# Makefile for sample - AVR Sample code

# Each rule is in the form:
# target: dependency1 dependency2
# 	command to make target from dependencies

# make looks at all dependencies for a target before making it:
#	1) If there is a rule to make dependency, then do that rule
#	2) If there is no rule, and the dependency file exists, then:
#	   a) if target file exists and is newer than dependency file,
#             then look at next dependency
#          b) if dependency file is newer than target (or target doesn't
#             exist), then run command to make target.

# default target when "make" is run w/o arguments
all: sample.rom

# compile timer.c into timer.o
timer.o: timer.c sample.h
	avr-gcc -c -g -O3 -Wall -mmcu=at90s8535 -I. timer.c -o timer.o

# compile sample.c into sample.o
sample.o: sample.c sample.h
	avr-gcc -c -g -O3 -Wall -mmcu=at90s8535 -I. sample.c -o sample.o

# link up sample.o and timer.o into sample.elf
sample.elf: timer.o sample.o
	avr-gcc timer.o sample.o -Wl,-Map=sample.map,--cref -mmcu=at90s8535 -o sample.elf

# copy ROM (FLASH) object out of sample.elf into sample.rom
sample.rom: sample.elf
	avr-objcopy -O ihex sample.elf sample.rom

# command to program chip (optional) (invoked by running "make install")
install:
	avr-prog -p 4 sample.rom

# command to clean up junk (no source files) (invoked by "make clean")
clean:
	rm -f *.o *.rom *.elf *.map *~