Makefile

CXXFILES  := $(shell find src/ -type f -name '*.cpp')
ASMFILES  := $(shell find src/ -type f -name '*.asm')
CXXC       = ~/.local/bin/cross_compiler/x86_64/bin/x86_64-elf-g++
GDB       = ~/.local/bin/cross_compiler/x86_64/bin/x86_64-elf-gdb
LD         = ~/.local/bin/cross_compiler/x86_64/bin/x86_64-elf-ld
OBJ       := ${CXXFILES:.cpp=.o} $(ASMFILES:.asm=.o)

ifeq ($(MAKECMDGOALS), log)
LIMINE_CFG = limine_text.cfg
else ifeq ($(MAKECMDGOALS), logs)
LIMINE_CFG = limine_text.cfg
else
LIMINE_CFG = limine.cfg
endif
	
KERNEL_HDD = build/disk.hdd
KERNEL_ELF = kernel.elf

QEMU_FLAGS = -m 2G                                        \
	-drive format=raw,media=disk,index=0,file=$(KERNEL_HDD) \

KVM_FLAGS = -enable-kvm \
	-cpu host

QEMU_LOG_FLAGS = -no-reboot \
	-monitor stdio            \
	-d int                    \
	-D logs/qemu.log

CXXFLAGS = -O2 -pipe -Wall -Wextra

CXXHARDFLAGS := $(CXXFLAGS)      \
	-std=c++17                     \
	-fno-pic                       \
	-mno-sse                       \
	-mno-sse2                      \
	-mno-mmx                       \
	-mno-80387                     \
	-mno-red-zone                  \
	-mcmodel=kernel                \
	-ffreestanding                 \
	-fno-stack-protector           \
	-Isrc                          \

LDHARDFLAGS := $(LDFLAGS)   \
	-static                   \
	-nostdlib                 \
	-no-pie                   \
	-z max-page-size=0x1000   \
	-T linker.ld

NASMFLAGS := -felf64 -F dwarf

.PHONY: clean

.DEFAULT_GOAL = $(KERNEL_HDD)

disk: $(KERNEL_HDD)

all: disk

logs: log

run: $(KERNEL_HDD)
	qemu-system-x86_64 $(QEMU_FLAGS) $(KVM_FLAGS)

debug: $(KERNEL_HDD)
	qemu-system-x86_64 -s $(QEMU_FLAGS) $(KVM_FLAGS) &
	${GDB} -ex "target remote localhost:1234" -ex "symbol-file $(KERNEL_ELF)"

log: $(KERNEL_HDD)
	-mkdir -p logs
	qemu-system-x86_64 $(QEMU_LOG_FLAGS) $(QEMU_FLAGS)

%.o: %.asm
	nasm $(NASMFLAGS) $< -o $@

%.o: %.cpp
	$(CXXC) $(CXXHARDFLAGS) -c $< -o $@

$(KERNEL_ELF): $(OBJ)
	$(LD) $(LDHARDFLAGS) $(OBJ) -o $@

limine/limine-install:
	$(MAKE) -C limine/ limine-install

$(KERNEL_HDD): $(KERNEL_ELF) limine/limine-install 
	-mkdir -p build
	rm -f $(KERNEL_HDD)
	dd if=/dev/zero bs=1M count=0 seek=64 of=$(KERNEL_HDD)
	parted -s $(KERNEL_HDD) mklabel msdos
	parted -s $(KERNEL_HDD) mkpart primary 1 100%
	echfs-utils -m -p0 $(KERNEL_HDD) quick-format 32768
	echfs-utils -m -p0 $(KERNEL_HDD) import $(KERNEL_ELF) $(KERNEL_ELF)
	echfs-utils -m -p0 $(KERNEL_HDD) import $(LIMINE_CFG) limine.cfg
	echfs-utils -m -p0 $(KERNEL_HDD) import bg.bmp bg.bmp
	limine/limine-install limine/limine.bin $(KERNEL_HDD)

clean:
	-rm -rf $(KERNEL_HDD) $(KERNEL_ELF) $(OBJ) build logs