.DEFAULT_GOAL := all

PLATFORM ?= posix

TARGET_FILE ?= firmware.elf

CC = $(CROSS_COMPILE)gcc
CPP = $(CROSS_COMPILE)cpp
OBJCOPY = $(CROSS_COMPILE)objcopy

SRC_DIR = src
OBJ_DIR = obj
BIN_DIR = bin

CPP_FLAGS += $(addprefix -I, $(INCLUDES))

C_SRCS = $(wildcard $(SRC_DIR)/*.c)
C_SRCS += $(wildcard $(SRC_DIR)/platform/$(PLATFORM)/*.c)
C_OBJS = $(patsubst $(SRC_DIR)%,$(OBJ_DIR)%,$(patsubst %.c,%.o,$(C_SRCS)))
OBJS = $(NRF_A_OBJS) $(NRF_C_OBJS) $(C_OBJS)

TARGET = $(BIN_DIR)/$(TARGET_FILE)
TARGET_HEX = $(patsubst %.elf,%.hex,$(TARGET))
TARGET_PACKAGE = $(patsubst %.hex,%.zip,$(TARGET_HEX))
THIS_MAKEFILE := $(lastword $(MAKEFILE_LIST))

INCLUDES += include/

OPT = 3
C_FLAGS += -O$(OPT) -g$(OPT)
C_FLAGS += -Wall -Werror
C_FLAGS += -ffunction-sections -fdata-sections -fno-strict-aliasing

LIBS += c nosys m

include Makefile.$(PLATFORM)

.PHONY: all install uninstall clean distclean debug
all: $(TARGET)

debug:
	@echo $(TARGET_HEX)

clean:
	rm -f $(TARGET) $(TARGET_HEX) $(TARGET_PACKAGE)
	rm -f $(OBJS) $(patsubst %.o,%.d,$(OBJS))

distclean:
	rm -rf $(OBJ_DIR) $(BIN_DIR)

$(TARGET): $(OBJS) $(THIS_MAKEFILE)
	@mkdir -p $(dir $@)
	$(CC) $(CC_FLAGS) $(LD_FLAGS) $(OBJS) $(addprefix -l,$(LIBS)) -o $@

$(TARGET_HEX): $(TARGET) $(THIS_MAKEFILE)
	$(OBJCOPY) -O ihex $(TARGET) $(TARGET_HEX)

$(OBJ_DIR)/%.d: $(SRC_DIR)/%.c
	@mkdir -p $(dir $@)
	$(CPP) -MM -MF $@ -MP -MT $(patsubst %.d,%.o,$@) $(C_FLAGS) $(CPP_FLAGS) $(patsubst $(OBJ_DIR)/%.d,$(SRC_DIR)/%.c,$@)

$(OBJ_DIR)/%.o: $(SRC_DIR)/%.c
	@mkdir -p $(dir $@)
	$(CC) -c $(CPP_FLAGS) $(C_FLAGS) $< -o $@

ifneq ($(MAKECMDGOALS),clean)
-include $(patsubst %.o,%.d,$(OBJS))
endif