init/main.c

/* */
This source file includes following definitions.
get_options
profile_setup
ramdisk_start_setup
load_ramdisk
prompt_ramdisk
checksetup
calibrate_delay
parse_options
cpu_idle
start_secondary
smp_init
smp_begin
start_kernel
printf
do_rc
do_shell
do_linuxrc
no_initrd
init
   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  */
   9 
  10 #define __KERNEL_SYSCALLS__
  11 #include <stdarg.h>
  12 
  13 #include <asm/system.h>
  14 #include <asm/io.h>
  15 
  16 #include <linux/types.h>
  17 #include <linux/fcntl.h>
  18 #include <linux/config.h>
  19 #include <linux/sched.h>
  20 #include <linux/kernel.h>
  21 #include <linux/tty.h>
  22 #include <linux/head.h>
  23 #include <linux/unistd.h>
  24 #include <linux/string.h>
  25 #include <linux/timer.h>
  26 #include <linux/fs.h>
  27 #include <linux/ctype.h>
  28 #include <linux/delay.h>
  29 #include <linux/utsname.h>
  30 #include <linux/ioport.h>
  31 #include <linux/hdreg.h>
  32 #include <linux/mm.h>
  33 #include <linux/major.h>
  34 #include <linux/blk.h>
  35 #ifdef CONFIG_APM
  36 #include <linux/apm_bios.h>
  37 #endif
  38 #ifdef CONFIG_ROOT_NFS
  39 #include <linux/nfs_fs.h>
  40 #endif
  41 
  42 #include <asm/bugs.h>
  43 
  44 extern char _stext, _etext;
  45 extern char *linux_banner;
  46 
  47 static char printbuf[1024];
  48 
  49 extern int console_loglevel;
  50 
  51 static int init(void *);
  52 extern int bdflush(void *);
  53 extern int kswapd(void *);
  54 
  55 extern void init_IRQ(void);
  56 extern void init_modules(void);
  57 extern long console_init(long, long);
  58 extern long kmalloc_init(long,long);
  59 extern void sock_init(void);
  60 extern long pci_init(long, long);
  61 extern void sysctl_init(void);
  62 
  63 extern void swap_setup(char *str, int *ints);
  64 extern void buff_setup(char *str, int *ints);
  65 extern void panic_setup(char *str, int *ints);
  66 extern void bmouse_setup(char *str, int *ints);
  67 extern void eth_setup(char *str, int *ints);
  68 extern void xd_setup(char *str, int *ints);
  69 extern void floppy_setup(char *str, int *ints);
  70 extern void st_setup(char *str, int *ints);
  71 extern void st0x_setup(char *str, int *ints);
  72 extern void advansys_setup(char *str, int *ints);
  73 extern void tmc8xx_setup(char *str, int *ints);
  74 extern void t128_setup(char *str, int *ints);
  75 extern void pas16_setup(char *str, int *ints);
  76 extern void generic_NCR5380_setup(char *str, int *intr);
  77 extern void generic_NCR53C400_setup(char *str, int *intr);
  78 extern void aha152x_setup(char *str, int *ints);
  79 extern void aha1542_setup(char *str, int *ints);
  80 extern void aic7xxx_setup(char *str, int *ints);
  81 extern void AM53C974_setup(char *str, int *ints);
  82 extern void BusLogic_Setup(char *str, int *ints);
  83 extern void fdomain_setup(char *str, int *ints);
  84 extern void NCR53c406a_setup(char *str, int *ints);
  85 extern void scsi_luns_setup(char *str, int *ints);
  86 extern void sound_setup(char *str, int *ints);
  87 #ifdef CONFIG_CDU31A
  88 extern void cdu31a_setup(char *str, int *ints);
  89 #endif CONFIG_CDU31A
  90 #ifdef CONFIG_MCD
  91 extern void mcd_setup(char *str, int *ints);
  92 #endif CONFIG_MCD
  93 #ifdef CONFIG_MCDX
  94 extern void mcdx_setup(char *str, int *ints);
  95 #endif CONFIG_MCDX
  96 #ifdef CONFIG_SBPCD
  97 extern void sbpcd_setup(char *str, int *ints);
  98 #endif CONFIG_SBPCD
  99 #ifdef CONFIG_AZTCD
 100 extern void aztcd_setup(char *str, int *ints);
 101 #endif CONFIG_AZTCD
 102 #ifdef CONFIG_CDU535
 103 extern void sonycd535_setup(char *str, int *ints);
 104 #endif CONFIG_CDU535
 105 #ifdef CONFIG_GSCD
 106 extern void gscd_setup(char *str, int *ints);
