init/main.c

/* */
This source file includes following definitions.
get_options
profile_setup
ramdisk_start_setup
load_ramdisk
prompt_ramdisk
ramdisk_size
checksetup
calibrate_delay
parse_root_dev
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_ROOT_NFS
  36 #include <linux/nfs_fs.h>
  37 #endif
  38 
  39 #include <asm/bugs.h>
  40 
  41 extern char _stext, _etext;
  42 extern char *linux_banner;
  43 
  44 static char printbuf[1024];
  45 
  46 extern int console_loglevel;
  47 
  48 static int init(void *);
  49 extern int bdflush(void *);
  50 extern int kswapd(void *);
  51 
  52 extern void init_IRQ(void);
  53 extern void init_modules(void);
  54 extern long console_init(long, long);
  55 extern long kmalloc_init(long,long);
  56 extern void sock_init(void);
  57 extern long pci_init(long, long);
  58 extern void sysctl_init(void);
  59 
  60 extern void no_scroll(char *str, int *ints);
  61 extern void swap_setup(char *str, int *ints);
  62 extern void buff_setup(char *str, int *ints);
  63 extern void panic_setup(char *str, int *ints);
  64 extern void bmouse_setup(char *str, int *ints);
  65 extern void lp_setup(char *str, int *ints);
  66 extern void eth_setup(char *str, int *ints);
  67 extern void xd_setup(char *str, int *ints);
  68 extern void floppy_setup(char *str, int *ints);
  69 extern void st_setup(char *str, int *ints);
  70 extern void st0x_setup(char *str, int *ints);
  71 extern void advansys_setup(char *str, int *ints);
  72 extern void tmc8xx_setup(char *str, int *ints);
  73 extern void t128_setup(char *str, int *ints);
  74 extern void pas16_setup(char *str, int *ints);
  75 extern void generic_NCR5380_setup(char *str, int *intr);
  76 extern void generic_NCR53C400_setup(char *str, int *intr);
  77 extern void aha152x_setup(char *str, int *ints);
  78 extern void aha1542_setup(char *str, int *ints);
  79 extern void aic7xxx_setup(char *str, int *ints);
  80 extern void AM53C974_setup(char *str, int *ints);
  81 extern void BusLogic_Setup(char *str, int *ints);
  82 extern void fdomain_setup(char *str, int *ints);
  83 extern void in2000_setup(char *str, int *ints);
  84 extern void NCR53c406a_setup(char *str, int *ints);
  85 extern void ppa_setup(char *str, int *ints);
  86 extern void scsi_luns_setup(char *str, int *ints);
  87 extern void sound_setup(char *str, int *ints);
  88 #ifdef CONFIG_CDU31A
  89 extern void cdu31a_setup(char *str, int *ints);
  90 #endif CONFIG_CDU31A
  91 #ifdef CONFIG_MCD
  92 extern void mcd_setup(char *str, int *ints);
  93 #endif CONFIG_MCD
  94 #ifdef CONFIG_MCDX
  95 extern void mcdx_setup(char *str, int *ints);
  96 #endif CONFIG_MCDX
  97 #ifdef CONFIG_SBPCD
  98 extern void sbpcd_setup(char *str, int *ints);
  99 #endif CONFIG_SBPCD
 100 #ifdef CONFIG_AZTCD
 101 extern void aztcd_setup(char *str, int *ints);
 102 #endif CONFIG_AZTCD
 103 #ifdef CONFIG_CDU535
 104 extern void sonycd535_setup(char *str, int *ints);
 105 #endif CONFIG_CDU535
 106 #ifdef CONFIG_GSCD
 107 extern void gscd_setup(char *str, int *ints);
 108 #endif CONFIG_GSCD
 109 #ifdef CONFIG_CM206
 110 extern void cm206_setup(char *str, int *ints);
 111 #endif CONFIG_CM206
 112 #ifdef CONFIG_OPTCD
 113 extern void optcd_setup(char *str, int *ints);
 114 #endif CONFIG_OPTCD
 115 #ifdef CONFIG_SJCD
 116 extern void sjcd_setup(char *str, int *ints);
 117 #endif CONFIG_SJCD
 118 #ifdef CONFIG_ISP16_CDI
 119 extern void isp16_setup(char *str, int *ints);
 120 #endif CONFIG_ISP16_CDI
 121 #ifdef CONFIG_BLK_DEV_RAM
 122 static void ramdisk_start_setup(char *str, int *ints);
 123 static void load_ramdisk(char *str, int *ints);
 124 static void prompt_ramdisk(char *str, int *ints);
