AS = nasm
CC = clang
LD = lld

ASM_FLAGS=-f bin -o
CFLAGS=-ffreestanding -m32 -target i386-pc-none-elf -c -Wall -Wextra -Werror -mno-red-zone -std=c17 -o

STAGE1_TARGET=stage1.bin
ASM_TARGET=stage2.bin stage1.bin stage3.bin
TARGET_DIR=out

all : createdir $(ASM_TARGET) kernel.bin image

createdir:
	mkdir -p $(TARGET_DIR)

clean:
	sudo umount $(TARGET_DIR)/mount || /bin/true
	sudo rm -rf out

kernel.bin: kernel.c
	$(CC) $(CFLAGS) $(TARGET_DIR)/$@.o $<
	ld.$(LD) -e kmain -Ttext 0x40000 $(TARGET_DIR)/$@.o -o $(TARGET_DIR)/$@.old
	objcopy -O binary $(TARGET_DIR)/$@.old $(TARGET_DIR)/$@

$(ASM_TARGET):%.bin : %.asm
	$(AS) $(ASM_FLAGS) $(TARGET_DIR)/$@ $<

image:
	rm -rf $(TARGET_DIR)/boot.img
	mkfs.msdos -C $(TARGET_DIR)/boot.img 1440
	dd if=$(TARGET_DIR)/$(STAGE1_TARGET) of=$(TARGET_DIR)/boot.img bs=512 count=1 conv=notrunc
	mkdir -p $(TARGET_DIR)/mount
	sudo mount -o loop $(TARGET_DIR)/boot.img $(TARGET_DIR)/mount
	sudo cp $(addprefix $(TARGET_DIR)/, $(ASM_TARGET)) $(TARGET_DIR)/kernel.bin $(TARGET_DIR)/mount
	sudo umount $(TARGET_DIR)/mount