init/main.c

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

DEFINITIONS
