { "pda",        0x2d00 },
 235         { "pdb",        0x2d10 },
 236         { "pdc",        0x2d20 },
 237         { "pdd",        0x2d30 },
 238         { "pcd",        0x2e00 },
 239         { "pf",         0x2f00 },
 240         { "apblock", APBLOCK_MAJOR << 8},
 241         { "ddv", DDV_MAJOR << 8},
 242         { NULL, 0 }
 243 };
 244
 245 kdev_t __init name_to_kdev_t(char *line)
 246 {
 247         int base = 0;
 248         if (strncmp(line,"/dev/",5) == 0) {
 249                 struct dev_name_struct *dev = root_dev_names;
 250                 line += 5;
 251                 do {
 252                         int len = strlen(dev->name);
 253                         if (strncmp(line,dev->name,len) == 0) {
 254                                 line += len;
 255                                 base = dev->num;
 256                                 break;
 257                         }
 258                         dev++;
 259                 } while (dev->name);
 260         }
 261         return to_kdev_t(base + simple_strtoul(line,NULL,base?10:16));
 262 }
 263
 264 static int __init root_dev_setup(char *line)
 265 {
 266         ROOT_DEV = name_to_kdev_t(line);
 267         return 1;
 268 }
 269
 270 __setup("root=", root_dev_setup);
 271
 272 static int __init checksetup(char *line)
 273 {
 274         struct kernel_param *p;
 275
 276         p = &__setup_start;
 277         do {
 278                 int n = strlen(p->str);
 279                 if (!strncmp(line,p->str,n)) {
 280                         if (p->setup_func(line+n))
 281                                 return 1;
 282                 }
 283                 p++;
 284         } while (p < &__setup_end);
 285         return 0;
 286 }
 287
 288 /* this should be approx 2 Bo*oMips to start (note initial shift), and will
 289    still work even if initially too large, it will just take slightly longer */
 290 unsigned long loops_per_sec = (1<<12);
 291
 292 /* This is the number of bits of precision for the loops_per_second.  Each
 293    bit takes on average 1.5/HZ seconds.  This (like the original) is a little
 294    better than 1% */
 295 #define LPS_PREC 8
 296
 297 void __init calibrate_delay(void)
 298 {
 299         unsigned long ticks, loopbit;
 300         int lps_precision = LPS_PREC;
 301
 302         loops_per_sec = (1<<12);
 303
 304         printk("Calibrating delay loop... ");
 305         while (loops_per_sec <<= 1) {
 306                 /* wait for "start of" clock tick */
 307                 ticks = jiffies;
 308                 while (ticks == jiffies)
 309                         /* nothing */;
 310                 /* Go .. */
 311                 ticks = jiffies;
 312                 __delay(loops_per_sec);
 313                 ticks = jiffies - ticks;
 314                 if (ticks)
 315                         break;
 316         }
 317
 318 /* Do a binary approximation to get loops_per_second set to equal one clock
 319    (up to lps_precision bits) */
 320         loops_per_sec >>= 1;
 321         loopbit = loops_per_sec;
 322         while ( lps_precision-- && (loopbit >>= 1) ) {
 323                 loops_per_sec |= loopbit;
 324                 ticks = jiffies;
 325                 while (ticks == jiffies);
 326                 ticks = jiffies;
 327                 __delay(loops_per_sec);
 328                 if (jiffies != ticks)   /* longer than 1 tick */
 329                         loops_per_sec &= ~loopbit;
 330         }
 331
 332 /* finally, adjust loops per second in terms of seconds instead of clocks */
 333         loops_per_sec *= HZ;
 334 /* Round the value and print it */
 335         printk("%lu.%02lu BogoMIPS\n",
 336                 (loops_per_sec+2500)/500000,
 337                 ((loops_per_sec+2500)/5000) % 100);
 338 }
 339
 340 static int __init readonly(char *str)
 341 {
 342         if (*str)
 343                 return 0;
 344         root_mountflags |= MS_RDONLY;
 345         return 1;
 346 }
 347
 348 static int __init readwrite(char *str)
 349 {
 350         if (*str)
 351                 return 0;
 352         root_mountflags &= ~MS_RDONLY;
 353         return 1;
 354 }
 355
 356 static int __init debug_kernel(char *str)
 357 {
 358         if (*str)
 359                 return 0;
 360         console_loglevel = 10;
 361         return 1;
 362 }
 363
 364 __setup("ro", readonly);
 365 __setup("rw", readwrite);
 366 __setup("debug", debug_kernel);
 367
 368 /*
 369  * This is a simple kernel command line parsing function: it parses
 370  * the command line, and fills in the arguments/environment to init
 371  * as appropriate. Any cmd-line option is taken to be an environment
 372  * variable if it contains the character '='.
