CC=i386-elf-gcc
LD=i386-elf-ld
CFLAGS=-ffreestanding -ggdb -m32 -std=gnu17 -O3 -Wall -Wextra -pedantic -lgcc -isystem ./libk/include

C_SOURCE=$(shell find kernel -type f -name "*.c")
C_OBJ=$(patsubst %.c,bin/%.o,$(C_SOURCE))

A_SOURCE=$(shell find kernel -type f -name "*.asm")
A_OBJ=$(patsubst %.asm,bin/%_asm.o,$(A_SOURCE))

LIBK_SOURCE=$(shell find libk -type f -name "*.c")
LIBK_OBJ=$(patsubst %.c,bin/%.o,$(LIBK_SOURCE))

.PHONY: test all run clean mkdiskimg

all: bin/os.iso

$(A_OBJ): bin/%_asm.o : %.asm
	@mkdir -p $(@D)
	nasm $< -f elf -o $@

$(C_OBJ): bin/%.o : %.c
	@mkdir -p $(@D)
	$(CC) -c $(CFLAGS) -o $@ $<

$(LIBK_OBJ): bin/%.o : %.c
	@mkdir -p $(@D)
	$(CC) -c $(CFLAGS) -o $@ $<

bin/libk.a: $(LIBK_OBJ)
	@mkdir -p $(@D)
	$(AR) rcs bin/libk.a $(LIBK_OBJ)

bin/kernel.bin: bin/libk.a linker.ld $(A_OBJ) $(C_OBJ)
	@mkdir -p $(@D)
	$(LD) -nmagic -o bin/kernel.bin -T linker.ld $(A_OBJ) $(C_OBJ) bin/libk.a

bin/os.iso: bin/kernel.bin grub.cfg
	@mkdir -p $(@D)
	@mkdir -p bin/iso/boot/grub
	cp grub.cfg bin/iso/boot/grub
	cp bin/kernel.bin bin/iso/boot
	grub-mkrescue -o bin/os.iso bin/iso

bin/disk.img:
	@mkdir -p bin
	cp disk.img bin/disk.img

run: bin/os.iso bin/disk.img
	qemu-system-i386 -cdrom bin/os.iso \
		-drive file=bin/disk.img,format=raw,if=ide \
		-boot order=d

clean:
	rm -rf bin