diff --git a/Makefile.base b/Makefile.base
index f9cf7bbf30..6e56df9e6f 100644
--- a/Makefile.base
+++ b/Makefile.base
@@ -22,49 +22,49 @@ ${DIRS:%=ALL--%}:
 ${DIRS:%=CLEAN--%}:
 	"$(MAKE)" -C ${@:CLEAN--%=%} clean
 
-ASMSRC = $(wildcard *.s)
-ASSMSRC = $(wildcard *.S)
-ASMOBJ = $(ASMSRC:%.s=$(BINDIR)$(MODULE)/%.o)
-ASMOBJ += $(ASSMSRC:%.S=$(BINDIR)$(MODULE)/%.o)
-
 ifeq ($(strip $(SRC)),)
-	SRC = $(wildcard *.c)
+    SRC := $(wildcard *.c)
 endif
-
 ifeq ($(strip $(SRCXX)),)
-	SRCXX = $(wildcard *.cpp)
+    SRCXX := $(wildcard *.cpp)
+endif
+ifeq ($(strip $(ASMSRC)),)
+    ASMSRC := $(wildcard *.s)
+endif
+ifeq ($(strip $(ASSMSRC)),)
+    ASSMSRC := $(wildcard *.S)
 endif
 
-OBJC = $(SRC:%.c=$(BINDIR)$(MODULE)/%.o)
-OBJCXX = $(SRCXX:%.cpp=$(BINDIR)$(MODULE)/%.o)
+OBJC    := $(SRC:%.c=$(BINDIR)$(MODULE)/%.o)
+OBJCXX  := $(SRCXX:%.cpp=$(BINDIR)$(MODULE)/%.o)
+ASMOBJ  := $(ASMSRC:%.s=$(BINDIR)$(MODULE)/%.o)
+ASSMOBJ := $(ASSMSRC:%.S=$(BINDIR)$(MODULE)/%.o)
 
-OBJ = $(OBJC)
-OBJ += $(OBJCXX)
+OBJ := $(OBJC) $(OBJCXX) $(ASMOBJ) $(ASSMOBJ)
+DEP := $(OBJC:.o=.d) $(OBJCXX:.o=.d) $(ASSMOBJ:.o=.d)
 
-DEP = $(SRC:%.c=$(BINDIR)$(MODULE)/%.d)
-DEP += $(SRCXX:%.cpp=$(BINDIR)$(MODULE)/%.d)
+$(BINDIR)$(MODULE)/:
+	$(AD)mkdir -p $@
 
-$(BINDIR)$(MODULE).a: $(OBJ) $(ASMOBJ) ${DIRS:%=ALL--%}
-	@mkdir -p $(BINDIR)$(MODULE)
-	$(AD)$(AR) -rc $(BINDIR)$(MODULE).a $(OBJ) $(ASMOBJ)
+$(BINDIR)$(MODULE).a: $(OBJ) ${DIRS:%=ALL--%} $(BINDIR)$(MODULE)/
+	$(AD)$(AR) -rcs $@ $(OBJ)
+
+CXXFLAGS = $(filter-out $(CXXUWFLAGS), $(CFLAGS)) $(CXXEXFLAGS)
+
+# compile and generate dependency info
+
+$(OBJC): $(BINDIR)$(MODULE)/%.o: %.c $(BINDIR)$(MODULE)/
+	$(AD)$(CC) $(CFLAGS) $(INCLUDES) -MD -MP -c -o $@ $(abspath $<)
+
+$(OBJCXX): $(BINDIR)$(MODULE)/%.o: %.cpp $(BINDIR)$(MODULE)/
+	$(AD)$(CXX) $(CXXFLAGS) $(INCLUDES) -MD -MP -c -o $@ $(abspath $<)
+
+$(ASMOBJ): $(BINDIR)$(MODULE)/%.o: %.s $(BINDIR)$(MODULE)/
+	$(AD)$(AS) $(ASFLAGS) -o $@ $(abspath $<)
+
+$(ASSMOBJ): $(BINDIR)$(MODULE)/%.o: %.S $(BINDIR)$(MODULE)/
+	$(AD)$(CC) $(CFLAGS) $(INCLUDES) -MD -MP -c -o $@ $(abspath $<)
 
 # pull in dependency info for *existing* .o files
 # deleted header files will be silently ignored
--include $(OBJ:.o=.d)
-
-# compile and generate dependency info
-$(BINDIR)$(MODULE)/%.o: %.c
-	@mkdir -p $(BINDIR)$(MODULE)
-	$(AD)$(CC) $(CFLAGS) $(INCLUDES) -MD -MP -c -o $(BINDIR)$(MODULE)/$*.o $(abspath $*.c)
-
-$(BINDIR)$(MODULE)/%.o: %.cpp
-	@mkdir -p $(BINDIR)$(MODULE)
-	$(AD)$(CXX) $(filter-out $(CXXUWFLAGS), $(CFLAGS)) $(CXXEXFLAGS) $(INCLUDES) -MD -MP -c -o $(BINDIR)$(MODULE)/$*.o $(abspath $*.cpp)
-
-$(BINDIR)$(MODULE)/%.o: %.s
-	@mkdir -p $(BINDIR)$(MODULE)
-	$(AD)$(AS) $(ASFLAGS) $*.s -o $(BINDIR)$(MODULE)/$*.o
-
-$(BINDIR)$(MODULE)/%.o: %.S
-	@mkdir -p $(BINDIR)$(MODULE)
-	$(AD)$(CC) $(CFLAGS) $(INCLUDES) -MD -MP -c -o $(BINDIR)$(MODULE)/$*.o $(abspath $*.S)
+-include $(DEP)