 125 static void ramdisk_size(char *str, int *ints);
 126 #ifdef CONFIG_BLK_DEV_INITRD
 127 static void no_initrd(char *s,int *ints);
 128 #endif
 129 #endif CONFIG_BLK_DEV_RAM
 130 #ifdef CONFIG_ISDN_DRV_ICN
 131 extern void icn_setup(char *str, int *ints);
 132 #endif
 133 #ifdef CONFIG_ISDN_DRV_TELES
 134 extern void teles_setup(char *str, int *ints);
 135 #endif
 136 
 137 #ifdef CONFIG_ATARIMOUSE
 138 extern void atari_mouse_setup (char *str, int *ints);
 139 #endif
 140 #ifdef CONFIG_DMASOUND
 141 extern void dmasound_setup (char *str, int *ints);
 142 #endif
 143 #ifdef CONFIG_ATARI_SCSI
 144 extern void atari_scsi_setup (char *str, int *ints);
 145 #endif
 146 extern void wd33c93_setup (char *str, int *ints);
 147 extern void gvp11_setup (char *str, int *ints);
 148 
 149 #ifdef CONFIG_DIGI
 150 extern void pcxx_setup(char *str, int *ints);
 151 #endif
 152 #ifdef CONFIG_ISDN_DRV_PCBIT
 153 extern void pcbit_setup(char *str, int *ints);
 154 #endif
 155 #ifdef CONFIG_RISCOM8
 156 extern void riscom8_setup(char *str, int *ints);
 157 #endif
 158 
 159 
 160 #if defined(CONFIG_SYSVIPC) || defined(CONFIG_KERNELD)
 161 extern void ipc_init(void);
 162 #endif
 163 
 164 /*
 165  * Boot command-line arguments
 166  */
 167 #define MAX_INIT_ARGS 8
 168 #define MAX_INIT_ENVS 8
 169 
 170 extern void time_init(void);
 171 
 172 static unsigned long memory_start = 0;
 173 static unsigned long memory_end = 0;
 174 
 175 int rows, cols;
 176 
 177 #ifdef CONFIG_BLK_DEV_RAM
 178 extern int rd_doload;           /* 1 = load ramdisk, 0 = don't load */
 179 extern int rd_prompt;           /* 1 = prompt for ramdisk, 0 = don't prompt */
 180 extern int rd_size;             /* Size of the ramdisk(s) */
 181 extern int rd_image_start;      /* starting block # of image */
 182 #ifdef CONFIG_BLK_DEV_INITRD
 183 kdev_t real_root_dev;
 184 #endif
 185 #endif
 186 
 187 int root_mountflags = MS_RDONLY;
 188 char *execute_command = 0;
 189 
 190 #ifdef CONFIG_ROOT_NFS
 191 char nfs_root_name[NFS_ROOT_NAME_LEN] = { "default" };
 192 char nfs_root_addrs[NFS_ROOT_ADDRS_LEN] = { "" };
 193 #endif
 194 
 195 extern void dquot_init(void);
 196 
 197 static char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
 198 static char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", "TERM=linux", NULL, };
 199 
 200 static char * argv_rc[] = { "/bin/sh", NULL };
 201 static char * envp_rc[] = { "HOME=/", "TERM=linux", NULL };
 202 
 203 static char * argv[] = { "-/bin/sh",NULL };
 204 static char * envp[] = { "HOME=/usr/root", "TERM=linux", NULL };
 205 
 206 char *get_options(char *str, int *ints)
     /*  */
 207 {
 208         char *cur = str;
 209         int i=1;
 210 
 211         while (cur && isdigit(*cur) && i <= 10) {
 212                 ints[i++] = simple_strtoul(cur,NULL,0);
 213                 if ((cur = strchr(cur,',')) != NULL)
 214                         cur++;
 215         }
 216         ints[0] = i-1;
 217         return(cur);
 218 }
 219 
 220 static void profile_setup(char *str, int *ints)
     /*  */
 221 {
 222         if (ints[0] > 0)
 223                 prof_shift = (unsigned long) ints[1];
 224         else
 225 #ifdef CONFIG_PROFILE_SHIFT
 226                 prof_shift = CONFIG_PROFILE_SHIFT;
 227 #else
 228                 prof_shift = 2;
 229 #endif
 230 }
 231 
 232 struct {
 233         const char *str;
 234         void (*setup_func)(char *, int *);
 235 } bootsetups[] = {
 236         { "reserve=", reserve_setup },
 237         { "profile=", profile_setup },
 238 #ifdef CONFIG_BLK_DEV_RAM
 239         { "ramdisk_start=", ramdisk_start_setup },
 240         { "load_ramdisk=", load_ramdisk },
