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