FLOPPY = 360

PROGRAMS = $(patsubst %.asm,%.com,$(wildcard com/*.asm))
DISTFILES = $(PROGRAMS)
ROMS =

QEMU_ARCH = $(shell uname -m)
QEMU = qemu-system-$(QEMU_ARCH)
QEMU_ARGS = $(addprefix --option-rom ,$(ROMS))

NASM = nasm
NASM_ARGS = -s -Ilib -Plib/nasmcomp.asm -w-macro-params

EMUL = utils/emul

ifdef KVM
QEMU_ARGS += --enable-kvm
endif

ifdef DEBUG
ROMS += rom/debug.rom
NASM_ARGS += -l $(basename $@).lst
endif

ifndef DISPLAY
QEMU_ARGS += --display curses
endif

.PHONY: default bootstrap clean qemu-rom qemu-floppy qemu-pxe

default: fdimage.img

# Host utils
utils/%: src/utils/%.c
	mkdir -p utils
	$(CC) -o $@ $<

cp437.bin: src/cp437.bmp utils/bmp2font
	utils/bmp2font $< $@

# BIOS option roms
rom/%.rom: rom/%.asm utils/fix-rom
	$(NASM) $(NASM_ARGS) -o $@ $< && utils/fix-rom $@

# COM programs
%.com: %.asm
	$(NASM) $(NASM_ARGS) -DCOM -DBASE=0x0100 -o $@ $<

# Bootloaders, first sector on partition
%.bs: %.asm
	$(NASM) $(NASM_ARGS) -DBOOT -DBASE=0x7C00 -o $@ $<
	: check boot signature
	test "$$(echo $$(xxd -p -l 2 -s 510 pxe.bs))" == 55aa

# Network bootstrap protocol as used for PXE
%.0: %.asm
	$(NASM) $(NASM_ARGS) -DNBP -DBASE=0x7C00 -o $@ $<

fdimage.img: boot/fat.bs $(BDOSIMG) $(BIOSIMG) $(DISTFILES)
	mformat -R 9 -C -i $@ -f $(FLOPPY) -B boot/fat.bs ::
	dd if=$(BDOSIMG) bs=512 seek=1 count=4 conv=notrunc of=$@
	dd if=$(BIOSIMG) bs=512 seek=5 count=4 conv=notrunc of=$@
	mcopy -i $@ $(DISTFILES) ::

hdimage.img: boot/mbr.bs fdimage.img
	cat boot/mbr.bs fdimage.img >$@

clean:
	rm -f *.com *.bs *.0 *.lst *.img *.bin *.rom

qemu-floppy: fdimage.img $(ROMS)
	$(QEMU) $(QEMU_ARGS) -boot a -fda fdimage.img

qemu-hdd: hdimage.img $(ROMS)
	$(QEMU) $(QEMU_ARGS) -boot c -hda hdimage.img

qemu-pxe: pxe.bs $(ROMS)
	$(QEMU) $(QEMU_ARGS) -boot n \
		-option-rom /usr/share/qemu/pxe-rtl8139.rom \
		-device e1000,netdev=mynet0,mac=52:54:00:12:34:56 \
		-netdev user,id=mynet0,net=192.168.76.0/24,dhcpstart=192.168.76.9,tftp=$(CURDIR),bootfile=pxe.bs