PROGRAMS = hello.com
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

KVM = $(shell test -w /dev/kvm && echo 1)

ifdef KVM
QEMU_ARGS += --enable-kvm
endif

ifdef DEBUG
ROMS += dprintf.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: fd1440.img

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

# COM programs
%.com: com/%.asm
	$(NASM) $(NASM_ARGS) -o $@ $<

# Bootloaders, first sector on partition
%.bs: boot/%.asm
	$(NASM) $(NASM_ARGS) -o $@ $<

kernel.bs: kernel/*.asm

# Special case: variations of FAT vbr
fat1.bs: boot/fat.asm
	$(NASM) $(NASM_ARGS) -DFAT12 -DCHS -o $@ $<

fat4.bs: boot/fat.asm
	$(NASM) $(NASM_ARGS) -DFAT16 -DCHS -o $@ $<

fat6.bs: boot/fat.asm
	$(NASM) $(NASM_ARGS) -DFAT16 -DCHS -DLARGE -o $@ $<

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

fd%.img: kernel.bs $(DISTFILES)
	mformat -C -i $@ -f $* -R 8 -B kernel.bs ::
	dd if=kernel.bs conv=notrunc bs=512 skip=1 seek=1 of=$@
	mcopy -i $@ $(DISTFILES) ::

hdimage.img: mbr.bs fd1440.img
	cat mbr.bs fd1440 >$@

part.img: fatc.bs $(DISTFILES)
	dd if=/dev/zero bs=1024 count=33k of=$@
	mformat -i $@ -F -B fatc.bs ::
	mmd -i $@ ::rdos
	mcopy -i $@ $(DISTFILES) ::rdos
	mattrib -i $@ +s ::rdos ::rdos/kernel.bs

hdd.img: part.img mbr.bs
	cat mbr.bs part.img > $@

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

qemu-floppy: fd1440.img $(ROMS)
	$(QEMU) $(QEMU_ARGS) -boot a -fda fd1440.img

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

qemu-pxe: pxeboot.0 $(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=pxeboot.0

qemu-rom: kernel.rom
	$(QEMU) $(QEMU_ARGS) --option-rom kernel.rom