 241         { "prompt_ramdisk=", prompt_ramdisk },
 242         { "ramdisk=", ramdisk_size },
 243         { "ramdisk_size=", ramdisk_size },
 244 #ifdef CONFIG_BLK_DEV_INITRD
 245         { "noinitrd", no_initrd },
 246 #endif
 247 #endif
 248         { "swap=", swap_setup },
 249         { "buff=", buff_setup },
 250         { "panic=", panic_setup },
 251         { "no-scroll", no_scroll },
 252 #ifdef CONFIG_BUGi386
 253         { "no-hlt", no_halt },
 254         { "no387", no_387 },
 255 #endif
 256 #ifdef CONFIG_INET
 257         { "ether=", eth_setup },
 258 #endif
 259 #ifdef CONFIG_PRINTER
 260         { "lp=", lp_setup },
 261 #endif
 262 #ifdef CONFIG_SCSI
 263         { "max_scsi_luns=", scsi_luns_setup },
 264 #endif
 265 #ifdef CONFIG_SCSI_ADVANSYS
 266         { "advansys=", advansys_setup },
 267 #endif
 268 #if defined(CONFIG_BLK_DEV_HD)
 269         { "hd=", hd_setup },
 270 #endif
 271 #ifdef CONFIG_CHR_DEV_ST
 272         { "st=", st_setup },
 273 #endif
 274 #ifdef CONFIG_BUSMOUSE
 275         { "bmouse=", bmouse_setup },
 276 #endif
 277 #ifdef CONFIG_SCSI_SEAGATE
 278         { "st0x=", st0x_setup },
 279         { "tmc8xx=", tmc8xx_setup },
 280 #endif
 281 #ifdef CONFIG_SCSI_T128
 282         { "t128=", t128_setup },
 283 #endif
 284 #ifdef CONFIG_SCSI_PAS16
 285         { "pas16=", pas16_setup },
 286 #endif
 287 #ifdef CONFIG_SCSI_GENERIC_NCR5380
 288         { "ncr5380=", generic_NCR5380_setup },
 289         { "ncr53c400=", generic_NCR53C400_setup },
 290 #endif
 291 #ifdef CONFIG_SCSI_AHA152X
 292         { "aha152x=", aha152x_setup},
 293 #endif
 294 #ifdef CONFIG_SCSI_AHA1542
 295         { "aha1542=", aha1542_setup},
 296 #endif
 297 #ifdef CONFIG_SCSI_AIC7XXX
 298         { "aic7xxx=", aic7xxx_setup},
 299 #endif
 300 #ifdef CONFIG_SCSI_BUSLOGIC
 301         { "BusLogic=", BusLogic_Setup},
 302 #endif
 303 #ifdef CONFIG_SCSI_AM53C974
 304         { "AM53C974=", AM53C974_setup},
 305 #endif
 306 #ifdef CONFIG_SCSI_NCR53C406A
 307         { "ncr53c406a=", NCR53c406a_setup},
 308 #endif
 309 #ifdef CONFIG_SCSI_FUTURE_DOMAIN
 310         { "fdomain=", fdomain_setup},
 311 #endif
 312 #ifdef CONFIG_SCSI_IN2000
 313         { "in2000=", in2000_setup},
 314 #endif
 315 #ifdef CONFIG_SCSI_PPA
 316         { "ppa=", ppa_setup },
 317 #endif
 318 #ifdef CONFIG_BLK_DEV_XD
 319         { "xd=", xd_setup },
 320 #endif
 321 #ifdef CONFIG_BLK_DEV_FD
 322         { "floppy=", floppy_setup },
 323 #endif
 324 #ifdef CONFIG_CDU31A
 325         { "cdu31a=", cdu31a_setup },
 326 #endif CONFIG_CDU31A
 327 #ifdef CONFIG_MCD
 328         { "mcd=", mcd_setup },
 329 #endif CONFIG_MCD
 330 #ifdef CONFIG_MCDX
 331         { "mcdx=", mcdx_setup },
 332 #endif CONFIG_MCDX
 333 #ifdef CONFIG_SBPCD
 334         { "sbpcd=", sbpcd_setup },
 335 #endif CONFIG_SBPCD
 336 #ifdef CONFIG_AZTCD
 337         { "aztcd=", aztcd_setup },
 338 #endif CONFIG_AZTCD
 339 #ifdef CONFIG_CDU535
 340         { "sonycd535=", sonycd535_setup },
 341 #endif CONFIG_CDU535
 342 #ifdef CONFIG_GSCD
 343         { "gscd=", gscd_setup },
 344 #endif CONFIG_GSCD
 345 #ifdef CONFIG_CM206
 346         { "cm206=", cm206_setup },
 347 #endif CONFIG_CM206
 348 #ifdef CONFIG_OPTCD
 349         { "optcd=", optcd_setup },
 350 #endif CONFIG_OPTCD
 351 #ifdef CONFIG_SJCD
 352         { "sjcd=", sjcd_setup },
 353 #endif CONFIG_SJCD
 354 #ifdef CONFIG_ISP16_CDI
 355         { "isp16=", isp16_setup },
 356 #endif CONFIG_ISP16_CDI
 357 #ifdef CONFIG_SOUND
 358         { "sound=", sound_setup },
 359 #endif
 360 #ifdef CONFIG_ISDN_DRV_ICN
 361         { "icn=", icn_setup },
 362 #endif
 363 #ifdef CONFIG_ISDN_DRV_TELES
 364         { "teles=", teles_setup },
