From 97af2ff8caa782f623e79408f0dfe608c878d5a6 Mon Sep 17 00:00:00 2001
From: Alexander Shishkin <virtuoso@slind.org>
Date: Mon, 27 Jul 2009 02:49:35 +0200
Subject: [PATCH] halt/reboot/poweroff: add a CONFIG_xxx to act SysV compatibly

Signed-off-by: Alexander Shishkin <virtuoso@slind.org>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
---
 init/Config.in | 20 ++++++++++++++++++++
 init/halt.c    | 18 +++++++++++++++++-
 2 files changed, 37 insertions(+), 1 deletion(-)

diff --git a/init/Config.in b/init/Config.in
index 1a1be4a9b..3d99d4792 100644
--- a/init/Config.in
+++ b/init/Config.in
@@ -93,6 +93,26 @@ config HALT
 	help
 	  Stop all processes and either halt, reboot, or power off the system.
 
+config FEATURE_CALL_TELINIT
+	bool "Call telinit on shutdown and reboot"
+	default n
+	depends on HALT && !INIT
+	help
+	  Call an external program (normally telinit) to facilitate
+	  a switch to a proper runlevel.
+
+	  This option is only available if you selected halt and friends,
+	  but did not select init.
+
+config TELINIT_PATH
+	string "Path to telinit executable"
+	default "/sbin/telinit"
+	depends on FEATURE_CALL_TELINIT
+	help
+	  When busybox halt and friends have to call external telinit
+	  to facilitate proper shutdown, this path is to be used when
+	  locating telinit executable.
+
 config MESG
 	bool "mesg"
 	default n
diff --git a/init/halt.c b/init/halt.c
index 3a23ecabb..c88c333e7 100644
--- a/init/halt.c
+++ b/init/halt.c
@@ -85,6 +85,8 @@ int halt_main(int argc UNUSED_PARAM, char **argv)
 //TODO: I tend to think that signalling linuxrc is wrong
 // pity original author didn't comment on it...
 		if (ENABLE_FEATURE_INITRD) {
+			/* talk to linuxrc */
+			/* bbox init/linuxrc assumed */
 			pid_t *pidlist = find_pid_by_name("linuxrc");
 			if (pidlist[0] > 0)
 				rc = kill(pidlist[0], signals[which]);
@@ -92,7 +94,21 @@ int halt_main(int argc UNUSED_PARAM, char **argv)
 				free(pidlist);
 		}
 		if (rc) {
-			rc = kill(1, signals[which]);
+			/* talk to init */
+			if (!ENABLE_FEATURE_CALL_TELINIT) {
+				/* bbox init assumed */
+				rc = kill(1, signals[which]);
+			} else {
+				/* SysV style init assumed */
+				/* runlevels:
+				 * 0 == shutdown
+				 * 6 == reboot */
+				rc = execlp(CONFIG_TELINIT_PATH,
+						CONFIG_TELINIT_PATH,
+						which == 2 ? "6" : "0",
+						(char *)NULL
+				);
+			}
 		}
 	} else {
 		rc = reboot(magic[which]);