diff --git a/board/sandburst/karef/Makefile b/board/sandburst/karef/Makefile
index af758f9..05c8187 100644
--- a/board/sandburst/karef/Makefile
+++ b/board/sandburst/karef/Makefile
@@ -9,37 +9,16 @@
 # SPDX-License-Identifier:	GPL-2.0+
 #
 
-include $(TOPDIR)/config.mk
 ifneq ($(OBJTREE),$(SRCTREE))
 $(shell mkdir -p $(obj)../common)
 endif
 
 # TBS: add for debugging purposes
 BUILDUSER := $(shell whoami)
-FORCEBUILD := $(shell rm -f $(LIB) $(BOARD).o)
+FORCEBUILD := $(shell rm -f karef.o)
 
 CFLAGS += -DBUILDUSER='"$(BUILDUSER)"'
 # TBS: end debugging
 
-
-LIB	= $(obj)lib$(BOARD).o
-
-COBJS	= $(BOARD).o ../common/flash.o ../common/sb_common.o
-
-SOBJS	= init.o
-
-SRCS	:= $(SOBJS:.o=.S) $(COBJS:.o=.c)
-OBJS	:= $(addprefix $(obj),$(COBJS))
-SOBJS	:= $(addprefix $(obj),$(SOBJS))
-
-$(LIB):	$(OBJS) $(SOBJS)
-	$(call cmd_link_o_target, $(OBJS))
-
-#########################################################################
-
-# defines $(obj).depend target
-include $(SRCTREE)/rules.mk
-
-sinclude $(obj).depend
-
-#########################################################################
+obj-y	= karef.o ../common/flash.o ../common/sb_common.o
+extra-y	+= init.o
diff --git a/board/sandburst/metrobox/Makefile b/board/sandburst/metrobox/Makefile
index 163f2b9..76dfffc 100644
--- a/board/sandburst/metrobox/Makefile
+++ b/board/sandburst/metrobox/Makefile
@@ -8,36 +8,16 @@
 # SPDX-License-Identifier:	GPL-2.0+
 #
 
-include $(TOPDIR)/config.mk
 ifneq ($(OBJTREE),$(SRCTREE))
 $(shell mkdir -p $(obj)../common)
 endif
 
 # TBS: add for debugging purposes
 BUILDUSER := $(shell whoami)
-FORCEBUILD := $(shell rm -f $(LIB) $(BOARD).o)
+FORCEBUILD := $(shell rm -f metrobox.o)
 
 CFLAGS += -DBUILDUSER='"$(BUILDUSER)"'
 # TBS: end debugging
 
-
-LIB	= $(obj)lib$(BOARD).o
-
-COBJS	= $(BOARD).o ../common/flash.o ../common/sb_common.o
-SOBJS	= init.o
-
-SRCS	:= $(SOBJS:.o=.S) $(COBJS:.o=.c)
-OBJS	:= $(addprefix $(obj),$(COBJS))
-SOBJS	:= $(addprefix $(obj),$(SOBJS))
-
-$(LIB):	$(OBJS) $(SOBJS)
-	$(call cmd_link_o_target, $(OBJS))
-
-#########################################################################
-
-# defines $(obj).depend target
-include $(SRCTREE)/rules.mk
-
-sinclude $(obj).depend
-
-#########################################################################
+obj-y	= metrobox.o ../common/flash.o ../common/sb_common.o
+extra-y	+= init.o