Make it possible to pass boot()'s flags to shutdown_nice() so that the

kernel can instigate an orderly shutdown but still determine the form of
that shutdown.  Make it possible eg. to cleanly shutdown and power off the
system under ACPI when the power button is pressed.

sys/dev/syscons/syscons.c

@@ -3098,7 +3098,7 @@ next_code:
 
 	    case RBT:
 #ifndef SC_DISABLE_REBOOT
-		shutdown_nice();
+		shutdown_nice(0);
 #endif
 		break;
 

sys/i386/isa/pcvt/pcvt_kbd.c

@@ -938,7 +938,7 @@ scroll_reset:
 
 #if PCVT_CTRL_ALT_DEL		/*   Check for cntl-alt-del	*/
 	if((key == 76) && ctrl_down && (meta_down||altgr_down))
-		shutdown_nice();
+		shutdown_nice(0);
 #endif /* PCVT_CTRL_ALT_DEL */
 
 #if defined(DDB)		 /*   Check for cntl-alt-esc	*/

sys/kern/kern_shutdown.c

@@ -150,9 +150,13 @@ reboot(p, uap)
 /*
  * Called by events that want to shut down.. e.g  <CTL><ALT><DEL> on a PC
  */
+static int shutdown_howto = 0;
+
 void
-shutdown_nice()
+shutdown_nice(int howto)
 {
+	shutdown_howto = howto;
+	
 	/* Send a signal to init(8) and have it shutdown the world */
 	if (initproc != NULL) {
 		psignal(initproc, SIGINT);
@@ -202,6 +206,9 @@ boot(howto)
 	int howto;
 {
 
+	/* collect extra flags that shutdown_nice might have set */
+	howto |= shutdown_howto;
+
 #ifdef SMP
 	if (smp_active) {
 		printf("boot() called on cpu#%d\n", cpuid);

sys/sys/systm.h

@@ -184,7 +184,7 @@ void	usrinfoinit __P((void));
 void	vntblinit __P((void));
 
 /* Finalize the world. */
-void	shutdown_nice __P((void));
+void	shutdown_nice __P((int));
 
 /*
  * Kernel to clock driver interface.