~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~ [ freetext search ] ~ [ file search ] ~

Linux Cross Reference
Linux/init/main.c

Version: ~ [ 0.6-2.3.46 ] ~
Architecture: ~ [ um ] ~

** Warning: Cannot open xref database.

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_MAC 51 extern void nubus_init(void); 52 #endif 53 54 #ifdef CONFIG_ISAPNP 55 #include <linux/isapnp.h> 56 #endif 57 58 #ifdef CONFIG_IRDA 59 #include <net/irda/irda_device.h> 60 #endif 61 62 #ifdef CONFIG_X86_IO_APIC 63 #include <asm/smp.h> 64 #endif 65 66 /* 67 * Versions of gcc older than that listed below may actually compile 68 * and link okay, but the end product can have subtle run time bugs. 69 * To avoid associated bogus bug reports, we flatly refuse to compile 70 * with a gcc that is known to be too old from the very beginning. 71 */ 72 #if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 6) 73 #error sorry, your GCC is too old. It builds incorrect kernels. 74 #endif 75 76 extern char _stext, _etext; 77 extern char *linux_banner; 78 79 extern int console_loglevel; 80 81 static int init(void *); 82 83 extern void init_IRQ(void); 84 extern void init_modules(void); 85 extern void sock_init(void); 86 extern void fork_init(unsigned long); 87 extern void mca_init(void); 88 extern void sbus_init(void); 89 extern void ppc_init(void); 90 extern void sysctl_init(void); 91 extern void filescache_init(void); 92 extern void signals_init(void); 93 extern void bdev_init(void); 94 extern int init_pcmcia_ds(void); 95 extern int usb_init(void); 96 97 extern void free_initmem(void); 98 extern void filesystem_setup(void); 99 100 extern void ecard_init(void); 101 102 #if defined(CONFIG_SYSVIPC) 103 extern void ipc_init(void); 104 #endif 105 #if defined(CONFIG_QUOTA) 106 extern void dquot_init_hash(void); 107 #endif 108 109 /* 110 * Boot command-line arguments 111 */ 112 #define MAX_INIT_ARGS 8 113 #define MAX_INIT_ENVS 8 114 115 extern void time_init(void); 116 extern void softirq_init(void); 117 118 int rows, cols; 119 120 #ifdef CONFIG_BLK_DEV_INITRD 121 kdev_t real_root_dev; 122 #endif 123 124 int root_mountflags = MS_RDONLY; 125 char *execute_command = NULL; 126 char root_device_name[64]; 127 128 129 static char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, }; 130 static char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, }; 131 132 /* 133 * Read an int from an option string; if available accept a subsequent 134 * comma as well. 135 * 136 * Return values: 137 * 0 : no int in string 138 * 1 : int found, no subsequent comma 139 * 2 : int found including a subsequent comma 140 */ 141 int get_option(char **str, int *pint) 142 { 143 char *cur = *str; 144 145 if (!cur || !(*cur)) return 0; 146 *pint = simple_strtol(cur,str,0); 147 if (cur==*str) return 0; 148 if (**str==',') { 149 (*str)++; 150 return 2; 151 } 152 153 return 1; 154 } 155 156 char *get_options(char *str, int nints, int *ints) 157 { 158 int res,i=1; 159 160 while (i<nints) { 161 res = get_option(&str, ints+i); 162 if (res==0) break; 163 i++; 164 if (res==1) break; 165 } 166 ints[0] = i-1; 167 return(str); 168 } 169 170 static int __init profile_setup(char *str) 171 { 172 int par; 173 if (get_option(&str,&par)) prof_shift = par; 174 return 1; 175 } 176 177 __setup("profile=", profile_setup); 178 179 180 static struct dev_name_struct { 181 const char *name; 182 const int num; 183 } root_dev_names[] __initdata = { 184 { "nfs", 0x00ff }, 185 { "hda", 0x0300 }, 186 { "hdb", 0x0340 }, 187 { "hdc", 0x1600 }, 188 { "hdd", 