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>

2 files changed, 37 insertions, 1 deletions

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]);