4d1d0113fd
and linux kernel 2.0.36 (though the dubious reasons why someone would want to do that defy imagination ;) -Erik
610 lines
16 KiB
C
610 lines
16 KiB
C
/*
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* Mini init implementation for busybox
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*
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*
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* Copyright (C) 1995, 1996 by Bruce Perens <bruce@pixar.com>.
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* Adjusted by so many folks, it's impossible to keep track.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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*/
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#include "internal.h"
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#include <stdio.h>
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#include <stdlib.h>
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#include <stdarg.h>
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#include <unistd.h>
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#include <errno.h>
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#include <signal.h>
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#include <termios.h>
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#include <paths.h>
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#include <sys/types.h>
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#include <sys/fcntl.h>
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#include <sys/wait.h>
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#include <string.h>
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#include <sys/mount.h>
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#include <sys/reboot.h>
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#include <sys/kdaemon.h>
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#include <sys/sysmacros.h>
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#include <linux/serial.h> /* for serial_struct */
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#include <sys/vt.h> /* for vt_stat */
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#include <sys/ioctl.h>
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#include <linux/version.h>
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#ifdef BB_SYSLOGD
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#include <sys/syslog.h>
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#endif
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#if ! defined BB_FEATURE_USE_PROCFS
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#error Sorry, I depend on the /proc filesystem right now.
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#endif
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#ifndef KERNEL_VERSION
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#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + (c))
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#endif
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#define VT_PRIMARY "/dev/tty1" /* Primary virtual console */
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#define VT_SECONDARY "/dev/tty2" /* Virtual console */
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#define VT_LOG "/dev/tty3" /* Virtual console */
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#define SERIAL_CON0 "/dev/ttyS0" /* Primary serial console */
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#define SERIAL_CON1 "/dev/ttyS1" /* Serial console */
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#define GETTY "/sbin/getty" /* Default location of getty */
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#define SHELL "/bin/sh" /* Default shell */
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#define INITSCRIPT "/etc/init.d/rcS" /* Initscript. */
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#define LOG 0x1
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#define CONSOLE 0x2
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static char *console = _PATH_CONSOLE;
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static char *second_console = VT_SECONDARY;
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static char *log = VT_LOG;
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static int kernel_version = 0;
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/* try to open up the specified device */
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int device_open(char *device, int mode)
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{
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int m, f, fd = -1;
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m = mode | O_NONBLOCK;
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/* Retry up to 5 times */
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for (f = 0; f < 5; f++)
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if ((fd = open(device, m)) >= 0)
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break;
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if (fd < 0)
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return fd;
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/* Reset original flags. */
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if (m != mode)
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fcntl(fd, F_SETFL, mode);
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return fd;
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}
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/* print a message to the specified device:
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* device may be bitwise-or'd from LOG | CONSOLE */
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void message(int device, char *fmt, ...)
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{
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int fd;
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va_list arguments;
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#ifdef BB_SYSLOGD
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/* Log the message to syslogd */
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if (device & LOG ) {
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char msg[1024];
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va_start(arguments, fmt);
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vsnprintf(msg, sizeof(msg), fmt, arguments);
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va_end(arguments);
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syslog(LOG_DAEMON|LOG_NOTICE, msg);
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}
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#else
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static int log_fd=-1;
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/* Take full control of the log tty, and never close it.