 107 #endif CONFIG_GSCD
 108 #ifdef CONFIG_CM206
 109 extern void cm206_setup(char *str, int *ints);
 110 #endif CONFIG_CM206
 111 #ifdef CONFIG_OPTCD
 112 extern void optcd_setup(char *str, int *ints);
 113 #endif CONFIG_OPTCD
 114 #ifdef CONFIG_SJCD
 115 extern void sjcd_setup(char *str, int *ints);
 116 #endif CONFIG_SJCD
 117 #ifdef CONFIG_ISP16_CDI
 118 extern void isp16_setup(char *str, int *ints);
 119 #endif CONFIG_ISP16_CDI
 120 #ifdef CONFIG_BLK_DEV_RAM
 121 static void ramdisk_start_setup(char *str, int *ints);
 122 static void load_ramdisk(char *str, int *ints);
 123 static void prompt_ramdisk(char *str, int *ints);
 124 #ifdef CONFIG_BLK_DEV_INITRD
 125 static void no_initrd(char *s,int *ints);
 126 #endif
 127 #endif CONFIG_BLK_DEV_RAM
 128 #ifdef CONFIG_ISDN_DRV_ICN
 129 extern void icn_setup(char *str, int *ints);
 130 #endif
 131 #ifdef CONFIG_ISDN_DRV_TELES
 132 extern void teles_setup(char *str, int *ints);
 133 #endif
 134 
 135 #if defined(CONFIG_SYSVIPC) || defined(CONFIG_KERNELD)
 136 extern void ipc_init(void);
 137 #endif
 138 
 139 /*
 140  * Boot command-line arguments
 141  */
 142 #define MAX_INIT_ARGS 8
 143 #define MAX_INIT_ENVS 8
 144 
 145 extern void time_init(void);
 146 
 147 static unsigned long memory_start = 0;
 148 static unsigned long memory_end = 0;
 149 
 150 int rows, cols;
 151 
 152 #ifdef CONFIG_BLK_DEV_RAM
 153 extern int rd_doload;           /* 1 = load ramdisk, 0 = don't load */
 154 extern int rd_prompt;           /* 1 = prompt for ramdisk, 0 = don't prompt */
 155 extern int rd_image_start;      /* starting block # of image */
 156 #ifdef CONFIG_BLK_DEV_INITRD
 157 kdev_t real_root_dev;
 158 #endif
 159 #endif
 160 
 161 int root_mountflags = MS_RDONLY;
 162 char *execute_command = 0;
 163 
 164 #ifdef CONFIG_ROOT_NFS
 165 char nfs_root_name[NFS_ROOT_NAME_LEN] = { NFS_ROOT };
 166 char nfs_root_addrs[NFS_ROOT_ADDRS_LEN] = { "" };
 167 #endif
 168 
 169 extern void dquot_init(void);
 170 
 171 static char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
 172 static char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
 173 
 174 static char * argv_rc[] = { "/bin/sh", NULL };
 175 static char * envp_rc[] = { "HOME=/", "TERM=linux", NULL };
 176 
 177 static char * argv[] = { "-/bin/sh",NULL };
 178 static char * envp[] = { "HOME=/usr/root", "TERM=linux", NULL };
 179 
 180 char *get_options(char *str, int *ints)
     /*  */
 181 {
 182         char *cur = str;
 183         int i=1;
 184 
 185         while (cur && isdigit(*cur) && i <= 10) {
 186                 ints[i++] = simple_strtoul(cur,NULL,0);
 187                 if ((cur = strchr(cur,',')) != NULL)
 188                         cur++;
 189         }
 190         ints[0] = i-1;
 191         return(cur);
 192 }
 193 
 194 static void profile_setup(char *str, int *ints)
     /*  */
 195 {
 196         if (ints[0] > 0)
 197                 prof_shift = (unsigned long) ints[1];
 198         else
 199 #ifdef CONFIG_PROFILE_SHIFT
 200                 prof_shift = CONFIG_PROFILE_SHIFT;
 201 #else
 202                 prof_shift = 2;
 203 #endif
 204 }
 205 
 206 struct {
 207         const char *str;
 208         void (*setup_func)(char *, int *);
 209 } bootsetups[] = {
 210         { "reserve=", reserve_setup },
 211         { "profile=", profile_setup },
 212 #ifdef CONFIG_BLK_DEV_RAM
 213         { "ramdisk_start=", ramdisk_start_setup },
 214         { "load_ramdisk=", load_ramdisk },
 215         { "prompt_ramdisk=", prompt_ramdisk },
 216 #ifdef CONFIG_BLK_DEV_INITRD
 217         { "noinitrd", no_initrd },
 218 #endif
 219 #endif
 220         { "swap=", swap_setup },
 221         { "buff=", buff_setup },
