root/init/main.c

/* */

DEFINITIONS

1. get_options
2. ramdisk_setup
3. checksetup
4. calibrate_delay
5. parse_options
6. start_kernel
7. printf
8. init

   1 /*
   2  *  linux/init/main.c
   3  *
   4  *  Copyright (C) 1991, 1992  Linus Torvalds
   5  */
   6 
   7 #define __KERNEL_SYSCALLS__
   8 #include <stdarg.h>
   9 
  10 #include <asm/system.h>
  11 #include <asm/io.h>
  12 
  13 #include <linux/types.h>
  14 #include <linux/fcntl.h>
  15 #include <linux/config.h>
  16 #include <linux/sched.h>
  17 #include <linux/tty.h>
  18 #include <linux/head.h>
  19 #include <linux/unistd.h>
  20 #include <linux/string.h>
  21 #include <linux/timer.h>
  22 #include <linux/fs.h>
  23 #include <linux/ctype.h>
  24 #include <linux/delay.h>
  25 #include <linux/utsname.h>
  26 #include <linux/ioport.h>
  27 #include <linux/hdreg.h>
  28 #include <linux/mm.h>
  29 
  30 #include <asm/bugs.h>
  31 
  32 extern unsigned long * prof_buffer;
  33 extern unsigned long prof_len;
  34 extern char etext, end;
  35 extern char *linux_banner;
  36 
  37 static char printbuf[1024];
  38 
  39 extern int console_loglevel;
  40 
  41 extern void init(void);
  42 extern void init_IRQ(void);
  43 extern void init_modules(void);
  44 extern long console_init(long, long);
  45 extern long kmalloc_init(long,long);
  46 extern long blk_dev_init(long,long);
  47 extern long chr_dev_init(long,long);
  48 extern void sock_init(void);
  49 extern long rd_init(long mem_start, int length);
  50 unsigned long net_dev_init(unsigned long, unsigned long);
  51 extern long bios32_init(long, long);
  52 
  53 extern void bmouse_setup(char *str, int *ints);
  54 extern void eth_setup(char *str, int *ints);
  55 extern void xd_setup(char *str, int *ints);
  56 extern void floppy_setup(char *str, int *ints);
  57 extern void mcd_setup(char *str, int *ints);
  58 extern void aztcd_setup(char *str, int *ints);
  59 extern void st_setup(char *str, int *ints);
  60 extern void st0x_setup(char *str, int *ints);
  61 extern void tmc8xx_setup(char *str, int *ints);
  62 extern void t128_setup(char *str, int *ints);
  63 extern void pas16_setup(char *str, int *ints);
  64 extern void generic_NCR5380_setup(char *str, int *intr);
  65 extern void aha152x_setup(char *str, int *ints);
  66 extern void aha1542_setup(char *str, int *ints);
  67 extern void aha274x_setup(char *str, int *ints);
  68 extern void buslogic_setup(char *str, int *ints);
  69 extern void scsi_luns_setup(char *str, int *ints);
  70 extern void sound_setup(char *str, int *ints);
  71 #ifdef CONFIG_SBPCD
  72 extern void sbpcd_setup(char *str, int *ints);
  73 #endif CONFIG_SBPCD
  74 #ifdef CONFIG_CDU31A
  75 extern void cdu31a_setup(char *str, int *ints);
  76 #endif CONFIG_CDU31A
  77 #ifdef CONFIG_CDU535
  78 extern void sonycd535_setup(char *str, int *ints);
  79 #endif CONFIG_CDU535
  80 void ramdisk_setup(char *str, int *ints);
  81 
  82 #ifdef CONFIG_SYSVIPC
  83 extern void ipc_init(void);
  84 #endif
  85 #ifdef CONFIG_SCSI
  86 extern unsigned long scsi_dev_init(unsigned long, unsigned long);
  87 #endif
  88 
  89 /*
  90  * Boot command-line arguments
  91  */
  92 #define MAX_INIT_ARGS 8
  93 #define MAX_INIT_ENVS 8
  94 
  95 extern void time_init(void);
  96 
  97 static unsigned long memory_start = 0;
  98 static unsigned long memory_end = 0;
  99 
 100 static char term[21];
 101 int rows, cols;
 102 
 103 int ramdisk_size;
 104 int root_mountflags = 0;
 105 
 106 static char * argv_init[MAX_INIT_ARGS+2] = { "init", NULL, };
 107 static char * envp_init[MAX_INIT_ENVS+2] = { "HOME=/", term, NULL, };
 108 
 109 static char * argv_rc[] = { "/bin/sh", NULL };
 110 static char * envp_rc[] = { "HOME=/", term, NULL };
