.SUFFIXES:

MCU := atmega328p
PROGRAMMER := usbasp
SPEED := 8000000UL

TARGET := main.hex
EEP := main.eep
BIN := main.elf
OBJ := main.o

LOW_FUSE := 0xE2
HIGH_FUSE := 0xD6

SHELL := sh
CC := avr-gcc
OBJCOPY := avr-objcopy
SIZE := avr-size
AVRDUDE := avrdude

CFLAGS := -mmcu=$(MCU) -D F_CPU=$(SPEED) -Os -Wall -Werror -Wextra -Wpedantic

all: $(TARGET) $(EEP)

$(TARGET): $(BIN)
	${OBJCOPY} -O ihex -j .text -j .data $< $@

$(EEP): $(BIN)
	${OBJCOPY} --change-section-lma .eeprom=0 -O ihex -j .eeprom $< $@

$(BIN): $(OBJ)
	$(CC) $(CFLAGS) $< -o $@

%.o: %.c
	$(CC) $(CFLAGS) -c $< -o $@

.PHONY: flash eeprom fuses clean check size

flash: $(TARGET) size
	$(AVRDUDE) -p $(MCU) -c $(PROGRAMMER) -U flash:w:$<:a

eeprom: $(EEP) size
	$(AVRDUDE) -p $(MCU) -c $(PROGRAMMER) -U eeprom:w:$<:a

fuses:
	$(AVRDUDE) -p $(MCU) -c $(PROGRAMMER) -U lfuse:w:$(LOW_FUSE):m -U hfuse:w:$(HIGH_FUSE):m

clean:
	$(RM) $(TARGET) $(EEP) $(BIN) $(OBJ)

check:
	cppcheck main.c

size: $(BIN)
	$(SIZE) --format=avr --mcu=$(MCU) $<