ASM=nasm

SRC_DIR=src
BUILD_DIR=build

.PHONY: all floppy_image kernel bootloader clean always

#
# Floppy image
#  * use dd to create 1.44MB blank image file
#  * apply FAT12 filesystem to image
#  * copy 512 byte bootloader binary to image using dd (overwriting first sector)
#  * copy kernel binary to filesystem
#    + this step wtill fail if bootloader binary does not contain proper FAT12 headers
#
floppy_image: $(BUILD_DIR)/main_floppy.img

$(BUILD_DIR)/main_floppy.img: bootloader kernel
	dd if=/dev/zero of=$(BUILD_DIR)/main_floppy.img bs=512 count=2880
	mkfs.fat -F 12 -n "WEESLOS" $(BUILD_DIR)/main_floppy.img
	dd if=$(BUILD_DIR)/bootloader.bin of=$(BUILD_DIR)/main_floppy.img conv=notrunc
	mcopy -i $(BUILD_DIR)/main_floppy.img $(BUILD_DIR)/kernel.bin "::kernel.bin"

#
# Bootloader
#
bootloader: $(BUILD_DIR)/bootloader.bin

$(BUILD_DIR)/bootloader.bin: always
	$(ASM) $(SRC_DIR)/bootloader/boot.asm -f bin -o $(BUILD_DIR)/bootloader.bin

#
# Kernel
#
kernel: $(BUILD_DIR)/kernel.bin

$(BUILD_DIR)/kernel.bin: always
	$(ASM) $(SRC_DIR)/kernel/main.asm -f bin -o $(BUILD_DIR)/kernel.bin

#
# Always
#
always:
	mkdir -p $(BUILD_DIR)

#
# Clean
#
clean:
	rm -rf $(BUILD_DIR)/*