init/main.c

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

DEFINITIONS