0x1640 }, 189 { "hde", 0x2100 }, 190 { "hdf", 0x2140 }, 191 { "hdg", 0x2200 }, 192 { "hdh", 0x2240 }, 193 { "hdi", 0x3800 }, 194 { "hdj", 0x3840 }, 195 { "hdk", 0x3900 }, 196 { "hdl", 0x3940 }, 197 { "hdm", 0x5800 }, 198 { "hdn", 0x5840 }, 199 { "hdo", 0x5900 }, 200 { "hdp", 0x5940 }, 201 { "hdq", 0x5A00 }, 202 { "hdr", 0x5A40 }, 203 { "hds", 0x5B00 }, 204 { "hdt", 0x5B40 }, 205 { "sda", 0x0800 }, 206 { "sdb", 0x0810 }, 207 { "sdc", 0x0820 }, 208 { "sdd", 0x0830 }, 209 { "sde", 0x0840 }, 210 { "sdf", 0x0850 }, 211 { "sdg", 0x0860 }, 212 { "sdh", 0x0870 }, 213 { "sdi", 0x0880 }, 214 { "sdj", 0x0890 }, 215 { "sdk", 0x08a0 }, 216 { "sdl", 0x08b0 }, 217 { "sdm", 0x08c0 }, 218 { "sdn", 0x08d0 }, 219 { "sdo", 0x08e0 }, 220 { "sdp", 0x08f0 }, 221 { "ada", 0x1c00 }, 222 { "adb", 0x1c10 }, 223 { "adc", 0x1c20 }, 224 { "add", 0x1c30 }, 225 { "ade", 0x1c40 }, 226 { "fd", 0x0200 }, 227 { "md", 0x0900 }, 228 { "xda", 0x0d00 }, 229 { "xdb", 0x0d40 }, 230 { "ram", 0x0100 }, 231 { "scd", 0x0b00 }, 232 { "mcd", 0x1700 }, 233 { "cdu535", 0x1800 }, 234 { "sonycd", 0x1800 }, 235 { "aztcd", 0x1d00 }, 236 { "cm206cd", 0x2000 }, 237 { "gscd", 0x1000 }, 238 { "sbpcd", 0x1900 }, 239 { "eda", 0x2400 }, 240 { "edb", 0x2440 }, 241 { "pda", 0x2d00 }, 242 { "pdb", 0x2d10 }, 243 { "pdc", 0x2d20 }, 244 { "pdd", 0x2d30 }, 245 { "pcd", 0x2e00 }, 246 { "pf", 0x2f00 }, 247 { "apblock", APBLOCK_MAJOR << 8}, 248 { "ddv", DDV_MAJOR << 8}, 249 { "fhd", 0x3e00 }, 250 { NULL, 0 } 251 }; 252 253 kdev_t __init name_to_kdev_t(char *line) 254 { 255 int base = 0; 256 257 if (strncmp(line,"/dev/",5) == 0) { 258 struct dev_name_struct *dev = root_dev_names; 259 line += 5; 260 do { 261 int len = strlen(dev->name); 262 if (strncmp(line,dev->name,len) == 0) { 263 line += len; 264 base = dev->num; 265 break; 266 } 267 dev++; 268 } while (dev->name); 269 } 270 return to_kdev_t(base + simple_strtoul(line,NULL,base?10:16)); 271 } 272 273 static int __init root_dev_setup(char *line) 274 { 275 int i; 276 char ch; 277 278 ROOT_DEV = name_to_kdev_t(line); 279 memset (root_device_name, 0, sizeof root_device_name); 280 if (strncmp (line, "/dev/", 5) == 0) line += 5; 281 for (i = 0; i < sizeof root_device_name - 1; ++i) 282 { 283 ch = line[i]; 284 if ( isspace (ch) || (ch == ',') || (ch == '\0') ) break; 285 root_device_name[i] = ch; 286 } 287 return 1; 288 } 289 290 __setup("root=", root_dev_setup); 291 292 static int __init checksetup(char *line) 293 { 294 struct kernel_param *p; 295 296 p = &__setup_start; 297 do { 298 int n = strlen(p->str); 299 if (!strncmp(line,p->str,n)) { 300 if (p->setup_func(line+n)) 301 return 1; 302 } 303 p++; 304 } while (p < &__setup_end); 305 return 0; 306 } 307 308 /* this should be approx 2 Bo*oMips to start (note initial shift), and will 309 still work even if initially too large, it will just take slightly longer */ 310 unsigned long loops_per_sec = (1<<12); 311 312 /* This is the number of bits of precision for the loops_per_second. Each 313 bit takes on average 1.5/HZ seconds. This (like the original) is a little 314 better than 1% */ 315 #define LPS_PREC 8 316 317 void __init calibrate_delay(void) 318 { 319 unsigned long ticks, loopbit; 320 int lps_precision = LPS_PREC; 321 322 loops_per_sec = (1<<12); 323 324 printk("Calibrating delay loop... "); 325 while (loops_per_sec <<= 1) { 326 /* wait for "start of" clock tick */ 327 ticks = jiffies; 328 while (ticks == jiffies) 329 /* nothing */; 330 /* Go .. */ 331 ticks = jiffies; 332 __delay(loops_per_sec); 333 ticks = jiffies - ticks; 334 if (ticks) 335 break; 336 } 337 338 /* Do a binary approximation to get loops_per_second set to equal one clock 339 (up to lps_precision bits) */ 340 loops_per_sec >>= 1; 341 loopbit = loops_per_sec; 342 while ( lps_precision-- && (loopbit >>= 1) ) { 343 loops_per_sec |= loopbit; 344 ticks = jiffies; 345 while (ticks == jiffies); 346 ticks = jiffies; 347 __delay(loops_per_sec); 348 if (jiffies != ticks) /* longer than 1 tick */ 349 loops_per_sec &= ~loopbit; 350 } 351 352 /* finally, adjust loops per second in terms of seconds instead of clocks */ 353 loops_per_sec *= HZ; 354 /* Round the value and print it */ 355 printk("%lu.%02lu BogoMIPS\n", 356 (loops_per_sec+2500)/500000, 357 ((loops_per_sec+2500)/5000) % 100); 358 } 359 360 static int __init readonly(char *str) 361 { 362 if (*str) 363 return 0; 364 root_mountflags |= MS_RDONLY; 365 return 1; 366 } 367 368 static int __init readwrite(char *str) 369 { 370 if (*str) 371 return 0; 372 root_mountflags &= ~MS_RDONLY; 373 return 1; 374 } 375 376 static int __init debug_kernel(char *str) 377 { 378 if (*str) 379 return 0; 380 console_loglevel = 10; 381 return 1; 382 } 383 384 __setup("ro", readonly); 385 __setup("rw", readwrite); 386 __setup("debug", debug_kernel); 387 388 /* 389 * This is a simple kernel command line parsing function: it parses 390 * the command line, and fills in the arguments/environment to init 391 * as appropriate. Any cmd-line option is taken to be an environment 392 * variable if it contains the character '='. 393 * 394 * This routine also checks for options meant for the kernel. 395 * These options are not given to init - they are for internal kernel use only. 396 */ 397 static void __init parse_options(char *line) 398 { 399 char *next; 400 int args, envs; 401 402 if (!*line) 403 return; 404 args = 0; 405 envs = 1; /* TERM is set to 'linux' by default */ 406 next = line; 407 while ((line = next) != NULL) { 408 if ((next = strchr(line,' ')) != NULL) 409 *next++ = 0; 410 if (!strncmp(line,"init=",5)) { 411 line += 5; 412 execute_command = line; 413 /* In case LILO is going to boot us with default command line, 414 * it prepends "auto" before the whole cmdline which makes 415 * the shell think it should execute a script with such name. 416 * So we ignore all arguments entered _before_ init=... [MJ] 417 */ 418 args = 0; 419 continue; 420 } 421 if (checksetup(line)) 422 continue; 423 424 /* 425 * Then check if it's an environment variable or 426 * an option. 427 */ 428 if (strchr(line,'=')) { 429 if (envs >= MAX_INIT_ENVS) 430 break; 431 envp_init[++envs] = line; 432 } else { 433 if (args >= MAX_INIT_ARGS) 434 break; 435 argv_init[++args] = line; 436 } 437 } 438 argv_init[args+1] = NULL; 439 envp_init[envs+1] = NULL; 440 } 441 442 443 extern void setup_arch(char **); 444 extern void cpu_idle(void); 445 446 #ifndef __SMP__ 447 448 #ifdef CONFIG_X86_IO_APIC 449 static void __init smp_init(void) 450 { 451 IO_APIC_init_uniprocessor(); 452 } 453 #else 454 #define smp_init() do { } while (0) 455 #endif 456 457 #else 458 459 /* Called by boot processor to activate the rest. */ 460 static void __init smp_init(void) 461 { 462 /* Get other processors into their bootup holding patterns. */ 463 smp_boot_cpus(); 464 smp_threads_ready=1; 465 smp_commence(); 466 } 467 468 #endif 469 470 /* 471 * Activate the first processor. 