diff --git a/cpu/z80/Makefile.z80 b/cpu/z80/Makefile.z80
index f7a2a16f1..69bd4e6e3 100644
--- a/cpu/z80/Makefile.z80
+++ b/cpu/z80/Makefile.z80
@@ -2,7 +2,7 @@
 # Makefile for z80/SDCC
 # @author Takahide Matsutsuka <markn@markn.org>
 #
-# $Id: Makefile.z80,v 1.4 2007/09/09 13:41:15 matsutsuka Exp $
+# $Id: Makefile.z80,v 1.5 2007/09/10 15:09:28 matsutsuka Exp $
 #
 
 ### Compiler definitions
@@ -14,19 +14,50 @@ AR	 = sdcclib
 OBJCOPY  = objcopy
 STRIP    = strip
 
+### Custom rules
+CUSTOM_RULE_C_TO_OBJECTDIR_D=1
+CUSTOM_RULE_ALLOBJS_TO_TARGETLIB=1
+CUSTOM_RULE_LINK=1
+
+### Default flags
 CFLAGS  += --std-c99 --vc -mz80
 ASFLAGS += -l
 LDFLAGS += -mz80
 AROPTS   = -a
 
+### CPU-dependent directories
 CONTIKI_CPU_DIRS = . dev lib
+
+### CPU-dependent source files
 CONTIKI_SOURCEFILES += strcasecmp.c mtarch.c uip_arch.c \
 	libconio_arch.c log-conio.c rs232.c
 CONTIKI_ASMFILES += uip_arch-asm.S
 
-contiki-$(TARGET).o: $(CONTIKI_OBJECTFILES) $(PROJECT_OBJECTFILES) $(CONTIKI_ASMOBJECTFILES)
+CONTIKI_HASMOBJECTFILES = ${addprefix $(OBJECTDIR)/,$(CONTIKI_HASMFILES:.hS=.o)}
+
+CONTIKI_PLATFORM_DIRS = $(PLATFORM_APPDIRS) \
+	 ${addprefix $(CONTIKI)/platform/$(TARGET)/, $(CONTIKI_TARGET_DIRS)}
+
+#".hS" suffix means assembler file with #include directive
+#so that a developer can use definitions of C-style include file
+#in assembler file.  Make sure the header file contains only compiler
+#directives. (i.e. #define, etc.)
+vpath %.hS $(CONTIKI_PLATFORM_DIRS)
+
+ifndef CUSTOM_RULE_HS_TO_OBJECTDIR_O
+$(OBJECTDIR)/%.o: %.hS
+	cp $< $(OBJECTDIR)/$*.c
+	$(CC) $(CFLAGS) -E $(OBJECTDIR)/$*.c > $(OBJECTDIR)/tmp
+	perl -pe "s/^#(.*)/;$$1/" $(OBJECTDIR)/tmp > $(OBJECTDIR)/$*.S
+	$(AS) $(ASFLAGS) -o $@ $(OBJECTDIR)/$*.S
+	rm -f $(OBJECTDIR)/tmp
+endif
+
+#CUSTOM_RULE_ALLOBJS_TO_TARGETLIB
+contiki-$(TARGET).o: $(CONTIKI_OBJECTFILES) $(PROJECT_OBJECTFILES) $(CONTIKI_ASMOBJECTFILES) $(CONTIKI_HASMOBJECTFILES)
 	for target in $^; do $(AR) $(AROPTS) $@ $$target; done
 
+#CUSTOM_RULE_LINK
 contiki.ihex: contiki-$(TARGET).o
 	$(LD) $(LDFLAGS) -DAUTOSTART_ENABLE $(CONTIKI_TARGET_MAIN) -lcontiki-$(TARGET).o -o $@