 111 
 112 static char * argv[] = { "-/bin/sh",NULL };
 113 static char * envp[] = { "HOME=/usr/root", term, NULL };
 114 
 115 char *get_options(char *str, int *ints)
     /*  */
 116 {
 117         char *cur = str;
 118         int i=1;
 119 
 120         while (cur && isdigit(*cur) && i <= 10) {
 121                 ints[i++] = simple_strtoul(cur,NULL,0);
 122                 if ((cur = strchr(cur,',')) != NULL)
 123                         cur++;
 124         }
 125         ints[0] = i-1;
 126         return(cur);
 127 }
 128 
 129 struct {
 130         char *str;
 131         void (*setup_func)(char *, int *);
 132 } bootsetups[] = {
 133         { "reserve=", reserve_setup },
 134         { "ramdisk=", ramdisk_setup },
 135 #ifdef CONFIG_BUGi386
 136         { "no-hlt", no_halt },
 137         { "no387", no_387 },
 138 #endif
 139 #ifdef CONFIG_INET
 140         { "ether=", eth_setup },
 141 #endif
 142 #ifdef CONFIG_SCSI
 143         { "max_scsi_luns=", scsi_luns_setup },
 144 #endif
 145 #ifdef CONFIG_BLK_DEV_IDE
 146         { "hda=", hda_setup },
 147         { "hdb=", hdb_setup },
 148         { "hdc=", hdc_setup },
 149         { "hdd=", hdd_setup },
 150         { "hd=",  ide_setup },
 151 #elif defined(CONFIG_BLK_DEV_HD)
 152         { "hd=", hd_setup },
 153 #endif
 154 #ifdef CONFIG_CHR_DEV_ST
 155         { "st=", st_setup },
 156 #endif
 157 #ifdef CONFIG_BUSMOUSE
 158         { "bmouse=", bmouse_setup },
 159 #endif
 160 #ifdef CONFIG_SCSI_SEAGATE
 161         { "st0x=", st0x_setup },
 162         { "tmc8xx=", tmc8xx_setup },
 163 #endif
 164 #ifdef CONFIG_SCSI_T128
 165         { "t128=", t128_setup },
 166 #endif
 167 #ifdef CONFIG_SCSI_PAS16
 168         { "pas16=", pas16_setup },
 169 #endif
 170 #ifdef CONFIG_SCSI_GENERIC_NCR5380
 171         { "ncr5380=", generic_NCR5380_setup },
 172 #endif
 173 #ifdef CONFIG_SCSI_AHA152X
 174         { "aha152x=", aha152x_setup},
 175 #endif
 176 #ifdef CONFIG_SCSI_AHA1542
 177         { "aha1542=", aha1542_setup},
 178 #endif
 179 #ifdef CONFIG_SCSI_AHA274X
 180         { "aha274x=", aha274x_setup},
 181 #endif
 182 #ifdef CONFIG_SCSI_BUSLOGIC
 183         { "buslogic=", buslogic_setup},
 184 #endif
 185 #ifdef CONFIG_BLK_DEV_XD
 186         { "xd=", xd_setup },
 187 #endif
 188 #ifdef CONFIG_BLK_DEV_FD
 189         { "floppy=", floppy_setup },
 190 #endif
 191 #ifdef CONFIG_MCD
 192         { "mcd=", mcd_setup },
 193 #endif
 194 #ifdef CONFIG_AZTCD
 195         { "aztcd=", aztcd_setup },
 196 #endif
 197 #ifdef CONFIG_CDU535
 198         { "sonycd535=", sonycd535_setup },
 199 #endif CONFIG_CDU535
 200 #ifdef CONFIG_SOUND
 201         { "sound=", sound_setup },
 202 #endif
 203 #ifdef CONFIG_SBPCD
 204         { "sbpcd=", sbpcd_setup },
 205 #endif CONFIG_SBPCD
 206 #ifdef CONFIG_CDU31A
 207         { "cdu31a=", cdu31a_setup },
 208 #endif CONFIG_CDU31A
 209         { 0, 0 }
 210 };
 211 
 212 void ramdisk_setup(char *str, int *ints)
     /*  */
 213 {
 214    if (ints[0] > 0 && ints[1] >= 0)
 215       ramdisk_size = ints[1];
 216 }
 217 
 218 static int checksetup(char *line)
     /*  */
 219 {
 220         int i = 0;
 221         int ints[11];
 222 
 223         while (bootsetups[i].str) {
 224                 int n = strlen(bootsetups[i].str);
 225                 if (!strncmp(line,bootsetups[i].str,n)) {
 226                         bootsetups[i].setup_func(get_options(line+n,ints), ints);
 227                         return 1;
 228                 }
 229                 i++;
 230         }
 231         return 0;
 232 }
 233 
 234 unsigned long loops_per_sec = 1;
 235 
 236 static void calibrate_delay(void)
     /*  */
 237 {
 238         int ticks;
 239 