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* It's mine, all mine! Muhahahaha! */
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if (log_fd < 0) {
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if (log == NULL) {
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/* don't even try to log, because there is no such console */
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log_fd = -2;
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/* log to main console instead */
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device = CONSOLE;
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}
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else if ((log_fd = device_open(log, O_RDWR|O_NDELAY)) < 0) {
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log_fd=-1;
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fprintf(stderr, "Bummer, can't write to log on %s!\r\n", log);
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fflush(stderr);
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return;
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}
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}
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if ( (device & LOG) && (log_fd >= 0) ) {
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va_start(arguments, fmt);
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vdprintf(log_fd, fmt, arguments);
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va_end(arguments);
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}
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#endif
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if (device & CONSOLE) {
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/* Always send console messages to /dev/console so people will see them. */
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if ((fd = device_open(_PATH_CONSOLE, O_WRONLY|O_NOCTTY|O_NDELAY)) >= 0) {
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va_start(arguments, fmt);
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vdprintf(fd, fmt, arguments);
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va_end(arguments);
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close(fd);
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} else {
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fprintf(stderr, "Bummer, can't print: ");
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va_start(arguments, fmt);
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vfprintf(stderr, fmt, arguments);
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fflush(stderr);
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va_end(arguments);
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}
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}
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}
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/* Set terminal settings to reasonable defaults */
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void set_term( int fd)
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{
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struct termios tty;
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static const char control_characters[] = {
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'\003', '\034', '\177', '\025', '\004', '\0',
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'\1', '\0', '\021', '\023', '\032', '\0', '\022',
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'\017', '\027', '\026', '\0'
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};
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tcgetattr(fd, &tty);
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/* set control chars */
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memcpy(tty.c_cc, control_characters, sizeof(control_characters));
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/* use line dicipline 0 */
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tty.c_line = 0;
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/* Make it be sane */
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//tty.c_cflag &= CBAUD|CBAUDEX|CSIZE|CSTOPB|PARENB|PARODD;
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//tty.c_cflag |= HUPCL|CLOCAL;
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/* input modes */
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tty.c_iflag = ICRNL|IXON|IXOFF;
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/* output modes */
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tty.c_oflag = OPOST|ONLCR;
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/* local modes */
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tty.c_lflag = ISIG|ICANON|ECHO|ECHOE|ECHOK|ECHOCTL|ECHOKE|IEXTEN;
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tcsetattr(fd, TCSANOW, &tty);
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}
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/* How much memory does this machine have? */
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static int mem_total()
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{
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char s[80];
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char *p = "/proc/meminfo";
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FILE *f;
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const char pattern[] = "MemTotal:";
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if ((f = fopen(p, "r")) < 0) {
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message(LOG, "Error opening %s: %s\n", p, strerror( errno));
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return -1;
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}
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while (NULL != fgets(s, 79, f)) {
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p = strstr(s, pattern);
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if (NULL != p) {
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fclose(f);
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return (atoi(p + strlen(pattern)));
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}
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}
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return -1;
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}
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static void console_init()
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{
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int fd;
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int tried_devcons = 0;
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int tried_vtprimary = 0;
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struct serial_struct sr;
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char *s;
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if ((s = getenv("CONSOLE")) != NULL) {
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console = s;
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}
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#if #cpu(sparc)
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/* sparc kernel supports console=tty[ab] parameter which is also
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* passed to init, so catch it here */
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else if ((s = getenv("console")) != NULL) {
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/* remap tty[ab] to /dev/ttyS[01] */
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if (strcmp( s, "ttya" )==0)
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console = SERIAL_CON0;