472 */ 473 474 asmlinkage void __init start_kernel(void) 475 { 476 char * command_line; 477 unsigned long mempages; 478 /* 479 * Interrupts are still disabled. Do necessary setups, then 480 * enable them 481 */ 482 lock_kernel(); 483 printk(linux_banner); 484 setup_arch(&command_line); 485 paging_init(); 486 trap_init(); 487 init_IRQ(); 488 sched_init(); 489 time_init(); 490 softirq_init(); 491 parse_options(command_line); 492 493 /* 494 * HACK ALERT! This is early. We're enabling the console before 495 * we've done PCI setups etc, and console_init() must be aware of 496 * this. But we do want output early, in case something goes wrong. 497 */ 498 console_init(); 499 #ifdef CONFIG_MODULES 500 init_modules(); 501 #endif 502 if (prof_shift) { 503 unsigned int size; 504 /* only text is profiled */ 505 prof_len = (unsigned long) &_etext - (unsigned long) &_stext; 506 prof_len >>= prof_shift; 507 508 size = prof_len * sizeof(unsigned int) + PAGE_SIZE-1; 509 prof_buffer = (unsigned int *) alloc_bootmem(size); 510 } 511 512 kmem_cache_init(); 513 sti(); 514 calibrate_delay(); 515 #if 0000 516 #ifdef CONFIG_BLK_DEV_INITRD 517 // FIXME, use the bootmem.h interface. 518 if (initrd_start && !initrd_below_start_ok && initrd_start < memory_start) { 519 printk(KERN_CRIT "initrd overwritten (0x%08lx < 0x%08lx) - " 520 "disabling it.\n",initrd_start,memory_start); 521 initrd_start = 0; 522 } 523 #endif 524 #endif /* 0000 */ 525 mem_init(); 526 kmem_cache_sizes_init(); 527 #ifdef CONFIG_PROC_FS 528 proc_root_init(); 529 #endif 530 mempages = num_physpages; 531 532 fork_init(mempages); 533 filescache_init(); 534 dcache_init(); 535 vma_init(); 536 buffer_init(mempages); 537 page_cache_init(mempages); 538 kiobuf_init(); 539 signals_init(); 540 bdev_init(); 541 inode_init(); 542 file_table_init(); 543 #if defined(CONFIG_SYSVIPC) 544 ipc_init(); 545 #endif 546 #if defined(CONFIG_QUOTA) 547 dquot_init_hash(); 548 #endif 549 check_bugs(); 550 printk("POSIX conformance testing by UNIFIX\n"); 551 552 /* 553 * We count on the initial thread going ok 554 * Like idlers init is an unlocked kernel thread, which will 555 * make syscalls (and thus be locked). 556 */ 557 smp_init(); 558 kernel_thread(init, NULL, CLONE_FS | CLONE_FILES | CLONE_SIGHAND); 559 unlock_kernel(); 560 current->need_resched = 1; 561 cpu_idle(); 562 } 563 564 #ifdef CONFIG_BLK_DEV_INITRD 565 static int do_linuxrc(void * shell) 566 { 567 static char *argv[] = { "linuxrc", NULL, }; 568 569 close(0);close(1);close(2); 570 setsid(); 571 (void) open("/dev/console",O_RDWR,0); 572 (void) dup(0); 573 (void) dup(0); 574 return execve(shell, argv, envp_init); 575 } 576 577 static int __init no_initrd(char *s) 578 { 579 mount_initrd = 0; 580 return 1; 581 } 582 583 __setup("noinitrd", no_initrd); 584 585 #endif 586 587 struct task_struct *child_reaper = &init_task; 588 589 static void __init do_initcalls(void) 590 { 591 initcall_t *call; 592 593 call = &__initcall_start; 594 do { 595 (*call)(); 596 call++; 597 } while (call < &__initcall_end); 598 } 599 600 /* 601 * Ok, the machine is now initialized. None of the devices 602 * have been touched yet, but the CPU subsystem is up and 603 * running, and memory and process management works. 604 * 605 * Now we can finally start doing some real work.. 606 */ 607 static void __init do_basic_setup(void) 608 { 609 #ifdef CONFIG_BLK_DEV_INITRD 610 int real_root_mountflags; 611 #endif 612 613 /* 614 * Tell the world that we're going to be the grim 615 * reaper of innocent orphaned children. 616 * 617 * We don't want people to have to make incorrect 618 * assumptions about where in the task array this 619 * can be found. 