 240         printk("Calibrating delay loop.. ");
 241         while (loops_per_sec <<= 1) {
 242                 /* wait for "start of" clock tick */
 243                 ticks = jiffies;
 244                 while (ticks == jiffies)
 245                         /* nothing */;
 246                 /* Go .. */
 247                 ticks = jiffies;
 248                 __delay(loops_per_sec);
 249                 ticks = jiffies - ticks;
 250                 if (ticks >= HZ) {
 251                         loops_per_sec = muldiv(loops_per_sec, HZ, ticks);
 252                         printk("ok - %lu.%02lu BogoMips\n",
 253                                 loops_per_sec/500000,
 254                                 (loops_per_sec/5000) % 100);
 255                         return;
 256                 }
 257         }
 258         printk("failed\n");
 259 }
 260 
 261 
 262 /*
 263  * This is a simple kernel command line parsing function: it parses
 264  * the command line, and fills in the arguments/environment to init
 265  * as appropriate. Any cmd-line option is taken to be an environment
 266  * variable if it contains the character '='.
 267  *
 268  *
 269  * This routine also checks for options meant for the kernel.
 270  * These options are not given to init - they are for internal kernel use only.
 271  */
 272 static void parse_options(char *line)
     /*  */
 273 {
 274         char *next;
 275         char *devnames[] = { "hda", "hdb", "hdc", "hdd", "sda", "sdb", "sdc", "sdd", "sde", "fd", "xda", "xdb", NULL };
 276         int devnums[]    = { 0x300, 0x340, 0x1600, 0x1640, 0x800, 0x810, 0x820, 0x830, 0x840, 0x200, 0xD00, 0xD40, 0};
 277         int args, envs;
 278 
 279         if (!*line)
 280                 return;
 281         args = 0;
 282         envs = 1;       /* TERM is set to 'console' by default */
 283         next = line;
 284         while ((line = next) != NULL) {
 285                 if ((next = strchr(line,' ')) != NULL)
 286                         *next++ = 0;
 287                 /*
 288                  * check for kernel options first..
 289                  */
 290                 if (!strncmp(line,"root=",5)) {
 291                         int n;
 292                         line += 5;
 293                         if (strncmp(line,"/dev/",5)) {
 294                                 ROOT_DEV = simple_strtoul(line,NULL,16);
 295                                 continue;
 296                         }
 297                         line += 5;
 298                         for (n = 0 ; devnames[n] ; n++) {
 299                                 int len = strlen(devnames[n]);
 300                                 if (!strncmp(line,devnames[n],len)) {
 301                                         ROOT_DEV = devnums[n]+simple_strtoul(line+len,NULL,0);
 302                                         break;
 303                                 }
 304                         }
 305                         continue;
 306                 }
 307                 if (!strcmp(line,"ro")) {
 308                         root_mountflags |= MS_RDONLY;
 309                         continue;
 310                 }
 311                 if (!strcmp(line,"rw")) {
 312                         root_mountflags &= ~MS_RDONLY;
 313                         continue;
 314                 }
 315                 if (!strcmp(line,"debug")) {
 316                         console_loglevel = 10;
 317                         continue;
 318                 }
 319                 if (checksetup(line))
 320                         continue;
 321                 /*
 322                  * Then check if it's an environment variable or
 323                  * an option.
