Makefile

# ==============================================================================
# PyramidOS Master Makefile (Restructured)
# ==============================================================================

# --- Toolchain Configuration ---
CC = i686-elf-gcc
LD = i686-elf-ld
OBJCOPY = i686-elf-objcopy

# Fallback to native GCC with 32-bit flags if cross-compiler is missing
ifeq ($(shell which $(CC) 2>/dev/null),)
    CC = gcc
    LD = ld
    OBJCOPY = objcopy
    CFLAGS_EXTRA = -m32
    LDFLAGS_EXTRA = -melf_i386
endif

ASM = nasm

# --- Directories ---
BUILD_DIR = build
BOOT_DIR = boot/src/legacy
KERNEL_DIR = kernel

# Subdirectories for Source
ARCH_DIR    = $(KERNEL_DIR)/arch/i386
CORE_DIR    = $(KERNEL_DIR)/core
DRIVERS_DIR = $(KERNEL_DIR)/drivers
LIB_DIR     = $(KERNEL_DIR)/lib
FS_DIR      = $(KERNEL_DIR)/fs

# Define include paths for all modules to find headers
INCLUDES = -I$(KERNEL_DIR) \
           -I$(ARCH_DIR) \
           -I$(CORE_DIR) \
           -I$(DRIVERS_DIR) \
           -I$(LIB_DIR)

# --- Targets ---
KERNEL_ELF = $(BUILD_DIR)/kernel.elf
KERNEL_BIN = $(BUILD_DIR)/kernel.bin
KERNEL_HDR = $(BUILD_DIR)/kernel.hdr
KERNEL_IMG = $(BUILD_DIR)/kernel.img
STAGE1_BIN = $(BUILD_DIR)/stage1.bin
STAGE2_BIN = $(BUILD_DIR)/stage2.bin
DISK_IMG   = $(BUILD_DIR)/pyramidos.img
KERNEL_MAP = $(BUILD_DIR)/kernel.map

# Stage 2 grew to include an Arabic-capable bitmap font + shaping tables.
# Keep it well below the kernel placement at LBA 60.
STAGE2_SECTORS ?= 32

# --- Build Profile ---
# BUILD=release (default) or BUILD=debug
BUILD ?= release
# STRICT=1 enables -Werror (opt-in until the codebase is fully warning-clean)
STRICT ?= 0

# --- Flags ---
CFLAGS_COMMON = $(CFLAGS_EXTRA) \
	-ffreestanding \
	-std=gnu11 \
	-Wall -Wextra \
	-fno-pie -fno-pic \
	-fno-stack-protector \
	-fno-builtin \
	$(INCLUDES)

CFLAGS_release = -O2
CFLAGS_debug   = -O0 -g3 -ggdb -DDEBUG -fno-omit-frame-pointer

CFLAGS = $(CFLAGS_COMMON) $(CFLAGS_$(BUILD))

ifeq ($(STRICT),1)
	CFLAGS += -Werror
endif

NASMFLAGS = -f elf32
ifeq ($(BUILD),debug)
	NASMFLAGS += -g -F dwarf
endif

LDFLAGS = $(LDFLAGS_EXTRA) -T $(ARCH_DIR)/linker.ld -Map $(KERNEL_MAP)

# ==============================================================================
# Build Rules
# ==============================================================================

.PHONY: all clean run debug release

all: $(DISK_IMG)

debug: BUILD=debug
debug: $(DISK_IMG)

release: BUILD=release
release: $(DISK_IMG)

# Ensure build directory exists
$(BUILD_DIR):
	@mkdir -p $@

# --- Source Discovery (VPATH) ---
# Tell Make to look for .c and .asm files in these directories
vpath %.c $(CORE_DIR) $(DRIVERS_DIR) $(LIB_DIR) $(FS_DIR) $(ARCH_DIR)
vpath %.asm $(ARCH_DIR)

# --- Compile C Sources ---
$(BUILD_DIR)/%.o: %.c | $(BUILD_DIR)
	$(CC) $(CFLAGS) -c $< -o $@

# --- Compile ASM Sources ---
$(BUILD_DIR)/%.o: %.asm | $(BUILD_DIR)
	$(ASM) $(NASMFLAGS) $< -o $@

# --- Special ASM rules for Bootloader ---
$(STAGE1_BIN): $(BOOT_DIR)/stage1.asm | $(BUILD_DIR)
	$(ASM) -f bin -D STAGE2_SECTOR_COUNT=$(STAGE2_SECTORS) $< -o $@

