# We deliberately do not make use of implicit rules, nor the standard variables they use


include local.make

arduino_packages = ~/.arduino15/packages/arduino
arduino_lib = $(arduino_packages)/hardware/avr/1.8.6

# Flags
debug = -g
lto = -flto
mcu = -mmcu=atmega32u4
optimization = -O3
macros = \
	-D F_CPU=16000000L \
	-D ARDUINO=10607 \
	-D ARDUINO_AVR_MICRO \
	-D ARDUINO_ARCH_AVR \
	-D USB_PRODUCT='"Arduino Micro"' \
	-D USB_MANUFACTURER='"Unknown"' \
	-D USB_VID=0x2341 \
	-D USB_PID=0x8037
header_locations = \
	-I $(arduino_lib)/cores/arduino \
	-I $(arduino_lib)/variants/micro

# Flag sets
c_flags = $(debug) $(lto) $(mcu) $(optimization) $(macros) $(header_locations) \
	-std=gnu11 \
	-ffunction-sections \
	-fdata-sections \
	-fno-fat-lto-objects
cplusplus_flags = $(debug) $(lto) $(mcu) $(optimization) $(macros) $(header_locations) \
	-std=gnu++11 \
	-ffunction-sections \
	-fdata-sections \
	-fpermissive \
	-fno-exceptions \
	-fno-threadsafe-statics \
	-Wno-error=narrowing
assembly_flags = $(debug) $(lto) $(mcu) $(macros) $(header_locations)
linking_flags = $(debug) $(lto) $(mcu) $(optimization) \
	-fuse-linker-plugin \
	-Wl,--gc-sections \
	-lm


build/kulifuli-cpp.o : src/main.cpp
	mkdir -p build
	avr-g++ -c $(cplusplus_flags) -o $@ $<

build/arduino-lib/%-cpp.o : $(arduino_lib)/cores/arduino/%.cpp
	mkdir -p build/arduino-lib
	avr-g++ -c $(cplusplus_flags) -o $@ $<

build/arduino-lib/%-c.o : $(arduino_lib)/cores/arduino/%.c
	mkdir -p build/arduino-lib
	avr-gcc -c $(c_flags) -o $@ $<

build/arduino-lib/%-s.o : $(arduino_lib)/cores/arduino/%.S
	mkdir -p build/arduino-lib
	avr-gcc -c $(assembly_flags) -x assembler-with-cpp -o $@ $<

core_objects = $(addprefix build/arduino-lib/, \
	abi-cpp.o \
	CDC-cpp.o \
	HardwareSerial-cpp.o \
	HardwareSerial1-cpp.o \
	new-cpp.o \
	PluggableUSB-cpp.o \
	Print-cpp.o \
	Stream-cpp.o \
	USBCore-cpp.o \
	WMath-cpp.o \
	WString-cpp.o \
	hooks-c.o \
	WInterrupts-c.o \
	wiring_analog-c.o \
	wiring_digital-c.o \
	wiring_pulse-c.o \
	wiring_shift-c.o \
	wiring-c.o \
	wiring_pulse-s.o \
)

build/arduino-lib/core.a : $(core_objects)
	avr-gcc-ar rcs $@ $^

# The order of the prerequisites is significant here for GCC
build/kulifuli.elf : build/kulifuli-cpp.o build/arduino-lib/core.a
	avr-gcc $(linking_flags) -o $@ $^

build/kulifuli.eep : build/kulifuli.elf
	avr-objcopy \
		--output-target=ihex \
		--only-section=.eeprom \
		--set-section-flags=.eeprom=alloc,load \
		--no-change-warnings \
		--change-section-lma .eeprom=0 \
		$< $@

build/kulifuli.hex : build/kulifuli.elf
	avr-objcopy \
		--output-target=ihex \
		--remove-section=.eeprom \
		$< $@


.PHONY : build
build : build/kulifuli.eep build/kulifuli.hex

# This target includes the so-called 1200 baud touch, which puts the Arduino into bootloader mode
.PHONY : upload
upload : build/kulifuli.hex
	stty --file=$(arduino_serial_port) speed 1200 > /dev/null
	sleep 1
	avrdude \
		--part atmega32u4 \
		--programmer avr109 \
		--memory flash:w:build/kulifuli.hex:i \
		--noverify-memory \
		--noerase \
		--port $(arduino_serial_port) \
		--baud 57600

.PHONY : clean
clean :
	rm -rf build/*