init/init.c - codeaurora/busybox - Gitiles

 /*
  * Mini init implementation for busybox
  *
  *
  * Copyright (C) 1995, 1996 by Bruce Perens <bruce@pixar.com>.
  * Adjusted by so many folks, it's impossible to keep track.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  * General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  *
  */

 #include "internal.h"
 #include <stdio.h>
 #include <stdlib.h>
 #include <stdarg.h>
 #include <unistd.h>
 #include <errno.h>
 #include <signal.h>
 #include <termios.h>
 #include <sys/types.h>
 #include <sys/fcntl.h>
 #include <sys/wait.h>
 #include <string.h>
 #include <sys/mount.h>
 #include <sys/reboot.h>
 #include <sys/kdaemon.h>
 #include <sys/sysmacros.h>
 #include <linux/serial.h>	/* for serial_struct */
 #include <sys/vt.h>		/* for vt_stat */
 #include <sys/ioctl.h>

 #define DEBUG_INIT

 #define CONSOLE         "/dev/console"	/* Logical system console */
 #define VT_PRIMARY      "/dev/tty0"	/* Virtual console master */
 #define VT_SECONDARY    "/dev/tty1"	/* Virtual console master */
 #define VT_LOG          "/dev/tty2"	/* Virtual console master */
 #define SHELL           "/bin/sh"	/* Default shell */
 #define INITSCRIPT      "/etc/init.d/rcS"	/* Initscript. */
 #define PATH_DEFAULT    "PATH=/usr/local/sbin:/sbin:/bin:/usr/sbin:/usr/bin"

 static char *console = CONSOLE;
 static char *second_terminal = "/dev/tty2";
 static char *log = "/dev/tty3";


 /* try to open up the specified device */
 int device_open(char *device, int mode)
 {
     int m, f, fd = -1;

     mode = m | O_NONBLOCK;

     /* Retry up to 5 times */
     for (f = 0; f < 5; f++)
 	if ((fd = open(device, m)) >= 0)
 	    break;
     if (fd < 0)
 	return fd;
     /* Set original flags. */
     if (m != mode)
 	fcntl(fd, F_SETFL, mode);
     return fd;
 }

 /* print a message to the specified device */
 void message(char *device, char *fmt, ...)
 {
     int fd;
     va_list arguments;

     if ((fd = device_open(device, O_WRONLY | O_NOCTTY | O_NDELAY)) >= 0) {
 	va_start(arguments, fmt);
 	vdprintf(fd, fmt, arguments);
 	va_end(arguments);
 	close(fd);
     } else
 	vprintf(fmt, arguments);
 }

 /* Set terminal settings to reasonable defaults */
 void set_term()
 {
     int fd;
     struct termios tty;

     if ((fd = device_open(console, O_RDWR | O_NOCTTY)) < 0) {
 	message(log, "can't open %s\n", console);
 	return;
     }
     ioctl(fd, TCGETS, &tty);
     tty.c_cflag &= CBAUD | CBAUDEX | CSIZE | CSTOPB | PARENB | PARODD;
     tty.c_cflag |= HUPCL | CLOCAL;

     tty.c_cc[VINTR] = 3;
     tty.c_cc[VQUIT] = 28;
     tty.c_cc[VERASE] = 127;
     tty.c_cc[VKILL] = 24;
     tty.c_cc[VEOF] = 4;
     tty.c_cc[VTIME] = 0;
     tty.c_cc[VMIN] = 1;
     tty.c_cc[VSTART] = 17;
     tty.c_cc[VSTOP] = 19;
     tty.c_cc[VSUSP] = 26;

     /* Set pre and post processing */
     tty.c_iflag = IGNPAR | ICRNL | IXON | IXANY;
     tty.c_oflag = OPOST | ONLCR;
     tty.c_lflag = ISIG | ICANON | ECHO | ECHOCTL | ECHOPRT | ECHOKE;