 365 #endif
 366 #ifdef CONFIG_ISDN_DRV_PCBIT
 367         { "pcbit=", pcbit_setup },
 368 #endif
 369 #ifdef CONFIG_ATARIMOUSE
 370         { "atamouse=", atari_mouse_setup },
 371 #endif
 372 #ifdef CONFIG_DMASOUND
 373         { "dmasound=", dmasound_setup },
 374 #endif
 375 #ifdef CONFIG_ATARI_SCSI
 376         { "atascsi=", atari_scsi_setup },
 377 #endif
 378 #if defined(CONFIG_A3000_SCSI) || defined(CONFIG_A2091_SCSI) \
 379             || defined(CONFIG_GVP11_SCSI)
 380         { "wd33c93=", wd33c93_setup },
 381 #endif
 382 #if defined(CONFIG_GVP11_SCSI)
 383         { "gvp11=", gvp11_setup },
 384 #endif
 385 #ifdef CONFIG_DIGI
 386         { "digi=", pcxx_setup },
 387 #endif
 388 #ifdef CONFIG_RISCOM8
 389         { "riscom8=", riscom8_setup },
 390 #endif
 391         { 0, 0 }
 392 };
 393 
 394 #ifdef CONFIG_BLK_DEV_RAM
 395 static void ramdisk_start_setup(char *str, int *ints)
     /*  */
 396 {
 397    if (ints[0] > 0 && ints[1] >= 0)
 398       rd_image_start = ints[1];
 399 }
 400 
 401 static void load_ramdisk(char *str, int *ints)
     /*  */
 402 {
 403    if (ints[0] > 0 && ints[1] >= 0)
 404       rd_doload = ints[1] & 1;
 405 }
 406 
 407 static void prompt_ramdisk(char *str, int *ints)
     /*  */
 408 {
 409    if (ints[0] > 0 && ints[1] >= 0)
 410       rd_prompt = ints[1] & 1;
 411 }
 412 
 413 static void ramdisk_size(char *str, int *ints)
     /*  */
 414 {
 415         if (ints[0] > 0 && ints[1] >= 0)
 416                 rd_size = ints[1];
 417 }
 418 
 419 #endif
 420 
 421 static int checksetup(char *line)
     /*  */
 422 {
 423         int i = 0;
 424         int ints[11];
 425 
 426 #ifdef CONFIG_BLK_DEV_IDE
 427         /* ide driver needs the basic string, rather than pre-processed values */
 428         if (!strncmp(line,"ide",3) || (!strncmp(line,"hd",2) && line[2] != '=')) {
 429                 ide_setup(line);
 430                 return 1;
 431         }
 432 #endif
 433         while (bootsetups[i].str) {
 434                 int n = strlen(bootsetups[i].str);
 435                 if (!strncmp(line,bootsetups[i].str,n)) {
 436                         bootsetups[i].setup_func(get_options(line+n,ints), ints);
 437                         return 1;
 438                 }
 439                 i++;
 440         }
 441         return 0;
 442 }
 443 
 444 /* this should be approx 2 Bo*oMips to start (note initial shift), and will
 445    still work even if initially too large, it will just take slightly longer */
 446 unsigned long loops_per_sec = (1<<12);
 447 
 448 /* This is the number of bits of precision for the loops_per_second.  Each
 449    bit takes on average 1.5/HZ seconds.  This (like the original) is a little
 450    better than 1% */
 451 #define LPS_PREC 8
 452 
 453 void calibrate_delay(void)
     /*  */
 454 {
 455         int ticks;
 456         int loopbit;
 457         int lps_precision = LPS_PREC;
 458 
 459         loops_per_sec = (1<<12);
 460 
 461         printk("Calibrating delay loop.. ");
 462         while (loops_per_sec <<= 1) {
 463                 /* wait for "start of" clock tick */
 464                 ticks = jiffies;
 465                 while (ticks == jiffies)
 466                         /* nothing */;
 467                 /* Go .. */
 468                 ticks = jiffies;
 469                 __delay(loops_per_sec);
 470                 ticks = jiffies - ticks;
 471                 if (ticks)
 472                         break;
 473                 }
 474 
 475 /* Do a binary approximation to get loops_per_second set to equal one clock
 476    (up to lps_precision bits) */
 477         loops_per_sec >>= 1;
