Makefile.multiarch

# Vib-OS Multi-Architecture Makefile
# Supports: ARM64, x86_64, x86 (BIOS)

# ============================================================================
# Configuration
# ============================================================================

# Target architecture - can be overridden: make ARCH=x86_64
ARCH ?= arm64

# Directories
ROOT_DIR := $(shell pwd)
BUILD_DIR := $(ROOT_DIR)/build/$(ARCH)
BOOT_DIR := $(ROOT_DIR)/boot
KERNEL_DIR := $(ROOT_DIR)/kernel
DRIVERS_DIR := $(ROOT_DIR)/drivers
LIBC_DIR := $(ROOT_DIR)/libc
USERSPACE_DIR := $(ROOT_DIR)/userspace
RUNTIMES_DIR := $(ROOT_DIR)/runtimes
IMAGE_DIR := $(ROOT_DIR)/image
SYSROOT := $(BUILD_DIR)/sysroot

# Detect host OS
UNAME_S := $(shell uname -s)

# ============================================================================
# Architecture-Specific Configuration
# ============================================================================

ifeq ($(ARCH),arm64)
    CROSS_TARGET := --target=aarch64-unknown-none-elf
    ARCH_CFLAGS := -mcpu=cortex-a72 -mgeneral-regs-only
    QEMU := qemu-system-aarch64
    QEMU_MACHINE := virt,gic-version=3
    QEMU_CPU := max
    LINKER_SCRIPT := $(KERNEL_DIR)/linker.ld
    KERNEL_ENTRY := _start
else ifeq ($(ARCH),x86_64)
    CROSS_TARGET := --target=x86_64-unknown-none-elf
    ARCH_CFLAGS := -mcmodel=kernel -mno-red-zone -mno-mmx -mno-sse -mno-sse2
    QEMU := qemu-system-x86_64
    QEMU_MACHINE := q35
    QEMU_CPU := qemu64
    LINKER_SCRIPT := $(KERNEL_DIR)/linker_x86_64.ld
    KERNEL_ENTRY := _start
else ifeq ($(ARCH),x86)
    CROSS_TARGET := --target=i686-unknown-none-elf
    ARCH_CFLAGS := -m32 -march=i686
    QEMU := qemu-system-i386
    QEMU_MACHINE := pc
    QEMU_CPU := pentium3
    LINKER_SCRIPT := $(KERNEL_DIR)/linker_x86.ld
    KERNEL_ENTRY := _start
else
    $(error Unsupported architecture: $(ARCH). Use arm64, x86_64, or x86)
endif

# ============================================================================
# Toolchain
# ============================================================================

ifeq ($(UNAME_S),Darwin)
    # macOS with Homebrew
    LLVM_PATH ?= /opt/homebrew/opt/llvm/bin
    BREW_PATH ?= /opt/homebrew/bin
    export PATH := $(LLVM_PATH):$(BREW_PATH):$(PATH)
    CC := $(LLVM_PATH)/clang
    AS := $(LLVM_PATH)/clang
    LD := $(BREW_PATH)/ld.lld
    AR := $(LLVM_PATH)/llvm-ar
    OBJCOPY := $(LLVM_PATH)/llvm-objcopy
    OBJDUMP := $(LLVM_PATH)/llvm-objdump
else
    # Linux
    LLVM_PATH ?= /usr/bin
    CC := clang
    AS := clang
    LD := ld.lld
    AR := llvm-ar
    OBJCOPY := llvm-objcopy
    OBJDUMP := llvm-objdump
endif

# ============================================================================
# Compiler Flags
# ============================================================================

CFLAGS_COMMON := -Wall -Wextra -Wno-unused-function -ffreestanding \
                 -fno-stack-protector -fno-pic -O2 -g

CFLAGS_KERNEL := $(CFLAGS_COMMON) $(CROSS_TARGET) $(ARCH_CFLAGS) \
                 -I$(KERNEL_DIR)/include -I$(KERNEL_DIR) \
                 -fno-builtin -nostdlib -nostdinc \
                 -DARCH_$(shell echo $(ARCH) | tr a-z A-Z | tr - _)

ASFLAGS := $(CROSS_TARGET) $(ARCH_CFLAGS) -I$(KERNEL_DIR)/include

LDFLAGS_KERNEL := -nostdlib -static -T $(LINKER_SCRIPT) -e $(KERNEL_ENTRY)

# ============================================================================
# QEMU Configuration
# ============================================================================

QEMU_MEMORY := 4G
QEMU_FLAGS := -M $(QEMU_MACHINE) -cpu $(QEMU_CPU) -m $(QEMU_MEMORY) \
              -nographic -serial mon:stdio

# ============================================================================
# Source Files
# ============================================================================