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else if (strcmp( s, "ttyb" )==0)
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console = SERIAL_CON1;
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}
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#endif
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else {
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struct vt_stat vt;
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static char the_console[13];
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console = the_console;
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/* 2.2 kernels: identify the real console backend and try to use it */
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if (ioctl(0, TIOCGSERIAL, &sr) == 0) {
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/* this is a serial console */
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snprintf( the_console, sizeof the_console, "/dev/ttyS%d", sr.line );
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}
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else if (ioctl(0, VT_GETSTATE, &vt) == 0) {
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/* this is linux virtual tty */
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snprintf( the_console, sizeof the_console, "/dev/tty%d", vt.v_active );
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} else {
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console = _PATH_CONSOLE;
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tried_devcons++;
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}
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}
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while ((fd = open(console, O_RDONLY | O_NONBLOCK)) < 0) {
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/* Can't open selected console -- try /dev/console */
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if (!tried_devcons) {
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tried_devcons++;
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console = _PATH_CONSOLE;
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continue;
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}
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/* Can't open selected console -- try vt1 */
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if (!tried_vtprimary) {
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tried_vtprimary++;
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console = VT_PRIMARY;
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continue;
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}
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break;
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}
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if (fd < 0)
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/* Perhaps we should panic here? */
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console = "/dev/null";
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else {
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/* check for serial console and disable logging to tty3 & running a
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* shell to tty2 */
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if (ioctl(0,TIOCGSERIAL,&sr) == 0) {
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message(LOG|CONSOLE, "serial console detected. Disabling 2nd virtual terminal.\r\n", console );
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log = NULL;
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second_console = NULL;
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}
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close(fd);
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}
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message(LOG, "console=%s\n", console );
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}
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static int waitfor(int pid)
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{
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int status, wpid;
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message(LOG, "Waiting for process %d.\n", pid);
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while ((wpid = wait(&status)) != pid) {
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if (wpid > 0)
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message(LOG, "pid %d exited, status=0x%x.\n", wpid, status);
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}
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return wpid;
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}
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static pid_t run(const char * const* command,
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char *terminal, int get_enter)
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{
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int fd;
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pid_t pid;
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const char * const* cmd = command+1;
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static const char press_enter[] =
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"\nPlease press Enter to activate this console. ";
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if ((pid = fork()) == 0) {
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/* Clean up */
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close(0);
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close(1);
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close(2);
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setsid();
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/* Reset signal handlers set for parent process */
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signal(SIGUSR1, SIG_DFL);
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signal(SIGUSR2, SIG_DFL);
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signal(SIGINT, SIG_DFL);
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signal(SIGTERM, SIG_DFL);
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if ((fd = device_open(terminal, O_RDWR)) < 0) {
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message(LOG, "Bummer, can't open %s\r\n", terminal);
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exit(-1);
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}
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dup(fd);
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dup(fd);
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tcsetpgrp(0, getpgrp());
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set_term(0);
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if (get_enter==TRUE) {
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/*
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* Save memory by not exec-ing anything large (like a shell)
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* before the user wants it. This is critical if swap is not
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* enabled and the system has low memory. Generally this will
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* be run on the second virtual console, and the first will
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* be allowed to start a shell or whatever an init script
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* specifies.
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*/
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char c;