 222         { "panic=", panic_setup },
 223 #ifdef CONFIG_BUGi386
 224         { "no-hlt", no_halt },
 225         { "no387", no_387 },
 226 #endif
 227 #ifdef CONFIG_INET
 228         { "ether=", eth_setup },
 229 #endif
 230 #ifdef CONFIG_SCSI
 231         { "max_scsi_luns=", scsi_luns_setup },
 232 #endif
 233 #ifdef CONFIG_SCSI_ADVANSYS
 234         { "advansys=", advansys_setup },
 235 #endif
 236 #if defined(CONFIG_BLK_DEV_HD)
 237         { "hd=", hd_setup },
 238 #endif
 239 #ifdef CONFIG_CHR_DEV_ST
 240         { "st=", st_setup },
 241 #endif
 242 #ifdef CONFIG_BUSMOUSE
 243         { "bmouse=", bmouse_setup },
 244 #endif
 245 #ifdef CONFIG_SCSI_SEAGATE
 246         { "st0x=", st0x_setup },
 247         { "tmc8xx=", tmc8xx_setup },
 248 #endif
 249 #ifdef CONFIG_SCSI_T128
 250         { "t128=", t128_setup },
 251 #endif
 252 #ifdef CONFIG_SCSI_PAS16
 253         { "pas16=", pas16_setup },
 254 #endif
 255 #ifdef CONFIG_SCSI_GENERIC_NCR5380
 256         { "ncr5380=", generic_NCR5380_setup },
 257         { "ncr53c400=", generic_NCR53C400_setup },
 258 #endif
 259 #ifdef CONFIG_SCSI_AHA152X
 260         { "aha152x=", aha152x_setup},
 261 #endif
 262 #ifdef CONFIG_SCSI_AHA1542
 263         { "aha1542=", aha1542_setup},
 264 #endif
 265 #ifdef CONFIG_SCSI_AIC7XXX
 266         { "aic7xxx=", aic7xxx_setup},
 267 #endif
 268 #ifdef CONFIG_SCSI_BUSLOGIC
 269         { "BusLogic=", BusLogic_Setup},
 270 #endif
 271 #ifdef CONFIG_SCSI_AM53C974
 272         { "AM53C974=", AM53C974_setup},
 273 #endif
 274 #ifdef CONFIG_SCSI_NCR53C406A
 275         { "ncr53c406a=", NCR53c406a_setup},
 276 #endif
 277 #ifdef CONFIG_SCSI_FUTURE_DOMAIN
 278         { "fdomain=", fdomain_setup},
 279 #endif
 280 #ifdef CONFIG_BLK_DEV_XD
 281         { "xd=", xd_setup },
 282 #endif
 283 #ifdef CONFIG_BLK_DEV_FD
 284         { "floppy=", floppy_setup },
 285 #endif
 286 #ifdef CONFIG_CDU31A
 287         { "cdu31a=", cdu31a_setup },
 288 #endif CONFIG_CDU31A
 289 #ifdef CONFIG_MCD
 290         { "mcd=", mcd_setup },
 291 #endif CONFIG_MCD
 292 #ifdef CONFIG_MCDX
 293         { "mcdx=", mcdx_setup },
 294 #endif CONFIG_MCDX
 295 #ifdef CONFIG_SBPCD
 296         { "sbpcd=", sbpcd_setup },
 297 #endif CONFIG_SBPCD
 298 #ifdef CONFIG_AZTCD
 299         { "aztcd=", aztcd_setup },
 300 #endif CONFIG_AZTCD
 301 #ifdef CONFIG_CDU535
 302         { "sonycd535=", sonycd535_setup },
 303 #endif CONFIG_CDU535
 304 #ifdef CONFIG_GSCD
 305         { "gscd=", gscd_setup },
 306 #endif CONFIG_GSCD
 307 #ifdef CONFIG_CM206
 308         { "cm206=", cm206_setup },
 309 #endif CONFIG_CM206
 310 #ifdef CONFIG_OPTCD
 311         { "optcd=", optcd_setup },
 312 #endif CONFIG_OPTCD
 313 #ifdef CONFIG_SJCD
 314         { "sjcd=", sjcd_setup },
 315 #endif CONFIG_SJCD
 316 #ifdef CONFIG_ISP16_CDI
 317         { "isp16=", isp16_setup },
 318 #endif CONFIG_ISP16_CDI
 319 #ifdef CONFIG_SOUND
 320         { "sound=", sound_setup },
 321 #endif
 322 #ifdef CONFIG_ISDN_DRV_ICN
 323         { "icn=", icn_setup },
 324 #endif
 325 #ifdef CONFIG_ISDN_DRV_TELES
 326         { "teles=", teles_setup },
 327 #endif
 328         { 0, 0 }
 329 };
 330 
 331 #ifdef CONFIG_BLK_DEV_RAM
 332 static void ramdisk_start_setup(char *str, int *ints)
     /*  */
 333 {
 334    if (ints[0] > 0 && ints[1] >= 0)
 335       rd_image_start = ints[1];
 336 }
 337 
 338 static void load_ramdisk(char *str, int *ints)
     /*  */
 339 {
 340    if (ints[0] > 0 && ints[1] >= 0)
 341       rd_doload = ints[1] & 1;
 342 }
 343 
 344 static void prompt_ramdisk(char *str, int *ints)
     /*  */
 345 {
 346    if (ints[0] > 0 && ints[1] >= 0)
 347       rd_prompt = ints[1] & 1;
 348 }
 349 #endif
 350 
