Add MKMCONTEXT option

servers/pm/Makefile

@@ -1,8 +1,15 @@
+.include <bsd.own.mk>
+
 # Makefile for Process Manager (PM)
 PROG=	pm
 SRCS=	main.c forkexit.c break.c exec.c time.c alarm.c \
 	signal.c utility.c table.c trace.c getset.c misc.c \
-	profile.c dma.c mcontext.c schedule.c
+	profile.c dma.c schedule.c
+
+.if ${USE_MCONTEXT} != "no"
+SRCS+= mcontext.c
+CPPFLAGS+= -DUSE_MCONTEXT
+.endif
 
 DPADD+=	${LIBSYS} ${LIBTIMERS}
 LDADD+=	-lsys -ltimers

servers/pm/proto.h

@@ -49,6 +49,10 @@ _PROTOTYPE( void setreply, (int proc_nr, int result)			);
 /* mcontext.c */
 _PROTOTYPE( int do_getmcontext, (void)					);
 _PROTOTYPE( int do_setmcontext, (void)					);
+#if ! USE_MCONTEXT
+#define do_getmcontext no_sys
+#define do_setmcontext no_sys
+#endif
 
 /* misc.c */
 _PROTOTYPE( int do_reboot, (void)					);