     /* Now set the terminal line. */
     ioctl(fd, TCSETS, &tty);
     close(fd);
 }

 static int mem_total()
 {
     char s[80];
     char *p;
     FILE *f;
     const char pattern[] = "MemTotal:";

     f = fopen("/proc/meminfo", "r");
     while (NULL != fgets(s, 79, f)) {
 	p = strstr(s, pattern);
 	if (NULL != p) {
 	    fclose(f);
 	    return (atoi(p + strlen(pattern)));
 	}
     }
     return -1;
 }

 static void set_free_pages()
 {
     char s[80];
     FILE *f;

     f = fopen("/proc/sys/vm/freepages", "r");
     fgets(s, 79, f);
     if (atoi(s) < 32) {
 	fclose(f);
 	f = fopen("/proc/sys/vm/freepages", "w");
 	fprintf(f, "30\t40\t50\n");
 	printf("\nIncreased /proc/sys/vm/freepages values to 30/40/50\n");
     }
     fclose(f);
 }


 static void console_init()
 {
     int fd;
     int tried_devcons = 0;
     int tried_vtmaster = 0;
     char *s;

     if ((s = getenv("CONSOLE")) != NULL)
 	console = s;
     else {
 	console = CONSOLE;
 	tried_devcons++;
     }
     while ((fd = open(console, O_RDONLY | O_NONBLOCK)) < 0) {
 	if (!tried_devcons) {
 	    tried_devcons++;
 	    console = CONSOLE;
 	    continue;
 	}
 	if (!tried_vtmaster) {
 	    tried_vtmaster++;
 	    console = VT_PRIMARY;
 	    continue;
 	}
 	break;
     }
     if (fd < 0)
 	console = "/dev/null";
     else
 	close(fd);
 }

 static int waitfor(int pid)
 {
     int status, wpid;

     message(log, "Waiting for process %d.\n", pid);
     while ((wpid = wait(&status)) != pid) {
 	if (wpid > 0)
 	    message(log, "pid %d exited, status=%x.\n", wpid, status);
     }
     return wpid;
 }

 static int run(const char *command, char *terminal, int get_enter)
 {
     int f, pid;
     char *args[16];
     char buf[256];
     char *ptr;
     static const char press_enter[] =
 	"\nPlease press Enter to activate this console. ";


     /* Make a proper command from the command string */
     strcpy(buf, command);
     ptr = buf;
     for (f = 1; f < 15; f++) {
 	/* Skip white space */
 	while (*ptr == ' ' || *ptr == '\t')
 	    ptr++;
 	args[f] = ptr;
 	/* May be trailing space.. */
 	if (*ptr == 0)
 	    break;
 	/* Skip this `word' */
 	while (*ptr && *ptr != ' ' && *ptr != '\t' && *ptr != '#')
 	    ptr++;
 	/* If end-of-line, break */
 	if (*ptr == '#' || *ptr == 0) {
 	    f++;
 	    *ptr = 0;
 	    break;
 	}
 	/* End word with \0 and continue */
 	args[f] = NULL;
     }
     args[0] = args[1];


     if ((pid = fork()) == 0) {
 	/* Clean up */
 	close(0);
 	close(1);
 	close(2);
 	setsid();

 	if ((f = device_open(terminal, O_RDWR | O_NOCTTY)) < 0) {
 	    message(log, "open(%s) failed: %s\n", terminal, strerror(errno));
 	    return -1;
 	}
 	dup(f);
 	dup(f);
 	tcsetpgrp(0, getpgrp());
 	set_term();

 	if (get_enter) {
 	    /*
 	     * Save memory by not exec-ing anything large (like a shell)
 	     * before the user wants it. This is critical if swap is not
 	     * enabled and the system has low memory. Generally this will
 	     * be run on the second virtual console, and the first will
 	     * be allowed to start a shell or whatever an init script
 	     * specifies.
 	     */
 	    char c;
 	    write(1, press_enter, sizeof(press_enter) - 1);
 	    read(0, &c, 1);
 	    message(console, "Got an enter\r\n");
 	}