 351 static int checksetup(char *line)
     /*  */
 352 {
 353         int i = 0;
 354         int ints[11];
 355 
 356 #ifdef CONFIG_BLK_DEV_IDE
 357         /* ide driver needs the basic string, rather than pre-processed values */
 358         if (!strncmp(line,"ide",3) || (!strncmp(line,"hd",2) && line[2] != '=')) {
 359                 ide_setup(line);
 360                 return 1;
 361         }
 362 #endif
 363         while (bootsetups[i].str) {
 364                 int n = strlen(bootsetups[i].str);
 365                 if (!strncmp(line,bootsetups[i].str,n)) {
 366                         bootsetups[i].setup_func(get_options(line+n,ints), ints);
 367                         return 1;
 368                 }
 369                 i++;
 370         }
 371         return 0;
 372 }
 373 
 374 /* this should be approx 2 Bo*oMips to start (note initial shift), and will
 375    still work even if initally too large, it will just take slightly longer */
 376 unsigned long loops_per_sec = (1<<12);
 377 
 378 /* This is the number of bits of precision for the loops_per_second.  Each
 379    bit takes on average 1.5/HZ seconds.  This (like the original) is a little
 380    better than 1% */
 381 #define LPS_PREC 8
 382 
 383 void calibrate_delay(void)
     /*  */
 384 {
 385         int ticks;
 386         int loopbit;
 387         int lps_precision = LPS_PREC;
 388 
 389         loops_per_sec = (1<<12);
 390 
 391         printk("Calibrating delay loop.. ");
 392         while (loops_per_sec <<= 1) {
 393                 /* wait for "start of" clock tick */
 394                 ticks = jiffies;
 395                 while (ticks == jiffies)
 396                         /* nothing */;
 397                 /* Go .. */
 398                 ticks = jiffies;
 399                 __delay(loops_per_sec);
 400                 ticks = jiffies - ticks;
 401                 if (ticks)
 402                         break;
 403                 }
 404 
 405 /* Do a binary approximation to get loops_per_second set to equal one clock
 406    (up to lps_precision bits) */
 407         loops_per_sec >>= 1;
 408         loopbit = loops_per_sec;
 409         while ( lps_precision-- && (loopbit >>= 1) ) {
 410                 loops_per_sec |= loopbit;
 411                 ticks = jiffies;
 412                 while (ticks == jiffies);
 413                 ticks = jiffies;
 414                 __delay(loops_per_sec);
 415                 if (jiffies != ticks)   /* longer than 1 tick */
 416                         loops_per_sec &= ~loopbit;
 417         }
 418 
 419 /* finally, adjust loops per second in terms of seconds instead of clocks */    
 420         loops_per_sec *= HZ;
 421 /* Round the value and print it */      
 422         printk("ok - %lu.%02lu BogoMIPS\n",
 423                 (loops_per_sec+2500)/500000,
 424                 ((loops_per_sec+2500)/5000) % 100);
 425 }
 426 
 427 /*
 428  * This is a simple kernel command line parsing function: it parses
 429  * the command line, and fills in the arguments/environment to init
 430  * as appropriate. Any cmd-line option is taken to be an environment
 431  * variable if it contains the character '='.
 432  *
 433  *
 434  * This routine also checks for options meant for the kernel.
 435  * These options are not given to init - they are for internal kernel use only.
 436  */
 437 static void parse_options(char *line)
     /*  */
 438 {
 439         char *next;
 440         char *devnames[] = { "nfs", "hda", "hdb", "hdc", "hdd", "sda", "sdb",
 441                 "sdc", "sdd", "sde", "fd", "xda", "xdb", "ram", NULL };
 442         int devnums[]    = { 0x0FF, 0x300, 0x340, 0x1600, 0x1640, 0x800,
