TARGET=i686
ARCHDIR=arch/$(TARGET)/
SOURCEDIR=src/
BUILDDIR=build/

INCLUDEDIR=$(SOURCEDIR)include/

CFLAGS?=
ASFLAGS?=

# Define flags for C files

CFLAGS:=\
-O2 \
-ffreestanding \
-Wall -Wextra \
-fno-exceptions -fno-rtti \
-I$(INCLUDEDIR) \
$(CFLAGS)

CXXFLAGS:=$(CFLAGS)

# Define flags for assembly files
ASFLAGS:=\
-I$(SOURCEIDR)$(INCLUDEDIR) \
-I$(SOURCEDIR)$(ARCHDIR) \
$(ASFLAGS)

LINKERFLAGS:=\
-ffreestanding \
-O2 \
-nostdlib \
-lgcc

LIB_OBJS=\
$(BUILDDIR)$(ARCHDIR)bootstrap.o \
$(BUILDDIR)$(ARCHDIR)paging.o \
$(BUILDDIR)$(ARCHDIR)initialize_pages.o \
$(BUILDDIR)$(ARCHDIR)tty.o

KERNEL_OBJS=\
$(BUILDDIR)kernel/kernel.o

OBJS=$(LIB_OBJS) $(KERNEL_OBJS)

LINKER_PATH=$(SOURCEDIR)$(ARCHDIR)linker.ld

.PHONY: all clean snowstorm.iso debug
.SUFFIXES: .c .o .s

$(BUILDDIR)%.o : $(SOURCEDIR)%.cpp
	i686-elf-g++ -c $< -o $@ $(CXXFLAGS)

$(BUILDDIR)%.o : $(SOURCEDIR)%.c
	i686-elf-gcc -c $< -o $@ $(CFLAGS)

$(BUILDDIR)%.o : $(SOURCEDIR)%.s
	i686-elf-as $< -o $@ $(ASFLAGS)

all: snowstorm.iso

# Take the kernel file and make a bootable ISO through GRUB
snowstorm.iso: snowstorm.kernel
	cp build/snowstorm.kernel build/isodir/boot/snowstorm.kernel
	grub-mkrescue -o build/snowstorm.iso build/isodir

# link all object files together
snowstorm.kernel: $(OBJS)
	i686-elf-gcc -T $(LINKER_PATH) -o build/snowstorm.kernel $(OBJS) $(LINKERFLAGS) 
	grub-file --is-x86-multiboot build/snowstorm.kernel

debug: CXXFLAGS += -g -O1
debug: ASFLAGS += -g
debug: CFLAGS += -g -O1
debug: all

clean:
	rm -f $(OBJS)
	rm -f build/snowstorm.kernel
	rm -f build/snowstorm.iso
	rm -f build/isodir/boot/snowstorm.kernel

run: all
	qemu-system-i386 -d int -no-reboot -kernel build/snowstorm.kernel

run-debug: debug
	qemu-system-i386 -d int -no-reboot -S -gdb tcp::9000 -kernel build/snowstorm.kernel