 	/* Log the process name and args */
 	message(console, "Executing ");
 	message(console, "'%s'\r\n", command);

 	/* Now run it.  This should take over the PID, so nothing
 	 * further in init.c should be run by this PID. */
 	execvp(args[1], args + 1);

 	message(console, "Hmm.  Trying as a script.\r\n");
 	/* If shell scripts are not executed, force the issue */
 	if (errno == ENOEXEC) {
 	    char buf[256];
 	    args[1] = SHELL;
 	    args[2] = "-c";
 	    strcpy(buf, "exec ");
 	    strcat(buf, command);
 	    args[3] = buf;
 	    args[4] = NULL;
 	    execvp(args[1], args + 1);
 	}
 	message(console, "Could not execute '%s'\n", command);
 	exit(-1);
     }
     return pid;
 }

 #ifndef DEBUG_INIT
 static void shutdown_system(void)
 {

     message(console, "The system is going down NOW !!\r\n");
     sync();
     /* Allow Ctrl-Alt-Del to reboot system. */
     reboot(RB_ENABLE_CAD);

     /* Send signals to every process _except_ pid 1 */
     message(console, "Sending SIGHUP to all processes.\r\n");
     kill(-1, SIGHUP);
     sleep(2);
     sync();
     message(console, "Sending SIGKILL to all processes.\r\n");
     kill(-1, SIGKILL);
     sleep(1);
     waitfor(run("/bin/swapoff -a", console, 0));
     waitfor(run("/bin/umount -a -n", console, 0));
     sync();
     if (get_kernel_revision() <= 2 * 65536 + 2 * 256 + 11) {
 	/* Removed  bdflush call, kupdate in kernels >2.2.11 */
 	bdflush(1, 0);
 	sync();
     }
 }

 static void halt_signal(int sig)
 {
     shutdown_system();
     message(console,
 	    "The system is halted. Press CTRL-ALT-DEL or turn off power\r\n");
     reboot(RB_POWER_OFF);
     exit(0);
 }

 static void reboot_signal(int sig)
 {
     shutdown_system();
     message(console, "Please stand by while rebooting the system.\r\n");
     reboot(RB_AUTOBOOT);
     exit(0);
 }

 #endif

 extern int init_main(int argc, char **argv)
 {
     int run_rc = TRUE;
     int pid1 = 0;
     int pid2 = 0;
     struct stat statbuf;
     const char *init_commands = SHELL "-c exec " INITSCRIPT;
     const char *shell_commands = SHELL;
     const char *tty0_commands = init_commands;
     const char *tty1_commands = shell_commands;
     char *hello_msg_format =
 	"init started:  BusyBox v%s (%s) multi-call binary\r\n";
     const char *no_memory =
 	"Sorry, your computer does not have enough memory.\r\n";


 #ifndef DEBUG_INIT
     /* Set up sig handlers */
     signal(SIGUSR1, halt_signal);
     signal(SIGSEGV, halt_signal);
     signal(SIGPWR, halt_signal);
     signal(SIGALRM, halt_signal);
     signal(SIGHUP, halt_signal);
     signal(SIGUSR2, reboot_signal);
     signal(SIGINT, reboot_signal);
     signal(SIGTERM, reboot_signal);
 #endif
     /* Figure out where the default console should be */
     console_init();

     /* Turn off rebooting via CTL-ALT-DEL -- we get a
      * SIGINT on CAD so we can shut things down gracefully... */
 #ifndef DEBUG_INIT
     reboot(RB_DISABLE_CAD);
 #endif

     /* Close whatever files are open, and reset the console. */
     close(0);
     close(1);
     close(2);
     set_term();
     setsid();

     /* Make sure PATH is set to something sane */
     if (getenv("PATH") == NULL)
 	putenv(PATH_DEFAULT);

     /* Hello world */
     message(log, hello_msg_format, BB_VER, BB_BT);
     message(console, hello_msg_format, BB_VER, BB_BT);