# Kernel sources (common)
KERNEL_SOURCES_C := $(shell find $(KERNEL_DIR)/core -name '*.c' 2>/dev/null)
KERNEL_SOURCES_C += $(shell find $(KERNEL_DIR)/mm -name '*.c' 2>/dev/null)
KERNEL_SOURCES_C += $(shell find $(KERNEL_DIR)/fs -name '*.c' 2>/dev/null)
KERNEL_SOURCES_C += $(shell find $(KERNEL_DIR)/net -name '*.c' 2>/dev/null)
KERNEL_SOURCES_C += $(shell find $(KERNEL_DIR)/sched -name '*.c' 2>/dev/null)
KERNEL_SOURCES_C += $(shell find $(KERNEL_DIR)/syscall -name '*.c' 2>/dev/null)
KERNEL_SOURCES_C += $(shell find $(KERNEL_DIR)/ipc -name '*.c' 2>/dev/null)
KERNEL_SOURCES_C += $(shell find $(KERNEL_DIR)/lib -name '*.c' 2>/dev/null)
KERNEL_SOURCES_C += $(shell find $(KERNEL_DIR)/loader -name '*.c' 2>/dev/null)
KERNEL_SOURCES_C += $(shell find $(KERNEL_DIR)/gui -name '*.c' 2>/dev/null)
KERNEL_SOURCES_C += $(shell find $(KERNEL_DIR)/media -name '*.c' 2>/dev/null)
KERNEL_SOURCES_C += $(shell find $(KERNEL_DIR)/apps -name '*.c' 2>/dev/null)
KERNEL_SOURCES_C += $(shell find $(KERNEL_DIR)/drivers -name '*.c' 2>/dev/null)
KERNEL_SOURCES_C += $(shell find $(KERNEL_DIR)/sync -name '*.c' 2>/dev/null)
KERNEL_SOURCES_C += $(shell find $(KERNEL_DIR)/sandbox -name '*.c' 2>/dev/null)

# Architecture-specific sources
KERNEL_SOURCES_C += $(shell find $(KERNEL_DIR)/arch/$(ARCH) -name '*.c' 2>/dev/null)
KERNEL_SOURCES_ASM := $(shell find $(KERNEL_DIR)/arch/$(ARCH) -name '*.S' 2>/dev/null)
# Assembly files are now architecture-specific only

# Driver sources (exclude uart for x86_64/x86 as they have arch-specific versions)
DRIVER_SOURCES := $(shell find $(DRIVERS_DIR) -name '*.c' 2>/dev/null)
ifeq ($(ARCH),x86_64)
    DRIVER_SOURCES := $(filter-out $(DRIVERS_DIR)/uart/uart.c,$(DRIVER_SOURCES))
endif
ifeq ($(ARCH),x86)
    DRIVER_SOURCES := $(filter-out $(DRIVERS_DIR)/uart/uart.c,$(DRIVER_SOURCES))
endif

# Object files
KERNEL_OBJECTS := $(patsubst $(KERNEL_DIR)/%.c,$(BUILD_DIR)/kernel/%.o,$(KERNEL_SOURCES_C))
KERNEL_OBJECTS += $(patsubst $(KERNEL_DIR)/%.S,$(BUILD_DIR)/kernel/%.o,$(KERNEL_SOURCES_ASM))
DRIVER_OBJECTS := $(patsubst $(DRIVERS_DIR)/%.c,$(BUILD_DIR)/drivers/%.o,$(DRIVER_SOURCES))

ALL_OBJECTS := $(KERNEL_OBJECTS) $(DRIVER_OBJECTS)
KERNEL_BINARY := $(BUILD_DIR)/kernel/vibos-$(ARCH).elf

# ============================================================================
# Main Targets
# ============================================================================

.PHONY: all clean kernel image qemu qemu-debug help

all: kernel image
	@echo "=========================================="
	@echo "Vib-OS $(ARCH) build complete!"
	@echo "=========================================="
	@echo "Kernel: $(KERNEL_BINARY)"
	@echo "Run 'make qemu' to test in emulator"

help:
	@echo "Vib-OS Multi-Architecture Build System"
	@echo "======================================="
	@echo ""
	@echo "Usage: make [ARCH=<arch>] <target>"
	@echo ""
	@echo "Architectures:"
	@echo "  arm64    - ARM64 (default, Raspberry Pi, Apple Silicon)"
	@echo "  x86_64   - x86-64 (UEFI boot)"
	@echo "  x86      - x86 32-bit (BIOS boot)"
	@echo ""
	@echo "Build targets:"
	@echo "  all      - Build kernel and image"
	@echo "  kernel   - Build kernel only"
	@echo "  image    - Create bootable disk image"
	@echo "  qemu     - Run in QEMU emulator"
	@echo "  clean    - Remove build artifacts"
	@echo ""
	@echo "Examples:"
	@echo "  make ARCH=arm64 all"
	@echo "  make ARCH=x86_64 qemu"
	@echo "  make ARCH=x86 kernel"

# ============================================================================
# Directory Setup
# ============================================================================