 443                 0x810, 0x820, 0x830, 0x840, 0x200, 0xD00, 0xD40, 0x100, 0};
 444         int args, envs;
 445         if (!*line)
 446                 return;
 447         args = 0;
 448         envs = 1;       /* TERM is set to 'linux' by default */
 449         next = line;
 450         while ((line = next) != NULL) {
 451                 if ((next = strchr(line,' ')) != NULL)
 452                         *next++ = 0;
 453                 /*
 454                  * check for kernel options first..
 455                  */
 456                 if (!strncmp(line,"root=",5)) {
 457                         int n;
 458                         line += 5;
 459                         if (strncmp(line,"/dev/",5)) {
 460                                 ROOT_DEV = to_kdev_t(
 461                                              simple_strtoul(line,NULL,16));
 462                                 continue;
 463                         }
 464                         line += 5;
 465                         for (n = 0 ; devnames[n] ; n++) {
 466                                 int len = strlen(devnames[n]);
 467                                 if (!strncmp(line,devnames[n],len)) {
 468                                         ROOT_DEV = to_kdev_t(devnums[n]+
 469                                              simple_strtoul(line+len,NULL,0));
 470                                         break;
 471                                 }
 472                         }
 473                         continue;
 474                 }
 475 #ifdef CONFIG_ROOT_NFS
 476                 if (!strncmp(line, "nfsroot=", 8)) {
 477                         int n;
 478                         line += 8;
 479                         ROOT_DEV = MKDEV(UNNAMED_MAJOR, 255);
 480                         if (line[0] == '/' || (line[0] >= '0' && line[0] <= '9')) {
 481                                 strncpy(nfs_root_name, line, sizeof(nfs_root_name));
 482                                 nfs_root_name[sizeof(nfs_root_name)-1] = '\0';
 483                                 continue;
 484                         }
 485                         n = strlen(line) + strlen(NFS_ROOT);
 486                         if (n >= sizeof(nfs_root_name))
 487                                 line[sizeof(nfs_root_name) - strlen(NFS_ROOT) - 1] = '\0';
 488                         sprintf(nfs_root_name, NFS_ROOT, line);
 489                         continue;
 490                 }
 491                 if (!strncmp(line, "nfsaddrs=", 9)) {
 492                         line += 9;
 493                         strncpy(nfs_root_addrs, line, sizeof(nfs_root_addrs));
 494                         nfs_root_addrs[sizeof(nfs_root_addrs)-1] = '\0';
 495                         continue;
 496                 }
 497 #endif
 498                 if (!strcmp(line,"ro")) {
 499                         root_mountflags |= MS_RDONLY;
 500                         continue;
 501                 }
 502                 if (!strcmp(line,"rw")) {
 503                         root_mountflags &= ~MS_RDONLY;
 504                         continue;
 505                 }
 506                 if (!strcmp(line,"debug")) {
 507                         console_loglevel = 10;
 508                         continue;
 509                 }
 510                 if (!strncmp(line,"init=",5)) {
 511                         line += 5;
 512                         execute_command = line;
 513                         continue;
 514                 }
 515                 if (checksetup(line))
 516                         continue;
 517                 /*
 518                  * Then check if it's an environment variable or
 519                  * an option.
