diff --git a/Makefile.inc1 b/Makefile.inc1
index 6b6a17041543..b74da18d9886 100644
--- a/Makefile.inc1
+++ b/Makefile.inc1
@@ -193,9 +193,8 @@ CROSSENV=	MAKEOBJDIRPREFIX=${OBJTREE} \
 # bootstrap-tools stage
 BMAKEENV=	DESTDIR= \
 		INSTALL="sh ${.CURDIR}/tools/install.sh" \
-		__MAKE_CONF=${.CURDIR}/tools/build/Makefile.boot \
-		OLD_MAKE_CONF=${__MAKE_CONF} \
-		WORLDTMP=${WORLDTMP}
+		WORLDTMP=${WORLDTMP} \
+		MAKEFLAGS="-m ${.CURDIR}/tools/build/mk ${.MAKEFLAGS}"
 BMAKE=		MAKEOBJDIRPREFIX=${WORLDTMP} \
 		${BMAKEENV} ${MAKE} -f Makefile.inc1 \
 		BOOTSTRAPPING=${OSRELDATE} \
diff --git a/tools/build/Makefile.boot b/tools/build/mk/Makefile.boot
similarity index 58%
rename from tools/build/Makefile.boot
rename to tools/build/mk/Makefile.boot
index 4ad522e4e505..ba2c5f724aab 100644
--- a/tools/build/Makefile.boot
+++ b/tools/build/mk/Makefile.boot
@@ -3,18 +3,12 @@
 # FreeBSD didn't always have the __FBSDID() macro in <sys/cdefs.h>.
 # We could do this with a sys/cdefs.h wrapper, but given that this would
 # slow down all new builds for such a simple concept, we do it here.
-.if defined(BOOTSTRAPPING) && \
-    ( ${BOOTSTRAPPING} < 440001 || \
+.if ( ${BOOTSTRAPPING} < 440001 || \
     ( ${BOOTSTRAPPING} >= 500000 && ${BOOTSTRAPPING} < 500024 ))
 CFLAGS+=	-D__FBSDID=__RCSID
 .endif
 
 CFLAGS+=	-I${WORLDTMP}/legacy/usr/include
-DPADD=		${WORLDTMP}/legacy/usr/lib/libegacy.a
-LDADD=		-legacy
-LDFLAGS=	-L${WORLDTMP}/legacy/usr/lib
-
-OLD_MAKE_CONF?=	/etc/make.conf
-.if exists(${OLD_MAKE_CONF})
-.include "${OLD_MAKE_CONF}"
-.endif
+DPADD+=		${WORLDTMP}/legacy/usr/lib/libegacy.a
+LDADD+=		-legacy
+LDFLAGS+=	-L${WORLDTMP}/legacy/usr/lib
diff --git a/tools/build/mk/bsd.lib.mk b/tools/build/mk/bsd.lib.mk
new file mode 100644
index 000000000000..744f5b5a8b9d
--- /dev/null
+++ b/tools/build/mk/bsd.lib.mk
@@ -0,0 +1,4 @@
+# $FreeBSD$
+
+.include "../../../share/mk/bsd.lib.mk"
+.include "Makefile.boot"
diff --git a/tools/build/mk/bsd.prog.mk b/tools/build/mk/bsd.prog.mk
new file mode 100644
index 000000000000..d650665d6200
--- /dev/null
+++ b/tools/build/mk/bsd.prog.mk
@@ -0,0 +1,4 @@
+# $FreeBSD$
+
+.include "../../../share/mk/bsd.prog.mk"
+.include "Makefile.boot"