$(BUILD_DIR):
	@mkdir -p $(BUILD_DIR)/kernel/core
	@mkdir -p $(BUILD_DIR)/kernel/arch/$(ARCH)
	@mkdir -p $(BUILD_DIR)/kernel/mm
	@mkdir -p $(BUILD_DIR)/kernel/fs
	@mkdir -p $(BUILD_DIR)/kernel/net
	@mkdir -p $(BUILD_DIR)/kernel/sched
	@mkdir -p $(BUILD_DIR)/kernel/syscall
	@mkdir -p $(BUILD_DIR)/kernel/ipc
	@mkdir -p $(BUILD_DIR)/kernel/lib
	@mkdir -p $(BUILD_DIR)/kernel/loader
	@mkdir -p $(BUILD_DIR)/kernel/gui
	@mkdir -p $(BUILD_DIR)/kernel/media
	@mkdir -p $(BUILD_DIR)/kernel/apps
	@mkdir -p $(BUILD_DIR)/kernel/drivers
	@mkdir -p $(BUILD_DIR)/kernel/sync
	@mkdir -p $(BUILD_DIR)/kernel/sandbox
	@mkdir -p $(BUILD_DIR)/drivers
	@mkdir -p $(IMAGE_DIR)

# ============================================================================
# Kernel Build
# ============================================================================

kernel: $(BUILD_DIR) $(KERNEL_BINARY)
	@echo "[KERNEL] $(ARCH) build complete: $(KERNEL_BINARY)"

$(BUILD_DIR)/kernel/%.o: $(KERNEL_DIR)/%.c
	@mkdir -p $(dir $@)
	@echo "[CC] $<"
ifeq ($(ARCH),arm64)
	@# Media files need FP support on ARM64
	@if echo "$<" | grep -q "/media/"; then \
		$(CC) $(CFLAGS_COMMON) $(CROSS_TARGET) -mcpu=cortex-a72 -I$(KERNEL_DIR)/include -I$(KERNEL_DIR) -fno-builtin -nostdlib -nostdinc -DARCH_ARM64 -c $< -o $@; \
	else \
		$(CC) $(CFLAGS_KERNEL) -c $< -o $@; \
	fi
else
	@$(CC) $(CFLAGS_KERNEL) -c $< -o $@
endif

$(BUILD_DIR)/kernel/%.o: $(KERNEL_DIR)/%.S
	@mkdir -p $(dir $@)
	@echo "[AS] $<"
	@$(AS) $(ASFLAGS) -c $< -o $@

$(BUILD_DIR)/drivers/%.o: $(DRIVERS_DIR)/%.c
	@mkdir -p $(dir $@)
	@echo "[CC] $<"
	@$(CC) $(CFLAGS_KERNEL) -c $< -o $@

$(KERNEL_BINARY): $(ALL_OBJECTS)
	@echo "[LD] $@"
	@$(LD) $(LDFLAGS_KERNEL) -o $@ $^
	@if command -v $(OBJDUMP) >/dev/null 2>&1; then \
		$(OBJDUMP) -h $@ > $(BUILD_DIR)/kernel/sections.txt; \
		echo "[INFO] Kernel sections written to $(BUILD_DIR)/kernel/sections.txt"; \
	else \
		echo "[INFO] objdump not found, skipping sections dump"; \
	fi
	@echo "[KERNEL] $(ARCH) build complete: $@"

# ============================================================================
# Boot Image Creation
# ============================================================================

image: kernel
	@echo "[IMAGE] Creating $(ARCH) boot image..."
ifeq ($(ARCH),arm64)
	@./scripts/create-boot-image.sh $(BUILD_DIR) $(IMAGE_DIR)
else ifeq ($(ARCH),x86_64)
	@./scripts/create-uefi-image.sh $(BUILD_DIR) $(IMAGE_DIR)
else ifeq ($(ARCH),x86)
	@./scripts/create-bios-image.sh $(BUILD_DIR) $(IMAGE_DIR)
endif
	@echo "[IMAGE] Created: $(IMAGE_DIR)/vibos-$(ARCH).img"

# ============================================================================
# QEMU Testing
# ============================================================================

qemu: image
	@echo "[QEMU] Starting Vib-OS $(ARCH) in emulator..."
ifeq ($(ARCH),arm64)
	@$(QEMU) $(QEMU_FLAGS) -kernel $(KERNEL_BINARY)
else ifeq ($(ARCH),x86_64)
	@$(QEMU) $(QEMU_FLAGS) -kernel $(KERNEL_BINARY)
else ifeq ($(ARCH),x86)
	@$(QEMU) $(QEMU_FLAGS) -drive format=raw,file=$(IMAGE_DIR)/vibos-$(ARCH).img
endif

qemu-debug: image
	@echo "[QEMU] Starting Vib-OS $(ARCH) with GDB server on port 1234..."
	@$(QEMU) $(QEMU_FLAGS) -kernel $(KERNEL_BINARY) -s -S

# ============================================================================
# Clean
# ============================================================================

clean:
	@echo "[CLEAN] Removing $(ARCH) build artifacts..."
	@rm -rf $(BUILD_DIR)
	@echo "[CLEAN] Done"

clean-all:
	@echo "[CLEAN] Removing all build artifacts..."
	@rm -rf $(ROOT_DIR)/build
	@rm -rf $(IMAGE_DIR)
	@echo "[CLEAN] Done"