 520                  */
 521                 if (strchr(line,'=')) {
 522                         if (envs >= MAX_INIT_ENVS)
 523                                 break;
 524                         envp_init[++envs] = line;
 525                 } else {
 526                         if (args >= MAX_INIT_ARGS)
 527                                 break;
 528                         argv_init[++args] = line;
 529                 }
 530         }
 531         argv_init[args+1] = NULL;
 532         envp_init[envs+1] = NULL;
 533 }
 534 
 535 
 536 extern void setup_arch(char **, unsigned long *, unsigned long *);
 537 extern void arch_syms_export(void);
 538 
 539 #ifndef __SMP__
 540 
 541 /*
 542  *      Uniprocessor idle thread
 543  */
 544  
 545 int cpu_idle(void *unused)
     /*  */
 546 {
 547         for(;;)
 548                 idle();
 549 }
 550 
 551 #else
 552 
 553 /*
 554  *      Multiprocessor idle thread is in arch/...
 555  */
 556  
 557 extern int cpu_idle(void * unused);
 558 
 559 /*
 560  *      Activate a secondary processor.
 561  */
 562  
 563 asmlinkage void start_secondary(void)
     /*  */
 564 {
 565         trap_init();
 566         init_IRQ();
 567         smp_callin();
 568         cpu_idle(NULL);
 569 }
 570 
 571 
 572 
 573 /*
 574  *      Called by CPU#0 to activate the rest.
 575  */
 576  
 577 static void smp_init(void)
     /*  */
 578 {
 579         int i=0;
 580         smp_boot_cpus();
 581         
 582         /*
 583          *      Create the slave init tasks as sharing pid 0.
 584          */
 585 
 586         for (i=0; i<NR_CPUS; i++)
 587         {
 588                 /*
 589                  *      This should only do anything if the mapping
 590                  *      corresponds to a live CPU which is not the boot CPU.
 591                  */
 592                 if (cpu_number_map[i] > 0)
 593                 {
 594                         /*
 595                          *      We use kernel_thread for the idlers which are
 596                          *      unlocked tasks running in kernel space.
 597                          */
 598                         kernel_thread(cpu_idle, NULL, CLONE_PID);
 599                         /*
 600                          *      Don't assume linear processor numbering
 601                          */
 602                         current_set[i]=task[cpu_number_map[i]];
 603                         current_set[i]->processor=i;
 604                 }
 605         }
 606 }               
 607 
 608 /*
 609  *      The autoprobe routines assume CPU#0 on the i386
 610  *      so we don't actually set the game in motion until
 611  *      they are finished.
 612  */
 613  
 614 static void smp_begin(void)
     /*  */
 615 {
 616         smp_threads_ready=1;
 617         smp_commence();
 618 }
 619         
 620 #endif
 621 
 622 /*
 623  *      Activate the first processor.
 624  */
 625  
 626 asmlinkage void start_kernel(void)
     /*  */
 627 {
 628         char * command_line;
 629 
 630 /*
 631  *      This little check will move.
