OBJCOPY = avr-objcopy
CC = avr-gcc
BUILD = .build
TARGET = keyboard
OPT = s

CFLAGS = -Wall -Wextra -std=c18 -O$(OPT) -ffunction-sections -fdata-sections -MMD -flto -fno-fat-lto-objects -mmcu=atmega328p -DF_CPU=16000000L -Iinclude -Ilibs/avr-i2c-slave
LDFLAGS = -Wall -Wextra -O$(OPT) -flto -fuse-linker-plugin -Wl,--gc-sections -mmcu=atmega328p

SRC = \
src/main.c \
src/keyboard.c \
src/fifo.c \
src/scancode.c \
libs/avr-i2c-slave/I2CSlave.c

OBJ = $(addprefix $(BUILD)/, $(notdir $(SRC:.c=.o)))
# We can't use this as it will use the wrong main
# vpath %.c $(sort $(dir $(SRC)))
vpath %.c $(dir $(SRC))

.PHONY: all clean

all: $(BUILD) $(BUILD)/$(TARGET).bin

%.hex: %.elf | $(BUILD)
	$(OBJCOPY) -O ihex -R .eeprom $< $@

%.bin: %.hex | $(BUILD)
	$(OBJCOPY) -I ihex -O binary $< $@

$(BUILD)/%.o: %.c Makefile | $(BUILD)
	$(CC) -c $(CFLAGS) $< -o $@

$(BUILD)/$(TARGET).elf: $(OBJ) Makefile
	$(CC) $(LDFLAGS) $(OBJ) -o $@

$(BUILD):
	mkdir $@

clean:
	rm -fr $(BUILD)