     /* Mount /proc */
     if (mount("/proc", "/proc", "proc", 0, 0)) {
 	message(log, "Mounting /proc: failed!\n");
 	message(console, "Mounting /proc: failed!\r\n");
     } else {
 	message(console, "Mounting /proc: done.\r\n");
     }

     /* Make sure there is enough memory to do something useful */
     set_free_pages();
     if (mem_total() < 2000) {
 	int retval;
 	retval = stat("/etc/fstab", &statbuf);
 	if (retval) {
 	    message(console, "%s", no_memory);
 	    while (1) {
 		sleep(1);
 	    }
 	} else {
 	    /* Try to turn on swap */
 	    waitfor(run("/bin/swapon -a", console, 0));
 	    if (mem_total() < 2000) {
 		message(console, "%s", no_memory);
 		while (1) {
 		    sleep(1);
 		}
 	    }
 	}
     }

     /* Check if we are supposed to be in single user mode */
     if ( argc > 1 && (!strcmp(argv[1], "single") ||
 		!strcmp(argv[1], "-s") || !strcmp(argv[1], "1"))) {
 	run_rc = FALSE;
 	tty0_commands = shell_commands;
 	tty1_commands = 0;
     }

     /* Make sure an init script exists before trying to run it */
     if (run_rc == TRUE && stat(INITSCRIPT, &statbuf)) {
 	tty0_commands = shell_commands;
 	tty1_commands = shell_commands;
     }

     /* Ok, now launch the rc script and/or prepare to
      * start up some VTs if somebody hits enter...
      */
     for (;;) {
 	int wpid;
 	int status;

 	if (pid1 == 0 && tty0_commands) {
 	    pid1 = run(tty0_commands, console, 1);
 	}
 	if (pid2 == 0 && tty1_commands) {
 	    pid2 = run(tty1_commands, second_terminal, 1);
 	}
 	wpid = wait(&status);
 	if (wpid > 0 && wpid != pid1) {
 	    message(log, "pid %d exited, status=%x.\n", wpid, status);
 	}
 	/* Don't respawn an init script if it exits */
 	if (run_rc == FALSE && wpid == pid1) {
 	    pid1 = 0;
 	}
 	if (wpid == pid2) {
 	    pid2 = 0;
 	}
 	sleep(1);
     }
 }
	/*
	* Mini init implementation for busybox
	*
	*
	* Copyright (C) 1995, 1996 by Bruce Perens <bruce@pixar.com>.
	* Adjusted by so many folks, it's impossible to keep track.
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License, or
	* (at your option) any later version.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	* General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	*
	*/

	#include "internal.h"
	#include <stdio.h>
	#include <stdlib.h>
	#include <stdarg.h>
	#include <unistd.h>
	#include <errno.h>
	#include <signal.h>
	#include <termios.h>
	#include <sys/types.h>
	#include <sys/fcntl.h>
	#include <sys/wait.h>
	#include <string.h>
	#include <sys/mount.h>
	#include <sys/reboot.h>
	#include <sys/kdaemon.h>
	#include <sys/sysmacros.h>
	#include <linux/serial.h> /* for serial_struct */
	#include <sys/vt.h> /* for vt_stat */
	#include <sys/ioctl.h>

	#define DEBUG_INIT

	#define CONSOLE "/dev/console" /* Logical system console */
	#define VT_PRIMARY "/dev/tty0" /* Virtual console master */
	#define VT_SECONDARY "/dev/tty1" /* Virtual console master */
	#define VT_LOG "/dev/tty2" /* Virtual console master */
	#define SHELL "/bin/sh" /* Default shell */
	#define INITSCRIPT "/etc/init.d/rcS" /* Initscript. */
	#define PATH_DEFAULT "PATH=/usr/local/sbin:/sbin:/bin:/usr/sbin:/usr/bin"

	static char *console = CONSOLE;
	static char *second_terminal = "/dev/tty2";
	static char *log = "/dev/tty3";



