override CC				:= x86_64-none-elf-gcc
override LD				:= x86_64-none-elf-ld
override OBJCOPY		:= x86_64-none-elf-objcopy

# For GNU-EFI
override PREFIX			:= $(shell	dirname $$(dirname $$(which $(CC))))
override INC			:= $(PREFIX)/include
override LIBS			:= $(PREFIX)/lib
override GNUEFICRT0		:= $(PREFIX)/lib/crt0-efi-x86_64.o
override GNUEFILDS		:= $(PREFIX)/lib/elf_x86_64_efi.lds

# OVMF supplied by OS
override OVMF_CODE		:= /usr/share/OVMF/OVMF_CODE.fd
override OVMF_VARS		:= /usr/share/OVMF/OVMF_VARS.fd
ifeq ("$(wildcard $(OVMF_CODE))","")
	override OVMF_CODE	:= /usr/share/edk2/x64/OVMF_CODE.fd
endif
ifeq ("$(wildcard $(OVMF_CODE))","")
	override OVMF_CODE	:= $(PREFIX)/share/OVMF/OVMF_CODE_4M.fd
endif
ifeq ("$(wildcard $(OVMF_VARS))","")
	override OVMF_VARS	:= /usr/share/edk2/x64/OVMF_VARS.fd
endif
ifeq ("$(wildcard $(OVMF_VARS))","")
	override OVMF_VARS	:= $(PREFIX)/share/OVMF/OVMF_VARS_4M.fd
endif

$(info $$OVMF_CODE is [${OVMF_CODE}])
$(info $$OVMF_VARS is [${OVMF_VARS}])

override CFLAGS :=			\
    -mno-red-zone			\
    -fshort-wchar			\
    -march=x86-64			\
	-mcmodel=large			\
	-Iarch/x86_64/include	\
    -D_ARCH_AMD64

override LDFLAGS :=				\
    -m elf_x86_64				\
	-T arch/x86_64/linker.ld

.PHONY: all
all: shinobu asagiri.img

.PHONY: run
run: shinobu asagiri.img
	if [ "$$(uname -a | grep -i 'microsoft')" ]; then						\
		export IMAGE_PATH=$$(wslpath -wa build/asagiri.img);				\
		export OVMF_CODE=$$(wslpath -wa $(OVMF_CODE));						\
		export OVMF_VARS=$$(wslpath -wa $(OVMF_VARS));						\
	else																	\
		export IMAGE_PATH=build/asagiri.img;								\
		export OVMF_CODE=$(OVMF_CODE);										\
		export OVMF_VARS=$(OVMF_VARS);										\
	fi;																		\
	qemu-system-x86_64 -cpu qemu64 -net none -monitor stdio -m 4G			\
		-drive if=pflash,format=raw,unit=0,file=$$OVMF_CODE,readonly=on 	\
		-drive if=pflash,format=raw,unit=1,file=$$OVMF_VARS,readonly=on 	\
		-drive if=ide,format=raw,file=$$IMAGE_PATH

### Bootloader
shinobu: build/bin/shinobu

override BCFILES		:= $(shell		find -L shinobu/* -type f -name '*.c')
override BOBJ			:= $(addprefix	build/shinobu/obj/,$(BCFILES:.c=.c.o))

# Compilation rules for bootloader *.c files.
build/shinobu/obj/%.c.o: %.c
	mkdir -p "$$(dirname $@)"
	
	$(CC) $(CFLAGS)				\
		-I$(INC)				\
		-Ishinobu/include		\
		-DEFI_FUNCTION_WRAPPER	\
		-c $< -o $@

# Linking the bootloader
build/bin/shinobu: $(BOBJ)
	mkdir -p "$$(dirname $@)"
	
	$(LD) $(BOBJ)				\
		$(GNUEFICRT0)			\
		-T $(GNUEFILDS)			\
		-L $(LIBS)				\
		-l:libgnuefi.a			\
		-l:libefi.a				\
		-nostdlib				\
		-znocombreloc			\
		-shared					\
		-z noexecstack			\
		-Bsymbolic				\
		--no-warn-rwx-segments	\
		-o $@
	
	$(OBJCOPY)					\
		-j .text				\
		-j .sdata				\
		-j .data				\
		-j .dynamic				\
		-j .dynsym				\
		-j .rel					\
		-j .rela				\
		-j .reloc				\
		--target=efi-app-x86_64	\
		$@ $$(dirname $@)/BOOTX64.EFI