 373  *
 374  * This routine also checks for options meant for the kernel.
 375  * These options are not given to init - they are for internal kernel use only.
 376  */
 377 static void __init parse_options(char *line)
 378 {
 379         char *next;
 380         int args, envs;
 381
 382         if (!*line)
 383                 return;
 384         args = 0;
 385         envs = 1;       /* TERM is set to 'linux' by default */
 386         next = line;
 387         while ((line = next) != NULL) {
 388                 if ((next = strchr(line,' ')) != NULL)
 389                         *next++ = 0;
 390                 if (!strncmp(line,"init=",5)) {
 391                         line += 5;
 392                         execute_command = line;
 393                         /* In case LILO is going to boot us with default command line,
 394                          * it prepends "auto" before the whole cmdline which makes
 395                          * the shell think it should execute a script with such name.
 396                          * So we ignore all arguments entered _before_ init=... [MJ]
 397                          */
 398                         args = 0;
 399                         continue;
 400                 }
 401                 if (checksetup(line))
 402                         continue;
 403
 404                 /*
 405                  * Then check if it's an environment variable or
 406                  * an option.
 407                  */
 408                 if (strchr(line,'=')) {
 409                         if (envs >= MAX_INIT_ENVS)
 410                                 break;
 411                         envp_init[++envs] = line;
 412                 } else {
 413                         if (args >= MAX_INIT_ARGS)
 414                                 break;
 415                         argv_init[++args] = line;
 416                 }
 417         }
 418         argv_init[args+1] = NULL;
 419         envp_init[envs+1] = NULL;
 420 }
 421
 422
 423 extern void setup_arch(char **);
 424 extern void cpu_idle(void);
 425
 426 #ifndef __SMP__
 427
 428 #define smp_init()      do { } while (0)
 429
 430 #else
 431
 432 /* Called by boot processor to activate the rest. */
 433 static void __init smp_init(void)
 434 {
 435         /* Get other processors into their bootup holding patterns. */
 436         smp_boot_cpus();
 437         smp_threads_ready=1;
 438         smp_commence();
 439 }
 440
 441 #endif
 442
 443 /*
 444  *      Activate the first processor.
 445  */
 446
 447 asmlinkage void __init start_kernel(void)
 448 {
 449         char * command_line;
 450         unsigned long mempages;
 451 /*
 452  * Interrupts are still disabled. Do necessary setups, then
 453  * enable them
 454  */
 455         lock_kernel();
 456         printk(linux_banner);
 457         setup_arch(&command_line);
 458         paging_init();
 459         trap_init();
 460         init_IRQ();
 461         sched_init();
 462         time_init();
 463         parse_options(command_line);
 464
 465         /*
 466          * HACK ALERT! This is early. We're enabling the console before
 467          * we've done PCI setups etc, and console_init() must be aware of
 468          * this. But we do want output early, in case something goes wrong.
