Use objcopy to build ramdisk object

. during build, uses much less memory,
	  disk space, and time
	. lets us throw out bintoc

drivers/memory/Makefile

@@ -1,6 +1,7 @@
 # Makefile for memory driver (MEMORY)
 PROG=	memory
-SRCS=	memory.c imgrd.c
+SRCS=	memory.c imgrd.mfs
+OBJS=	${SRCS:N*.h:R:S/$/.o/g}
 
 DPADD+=	${LIBBLOCKDRIVER} ${LIBCHARDRIVER} ${LIBSYS}
 LDADD+=	-lblockdriver -lchardriver -lsys
@@ -10,6 +11,22 @@ MAN=
 BINDIR?= /usr/sbin
 
 CPPFLAGS.memory.c+=	-I${MINIXSRCDIR}
-CPPFLAGS.imgrd.c+=	-I${.CURDIR}/../ramdisk 
+
+imgrd.d: touch-genfiles
+touch-genfiles:
+	[ -e ../ramdisk/image ] || touch -t 197001020000.00 ../ramdisk/image
+
+
+.SUFFIXES:      .mfs .c .o
+
+# 'elf32-${ARCH}-minix' below should really be ${MACHINE_GNU_PLATFORM}
+# but bsd.own.mk has to be upgraded for that.
+.mfs.o:
+	${_MKTARGET_CREATE}
+	${OBJCOPY} -Ibinary -B${ARCH} -Oelf32-${ARCH}-minix $< $@
+
+imgrd.mfs:
+	ln -s ../ramdisk/image $@
+CLEANFILES+=	imgrd.mfs
 
 .include <minix.bootprog.mk>