FD_CYLINDERS = 40
FD_HEADS = 2
FD_SECTORS = 9

QEMU_ARCH = $(shell uname -m)
QEMU = qemu-system-$(QEMU_ARCH)

ifdef KVM
QEMU_ARGS += --enable-kvm
endif

ifdef DEBUG
QEMU_ARGS += -option-rom debug.rom
DEBUGROM = debug.rom
endif

ifndef DISPLAY
QEMU_ARGS += --display curses
endif

.PHONY: default clean qemu-rom qemu-floppy

default: kernel.rom

kernel.com: kernel/*.asm lib/*.inc
	nasm -s -o $@ -l kernel.lst -I lib -I kernel kernel/main.asm

debug.rom: debug/*.asm lib/*.inc
	nasm -s -o $@ -I lib -I debug debug/main.asm && scripts/fix-rom.sh $@

floppy.bs: boot/fatvbr.asm
	nasm -s -DCMDLINE='"KERNEL.COM"' -o $@ $<

fdimage.img: floppy.bs kernel.com
	dd if=/dev/zero bs=512 count=$$(( $(FD_CYLINDERS) * $(FD_HEADS) * $(FD_SECTORS) )) of=$@
	mformat -i $@ -t $(FD_CYLINDERS) -h $(FD_HEADS) -n $(FD_SECTORS) -B floppy.bs ::
	mcopy -i $@ kernel.com ::kernel.com
	mattrib -i $@ +s ::kernel.com

clean:
	rm -f *.com *.bin *.rom *.img *.log *.bs *.lst

qemu-floppy: fdimage.img $(DEBUGROM)
	$(QEMU) $(QEMU_ARGS) -boot c -fda fdimage.img