1 /* vi: set sw=4 ts=4: */
3 * Mini watchdog implementation for busybox
5 * Copyright (C) 2003 Paul Mundt <lethal@linux-sh.org>
6 * Copyright (C) 2006 Bernhard Fischer <busybox@busybox.net>
8 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
18 #define OPT_FOREGROUND 0x01
19 #define OPT_TIMER 0x02
21 /* Watchdog file descriptor */
24 static void watchdog_shutdown(int ATTRIBUTE_UNUSED unused)
26 write(fd, "V", 1); /* Magic, see watchdog-api.txt in kernel */
31 int watchdog_main(int argc, char **argv)
34 unsigned long timer_duration = 30; /* Userspace timer duration, in seconds */
37 opts = bb_getopt_ulflags(argc, argv, "Ft:", &t_arg);
40 timer_duration = bb_xgetlarg(t_arg, 10, 0, INT_MAX);
42 /* We're only interested in the watchdog device .. */
43 if (optind < argc - 1 || argc == 1)
47 if (!(opts & OPT_FOREGROUND))
48 vfork_daemon_rexec(0, 1, argc, argv, "-F");
53 signal(SIGHUP, watchdog_shutdown);
54 signal(SIGINT, watchdog_shutdown);
56 fd = bb_xopen(argv[argc - 1], O_WRONLY);
60 * Make sure we clear the counter before sleeping, as the counter value
61 * is undefined at this point -- PFM
64 sleep(timer_duration);