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message(LOG, "Waiting for enter to start '%s' (pid %d, console %s)\r\n",
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*cmd, getpid(), terminal );
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write(1, press_enter, sizeof(press_enter) - 1);
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read(0, &c, 1);
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}
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/* Log the process name and args */
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message(LOG|CONSOLE, "Starting pid %d, console %s: '", getpid(), terminal);
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while ( *cmd) message(LOG|CONSOLE, "%s ", *cmd++);
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message(LOG|CONSOLE, "'\r\n");
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/* Now run it. The new program will take over this PID,
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* so nothing further in init.c should be run. */
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execvp(*command, (char**)command+1);
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message(LOG, "Bummer, could not run '%s'\n", command);
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exit(-1);
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}
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return pid;
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}
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/* Make sure there is enough memory to do something useful. *
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* Calls swapon if needed so be sure /proc is mounted. */
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static void check_memory()
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{
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struct stat statbuf;
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const char* const swap_on_cmd[] =
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{ "/bin/swapon", "swapon", "-a", 0};
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if (mem_total() > 3500)
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return;
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if (stat("/etc/fstab", &statbuf) == 0) {
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/* Try to turn on swap */
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waitfor(run(swap_on_cmd, log, FALSE));
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if (mem_total() < 3500)
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goto goodnight;
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} else
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goto goodnight;
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return;
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goodnight:
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message(CONSOLE, "Sorry, your computer does not have enough memory.\r\n");
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while (1) sleep(1);
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}
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static void shutdown_system(void)
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{
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const char* const swap_off_cmd[] = { "swapoff", "swapoff", "-a", 0};
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const char* const umount_cmd[] = { "umount", "umount", "-a", 0};
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#ifndef DEBUG_INIT
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/* Allow Ctrl-Alt-Del to reboot system. */
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reboot(RB_ENABLE_CAD);
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#endif
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message(CONSOLE, "\r\nThe system is going down NOW !!\r\n");
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sync();
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/* Send signals to every process _except_ pid 1 */
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message(CONSOLE, "Sending SIGHUP to all processes.\r\n");
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#ifndef DEBUG_INIT
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kill(-1, SIGHUP);
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#endif
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sleep(2);
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sync();
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message(CONSOLE, "Sending SIGKILL to all processes.\r\n");
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#ifndef DEBUG_INIT
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kill(-1, SIGKILL);
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#endif
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sleep(1);
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message(CONSOLE, "Disabling swap.\r\n");
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waitfor(run( swap_off_cmd, console, FALSE));
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message(CONSOLE, "Unmounting filesystems.\r\n");
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waitfor(run( umount_cmd, console, FALSE));
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sync();
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if (kernel_version > 0 && kernel_version <= 2 * 65536 + 2 * 256 + 11) {
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/* bdflush, kupdate not needed for kernels >2.2.11 */
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message(CONSOLE, "Flushing buffers.\r\n");
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bdflush(1, 0);
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sync();
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}
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}
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static void halt_signal(int sig)
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{
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shutdown_system();
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message(CONSOLE,
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"The system is halted. Press CTRL-ALT-DEL or turn off power\r\n");
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sync();
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#ifndef DEBUG_INIT
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#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,2,0)
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if (sig == SIGUSR2)
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reboot(RB_POWER_OFF);
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else
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#endif
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reboot(RB_HALT_SYSTEM);
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#endif
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exit(0);
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}
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static void reboot_signal(int sig)
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{
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shutdown_system();
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message(CONSOLE, "Please stand by while rebooting the system.\r\n");
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sync();
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#ifndef DEBUG_INIT
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reboot(RB_AUTOBOOT);
