First commit

init.c

@@ -0,0 +1,49 @@
+/* See LICENSE file for copyright and license details. */
+#include <signal.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+void boot(void);
+void shut(char);
+
+int main(void)
+{
+	int sig;
+	sigset_t set;
+	size_t i;
+
+	if (getpid() != 1)
+		return 1;
+
+	chdir("/");
+
+	sigfillset(&set);
+	sigprocmask(SIG_BLOCK, &set, NULL);
+
+	nice(15);
+	boot();
+
+restart:
+	while (1)
+	{
+		sigwait(&set, &sig);
+
+		switch (sig)
+		{
+		case SIGUSR1:
+			shut('p');
+			goto restart;
+		case SIGCHLD:
+		case SIGALRM:
+			while (waitpid(-1, NULL, WNOHANG) > 0)
+				;
+			goto restart;
+		case SIGINT:
+			shut('r');
+			goto restart;
+		}
+	}
+
+	/* not reachable */
+	return 0;
+}