 632  */
 633 
 634 #ifdef __SMP__
 635         static int first_cpu=1;
 636         
 637         if(!first_cpu)
 638                 start_secondary();
 639         first_cpu=0;
 640         
 641 #endif  
 642 /*
 643  * Interrupts are still disabled. Do necessary setups, then
 644  * enable them
 645  */
 646         setup_arch(&command_line, &memory_start, &memory_end);
 647         memory_start = paging_init(memory_start,memory_end);
 648         trap_init();
 649         init_IRQ();
 650         sched_init();
 651         time_init();
 652         parse_options(command_line);
 653 #ifdef CONFIG_MODULES
 654         init_modules();
 655 #endif
 656 #ifdef CONFIG_PROFILE
 657         if (!prof_shift)
 658 #ifdef CONFIG_PROFILE_SHIFT
 659                 prof_shift = CONFIG_PROFILE_SHIFT;
 660 #else
 661                 prof_shift = 2;
 662 #endif
 663 #endif
 664         if (prof_shift) {
 665                 prof_buffer = (unsigned int *) memory_start;
 666                 /* only text is profiled */
 667                 prof_len = (unsigned long) &_etext - (unsigned long) &_stext;
 668                 prof_len >>= prof_shift;
 669                 memory_start += prof_len * sizeof(unsigned int);
 670         }
 671         memory_start = console_init(memory_start,memory_end);
 672 #ifdef CONFIG_PCI
 673         memory_start = pci_init(memory_start,memory_end);
 674 #endif
 675         memory_start = kmalloc_init(memory_start,memory_end);
 676         sti();
 677         calibrate_delay();
 678         memory_start = inode_init(memory_start,memory_end);
 679         memory_start = file_table_init(memory_start,memory_end);
 680         memory_start = name_cache_init(memory_start,memory_end);
 681 #ifdef CONFIG_BLK_DEV_INITRD
 682         if (initrd_start && initrd_start < memory_start) {
 683                 printk(KERN_CRIT "initrd overwritten (0x%08lx < 0x%08lx) - "
 684                     "disabling it.\n",initrd_start,memory_start);
 685                 initrd_start = 0;
 686         }
 687 #endif
 688         mem_init(memory_start,memory_end);
 689         buffer_init();
 690         sock_init();
 691 #if defined(CONFIG_SYSVIPC) || defined(CONFIG_KERNELD)
 692         ipc_init();
 693 #endif
 694 #ifdef CONFIG_APM
 695         apm_bios_init();
 696 #endif
 697         dquot_init();
 698         arch_syms_export();
 699         sti();
 700         check_bugs();
 701 
 702         printk(linux_banner);
 703 #ifdef __SMP__
 704         smp_init();
 705 #endif
 706         sysctl_init();
 707         /* 
 708          *      We count on the initial thread going ok 
 709          *      Like idlers init is an unlocked kernel thread, which will
 710          *      make syscalls (and thus be locked).
 711          */
 712         kernel_thread(init, NULL, 0);
 713 /*
 714  * task[0] is meant to be used as an "idle" task: it may not sleep, but
 715  * it might do some general things like count free pages or it could be
 716  * used to implement a reasonable LRU algorithm for the paging routines:
 717  * anything that can be useful, but shouldn't take time from the real
 718  * processes.
 719  *
 720  * Right now task[0] just does a infinite idle loop.
 721  */
 722         cpu_idle(NULL);
 723 }
 724 
 725 static int printf(const char *fmt, ...)