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#endif
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exit(0);
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}
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extern int init_main(int argc, char **argv)
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{
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int run_rc = FALSE;
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int single = FALSE;
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int wait_for_enter_tty1 = TRUE;
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int wait_for_enter_tty2 = TRUE;
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pid_t pid1 = 0;
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pid_t pid2 = 0;
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struct stat statbuf;
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char which_vt1[30];
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char which_vt2[30];
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const char* const rc_script_command[] = { INITSCRIPT, INITSCRIPT, 0};
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const char* const getty1_command[] = { GETTY, GETTY, "38400", which_vt1, 0};
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const char* const getty2_command[] = { GETTY, GETTY, "38400", which_vt2, 0};
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const char* const shell_command[] = { SHELL, "-" SHELL, 0};
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const char* const* tty1_command = shell_command;
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const char* const* tty2_command = shell_command;
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#ifdef BB_INIT_CMD_IF_RC_SCRIPT_EXITS
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const char* const rc_exit_command[] = { "BB_INIT_CMD_IF_RC_SCRIPT_EXITS",
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"BB_INIT_CMD_IF_RC_SCRIPT_EXITS", 0 };
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#endif
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#ifdef DEBUG_INIT
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char *hello_msg_format =
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"init(%d) started: BusyBox v%s (%s) multi-call binary\r\n";
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#else
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char *hello_msg_format =
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"init started: BusyBox v%s (%s) multi-call binary\r\n";
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#endif
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#ifndef DEBUG_INIT
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/* Expect to be PID 1 iff we are run as init (not linuxrc) */
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if (getpid() != 1 && strstr(argv[0], "init")!=NULL ) {
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usage( "init\n\nInit is the parent of all processes.\n\n"
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"This version of init is designed to be run only by the kernel\n");
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}
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#endif
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/* Set up sig handlers -- be sure to
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* clear all of these in run() */
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signal(SIGUSR1, halt_signal);
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signal(SIGUSR2, reboot_signal);
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signal(SIGINT, reboot_signal);
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signal(SIGTERM, reboot_signal);
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/* Turn off rebooting via CTL-ALT-DEL -- we get a
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* SIGINT on CAD so we can shut things down gracefully... */
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#ifndef DEBUG_INIT
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reboot(RB_DISABLE_CAD);
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#endif
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/* Figure out where the default console should be */
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console_init();
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/* Close whatever files are open, and reset the console. */
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close(0);
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close(1);
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close(2);
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set_term(0);
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setsid();
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/* Make sure PATH is set to something sane */
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putenv(_PATH_STDPATH);
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/* Hello world */
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#ifndef DEBUG_INIT
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message(CONSOLE|LOG, hello_msg_format, BB_VER, BB_BT);
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|
#else
|
|
message(CONSOLE|LOG, hello_msg_format, getpid(), BB_VER, BB_BT);
|
|
#endif
|
|
|
|
|
|
/* Mount /proc */
|
|
if (mount ("proc", "/proc", "proc", 0, 0) == 0) {
|
|
message(CONSOLE|LOG, "Mounting /proc: done.\n");
|
|
kernel_version = get_kernel_revision();
|
|
} else
|
|
message(CONSOLE|LOG, "Mounting /proc: failed!\n");
|
|
|
|
/* Make sure there is enough memory to do something useful. */
|
|
check_memory();
|
|
|
|
/* 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"))) {
|
|
single = TRUE;
|
|
tty1_command = shell_command;
|
|
tty2_command = shell_command;
|
|
}
|
|
|
|
/* Make sure an init script exists before trying to run it */
|
|
if (single==FALSE && stat(INITSCRIPT, &statbuf)==0) {
|
|
run_rc = TRUE;
|
|
wait_for_enter_tty1 = FALSE;
|
|
tty1_command = rc_script_command;
|
|
}
|
|
|
|
/* Make sure /sbin/getty exists before trying to run it */
|
|
if (stat(GETTY, &statbuf)==0) {
|
|
char* where;
|
|
/* First do tty2 */
|
|
wait_for_enter_tty2 = FALSE;
|
|
where = strrchr( second_console, '/');
|
|
if ( where != NULL) {
|
|
where++;
|
|
strncpy( which_vt2, where, sizeof(which_vt2));
|
|
}
|
|
tty2_command = getty2_command;
|
|
|
|
/* Check on hooking a getty onto tty1 */
|
|
if (run_rc == FALSE && single==FALSE) {
|
|
wait_for_enter_tty1 = FALSE;
|
|
where = strrchr( console, '/');
|
|
if ( where != NULL) {
|
|
where++;
|
|
strncpy( which_vt1, where, sizeof(which_vt1));
|
|
}
|
|
tty1_command = getty1_command;
|
|
}
|
|
}
|
|
|
|
|
|
/* Ok, now launch the tty1_command and tty2_command */
|
|
for (;;) {
|
|
pid_t wpid;
|
|
int status;
|
|
|
|
if (pid1 == 0 && tty1_command) {
|
|
pid1 = run(tty1_command, console, wait_for_enter_tty1);
|
|
}
|
|
#ifdef BB_FEATURE_INIT_SECOND_CONSOLE
|
|
if (pid2 == 0 && tty2_command && second_console) {
|
|
pid2 = run(tty2_command, second_console, wait_for_enter_tty2);
|
|
}
|
|
#endif
|
|
wpid = wait(&status);
|
|
if (wpid > 0 ) {
|
|
message(LOG, "pid %d exited, status=%x.\n", wpid, status);
|
|
}
|
|
/* Don't respawn init script if it exits */
|
|
if (wpid == pid1) {
|
|
if (run_rc == FALSE) {
|
|
pid1 = 0;
|
|
}
|
|
#ifdef BB_INIT_CMD_IF_RC_SCRIPT_EXITS
|
|
else {
|
|
pid1 = 0;
|
|
run_rc=FALSE;
|
|
wait_for_enter_tty1=TRUE;
|
|
tty1_command=rc_exit_command;
|
|
}
|
|
#endif
|
|
}
|
|
#ifdef BB_FEATURE_INIT_SECOND_CONSOLE
|
|
if (wpid == pid2) {
|
|
pid2 = 0;
|
|
}
|
|
#endif
|
|
sleep(1);
|
|
}
|
|
}
|