 469          */
 470         console_init();
 471 #ifdef CONFIG_MODULES
 472         init_modules();
 473 #endif
 474         if (prof_shift) {
 475                 unsigned int size;
 476                 /* only text is profiled */
 477                 prof_len = (unsigned long) &_etext - (unsigned long) &_stext;
 478                 prof_len >>= prof_shift;
 479
 480                 size = prof_len * sizeof(unsigned int) + PAGE_SIZE-1;
 481                 prof_buffer = (unsigned int *) alloc_bootmem(size);
 482         }
 483
 484         kmem_cache_init();
 485         sti();
 486         calibrate_delay();
 487 #if 0000
 488 #ifdef CONFIG_BLK_DEV_INITRD
 489         // FIXME, use the bootmem.h interface.
 490         if (initrd_start && !initrd_below_start_ok && initrd_start < memory_start) {
 491                 printk(KERN_CRIT "initrd overwritten (0x%08lx < 0x%08lx) - "
 492                     "disabling it.\n",initrd_start,memory_start);
 493                 initrd_start = 0;
 494         }
 495 #endif
 496 #endif /* 0000 */
 497         mem_init();
 498         kmem_cache_sizes_init();
 499 #ifdef CONFIG_PROC_FS
 500         proc_root_init();
 501 #endif
 502         mempages = num_physpages;
 503
 504         fork_init(mempages);
 505         filescache_init();
 506         dcache_init();
 507         vma_init();
 508         buffer_init(mempages);
 509         page_cache_init(mempages);
 510         kiobuf_init();
 511         signals_init();
 512         inode_init();
 513         file_table_init();
 514 #if defined(CONFIG_SYSVIPC)
 515         ipc_init();
 516 #endif
 517 #if defined(CONFIG_QUOTA)
 518         dquot_init_hash();
 519 #endif
 520         check_bugs();
 521         printk("POSIX conformance testing by UNIFIX\n");
 522
 523         /*
 524          *      We count on the initial thread going ok
 525          *      Like idlers init is an unlocked kernel thread, which will
 526          *      make syscalls (and thus be locked).
 527          */
 528         smp_init();
 529         kernel_thread(init, NULL, CLONE_FS | CLONE_FILES | CLONE_SIGHAND);
 530         unlock_kernel();
 531         current->need_resched = 1;
 532         cpu_idle();
 533 }
 534
 535 #ifdef CONFIG_BLK_DEV_INITRD
 536 static int do_linuxrc(void * shell)
 537 {
 538         static char *argv[] = { "linuxrc", NULL, };
 539
 540         close(0);close(1);close(2);
 541         setsid();
 542         (void) open("/dev/console",O_RDWR,0);
 543         (void) dup(0);
 544         (void) dup(0);
 545         return execve(shell, argv, envp_init);
 546 }
 547
 548 static int __init no_initrd(char *s)
 549 {
 550         mount_initrd = 0;
 551         return 1;
 552 }
 553
 554 __setup("noinitrd", no_initrd);
 555
 556 #endif
 557
 558 struct task_struct *child_reaper = &init_task;
 559
 560 static void __init do_initcalls(void)
 561 {
 562         initcall_t *call;
 563
 564         call = &__initcall_start;
 565         do {
 566                 (*call)();
 567                 call++;
 568         } while (call < &__initcall_end);
 569 }
 570
 571 /*
 572  * Ok, the machine is now initialized. None of the devices
 573  * have been touched yet, but the CPU subsystem is up and
 574  * running, and memory and process management works.
 575  *
 576  * Now we can finally start doing some real work..
 577  */
 578 static void __init do_basic_setup(void)
 579 {
 580 #ifdef CONFIG_BLK_DEV_INITRD
 581         int real_root_mountflags;
 582 #endif
 583
 584         /*
 585          * Tell the world that we're going to be the grim
 586          * reaper of innocent orphaned children.
 587          *
 588          * We don't want people to have to make incorrect
 589          * assumptions about where in the task array this
 590          * can be found.
 591          */
 592         child_reaper = current;
 593
 594 #if defined(CONFIG_MTRR)        /* Do this after SMP initialization */
 595 /*
 596  * We should probably create some architecture-dependent "fixup after
 597  * everything is up" style function where this would belong better
 598  * than in init/main.c..
