Makefile

# PromptOS Main Makefile
# ========================

.PHONY: all clean run debug toolchain crosscompiler bootloader kernel userland image \
        check-toolchain check-image-tools iso usb test test-host tests tools

# Configuration
ARCH        := x86_64
TARGET      := $(ARCH)-elf
BUILD_DIR   := build
ISO_DIR     := $(BUILD_DIR)/iso
IMG_FILE    := $(BUILD_DIR)/promptos.img
TOOLCHAIN_DIR ?= toolchain
TOOLCHAIN_BIN := $(TOOLCHAIN_DIR)/bin

# Toolchain (prefer local toolchain, then cross-compiler, then system gcc)
ifeq ($(wildcard $(TOOLCHAIN_BIN)/$(TARGET)-gcc),)
    # Check if cross-compiler is in PATH
    ifneq ($(shell command -v $(TARGET)-gcc 2>/dev/null),)
        CROSS_PREFIX := $(TARGET)-
    else
        # Fallback to system gcc (works for same-arch builds, e.g., x86_64 host → x86_64 target)
        CROSS_PREFIX :=
    endif
else
    CROSS_PREFIX := $(TOOLCHAIN_BIN)/$(TARGET)-
endif
CC          ?= $(CROSS_PREFIX)gcc
LD          ?= $(CROSS_PREFIX)ld
AS          := nasm
OBJCOPY     ?= $(CROSS_PREFIX)objcopy

# Compiler Flags
CFLAGS_COMMON := -std=c17 -ffreestanding -fno-stack-protector \
                 -fno-pic -mno-red-zone -mno-mmx -mno-sse -mno-sse2 \
                 -mcmodel=kernel \
                 -Wall -Wextra -Werror -Wno-unused-parameter

ifdef RELEASE
    CFLAGS_COMMON += -O2 -DNDEBUG
else
    CFLAGS_COMMON += -O0 -g -DDEBUG
endif

# Include paths
INCLUDES := -I$(CURDIR)/kernel/include -I$(CURDIR)/libc/include

# QEMU Configuration
QEMU        := qemu-system-x86_64
OVMF_CODE   := /usr/share/OVMF/OVMF_CODE_4M.fd
OVMF_VARS   := /usr/share/OVMF/OVMF_VARS_4M.fd

# Windows QEMU paths (if on Windows)
ifeq ($(OS),Windows_NT)
    OVMF_CODE := C:/Program Files/qemu/share/OVMF_CODE-pure-efi.fd
    OVMF_VARS := C:/Program Files/qemu/share/OVMF_VARS-pure-efi.fd
    define MKDIR_P
    powershell -Command "New-Item -ItemType Directory -Force -Path '$(1)' | Out-Null"
    endef
    define COPY_FILE
    powershell -Command "if (Test-Path '$(1)') { Copy-Item -Force '$(1)' '$(2)' }"
    endef
else
    MKDIR_P   := mkdir -p
    define COPY_FILE
    cp $(1) $(2)
    endef
endif

QEMU_FLAGS  := -m 512M -smp 4 \
               -drive if=pflash,format=raw,readonly=on,file="$(OVMF_CODE)" \
               -drive format=raw,file=$(IMG_FILE) \
               -serial stdio \
               -no-reboot -no-shutdown

ifdef DEBUG
    QEMU_FLAGS += -s -S
endif

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

all: image

# Create bootable disk image
image: check-toolchain check-image-tools bootloader kernel userland
	@echo "[IMG] Creating GPT disk image..."
	@bash ./scripts/make-image.sh
	@echo "[IMG] Done: $(IMG_FILE)"

# Build bootloader
bootloader: check-toolchain
	@echo "[BOOT] Building UEFI bootloader..."
	@$(MAKE) -C bootloader BUILD_DIR=$(CURDIR)/$(BUILD_DIR)/bootloader

# Build kernel
kernel: check-toolchain
	@echo "[KERN] Building kernel..."
	@$(MAKE) -C kernel BUILD_DIR=$(CURDIR)/$(BUILD_DIR)/kernel \
	    CC="$(CC)" LD="$(LD)" AS="$(AS)" \
	    CFLAGS="$(CFLAGS_COMMON) $(INCLUDES)"

# Build userland
userland: check-toolchain
	@echo "[USER] Building userland..."
	@$(MAKE) -C userland BUILD_DIR=$(CURDIR)/$(BUILD_DIR)/userland \
	    CC="$(CC)" LD="$(LD)" AS="$(AS)"

# Build stress tests
tests: check-toolchain
	@echo "[TEST] Building stress tests..."
	@$(MAKE) -C tests BUILD_DIR=$(CURDIR)/$(BUILD_DIR)/tests \
	    CC="$(CC)" LD="$(LD)"

# Build host development tools
tools:
	@echo "[TOOLS] Building host tools..."
	@$(MAKE) -C tools
	@chmod +x tools/prompt-pkg-config tools/prompt-config 2>/dev/null || true

# Run host unit tests (no QEMU required)
test-host:
	@$(MAKE) -C tests host-tests

# Run all tests
test: test-host tests

# =============================================================================
# Run Targets
# =============================================================================

run: image
	@echo "[QEMU] Starting PromptOS..."
	$(QEMU) $(QEMU_FLAGS)

