2 * Mini init implementation for busybox
5 * Copyright (C) 1995, 1996 by Bruce Perens <bruce@pixar.com>.
6 * Adjusted by so many folks, it's impossible to keep track.
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
32 #include <sys/types.h>
33 #include <sys/fcntl.h>
36 #include <sys/mount.h>
37 #include <sys/reboot.h>
38 #include <sys/kdaemon.h>
39 #include <sys/sysmacros.h>
40 #include <linux/serial.h> /* for serial_struct */
41 #include <sys/vt.h> /* for vt_stat */
42 #include <sys/ioctl.h>
46 #define CONSOLE "/dev/console" /* Logical system console */
47 #define VT_PRIMARY "/dev/tty0" /* Virtual console master */
48 #define VT_SECONDARY "/dev/tty1" /* Virtual console master */
49 #define VT_LOG "/dev/tty2" /* Virtual console master */
50 #define SHELL "/bin/sh" /* Default shell */
51 #define INITSCRIPT "/etc/init.d/rcS" /* Initscript. */
52 #define PATH_DEFAULT "PATH=/usr/local/sbin:/sbin:/bin:/usr/sbin:/usr/bin"
54 static char *console = CONSOLE;
55 static char *first_terminal = "/dev/tty1";
56 static char *second_terminal = "/dev/tty2";
57 static char *log = "/dev/tty3";
61 /* try to open up the specified device */
62 int device_open(char *device, int mode)
66 mode = m | O_NONBLOCK;
68 /* Retry up to 5 times */
69 for (f = 0; f < 5; f++)
70 if ((fd = open(device, m)) >= 0)
74 /* Set original flags. */
76 fcntl(fd, F_SETFL, mode);
80 /* print a message to the specified device */
81 void message(char *device, char *fmt, ...)
86 if ((fd = device_open(device, O_WRONLY | O_NOCTTY | O_NDELAY)) >= 0) {
87 va_start(arguments, fmt);
88 vdprintf(fd, fmt, arguments);
92 fprintf(stderr, "Bummer, can't print: ");
93 va_start(arguments, fmt);
94 vfprintf(stderr, fmt, arguments);
100 /* Set terminal settings to reasonable defaults */
106 if ((fd = device_open(console, O_RDWR | O_NOCTTY)) < 0) {
107 message(log, "can't open %s\n", console);
110 ioctl(fd, TCGETS, &tty);
111 tty.c_cflag &= CBAUD | CBAUDEX | CSIZE | CSTOPB | PARENB | PARODD;
112 tty.c_cflag |= HUPCL | CLOCAL;
115 tty.c_cc[VQUIT] = 28;
116 tty.c_cc[VERASE] = 127;
117 tty.c_cc[VKILL] = 24;
121 tty.c_cc[VSTART] = 17;
122 tty.c_cc[VSTOP] = 19;
123 tty.c_cc[VSUSP] = 26;
125 /* Set pre and post processing */
126 tty.c_iflag = IGNPAR | ICRNL | IXON | IXANY;
127 tty.c_oflag = OPOST | ONLCR;
128 tty.c_lflag = ISIG | ICANON | ECHO | ECHOCTL | ECHOPRT | ECHOKE;
130 /* Now set the terminal line. */
131 ioctl(fd, TCSETS, &tty);
135 static int mem_total()
140 const char pattern[] = "MemTotal:";
142 f = fopen("/proc/meminfo", "r");
143 while (NULL != fgets(s, 79, f)) {
144 p = strstr(s, pattern);
147 return (atoi(p + strlen(pattern)));
153 static void set_free_pages()
158 f = fopen("/proc/sys/vm/freepages", "r");
162 f = fopen("/proc/sys/vm/freepages", "w");
163 fprintf(f, "30\t40\t50\n");
164 printf("\nIncreased /proc/sys/vm/freepages values to 30/40/50\n");
170 static void console_init()
174 int tried_devcons = 0;
175 int tried_vtmaster = 0;
178 if ((s = getenv("CONSOLE")) != NULL)
185 if ( stat(CONSOLE, &statbuf) && S_ISLNK(statbuf.st_mode)) {
186 fprintf(stderr, "/dev/console does not exist, or is a symlink.\n");
188 while ((fd = open(console, O_RDONLY | O_NONBLOCK)) < 0) {
189 if (!tried_devcons) {
194 if (!tried_vtmaster) {
196 console = VT_PRIMARY;
202 console = "/dev/null";
205 fprintf(stderr, "console=%s\n", console);
208 static int waitfor(int pid)
212 message(log, "Waiting for process %d.\n", pid);
213 while ((wpid = wait(&status)) != pid) {
215 message(log, "pid %d exited, status=%x.\n", wpid, status);
221 static int run(const char *command, char *terminal, int get_enter)
227 static const char press_enter[] =
228 "\nPlease press Enter to activate this console. ";
231 /* Make a proper command from the command string */
232 strcpy(buf, command);
234 for (f = 1; f < 15; f++) {
235 /* Skip white space */
236 while (*ptr == ' ' || *ptr == '\t')
239 /* May be trailing space.. */
242 /* Skip this `word' */
243 while (*ptr && *ptr != ' ' && *ptr != '\t' && *ptr != '#')
245 /* If end-of-line, break */
246 if (*ptr == '#' || *ptr == 0) {
251 /* End word with \0 and continue */
257 if ((pid = fork()) == 0) {
265 //if ((f = device_open(terminal, O_RDWR | O_NOCTTY)) < 0) {
266 if ((f = device_open(terminal, O_RDWR )) < 0) {
267 message(log, "open(%s) failed: %s\n",
268 terminal, strerror(errno));
274 open(terminal, O_RDWR);
277 //tcsetpgrp(0, getpgrp());
283 * Save memory by not exec-ing anything large (like a shell)
