SHELL:=/bin/bash

# -mgeneral-regs-only only needed for interrupt handlers

CFLAGS:= \
	-nostdlib \
	-nostdinc \
	-fno-builtin \
	-fno-stack-protector \
	-nostartfiles \
	-nodefaultlibs \
	-mgeneral-regs-only \
	-Wall \
	-Wextra

STAGE3 = \
	stage3/main.o \
	stage3/gfx.o \
	stage3/halt.o \
	stage3/interrupts.o \
	stage3/isr.o \
	stage3/pic.o \
	stage3/memory.o \
	stage3/paging.o \
	stage3/heap.o \
	stage3/font.o \
	stage3/font_classic.o \
	stage3/ata.o \
	stage3/string.o \
	stage3/pci.o \
	stage3/fs.o \
	stage3/yield.o \
	stage3/ps2.o \
	stage3/thread.o \
	stage3/shell.o

PAD_BOUNDARY = pad() { truncate -s $$(echo "($$(du -b $$1 | cut -f1)+$$2-1)/$$2*$$2" | bc) $$1; }; pad

cuddles.img: stage1.bin stage2.bin stage3.bin fs.tar
	cat stage{1,2,3}.bin fs.tar > cuddles.img
	$(PAD_BOUNDARY) cuddles.img 1048576

stage1.bin: stage1/main.asm stage1/print.asm stage2.bin stage3.bin
	nasm -f bin stage1/main.asm -o stage1.bin \
		-dKSIZE=$$(du -cb stage{2,3}.bin | tail -n1 | cut -f1)

stage2.bin: stage2/main.asm stage2/mmap.asm stage2/paging.asm stage2/vesa.asm stage1/print.asm
	nasm -f bin stage2/main.asm -o stage2.bin
	truncate -s 4608 stage2.bin

stage3.bin: $(STAGE3) stage3.ld
	ld $(STAGE3) -T stage3.ld -Map=stage3.map
	$(PAD_BOUNDARY) stage3.bin 512

stage3/%.o: stage3/%.asm
	nasm -f elf64 $< -o $@

stage3/%.o: stage3/%.c
	gcc $(CFLAGS) -c $< -o $@

stage3/isr.asm: stage3/isr.lua
	lua stage3/isr.lua > stage3/isr.asm

fs.tar: $(shell find fs | sed 's/ /\\ /g')
	cd fs && tar --format=ustar -cf ../fs.tar *

.PHONY: run clean flash disas map qemu bochs

bochs: cuddles.img
	rm -f cuddles.img.lock
	echo c | bochs -q

qemu: cuddles.img
	qemu-system-x86_64 -drive format=raw,file=cuddles.img

run: qemu

clean:
	rm -rf stage3/*.o *.bin *.img *.map stage3/isr.asm fs.tar

flash: cuddles.img
	dd if=cuddles.img of=$(DEV)

disas: stage3.bin
	objdump -b binary -D -M intel -m i386:x86-64 stage3.bin --adjust-vma 0x9000 --disassembler-color=on

map: stage3.bin
	cat stage3.map