	/* try to open up the specified device */
	int device_open(char *device, int mode)
	{
	int m, f, fd = -1;

	mode = m \| O_NONBLOCK;

	/* Retry up to 5 times */
	for (f = 0; f < 5; f++)
	if ((fd = open(device, m)) >= 0)
	break;
	if (fd < 0)
	return fd;
	/* Set original flags. */
	if (m != mode)
	fcntl(fd, F_SETFL, mode);
	return fd;
	}

	/* print a message to the specified device */
	void message(char device, char fmt, ...)
	{
	int fd;
	va_list arguments;

	if ((fd = device_open(device, O_WRONLY \| O_NOCTTY \| O_NDELAY)) >= 0) {
	va_start(arguments, fmt);
	vdprintf(fd, fmt, arguments);
	va_end(arguments);
	close(fd);
	} else
	vprintf(fmt, arguments);
	}

	/* Set terminal settings to reasonable defaults */
	void set_term()
	{
	int fd;
	struct termios tty;

	if ((fd = device_open(console, O_RDWR \| O_NOCTTY)) < 0) {
	message(log, "can't open %s\n", console);
	return;
	}
	ioctl(fd, TCGETS, &tty);
	tty.c_cflag &= CBAUD \| CBAUDEX \| CSIZE \| CSTOPB \| PARENB \| PARODD;
	tty.c_cflag \|= HUPCL \| CLOCAL;

	tty.c_cc[VINTR] = 3;
	tty.c_cc[VQUIT] = 28;
	tty.c_cc[VERASE] = 127;
	tty.c_cc[VKILL] = 24;
	tty.c_cc[VEOF] = 4;
	tty.c_cc[VTIME] = 0;
	tty.c_cc[VMIN] = 1;
	tty.c_cc[VSTART] = 17;
	tty.c_cc[VSTOP] = 19;
	tty.c_cc[VSUSP] = 26;

	/* Set pre and post processing */
	tty.c_iflag = IGNPAR \| ICRNL \| IXON \| IXANY;
	tty.c_oflag = OPOST \| ONLCR;
	tty.c_lflag = ISIG \| ICANON \| ECHO \| ECHOCTL \| ECHOPRT \| ECHOKE;

	/* Now set the terminal line. */
	ioctl(fd, TCSETS, &tty);
	close(fd);
	}

	static int mem_total()
	{
	char s[80];
	char *p;
	FILE *f;
	const char pattern[] = "MemTotal:";

	f = fopen("/proc/meminfo", "r");
	while (NULL != fgets(s, 79, f)) {
	p = strstr(s, pattern);
	if (NULL != p) {
	fclose(f);
	return (atoi(p + strlen(pattern)));
	}
	}
	return -1;
	}

	static void set_free_pages()
	{
	char s[80];
	FILE *f;

	f = fopen("/proc/sys/vm/freepages", "r");
	fgets(s, 79, f);
	if (atoi(s) < 32) {
	fclose(f);
	f = fopen("/proc/sys/vm/freepages", "w");
	fprintf(f, "30\t40\t50\n");
	printf("\nIncreased /proc/sys/vm/freepages values to 30/40/50\n");
	}
	fclose(f);
	}


	static void console_init()
	{
	int fd;
	int tried_devcons = 0;
	int tried_vtmaster = 0;
	char *s;

	if ((s = getenv("CONSOLE")) != NULL)
	console = s;
	else {
	console = CONSOLE;
	tried_devcons++;
	}
	while ((fd = open(console, O_RDONLY \| O_NONBLOCK)) < 0) {
	if (!tried_devcons) {
	tried_devcons++;
	console = CONSOLE;
	continue;
	}
	if (!tried_vtmaster) {
	tried_vtmaster++;
	console = VT_PRIMARY;
	continue;
	}
	break;
	}
	if (fd < 0)
	console = "/dev/null";
	else
	close(fd);
	}

	static int waitfor(int pid)
	{
	int status, wpid;

	message(log, "Waiting for process %d.\n", pid);
	while ((wpid = wait(&status)) != pid) {
	if (wpid > 0)
	message(log, "pid %d exited, status=%x.\n", wpid, status);
	}
	return wpid;
	}

	static int run(const char command, char terminal, int get_enter)
	{
	int f, pid;
	char *args[16];
	char buf[256];
	char *ptr;
	static const char press_enter[] =
	"\nPlease press Enter to activate this console. ";