284 * before the user wants it. This is critical if swap is not
285 * enabled and the system has low memory. Generally this will
286 * be run on the second virtual console, and the first will
287 * be allowed to start a shell or whatever an init script
291 write(1, press_enter, sizeof(press_enter) - 1);
293 message(console, "Got an enter\r\n");
296 /* Log the process name and args */
297 message(console, "Executing '%s'\r\n", command);
298 message(log, "Executing '%s'\r\n", command);
300 /* Now run it. This program should take over this PID,
301 * so nothing further in init.c should be run. */
302 execvp(args[1], args + 1);
304 message(console, "Hmm. Trying as a script.\r\n");
305 /* If shell scripts are not executed, force the issue */
306 if (errno == ENOEXEC) {
310 strcpy(buf, "exec ");
311 strcat(buf, command);
314 execvp(args[1], args + 1);
316 message(console, "Could not execute '%s'\n", command);
324 static void shutdown_system(void)
327 message(console, "The system is going down NOW !!\r\n");
329 /* Allow Ctrl-Alt-Del to reboot system. */
330 reboot(RB_ENABLE_CAD);
332 /* Send signals to every process _except_ pid 1 */
333 message(console, "Sending SIGHUP to all processes.\r\n");
337 message(console, "Sending SIGKILL to all processes.\r\n");
340 waitfor(run("/bin/swapoff -a", console, 0));
341 waitfor(run("/bin/umount -a -n", console, 0));
343 if (get_kernel_revision() <= 2 * 65536 + 2 * 256 + 11) {
344 /* Removed bdflush call, kupdate in kernels >2.2.11 */
350 static void halt_signal(int sig)
354 "The system is halted. Press CTRL-ALT-DEL or turn off power\r\n");
355 reboot(RB_POWER_OFF);
359 static void reboot_signal(int sig)
362 message(console, "Please stand by while rebooting the system.\r\n");
369 extern int init_main(int argc, char **argv)
375 const char *init_commands = SHELL " -c exec " INITSCRIPT;
376 const char *shell_commands = SHELL " -";
377 const char *tty0_commands = init_commands;
378 const char *tty1_commands = shell_commands;
379 char *hello_msg_format =
380 "init started: BusyBox v%s (%s) multi-call binary\r\n";
381 const char *no_memory =
382 "Sorry, your computer does not have enough memory.\r\n";
386 /* Set up sig handlers */
387 signal(SIGUSR1, halt_signal);
388 signal(SIGSEGV, halt_signal);
389 signal(SIGPWR, halt_signal);
390 signal(SIGALRM, halt_signal);
391 signal(SIGHUP, halt_signal);
392 signal(SIGUSR2, reboot_signal);
393 signal(SIGINT, reboot_signal);
394 signal(SIGTERM, reboot_signal);
396 /* Figure out where the default console should be */
399 /* Turn off rebooting via CTL-ALT-DEL -- we get a
400 * SIGINT on CAD so we can shut things down gracefully... */
402 reboot(RB_DISABLE_CAD);
405 /* Close whatever files are open, and reset the console. */
412 /* Make sure PATH is set to something sane */
413 if (getenv("PATH") == NULL)
414 putenv(PATH_DEFAULT);
417 message(log, hello_msg_format, BB_VER, BB_BT);
418 message(console, hello_msg_format, BB_VER, BB_BT);
421 if (mount("/proc", "/proc", "proc", 0, 0)) {
422 message(console, "Mounting /proc: failed!\r\n");
423 message(log, "Mounting /proc: failed!\n");
425 message(console, "Mounting /proc: done.\r\n");
426 message(log, "Mounting /proc: done.\n");
429 /* Make sure there is enough memory to do something useful */
431 if (mem_total() < 2000) {
433 retval = stat("/etc/fstab", &statbuf);
435 message(console, "%s", no_memory);
440 /* Try to turn on swap */
441 waitfor(run("/bin/swapon -a", console, 0));
442 if (mem_total() < 2000) {
443 message(console, "%s", no_memory);
451 /* Check if we are supposed to be in single user mode */
452 if ( argc > 1 && (!strcmp(argv[1], "single") ||
453 !strcmp(argv[1], "-s") || !strcmp(argv[1], "1"))) {
455 tty0_commands = shell_commands;
456 tty1_commands = shell_commands;
459 /* Make sure an init script exists before trying to run it */
460 if (run_rc == TRUE && stat(INITSCRIPT, &statbuf)) {
461 tty0_commands = shell_commands;
462 tty1_commands = shell_commands;
465 /* Ok, now launch the rc script and/or prepare to
466 * start up some VTs if somebody hits enter...
472 if (pid1 == 0 && tty0_commands) {
473 pid1 = run(tty0_commands, first_terminal, 1);
475 if (pid2 == 0 && tty1_commands) {
476 pid2 = run(tty1_commands, second_terminal, 1);
478 wpid = wait(&status);
480 message(log, "pid %d exited, status=%x.\n", wpid, status);
482 /* Don't respawn an init script if it exits */
483 if (run_rc == FALSE && wpid == pid1) {