new target for building static library: make lib

Makefile

@@ -3,6 +3,8 @@
 #OBJCOPY      = avr-objcopy
 CC           = gcc
 LD           = gcc
+AR           = ar
+ARFLAGS      = rcs
 CFLAGS       = -Wall -Os -c
 LDFLAGS      = -Wall -Os -Wl,-Map,test.map
 ifdef AES192
@@ -12,7 +14,7 @@ ifdef AES256
 CFLAGS += -DAES256=1
 endif
 
-OBJCOPYFLAFS = -j .text -O ihex
+OBJCOPYFLAGS = -j .text -O ihex
 OBJCOPY      = objcopy
 
 # include path to AVR library
@@ -27,7 +29,7 @@ default: test.elf
 
 test.hex : test.elf
 	echo copy object-code to new image and format in hex
-	$(OBJCOPY) ${OBJCOPYFLAFS} $< $@
+	$(OBJCOPY) ${OBJCOPYFLAGS} $< $@
 
 test.o : test.c aes.h aes.o
 	echo [CC] $@ $(CFLAGS)
@@ -41,9 +43,14 @@ test.elf : aes.o test.o
 	echo [LD] $@
 	$(LD) $(LDFLAGS) -o $@ $^
 
+aes.a : aes.o
+	echo [AR] $@
+	$(AR) $(ARFLAGS) $@ $^
+
+lib : aes.a
 
 clean:
-	rm -f *.OBJ *.LST *.o *.gch *.out *.hex *.map
+	rm -f *.OBJ *.LST *.o *.gch *.out *.hex *.map *.elf *.a
 
 test:
 	make clean && make && ./test.elf