 324                  */
 325                 if (strchr(line,'=')) {
 326                         if (envs >= MAX_INIT_ENVS)
 327                                 break;
 328                         envp_init[++envs] = line;
 329                 } else {
 330                         if (args >= MAX_INIT_ARGS)
 331                                 break;
 332                         argv_init[++args] = line;
 333                 }
 334         }
 335         argv_init[args+1] = NULL;
 336         envp_init[envs+1] = NULL;
 337 }
 338 
 339 extern void check_bugs(void);
 340 extern void setup_arch(char **, unsigned long *, unsigned long *);
 341 
 342 asmlinkage void start_kernel(void)
     /*  */
 343 {
 344         char * command_line;
 345 /*
 346  * Interrupts are still disabled. Do necessary setups, then
 347  * enable them
 348  */
 349         setup_arch(&command_line, &memory_start, &memory_end);
 350         memory_start = paging_init(memory_start,memory_end);
 351         trap_init();
 352         init_IRQ();
 353         sched_init();
 354         parse_options(command_line);
 355         init_modules();
 356 #ifdef CONFIG_PROFILE
 357         prof_buffer = (unsigned long *) memory_start;
 358         /* only text is profiled */
 359         prof_len = (unsigned long) &etext;
 360         prof_len >>= CONFIG_PROFILE_SHIFT;
 361         memory_start += prof_len * sizeof(unsigned long);
 362 #endif
 363         memory_start = console_init(memory_start,memory_end);
 364         memory_start = bios32_init(memory_start,memory_end);
 365         memory_start = kmalloc_init(memory_start,memory_end);
 366         sti();
 367         calibrate_delay();
 368         memory_start = chr_dev_init(memory_start,memory_end);
 369         memory_start = blk_dev_init(memory_start,memory_end);
 370         sti();
 371 #ifdef CONFIG_SCSI
 372         memory_start = scsi_dev_init(memory_start,memory_end);
 373 #endif
 374 #ifdef CONFIG_INET
 375         memory_start = net_dev_init(memory_start,memory_end);
 376 #endif
 377         memory_start = inode_init(memory_start,memory_end);
 378         memory_start = file_table_init(memory_start,memory_end);
 379         memory_start = name_cache_init(memory_start,memory_end);
 380         mem_init(memory_start,memory_end);
 381         buffer_init();
 382         time_init();
 383         sock_init();
 384 #ifdef CONFIG_SYSVIPC
 385         ipc_init();
 386 #endif
 387         sti();
 388         check_bugs();
 389 
 390         printk(linux_banner);
 391 
 392         if (!fork())            /* we count on this going ok */
 393                 init();
 394 /*
 395  * task[0] is meant to be used as an "idle" task: it may not sleep, but
 396  * it might do some general things like count free pages or it could be
 397  * used to implement a reasonable LRU algorithm for the paging routines:
 398  * anything that can be useful, but shouldn't take time from the real
 399  * processes.
 400  *
 401  * Right now task[0] just does a infinite idle loop.
 402  */
 403         for(;;)
 404                 idle();
 405 }
 406 
 407 static int printf(const char *fmt, ...)
     /*  */
 408 {
 409         va_list args;
 410         int i;
 411 
 412         va_start(args, fmt);
 413         write(1,printbuf,i=vsprintf(printbuf, fmt, args));
 414         va_end(args);
 415         return i;
 416 }
 417 
 418 void init(void)
     /*  */
 419 {
 420         int pid,i;
 421 
 422         setup();
 423         sprintf(term, "TERM=con%dx%d", ORIG_VIDEO_COLS, ORIG_VIDEO_LINES);
 424 
 425         #ifdef CONFIG_UMSDOS_FS
 426         {
 427                 /*
 428                         When mounting a umsdos fs as root, we detect
 429                         the pseudo_root (/linux) and initialise it here.
 430                         pseudo_root is defined in fs/umsdos/inode.c
 431                 */
 432                 extern struct inode *pseudo_root;
 433                 if (pseudo_root != NULL){
 434                         current->fs->root = pseudo_root;
 435                         current->fs->pwd  = pseudo_root;
 436                 }
 437         }
 438         #endif
 439 
 440         (void) open("/dev/tty1",O_RDWR,0);
 441         (void) dup(0);
 442         (void) dup(0);
 443 
 444         execve("/etc/init",argv_init,envp_init);
 445         execve("/bin/init",argv_init,envp_init);
 446         execve("/sbin/init",argv_init,envp_init);
 447         /* if this fails, fall through to original stuff */
 448 
 449         if (!(pid=fork())) {
 450                 close(0);
 451                 if (open("/etc/rc",O_RDONLY,0))
 452                         _exit(1);
 453                 execve("/bin/sh",argv_rc,envp_rc);
 454                 _exit(2);
 455         }
 456         if (pid>0)
 457                 while (pid != wait(&i))
 458                         /* nothing */;
 459         while (1) {
 460                 if ((pid = fork()) < 0) {
 461                         printf("Fork failed in init\n\r");
 462                         continue;
 463                 }
 464                 if (!pid) {
 465                         close(0);close(1);close(2);
 466                         setsid();
 467                         (void) open("/dev/tty1",O_RDWR,0);
 468                         (void) dup(0);
 469                         (void) dup(0);
 470                         _exit(execve("/bin/sh",argv,envp));
 471                 }
 472                 while (1)
 473                         if (pid == wait(&i))
 474                                 break;
 475                 printf("\n\rchild %d died with code %04x\n\r",pid,i);
 476                 sync();
 477         }
 478         _exit(0);
 479 }

/* */