# Debug with GDB
debug: QEMU_FLAGS += -s -S
debug: image
	@echo "[QEMU] Starting in debug mode (waiting for GDB on :1234)..."
	@echo "Connect with: gdb -ex 'target remote :1234' $(BUILD_DIR)/kernel/kernel.elf"
	$(QEMU) $(QEMU_FLAGS)

# Run with more verbose output
run-verbose: QEMU_FLAGS += -d int,cpu_reset -D qemu.log
run-verbose: run

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

TOOLCHAIN_DIR ?= toolchain
BINUTILS_VER    := 2.41
GCC_VER         := 13.2.0

toolchain:
	@echo "[TOOL] Building cross-compiler toolchain..."
	@mkdir -p $(TOOLCHAIN_DIR)
	@./scripts/build-toolchain.sh $(TOOLCHAIN_DIR) $(TARGET) $(BINUTILS_VER) $(GCC_VER)

crosscompiler: toolchain

# =============================================================================
# Cleanup
# =============================================================================

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

distclean: clean
	@echo "[CLEAN] Removing toolchain..."
	@rm -rf $(TOOLCHAIN_DIR)

# =============================================================================
# Toolchain & Image Checks
# =============================================================================

check-toolchain:
	@command -v $(CC) >/dev/null 2>&1 || command -v gcc >/dev/null 2>&1 || \
	    (echo "[ERR] No C compiler found: $(CC) or gcc. Run 'make toolchain' or install gcc."; exit 1)
	@command -v $(LD) >/dev/null 2>&1 || command -v ld >/dev/null 2>&1 || \
	    (echo "[ERR] No linker found: $(LD) or ld. Run 'make toolchain' or install binutils."; exit 1)
	@command -v $(AS) >/dev/null 2>&1 || (echo "[ERR] Assembler not found: $(AS). Install NASM."; exit 1)
	@# If cross-compiler not found, use system gcc as fallback
	@if ! command -v $(CC) >/dev/null 2>&1; then \
	    echo "[WARN] Cross-compiler $(CC) not found, falling back to system gcc"; \
	fi

check-image-tools:
	@command -v mkfs.fat >/dev/null 2>&1 || (echo "[ERR] mkfs.fat not found. Install dosfstools."; exit 1)
	@command -v mcopy >/dev/null 2>&1 || (echo "[ERR] mcopy not found. Install mtools."; exit 1)
	@command -v mmd >/dev/null 2>&1 || (echo "[ERR] mmd not found. Install mtools."; exit 1)
	@command -v sgdisk >/dev/null 2>&1 || (echo "[ERR] sgdisk not found. Install gdisk."; exit 1)

# =============================================================================
# Release Image Pipeline
# =============================================================================

# Create ISO9660 + UEFI El Torito bootable image
iso: image
	@echo "[ISO] Creating bootable PromptOS ISO..."
	@bash ./scripts/make-iso.sh
	@echo "[ISO] Done: $(BUILD_DIR)/promptos.iso"

# Create bootable USB image
usb: image
	@echo "[USB] Creating bootable USB image..."
	bash scripts/make-usb.sh $(BUILD_DIR)/promptos-usb.img
	@echo "[USB] Done: $(BUILD_DIR)/promptos-usb.img"
	@echo "[USB] Write with: dd if=$(BUILD_DIR)/promptos-usb.img of=/dev/sdX bs=4M status=progress"

# Run clang-format on all source files
format:
	@find . -name '*.c' -o -name '*.h' | xargs clang-format -i

# Check code style
check-style:
	@find . -name '*.c' -o -name '*.h' | xargs clang-format --dry-run -Werror

# Generate documentation
docs:
	@doxygen Doxyfile

# Create tags file
tags:
	@ctags -R kernel libc userland

# Release gate (run ./scripts/release.sh)
release:
	@chmod +x scripts/release.sh 2>/dev/null || true
	@./scripts/release.sh $(VERSION)

# =============================================================================
# Help
# =============================================================================

help:
	@echo "PromptOS Build System"
	@echo "====================="
	@echo ""
	@echo "Usage: make [target] [options]"
	@echo ""
	@echo "Targets:"
	@echo "  all        - Build everything (default)"
	@echo "  bootloader - Build UEFI bootloader"
	@echo "  kernel     - Build kernel"
	@echo "  userland   - Build userland applications"
	@echo "  image      - Create bootable disk image"
	@echo "  run        - Run in QEMU"
	@echo "  debug      - Run in QEMU with GDB"
	@echo "  toolchain  - Build cross-compiler"
	@echo "  test-host  - Run host unit tests (no QEMU required)"
	@echo "  test       - Run all tests"
	@echo "  clean      - Remove build artifacts"
	@echo "  distclean  - Remove everything including toolchain"
	@echo "  iso        - Create ISO9660 image (requires xorriso)"
	@echo "  usb        - Show instructions for USB boot"
	@echo "  release    - Run release gate, create v1.0.0 archive"
	@echo ""
	@echo "Options:"
	@echo "  RELEASE=1  - Build release version"
	@echo "  VERBOSE=1  - Verbose output"
	@echo ""