	/* Make a proper command from the command string */
	strcpy(buf, command);
	ptr = buf;
	for (f = 1; f < 15; f++) {
	/* Skip white space */
	while (ptr == ' ' \|\| ptr == '\t')
	ptr++;
	args[f] = ptr;
	/* May be trailing space.. */
	if (*ptr == 0)
	break;
	/* Skip this `word' */
	while (ptr && ptr != ' ' && ptr != '\t' && ptr != '#')
	ptr++;
	/* If end-of-line, break */
	if (ptr == '#' \|\| ptr == 0) {
	f++;
	*ptr = 0;
	break;
	}
	/* End word with \0 and continue */
	args[f] = NULL;
	}
	args[0] = args[1];


	if ((pid = fork()) == 0) {
	/* Clean up */
	close(0);
	close(1);
	close(2);
	setsid();

	if ((f = device_open(terminal, O_RDWR \| O_NOCTTY)) < 0) {
	message(log, "open(%s) failed: %s\n", terminal, strerror(errno));
	return -1;
	}
	dup(f);
	dup(f);
	tcsetpgrp(0, getpgrp());
	set_term();

	if (get_enter) {
	/*
	* Save memory by not exec-ing anything large (like a shell)
	* before the user wants it. This is critical if swap is not
	* enabled and the system has low memory. Generally this will
	* be run on the second virtual console, and the first will
	* be allowed to start a shell or whatever an init script
	* specifies.
	*/
	char c;
	write(1, press_enter, sizeof(press_enter) - 1);
	read(0, &c, 1);
	message(console, "Got an enter\r\n");
	}

	/* Log the process name and args */
	message(console, "Executing ");
	message(console, "'%s'\r\n", command);

	/* Now run it. This should take over the PID, so nothing
	* further in init.c should be run by this PID. */
	execvp(args[1], args + 1);

	message(console, "Hmm. Trying as a script.\r\n");
	/* If shell scripts are not executed, force the issue */
	if (errno == ENOEXEC) {
	char buf[256];
	args[1] = SHELL;
	args[2] = "-c";
	strcpy(buf, "exec ");
	strcat(buf, command);
	args[3] = buf;
	args[4] = NULL;
	execvp(args[1], args + 1);
	}
	message(console, "Could not execute '%s'\n", command);
	exit(-1);
	}
	return pid;
	}

	#ifndef DEBUG_INIT
	static void shutdown_system(void)
	{

	message(console, "The system is going down NOW !!\r\n");
	sync();
	/* Allow Ctrl-Alt-Del to reboot system. */
	reboot(RB_ENABLE_CAD);

	/* Send signals to every process _except_ pid 1 */
	message(console, "Sending SIGHUP to all processes.\r\n");
	kill(-1, SIGHUP);
	sleep(2);
	sync();
	message(console, "Sending SIGKILL to all processes.\r\n");
	kill(-1, SIGKILL);
	sleep(1);
	waitfor(run("/bin/swapoff -a", console, 0));
	waitfor(run("/bin/umount -a -n", console, 0));
	sync();
	if (get_kernel_revision() <= 2 * 65536 + 2 * 256 + 11) {
	/* Removed bdflush call, kupdate in kernels >2.2.11 */
	bdflush(1, 0);
	sync();
	}
	}

	static void halt_signal(int sig)
	{
	shutdown_system();
	message(console,
	"The system is halted. Press CTRL-ALT-DEL or turn off power\r\n");
	reboot(RB_POWER_OFF);
	exit(0);
	}

	static void reboot_signal(int sig)
	{
	shutdown_system();
	message(console, "Please stand by while rebooting the system.\r\n");
	reboot(RB_AUTOBOOT);
	exit(0);
	}

