CC = x86_64-elf-gcc
LD = x86_64-elf-ld

CFLAGS = -ffreestanding -m64

all: .build/nub-os.iso

clean:
	@rm -r .build 2>/dev/null || true

build-dir:
	mkdir .build 2>/dev/null || true

.build/nub-os.iso: build-dir .build/kernel.bin
	mkdir -p .build/iso/boot/grub
	cp grub.cfg .build/iso/boot/grub
	cp .build/kernel.bin .build/iso/boot/
	grub-mkrescue -o .build/nub-os.iso .build/iso/

.build/kernel.bin: build-dir .build/boot.o .build/kernel.o .build/print.o .build/idt.o .build/keyboard.o .build/exceptions.o .build/interrupts.o
	$(LD) -Ttext 0x100000 -o .build/kernel.bin .build/boot.o .build/kernel.o .build/print.o .build/idt.o .build/keyboard.o .build/exceptions.o .build/interrupts.o

.build/kernel.o: build-dir src/kernel.c
	$(CC) $(CFLAGS) -c -o .build/kernel.o src/kernel.c

.build/print.o: build-dir src/print.c
	$(CC) $(CFLAGS) -c -o .build/print.o src/print.c

.build/idt.o: build-dir src/idt.c
	$(CC) $(CFLAGS) -c -o .build/idt.o src/idt.c

.build/keyboard.o: build-dir src/keyboard.c
	$(CC) $(CFLAGS) -c -o .build/keyboard.o src/keyboard.c

.build/exceptions.o: build-dir src/exceptions.c
	$(CC) $(CFLAGS) -c -o .build/exceptions.o src/exceptions.c

.build/interrupts.o: build-dir src/interrupts.asm
	nasm -f elf64 -o .build/interrupts.o src/interrupts.asm

.build/boot.o: build-dir src/boot.asm
	nasm -f elf64 -o .build/boot.o src/boot.asm