Makefile

NASM       ?= nasm
CC         ?= gcc
LD         ?= ld
OBJCOPY    ?= objcopy

CONFLICT_CHECK := ./scripts/check-conflicts.sh

# Added -MMD -MP for automatic dependency tracking
CFLAGS := -std=gnu11 -O2 -ffreestanding -fno-stack-protector -fcf-protection=none \
          -fno-pic -mno-red-zone -mgeneral-regs-only -nostdlib -nostartfiles \
          -Wall -Wextra -Ikernel/include -mno-mmx -mno-sse -mno-sse2 -mno-sse3 \
          -mno-ssse3 -mno-sse4 -mno-avx -MMD -MP
NASMFLAGS := -Wall -Werror

BUILD_DIR := build
BOOT_BIN := $(BUILD_DIR)/boot.bin
STAGE2_BIN := $(BUILD_DIR)/stage2.bin
KERNEL_ELF := $(BUILD_DIR)/kernel.elf
KERNEL_BIN := $(BUILD_DIR)/kernel.bin
PAYLOAD_BIN := $(BUILD_DIR)/stage2_kernel.bin
OS_IMAGE := $(BUILD_DIR)/NostaluxOS.img
KERNEL_SRCS := $(wildcard kernel/*.c)
KERNEL_OBJS := $(patsubst kernel/%.c,$(BUILD_DIR)/%.o,$(KERNEL_SRCS))

# Include dependency files generated by GCC
DEPS := $(KERNEL_OBJS:.o=.d)

QEMU ?= qemu-system-x86_64

# QEMU Audio Flags
QEMU_AUDIO := -machine pcspk-audiodev=snd0 -audiodev pa,id=snd0

.PHONY: all clean run check-conflicts

all: check-conflicts $(OS_IMAGE)

check-conflicts:
	@$(CONFLICT_CHECK)

$(BUILD_DIR):
	@mkdir -p $(BUILD_DIR)

$(KERNEL_ELF): kernel/entry.asm $(KERNEL_OBJS) kernel/linker.ld | $(BUILD_DIR)
	$(NASM) -f elf64 kernel/entry.asm -o $(BUILD_DIR)/entry.o
	$(LD) -nostdlib -z max-page-size=0x1000 -T kernel/linker.ld -o $@ $(BUILD_DIR)/entry.o $(KERNEL_OBJS)

$(BUILD_DIR)/%.o: kernel/%.c Makefile | $(BUILD_DIR)
	$(CC) $(CFLAGS) -c $< -o $@

$(KERNEL_BIN): $(KERNEL_ELF) | $(BUILD_DIR)
	$(OBJCOPY) -O binary $(KERNEL_ELF) $@

$(STAGE2_BIN): bootloader/stage2.asm $(KERNEL_BIN) | $(BUILD_DIR)
	@KERNEL_SIZE=$$(stat -c%s $(KERNEL_BIN)); \
	$(NASM) -f bin $(NASMFLAGS) -DKERNEL_SIZE_BYTES=$$KERNEL_SIZE bootloader/stage2.asm -o $@

$(PAYLOAD_BIN): $(STAGE2_BIN) $(KERNEL_BIN) | $(BUILD_DIR)
	cat $(STAGE2_BIN) $(KERNEL_BIN) > $@

$(BOOT_BIN): bootloader/boot.asm $(PAYLOAD_BIN) | $(BUILD_DIR)
	@TOTAL_SIZE=$$(stat -c%s $(PAYLOAD_BIN)); \
	TOTAL_SECTORS=$$(( (TOTAL_SIZE + 511) / 512 )); \
	$(NASM) -f bin $(NASMFLAGS) -DTOTAL_SECTORS=$$TOTAL_SECTORS bootloader/boot.asm -o $@

$(OS_IMAGE): $(BOOT_BIN) $(PAYLOAD_BIN)
	cat $(BOOT_BIN) $(PAYLOAD_BIN) > $@
	@SIZE=$$(stat -c%s $(PAYLOAD_BIN)); \
	SECTORS=$$(( (SIZE + 511) / 512 )); \
	PADDING=$$(( SECTORS * 512 - SIZE )); \
	if [ $$PADDING -gt 0 ]; then \
		dd if=/dev/zero bs=1 count=$$PADDING >> $@ 2>/dev/null; \
	fi
	# Pad the image with 32MB of empty space
	dd if=/dev/zero bs=1M count=32 >> $@ 2>/dev/null

clean:
	rm -rf $(BUILD_DIR)

run: check-conflicts $(OS_IMAGE)
	$(QEMU) $(if $(HEADLESS),-display none -serial mon:stdio,) \
		$(QEMU_AUDIO) \
		-drive format=raw,file=$(OS_IMAGE)

-include $(DEPS)