 478         loopbit = loops_per_sec;
 479         while ( lps_precision-- && (loopbit >>= 1) ) {
 480                 loops_per_sec |= loopbit;
 481                 ticks = jiffies;
 482                 while (ticks == jiffies);
 483                 ticks = jiffies;
 484                 __delay(loops_per_sec);
 485                 if (jiffies != ticks)   /* longer than 1 tick */
 486                         loops_per_sec &= ~loopbit;
 487         }
 488 
 489 /* finally, adjust loops per second in terms of seconds instead of clocks */    
 490         loops_per_sec *= HZ;
 491 /* Round the value and print it */      
 492         printk("ok - %lu.%02lu BogoMIPS\n",
 493                 (loops_per_sec+2500)/500000,
 494                 ((loops_per_sec+2500)/5000) % 100);
 495 }
 496 
 497 static void parse_root_dev(char * line)
     /*  */
 498 {
 499         int base = 0;
 500         static struct dev_name_struct {
 501                 const char *name;
 502                 const int num;
 503         } devices[] = {
 504                 { "nfs",     0x00ff },
 505                 { "hda",     0x0300 },
 506                 { "hdb",     0x0340 },
 507                 { "hdc",     0x1600 },
 508                 { "hdd",     0x1640 },
 509                 { "sda",     0x0800 },
 510                 { "sdb",     0x0810 },
 511                 { "sdc",     0x0820 },
 512                 { "sdd",     0x0830 },
 513                 { "sde",     0x0840 },
 514                 { "fd",      0x0200 },
 515                 { "xda",     0x0d00 },
 516                 { "xdb",     0x0d40 },
 517                 { "ram",     0x0100 },
 518                 { "scd",     0x0b00 },
 519                 { "mcd",     0x1700 },
 520                 { "cdu535",  0x1800 },
 521                 { "aztcd",   0x1d00 },
 522                 { "cm206cd", 0x2000 },
 523                 { "gscd",    0x1000 },
 524                 { "sbpcd",   0x1900 },
 525                 { "sonycd",  0x1800 },
 526                 { NULL, 0 }
 527         };
 528 
 529         if (strncmp(line,"/dev/",5) == 0) {
 530                 struct dev_name_struct *dev = devices;
 531                 line += 5;
 532                 do {
 533                         int len = strlen(dev->name);
 534                         if (strncmp(line,dev->name,len) == 0) {
 535                                 line += len;
 536                                 base = dev->num;
 537                                 break;
 538                         }
 539                         dev++;
 540                 } while (dev->name);
 541         }
 542         ROOT_DEV = to_kdev_t(base + simple_strtoul(line,NULL,base?10:16));
 543 }
 544 
 545 /*
 546  * This is a simple kernel command line parsing function: it parses
 547  * the command line, and fills in the arguments/environment to init
 548  * as appropriate. Any cmd-line option is taken to be an environment
 549  * variable if it contains the character '='.
 550  *
 551  *
 552  * This routine also checks for options meant for the kernel.
 553  * These options are not given to init - they are for internal kernel use only.
 554  */
 555 static void parse_options(char *line)
     /*  */
 556 {
 557         char *next;
 558         int args, envs;
 559 
 560         if (!*line)
 561                 return;
 562         args = 0;
 563         envs = 1;       /* TERM is set to 'linux' by default */
 564         next = line;
 565         while ((line = next) != NULL) {
 566                 if ((next = strchr(line,' ')) != NULL)
 567                         *next++ = 0;
 568                 /*
 569                  * check for kernel options first..
