add assemly compilation capabililty

arduino_nano/Makefile

@@ -24,9 +24,12 @@ SIZE = avr-size
 
 # library directories, compiler, and linker flags
 LIBS = lib
-CFLAGS = -g -Wall -Werror -O3 -std=c99
+CFLAGS = -g -Wall -Werror -Os -mcall-prologues -std=c99
 CFLAGS += -I. $(patsubst %,-I%,$(LIBS))
 CFLAGS += -mmcu=$(DEVICE) -DF_CPU=$(F_CPU)
+AFLAGS = -Wall -Werror -x assembler-with-cpp
+AFLAGS += -I. $(patsubst %,-I%,$(LIBS))
+AFLAGS += -mmcu=$(DEVICE)
 LDFLAGS = -Wl,-Map=$(TARGET).map,--cref
 LDFLAGS += -I. $(patsubst %,-I%,$(LIBS))
 LDFLAGS += -mmcu=$(DEVICE)
@@ -36,14 +39,16 @@ LDFLAGS += -mmcu=$(DEVICE)
 #LDFLAGS += -lm
 
 # source files to compile
-SRC = $(wildcard *.c)
-SRC += $(foreach LIB,$(LIBS),$(wildcard $(LIB)/*.c))
+CSRC = $(wildcard *.c) $(foreach LIB,$(LIBS),$(wildcard $(LIB)/*.c))
+ASRC = $(wildcard *.S) $(foreach LIB,$(LIBS),$(wildcard $(LIB)/*.S))
 # header files
 HEADER = $(SRC:.c=.h)
 # object files
-OBJ = $(SRC:.c=.o)
-# listing files.
-LST = $(SRC:.c=.lst)
+OBJ = $(patsubst %.c,%.o,$(CSRC)) $(patsubst %.S,%.o,$(ASRC))
+# listing files
+LST = $(patsubst %.c,%.lst,$(CSRC)) $(patsubst %.S,%.lst,$(ASRC))
+
+$(info $(OBJ))
 
 all: compile flash
 	$(info EEPROM has to be programmed separately)
@@ -84,11 +89,15 @@ lst: $(TARGET).lst
 map: $(TARGET).map
 
 # compile source files
-%.o: %.c %.h
+%.o: %.c
 	$(CC) $(CFLAGS) -c -o $@ $<
 
+%.o: %.S
+	$(CC) $(AFLAGS) -c -o $@ $<
+
 # link compiled files
 %.elf: $(OBJ)
+	$(info elf)
 	$(CC) $(LDFLAGS) -o $@ $^
 
 $(TARGET).map: $(OBJ)