PROJECT = kernel
CC = arm-none-eabi-gcc
AS = arm-none-eabi-as
OBJCOPY = arm-none-eabi-objcopy
CFLAGS = -std=c99 -Wall -O2 -nostdlib -nostartfiles -ffreestanding
SRCDIR = src
LDFLAGS = -T $(SRCDIR)/memmap -lm
BUILDDIR = build
BINARY = $(BUILDDIR)/$(PROJECT)
CFILES = $(wildcard $(SRCDIR)/*.c)
OBJFILES = $(patsubst $(SRCDIR)/%.c,$(BUILDDIR)/%.o,$(CFILES))
SFILES = $(wildcard $(SRCDIR)/*.s)
OBJFILES += $(patsubst $(SRCDIR)/%.s,$(BUILDDIR)/%.o,$(SFILES))
DEPENDFILE = .makedepends

all: depend $(BINARY).img $(BINARY).hex

.PHONY: clean
clean:
	rm -rf $(BUILDDIR)
	rm -f $(DEPENDFILE)

.PHONY: depend
depend: $(SRC)
	$(CC) -MM $(CFILES) > $(DEPENDFILE)

$(BUILDDIR):
	mkdir -p $(BUILDDIR)

$(BINARY).elf: $(OBJFILES)
	$(CC) $(CFLAGS) -o $@ $^ $(LDFLAGS)

$(BINARY).img : $(BINARY).elf
	$(OBJCOPY) $< -O binary $@

$(BINARY).hex : $(BINARY).elf
	$(OBJCOPY) $< -O ihex $@

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

$(BUILDDIR)/%.o : $(SRCDIR)/%.s
	$(AS) -o $@ $<

-include $(DEPENDFILE)