$(STAGE2_BIN): $(BOOT_DIR)/stage2.asm | $(BUILD_DIR)
	$(ASM) -f bin -I$(BOOT_DIR)/ -D STAGE2_SECTOR_COUNT=$(STAGE2_SECTORS) $< -o $@

# --- Link Kernel ---
# Note: entry.o MUST be first
OBJECTS = $(BUILD_DIR)/entry.o \
          $(BUILD_DIR)/main.o \
          $(BUILD_DIR)/string.o \
          $(BUILD_DIR)/pmm.o \
          $(BUILD_DIR)/idt.o \
          $(BUILD_DIR)/idt_asm.o \
          $(BUILD_DIR)/vmm.o \
          $(BUILD_DIR)/pic.o \
          $(BUILD_DIR)/keyboard.o \
          $(BUILD_DIR)/terminal.o \
          $(BUILD_DIR)/shell.o \
          $(BUILD_DIR)/selftest.o \
          $(BUILD_DIR)/debug.o \
          $(BUILD_DIR)/timer.o \
          $(BUILD_DIR)/rtc.o \
          $(BUILD_DIR)/heap.o \
          $(BUILD_DIR)/ata.o \
          $(BUILD_DIR)/block.o \
          $(BUILD_DIR)/ata_block.o \
          $(BUILD_DIR)/mbr.o \
          $(BUILD_DIR)/vfs.o \
          $(BUILD_DIR)/nullfs.o \
          $(BUILD_DIR)/devfs.o \
          $(BUILD_DIR)/pyfs.o

$(KERNEL_BIN): $(OBJECTS)
	$(LD) $(LDFLAGS) -o $(KERNEL_ELF) $^
	$(OBJCOPY) -O binary $(KERNEL_ELF) $@

# 5. Generate Header (Calculates size dynamically)
$(KERNEL_HDR): $(KERNEL_BIN)
	@SIZE=$$(stat -c%s $(KERNEL_BIN) 2>/dev/null || stat -f%z $(KERNEL_BIN)); \
	CHECKSUM=$$(python3 -c "import sys; print(sum(open(sys.argv[1],'rb').read()) & 0xffffffff)" "$(KERNEL_BIN)" 2>/dev/null || \
	          python  -c "import sys; print(sum(open(sys.argv[1],'rb').read()) & 0xffffffff)" "$(KERNEL_BIN)" 2>/dev/null || \
	          echo 0); \
	echo "Kernel Size: $$SIZE bytes"; \
	echo "Kernel Checksum: $$CHECKSUM"; \
	$(ASM) -f bin $(ARCH_DIR)/header.asm -o $@ -D KERNEL_SIZE=$$SIZE -D KERNEL_CHECKSUM=$$CHECKSUM

# 6. Create Final Kernel Image (Header + Binary)
$(KERNEL_IMG): $(KERNEL_HDR) $(KERNEL_BIN)
	cat $^ > $@

# --- Disk Image Construction ---

$(DISK_IMG): $(STAGE1_BIN) $(STAGE2_BIN) $(KERNEL_IMG)
	@echo "--- Assembling Disk Image ---"
	# 1. Create blank 1.44MB image (2880 sectors * 512 bytes)
	dd if=/dev/zero of=$@ bs=512 count=2880 status=none
	
	# 2. Write Stage 1 (Sector 0)
	dd if=$(STAGE1_BIN) of=$@ bs=512 count=1 conv=notrunc status=none
	
	# 3. Write Stage 2 (Sector 1)
	dd if=$(STAGE2_BIN) of=$@ bs=512 seek=1 conv=notrunc status=none
	
	# 4. Write Kernel (Sector 60)
	dd if=$(KERNEL_IMG) of=$@ bs=512 seek=60 conv=notrunc status=none
	
	@echo "Build Complete: $@"

# --- Utilities ---

clean:
	rm -rf $(BUILD_DIR)

run: $(DISK_IMG)
	qemu-system-i386 -drive format=raw,file=$(DISK_IMG)