 599  */
 600         mtrr_init();
 601 #endif
 602
 603 #ifdef CONFIG_SYSCTL
 604         sysctl_init();
 605 #endif
 606
 607         /*
 608          * Ok, at this point all CPU's should be initialized, so
 609          * we can start looking into devices..
 610          */
 611 #ifdef CONFIG_PCI
 612         pci_init();
 613 #endif
 614 #ifdef CONFIG_SBUS
 615         sbus_init();
 616 #endif
 617 #if defined(CONFIG_PPC)
 618         ppc_init();
 619 #endif
 620 #ifdef CONFIG_MCA
 621         mca_init();
 622 #endif
 623 #ifdef CONFIG_ARCH_ACORN
 624         ecard_init();
 625 #endif
 626 #ifdef CONFIG_ZORRO
 627         zorro_init();
 628 #endif
 629 #ifdef CONFIG_DIO
 630         dio_init();
 631 #endif
 632 #ifdef CONFIG_MAC
 633         nubus_init();
 634 #endif
 635 #ifdef CONFIG_ISAPNP
 636         isapnp_init();
 637 #endif
 638
 639         /* Networking initialization needs a process context */
 640         sock_init();
 641
 642 #ifdef CONFIG_BLK_DEV_INITRD
 643         real_root_dev = ROOT_DEV;
 644         real_root_mountflags = root_mountflags;
 645         if (initrd_start && mount_initrd) root_mountflags &= ~MS_RDONLY;
 646         else mount_initrd =0;
 647 #endif
 648
 649         do_initcalls();
 650
 651         /* .. filesystems .. */
 652         filesystem_setup();
 653
 654 #ifdef CONFIG_IRDA
 655         irda_device_init(); /* Must be done after protocol initialization */
 656 #endif
 657 #ifdef CONFIG_PCMCIA
 658         init_pcmcia_ds();               /* Do this last */
 659 #endif
 660         /* Mount the root filesystem.. */
 661         mount_root();
 662
 663 #ifdef CONFIG_BLK_DEV_INITRD
 664         root_mountflags = real_root_mountflags;
 665         if (mount_initrd && ROOT_DEV != real_root_dev
 666             && MAJOR(ROOT_DEV) == RAMDISK_MAJOR && MINOR(ROOT_DEV) == 0) {
 667                 int error;
 668                 int i, pid;
 669
 670                 pid = kernel_thread(do_linuxrc, "/linuxrc", SIGCHLD);
 671                 if (pid>0)
 672                         while (pid != wait(&i));
 673                 if (MAJOR(real_root_dev) != RAMDISK_MAJOR
 674                      || MINOR(real_root_dev) != 0) {
 675                         error = change_root(real_root_dev,"/initrd");
 676                         if (error)
 677                                 printk(KERN_ERR "Change root to /initrd: "
 678                                     "error %d\n",error);
 679                 }
 680         }
 681 #endif
 682 }
 683
 684 static int init(void * unused)
 685 {
 686         lock_kernel();
 687         do_basic_setup();
 688
 689         /*
 690          * Ok, we have completed the initial bootup, and
 691          * we're essentially up and running. Get rid of the
 692          * initmem segments and start the user-mode stuff..
 693          */
 694         free_initmem();
 695         unlock_kernel();
 696
 697         if (open("/dev/console", O_RDWR, 0) < 0)
 698                 printk("Warning: unable to open an initial console.\n");
 699
 700         (void) dup(0);
 701         (void) dup(0);
 702
 703         /*
 704          * We try each of these until one succeeds.
 705          *
 706          * The Bourne shell can be used instead of init if we are
 707          * trying to recover a really broken machine.
 708          */
 709
 710         if (execute_command)
 711                 execve(execute_command,argv_init,envp_init);
 712         execve("/sbin/init",argv_init,envp_init);
 713         execve("/etc/init",argv_init,envp_init);
 714         execve("/bin/init",argv_init,envp_init);
 715         execve("/bin/sh",argv_init,envp_init);
 716         panic("No init found.  Try passing init= option to kernel.");
 717 }