 570                  */
 571                 if (!strncmp(line,"root=",5)) {
 572                         parse_root_dev(line+5);
 573                         continue;
 574                 }
 575 #ifdef CONFIG_ROOT_NFS
 576                 if (!strncmp(line, "nfsroot=", 8)) {
 577                         int n;
 578                         line += 8;
 579                         ROOT_DEV = MKDEV(UNNAMED_MAJOR, 255);
 580                         if (line[0] == '/' || line[0] == ',' || (line[0] >= '0' && line[0] <= '9')) {
 581                                 strncpy(nfs_root_name, line, sizeof(nfs_root_name));
 582                                 nfs_root_name[sizeof(nfs_root_name)-1] = '\0';
 583                                 continue;
 584                         }
 585                         n = strlen(line) + strlen(NFS_ROOT);
 586                         if (n >= sizeof(nfs_root_name))
 587                                 line[sizeof(nfs_root_name) - strlen(NFS_ROOT) - 1] = '\0';
 588                         sprintf(nfs_root_name, NFS_ROOT, line);
 589                         continue;
 590                 }
 591                 if (!strncmp(line, "nfsaddrs=", 9)) {
 592                         line += 9;
 593                         strncpy(nfs_root_addrs, line, sizeof(nfs_root_addrs));
 594                         nfs_root_addrs[sizeof(nfs_root_addrs)-1] = '\0';
 595                         continue;
 596                 }
 597 #endif
 598                 if (!strcmp(line,"ro")) {
 599                         root_mountflags |= MS_RDONLY;
 600                         continue;
 601                 }
 602                 if (!strcmp(line,"rw")) {
 603                         root_mountflags &= ~MS_RDONLY;
 604                         continue;
 605                 }
 606                 if (!strcmp(line,"debug")) {
 607                         console_loglevel = 10;
 608                         continue;
 609                 }
 610                 if (!strncmp(line,"init=",5)) {
 611                         line += 5;
 612                         execute_command = line;
 613                         continue;
 614                 }
 615                 if (checksetup(line))
 616                         continue;
 617                 /*
 618                  * Then check if it's an environment variable or
 619                  * an option.
 620                  */
 621                 if (strchr(line,'=')) {
 622                         if (envs >= MAX_INIT_ENVS)
 623                                 break;
 624                         envp_init[++envs] = line;
 625                 } else {
 626                         if (args >= MAX_INIT_ARGS)
 627                                 break;
 628                         argv_init[++args] = line;
 629                 }
 630         }
 631         argv_init[args+1] = NULL;
 632         envp_init[envs+1] = NULL;
 633 }
 634 
 635 
 636 extern void setup_arch(char **, unsigned long *, unsigned long *);
 637 extern void arch_syms_export(void);
 638 
 639 #ifndef __SMP__
 640 
 641 /*
 642  *      Uniprocessor idle thread
 643  */
 644  
 645 int cpu_idle(void *unused)
     /*  */
 646 {
 647         for(;;)
 648                 idle();
 649 }
 650 
 651 #else
 652 
 653 /*
 654  *      Multiprocessor idle thread is in arch/...
 655  */
 656  
 657 extern int cpu_idle(void * unused);
 658 
 659 /*
 660  *      Activate a secondary processor.
 661  */
 662  
 663 asmlinkage void start_secondary(void)
     /*  */
 664 {
 665         trap_init();
 666         init_IRQ();
 667         smp_callin();
 668         cpu_idle(NULL);
 669 }
 670 
 671 
 672 
 673 /*
 674  *      Called by CPU#0 to activate the rest.
 675  */
 676  
 677 static void smp_init(void)
     /*  */
 678 {
 679         int i, j;
 680         smp_boot_cpus();
 681         
 682         /*
 683          *      Create the slave init tasks as sharing pid 0.
 684          *
 685          *      This should only happen if we have virtual CPU numbers
 686          *      higher than 0.
 687          */
 688 
 689         for (i=1; i<smp_num_cpus; i++)
 690         {
 691                 struct task_struct *n, *p;
 692 
 693                 j = cpu_logical_map[i];
 694                 /*
 695                  *      We use kernel_thread for the idlers which are
 696                  *      unlocked tasks running in kernel space.
 697                  */
 698                 kernel_thread(cpu_idle, NULL, CLONE_PID);
 699                 /*
 700                  *      Don't assume linear processor numbering
 701                  */
 702                 current_set[j]=task[i];
 703                 current_set[j]->processor=j;
 704                 cli();
 705                 n = task[i]->next_run;
 706                 p = task[i]->prev_run;
 707                 nr_running--;
 708                 n->prev_run = p;
 709                 p->next_run = n;
 710                 task[i]->next_run = task[i]->prev_run = task[i];
 711                 sti();
 712         }
 713 }               
 714 
 715 /*
 716  *      The autoprobe routines assume CPU#0 on the i386
 717  *      so we don't actually set the game in motion until
 718  *      they are finished.