	#endif

	extern int init_main(int argc, char **argv)
	{
	int run_rc = TRUE;
	int pid1 = 0;
	int pid2 = 0;
	struct stat statbuf;
	const char *init_commands = SHELL "-c exec " INITSCRIPT;
	const char *shell_commands = SHELL;
	const char *tty0_commands = init_commands;
	const char *tty1_commands = shell_commands;
	char *hello_msg_format =
	"init started: BusyBox v%s (%s) multi-call binary\r\n";
	const char *no_memory =
	"Sorry, your computer does not have enough memory.\r\n";


	#ifndef DEBUG_INIT
	/* Set up sig handlers */
	signal(SIGUSR1, halt_signal);
	signal(SIGSEGV, halt_signal);
	signal(SIGPWR, halt_signal);
	signal(SIGALRM, halt_signal);
	signal(SIGHUP, halt_signal);
	signal(SIGUSR2, reboot_signal);
	signal(SIGINT, reboot_signal);
	signal(SIGTERM, reboot_signal);
	#endif
	/* Figure out where the default console should be */
	console_init();

	/* Turn off rebooting via CTL-ALT-DEL -- we get a
	* SIGINT on CAD so we can shut things down gracefully... */
	#ifndef DEBUG_INIT
	reboot(RB_DISABLE_CAD);
	#endif

	/* Close whatever files are open, and reset the console. */
	close(0);
	close(1);
	close(2);
	set_term();
	setsid();

	/* Make sure PATH is set to something sane */
	if (getenv("PATH") == NULL)
	putenv(PATH_DEFAULT);

	/* Hello world */
	message(log, hello_msg_format, BB_VER, BB_BT);
	message(console, hello_msg_format, BB_VER, BB_BT);

	/* Mount /proc */
	if (mount("/proc", "/proc", "proc", 0, 0)) {
	message(log, "Mounting /proc: failed!\n");
	message(console, "Mounting /proc: failed!\r\n");
	} else {
	message(console, "Mounting /proc: done.\r\n");
	}

	/* Make sure there is enough memory to do something useful */
	set_free_pages();
	if (mem_total() < 2000) {
	int retval;
	retval = stat("/etc/fstab", &statbuf);
	if (retval) {
	message(console, "%s", no_memory);
	while (1) {
	sleep(1);
	}
	} else {
	/* Try to turn on swap */
	waitfor(run("/bin/swapon -a", console, 0));
	if (mem_total() < 2000) {
	message(console, "%s", no_memory);
	while (1) {
	sleep(1);
	}
	}
	}
	}

	/* Check if we are supposed to be in single user mode */
	if ( argc > 1 && (!strcmp(argv[1], "single") \|\|
	!strcmp(argv[1], "-s") \|\| !strcmp(argv[1], "1"))) {
	run_rc = FALSE;
	tty0_commands = shell_commands;
	tty1_commands = 0;
	}

	/* Make sure an init script exists before trying to run it */
	if (run_rc == TRUE && stat(INITSCRIPT, &statbuf)) {
	tty0_commands = shell_commands;
	tty1_commands = shell_commands;
	}

	/* Ok, now launch the rc script and/or prepare to
	* start up some VTs if somebody hits enter...
	*/
	for (;;) {
	int wpid;
	int status;

	if (pid1 == 0 && tty0_commands) {
	pid1 = run(tty0_commands, console, 1);
	}
	if (pid2 == 0 && tty1_commands) {
	pid2 = run(tty1_commands, second_terminal, 1);
	}
	wpid = wait(&status);
	if (wpid > 0 && wpid != pid1) {
	message(log, "pid %d exited, status=%x.\n", wpid, status);
	}
	/* Don't respawn an init script if it exits */
	if (run_rc == FALSE && wpid == pid1) {
	pid1 = 0;
	}
	if (wpid == pid2) {
	pid2 = 0;
	}
	sleep(1);
	}
	}