620 */ 621 child_reaper = current; 622 623 #if defined(CONFIG_MTRR) /* Do this after SMP initialization */ 624 /* 625 * We should probably create some architecture-dependent "fixup after 626 * everything is up" style function where this would belong better 627 * than in init/main.c.. 628 */ 629 mtrr_init(); 630 #endif 631 632 #ifdef CONFIG_SYSCTL 633 sysctl_init(); 634 #endif 635 636 /* 637 * Ok, at this point all CPU's should be initialized, so 638 * we can start looking into devices.. 639 */ 640 #ifdef CONFIG_PCI 641 pci_init(); 642 #endif 643 #ifdef CONFIG_SBUS 644 sbus_init(); 645 #endif 646 #if defined(CONFIG_PPC) 647 ppc_init(); 648 #endif 649 #ifdef CONFIG_MCA 650 mca_init(); 651 #endif 652 #ifdef CONFIG_ARCH_ACORN 653 ecard_init(); 654 #endif 655 #ifdef CONFIG_ZORRO 656 zorro_init(); 657 #endif 658 #ifdef CONFIG_DIO 659 dio_init(); 660 #endif 661 #ifdef CONFIG_MAC 662 nubus_init(); 663 #endif 664 #ifdef CONFIG_ISAPNP 665 isapnp_init(); 666 #endif 667 #ifdef CONFIG_USB 668 usb_init(); /* Do this before doing initcalls, so that we can make 669 usbcore initialize here, and all drivers initialize later */ 670 #endif 671 672 /* Networking initialization needs a process context */ 673 sock_init(); 674 675 #ifdef CONFIG_BLK_DEV_INITRD 676 real_root_dev = ROOT_DEV; 677 real_root_mountflags = root_mountflags; 678 if (initrd_start && mount_initrd) root_mountflags &= ~MS_RDONLY; 679 else mount_initrd =0; 680 #endif 681 682 do_initcalls(); 683 684 /* .. filesystems .. */ 685 filesystem_setup(); 686 687 #ifdef CONFIG_IRDA 688 irda_device_init(); /* Must be done after protocol initialization */ 689 #endif 690 #ifdef CONFIG_PCMCIA 691 init_pcmcia_ds(); /* Do this last */ 692 #endif 693 /* Mount the root filesystem.. */ 694 mount_root(); 695 696 mount_devfs_fs (); 697 698 #ifdef CONFIG_BLK_DEV_INITRD 699 root_mountflags = real_root_mountflags; 700 if (mount_initrd && ROOT_DEV != real_root_dev 701 && MAJOR(ROOT_DEV) == RAMDISK_MAJOR && MINOR(ROOT_DEV) == 0) { 702 int error; 703 int i, pid; 704 705 pid = kernel_thread(do_linuxrc, "/linuxrc", SIGCHLD); 706 if (pid>0) 707 while (pid != wait(&i)); 708 if (MAJOR(real_root_dev) != RAMDISK_MAJOR 709 || MINOR(real_root_dev) != 0) { 710 #ifdef CONFIG_BLK_DEV_MD 711 autodetect_raid(); 712 #endif 713 error = change_root(real_root_dev,"/initrd"); 714 if (error) 715 printk(KERN_ERR "Change root to /initrd: " 716 "error %d\n",error); 717 } 718 } 719 #endif 720 } 721 722 static int init(void * unused) 723 { 724 lock_kernel(); 725 do_basic_setup(); 726 727 /* 728 * Ok, we have completed the initial bootup, and 729 * we're essentially up and running. Get rid of the 730 * initmem segments and start the user-mode stuff.. 731 */ 732 free_initmem(); 733 unlock_kernel(); 734 735 if (open("/dev/console", O_RDWR, 0) < 0) 736 printk("Warning: unable to open an initial console.\n"); 737 738 (void) dup(0); 739 (void) dup(0); 740 741 /* 742 * We try each of these until one succeeds. 743 * 744 * The Bourne shell can be used instead of init if we are 745 * trying to recover a really broken machine. 746 */ 747 748 if (execute_command) 749 execve(execute_command,argv_init,envp_init); 750 execve("/sbin/init",argv_init,envp_init); 751 execve("/etc/init",argv_init,envp_init); 752 execve("/bin/init",argv_init,envp_init); 753 execve("/bin/sh",argv_init,envp_init); 754 panic("No init found. Try passing init= option to kernel."); 755 } 756

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~ [ freetext search ] ~ [ file search ] ~

This page was automatically generated by the LXR engine.
Visit the LXR main site for more information.