 719  */
 720  
 721 static void smp_begin(void)
     /*  */
 722 {
 723         smp_threads_ready=1;
 724         smp_commence();
 725 }
 726         
 727 #endif
 728 
 729 /*
 730  *      Activate the first processor.
 731  */
 732  
 733 asmlinkage void start_kernel(void)
     /*  */
 734 {
 735         char * command_line;
 736 
 737 /*
 738  *      This little check will move.
 739  */
 740 
 741 #ifdef __SMP__
 742         static int first_cpu=1;
 743         
 744         if(!first_cpu)
 745                 start_secondary();
 746         first_cpu=0;
 747         
 748 #endif  
 749 /*
 750  * Interrupts are still disabled. Do necessary setups, then
 751  * enable them
 752  */
 753         setup_arch(&command_line, &memory_start, &memory_end);
 754         memory_start = paging_init(memory_start,memory_end);
 755         trap_init();
 756         init_IRQ();
 757         sched_init();
 758         time_init();
 759         parse_options(command_line);
 760 #ifdef CONFIG_MODULES
 761         init_modules();
 762 #endif
 763 #ifdef CONFIG_PROFILE
 764         if (!prof_shift)
 765 #ifdef CONFIG_PROFILE_SHIFT
 766                 prof_shift = CONFIG_PROFILE_SHIFT;
 767 #else
 768                 prof_shift = 2;
 769 #endif
 770 #endif
 771         if (prof_shift) {
 772                 prof_buffer = (unsigned int *) memory_start;
 773                 /* only text is profiled */
 774                 prof_len = (unsigned long) &_etext - (unsigned long) &_stext;
 775                 prof_len >>= prof_shift;
 776                 memory_start += prof_len * sizeof(unsigned int);
 777         }
 778         memory_start = console_init(memory_start,memory_end);
 779 #ifdef CONFIG_PCI
 780         memory_start = pci_init(memory_start,memory_end);
 781 #endif
 782         memory_start = kmalloc_init(memory_start,memory_end);
 783         sti();
 784         calibrate_delay();
 785         memory_start = inode_init(memory_start,memory_end);
 786         memory_start = file_table_init(memory_start,memory_end);
 787         memory_start = name_cache_init(memory_start,memory_end);
 788 #ifdef CONFIG_BLK_DEV_INITRD
 789         if (initrd_start && initrd_start < memory_start) {
 790                 printk(KERN_CRIT "initrd overwritten (0x%08lx < 0x%08lx) - "
 791                     "disabling it.\n",initrd_start,memory_start);
 792                 initrd_start = 0;
 793         }
 794 #endif
 795         mem_init(memory_start,memory_end);
 796         buffer_init();
 797         sock_init();
 798 #if defined(CONFIG_SYSVIPC) || defined(CONFIG_KERNELD)
 799         ipc_init();
 800 #endif
 801         dquot_init();
 802         arch_syms_export();
 803         sti();
 804         check_bugs();
 805 
 806         printk(linux_banner);
 807 #ifdef __SMP__
 808         smp_init();
 809 #endif
 810         sysctl_init();
 811         /* 
 812          *      We count on the initial thread going ok 
 813          *      Like idlers init is an unlocked kernel thread, which will
 814          *      make syscalls (and thus be locked).
 815          */
 816         kernel_thread(init, NULL, 0);
 817 /*
 818  * task[0] is meant to be used as an "idle" task: it may not sleep, but
 819  * it might do some general things like count free pages or it could be
 820  * used to implement a reasonable LRU algorithm for the paging routines:
 821  * anything that can be useful, but shouldn't take time from the real
 822  * processes.
 823  *
 824  * Right now task[0] just does a infinite idle loop.
 825  */
 826         cpu_idle(NULL);
 827 }
 828 
 829 static int printf(const char *fmt, ...)