     /*  */
 726 {
 727         va_list args;
 728         int i;
 729 
 730         va_start(args, fmt);
 731         write(1,printbuf,i=vsprintf(printbuf, fmt, args));
 732         va_end(args);
 733         return i;
 734 }
 735 
 736 static int do_rc(void * rc)
     /*  */
 737 {
 738         close(0);
 739         if (open(rc,O_RDONLY,0))
 740                 return -1;
 741         return execve("/bin/sh", argv_rc, envp_rc);
 742 }
 743 
 744 static int do_shell(void * shell)
     /*  */
 745 {
 746         close(0);close(1);close(2);
 747         setsid();
 748         (void) open("/dev/tty1",O_RDWR,0);
 749         (void) dup(0);
 750         (void) dup(0);
 751         return execve(shell, argv, envp);
 752 }
 753 
 754 #ifdef CONFIG_BLK_DEV_INITRD
 755 static int do_linuxrc(void * shell)
     /*  */
 756 {
 757         static char *argv[] = { "linuxrc", NULL, };
 758 
 759         close(0);close(1);close(2);
 760         setsid();
 761         (void) open("/dev/tty1",O_RDWR,0);
 762         (void) dup(0);
 763         (void) dup(0);
 764         return execve(shell, argv, envp_init);
 765 }
 766 
 767 static void no_initrd(char *s,int *ints)
     /*  */
 768 {
 769         mount_initrd = 0;
 770 }
 771 #endif
 772 
 773 static int init(void * unused)
     /*  */
 774 {
 775         int pid,i;
 776 #ifdef CONFIG_BLK_DEV_INITRD
 777         int real_root_mountflags;
 778 #endif
 779 
 780         /* Launch bdflush from here, instead of the old syscall way. */
 781         kernel_thread(bdflush, NULL, 0);
 782         /* Start the background pageout daemon. */
 783         kernel_thread(kswapd, NULL, 0);
 784 
 785 #ifdef CONFIG_BLK_DEV_INITRD
 786         real_root_dev = ROOT_DEV;
 787         real_root_mountflags = root_mountflags;
 788         if (initrd_start && mount_initrd) root_mountflags &= ~MS_RDONLY;
 789 #endif
 790         setup();
 791 
 792 #ifdef __SMP__
 793         /*
 794          *      With the devices probed and setup we can
 795          *      now enter SMP mode.
 796          */
 797         
 798         smp_begin();
 799 #endif  
 800 
 801         #ifdef CONFIG_UMSDOS_FS
 802         {
 803                 /*
 804                         When mounting a umsdos fs as root, we detect
 805                         the pseudo_root (/linux) and initialise it here.
 806                         pseudo_root is defined in fs/umsdos/inode.c
 807                 */
 808                 extern struct inode *pseudo_root;
 809                 if (pseudo_root != NULL){
 810                         current->fs->root = pseudo_root;
 811                         current->fs->pwd  = pseudo_root;
 812                 }
 813         }
 814         #endif
 815 
 816 #ifdef CONFIG_BLK_DEV_INITRD
 817         root_mountflags = real_root_mountflags;
 818         if (ROOT_DEV != real_root_dev && ROOT_DEV == MKDEV(RAMDISK_MAJOR,0)) {
 819                 int error;
 820 
 821                 pid = kernel_thread(do_linuxrc, "/linuxrc", SIGCHLD);
 822                 if (pid>0)
 823                         while (pid != wait(&i));
 824                 if (real_root_dev != MKDEV(RAMDISK_MAJOR, 0)) {
 825                         error = change_root(real_root_dev,"/initrd");
 826                         if (error)
 827                                 printk(KERN_ERR "Change root to /initrd: "
 828                                     "error %d\n",error);
 829                 }
 830         }
 831 #endif
 832 
 833         (void) open("/dev/tty1",O_RDWR,0);
 834         (void) dup(0);
 835         (void) dup(0);
 836 
 837         if (!execute_command) {
 838                 execve("/etc/init",argv_init,envp_init);
 839                 execve("/bin/init",argv_init,envp_init);
 840                 execve("/sbin/init",argv_init,envp_init);
 841                 /* if this fails, fall through to original stuff */
 842 
 843                 pid = kernel_thread(do_rc, "/etc/rc", SIGCHLD);
 844                 if (pid>0)
 845                         while (pid != wait(&i))
 846                                 /* nothing */;
 847         }
 848 
 849         while (1) {
 850                 pid = kernel_thread(do_shell,
 851                         execute_command ? execute_command : "/bin/sh",
 852                         SIGCHLD);
 853                 if (pid < 0) {
 854                         printf("Fork failed in init\n\r");
 855                         continue;
 856                 }
 857                 while (1)
 858                         if (pid == wait(&i))
 859                                 break;
 860                 printf("\n\rchild %d died with code %04x\n\r",pid,i);
 861                 sync();
 862         }
 863         return -1;
 864 }
/* */
root/init/main.c

DEFINITIONS