     /*  */
 830 {
 831         va_list args;
 832         int i;
 833 
 834         va_start(args, fmt);
 835         write(1,printbuf,i=vsprintf(printbuf, fmt, args));
 836         va_end(args);
 837         return i;
 838 }
 839 
 840 static int do_rc(void * rc)
     /*  */
 841 {
 842         close(0);
 843         if (open(rc,O_RDONLY,0))
 844                 return -1;
 845         return execve("/bin/sh", argv_rc, envp_rc);
 846 }
 847 
 848 static int do_shell(void * shell)
     /*  */
 849 {
 850         close(0);close(1);close(2);
 851         setsid();
 852         (void) open("/dev/tty1",O_RDWR,0);
 853         (void) dup(0);
 854         (void) dup(0);
 855         return execve(shell, argv, envp);
 856 }
 857 
 858 #ifdef CONFIG_BLK_DEV_INITRD
 859 static int do_linuxrc(void * shell)
     /*  */
 860 {
 861         static char *argv[] = { "linuxrc", NULL, };
 862 
 863         close(0);close(1);close(2);
 864         setsid();
 865         (void) open("/dev/tty1",O_RDWR,0);
 866         (void) dup(0);
 867         (void) dup(0);
 868         return execve(shell, argv, envp_init);
 869 }
 870 
 871 static void no_initrd(char *s,int *ints)
     /*  */
 872 {
 873         mount_initrd = 0;
 874 }
 875 #endif
 876 
 877 static int init(void * unused)
     /*  */
 878 {
 879         int pid,i;
 880 #ifdef CONFIG_BLK_DEV_INITRD
 881         int real_root_mountflags;
 882 #endif
 883 
 884         /* Launch bdflush from here, instead of the old syscall way. */
 885         kernel_thread(bdflush, NULL, 0);
 886         /* Start the background pageout daemon. */
 887         kernel_thread(kswapd, NULL, 0);
 888 
 889 #ifdef CONFIG_BLK_DEV_INITRD
 890         real_root_dev = ROOT_DEV;
 891         real_root_mountflags = root_mountflags;
 892         if (initrd_start && mount_initrd) root_mountflags &= ~MS_RDONLY;
 893         else mount_initrd =0;
 894 #endif
 895         setup();
 896 
 897 #ifdef __SMP__
 898         /*
 899          *      With the devices probed and setup we can
 900          *      now enter SMP mode.
 901          */
 902         
 903         smp_begin();
 904 #endif  
 905 
 906         #ifdef CONFIG_UMSDOS_FS
 907         {
 908                 /*
 909                         When mounting a umsdos fs as root, we detect
 910                         the pseudo_root (/linux) and initialise it here.
 911                         pseudo_root is defined in fs/umsdos/inode.c
 912                 */
 913                 extern struct inode *pseudo_root;
 914                 if (pseudo_root != NULL){
 915                         current->fs->root = pseudo_root;
 916                         current->fs->pwd  = pseudo_root;
 917                 }
 918         }
 919         #endif
 920 
 921 #ifdef CONFIG_BLK_DEV_INITRD
 922         root_mountflags = real_root_mountflags;
 923         if (mount_initrd && ROOT_DEV != real_root_dev && ROOT_DEV == MKDEV(RAMDISK_MAJOR,0)) {
 924                 int error;
 925 
 926                 pid = kernel_thread(do_linuxrc, "/linuxrc", SIGCHLD);
 927                 if (pid>0)
 928                         while (pid != wait(&i));
 929                 if (real_root_dev != MKDEV(RAMDISK_MAJOR, 0)) {
 930                         error = change_root(real_root_dev,"/initrd");
 931                         if (error)
 932                                 printk(KERN_ERR "Change root to /initrd: "
 933                                     "error %d\n",error);
 934                 }
 935         }
 936 #endif
 937 
 938         (void) open("/dev/tty1",O_RDWR,0);
 939         (void) dup(0);
 940         (void) dup(0);
 941 
 942         if (!execute_command) {
 943                 execve("/etc/init",argv_init,envp_init);
 944                 execve("/bin/init",argv_init,envp_init);
 945                 execve("/sbin/init",argv_init,envp_init);
 946                 /* if this fails, fall through to original stuff */
 947 
 948                 pid = kernel_thread(do_rc, "/etc/rc", SIGCHLD);
 949                 if (pid>0)
 950                         while (pid != wait(&i))
 951                                 /* nothing */;
 952         }
 953 
 954         while (1) {
 955                 pid = kernel_thread(do_shell,
 956                         execute_command ? execute_command : "/bin/sh",
 957                         SIGCHLD);
 958                 if (pid < 0) {
 959                         printf("Fork failed in init\n\r");
 960                         continue;
 961                 }
 962                 while (1)
 963                         if (pid == wait(&i))
 964                                 break;
 965                 printf("\n\rchild %d died with code %04x\n\r",pid,i);
 966                 sync();
 967         }
 968         return -1;
 969 }
/* */
root/init/main.c

DEFINITIONS
