# UniversalisOS Microkernel — Multi-target Makefile
#
# Usage:
#   make                           (default: QEMU lm3s6965evb)
#   make TARGET=stm32f0            (STM32F0 Nucleo boards)
#   make TARGET=stm32g0            (STM32G0 Nucleo boards)
#   make TARGET=stm32l0            (STM32L0 Nucleo/Discovery)
#   make TARGET=nxp_kl             (NXP Kinetis KL25Z/KL43Z/KL46Z/KW41Z)
#   make TARGET=nxp_lpc            (NXP LPC1114)
#   make TARGET=nuvoton_nano       (Nuvoton NANO130)
#   make run                       (run in QEMU — ARMv6m only)
#   make clean                     (clean build artifacts)

# === Target selection ===
TARGET  ?= lm3s6965evb

# Target → port directory mapping
ifeq ($(TARGET),lm3s6965evb)
  PORT_DIR = ports/armv6m
  CPU      = -mcpu=cortex-m0 -mthumb
  QEMU     = qemu-system-arm
  QEMU_MACH = lm3s6965evb
  QEMU_CPU  = cortex-m3
  QEMU_MEM  = 16K
else ifeq ($(TARGET),stm32f0)
  PORT_DIR = ports/stm32f0
  CPU      = -mcpu=cortex-m0 -mthumb
  QEMU     = qemu-system-arm
  QEMU_MACH = stm32f072b-discovery
  QEMU_CPU  = cortex-m0
  QEMU_MEM  = 16K
else ifeq ($(TARGET),stm32g0)
  PORT_DIR = ports/stm32g0
  CPU      = -mcpu=cortex-m0plus -mthumb
  QEMU     = qemu-system-arm
  QEMU_MACH = stm32g071b-st
  QEMU_CPU  = cortex-m0plus
  QEMU_MEM  = 36K
else ifeq ($(TARGET),stm32l0)
  PORT_DIR = ports/stm32l0
  CPU      = -mcpu=cortex-m0plus -mthumb
  QEMU     = qemu-system-arm
  QEMU_MACH = stm32l073rz
  QEMU_CPU  = cortex-m0plus
  QEMU_MEM  = 20K
else ifeq ($(TARGET),nxp_kl)
  PORT_DIR = ports/nxp_kl
  CPU      = -mcpu=cortex-m0plus -mthumb
  QEMU     = qemu-system-arm
  QEMU_MACH = frdm-kl25z
  QEMU_CPU  = cortex-m0plus
  QEMU_MEM  = 16K
else ifeq ($(TARGET),nxp_lpc)
  PORT_DIR = ports/nxp_lpc
  CPU      = -mcpu=cortex-m0 -mthumb
  QEMU     = qemu-system-arm
  QEMU_MACH = lpc1114
  QEMU_CPU  = cortex-m0
  QEMU_MEM  = 4K
else ifeq ($(TARGET),nuvoton_nano)
  PORT_DIR = ports/nuvoton_nano
  CPU      = -mcpu=cortex-m0 -mthumb
  QEMU     = qemu-system-arm
  QEMU_MACH = numaker-pfm-nano130
  QEMU_CPU  = cortex-m0
  QEMU_MEM  = 16K
else ifeq ($(TARGET),lpc55s69)
  PORT_DIR = ports/lpc55s69
  CPU      = -mcpu=cortex-m33 -mthumb -mfloat-abi=hard
  QEMU     = echo
  QEMU_MACH = mps2-an505
  QEMU_CPU  = cortex-m33
  QEMU_MEM  = 256K
  TIER_CFG  = -DUOS_TIER=2 -DUOS_HAS_TZ=1 -DUOS_HAS_MPU=1
else ifeq ($(TARGET),mps2_m4)
  PORT_DIR = ports/mps2_m4
  CPU      = -mcpu=cortex-m4 -mthumb
  QEMU     = qemu-system-arm
  QEMU_MACH = mps2-an386
  QEMU_CPU  = cortex-m4
  QEMU_MEM  = 512K
  TIER_CFG  = -DUOS_TIER=1 -DUOS_HAS_MPU=1
  CFLAGS_TIER = $(TIER_CFG)
else ifeq ($(TARGET),nordic_nrf51)
  PORT_DIR = ports/nordic_nrf51
  CPU      = -mcpu=cortex-m0 -mthumb
  QEMU     = qemu-system-arm
  QEMU_MACH = microbit
  QEMU_CPU  = cortex-m0
  QEMU_MEM  = 16K
else ifeq ($(TARGET),silabs_efm32)
  PORT_DIR = ports/silabs_efm32
  CPU      = -mcpu=cortex-m3 -mthumb
  QEMU     = qemu-system-arm
  QEMU_MACH = lm3s811evb
  QEMU_CPU  = cortex-m3
  QEMU_MEM  = 32K
else ifeq ($(TARGET),ambiq_apollo)
  PORT_DIR = ports/ambiq_apollo
  CPU      = -mcpu=cortex-m4 -mthumb -mfpu=fpv4-sp-d16 -mfloat-abi=hard
  QEMU     = qemu-system-arm
  QEMU_MACH = ast1030-evb
  QEMU_CPU  = cortex-m4
  QEMU_MEM  = 256K
else ifeq ($(TARGET),esp32)
  XTENSA_ROOT = $(HOME)/.espressif/tools/xtensa-esp-elf/esp-14.2.0_20260121/xtensa-esp-elf
  PORT_DIR = ports/esp32
  override CC = $(XTENSA_ROOT)/bin/xtensa-esp32-elf-gcc
  override AS = $(XTENSA_ROOT)/bin/xtensa-esp32-elf-as
  override LD = $(XTENSA_ROOT)/bin/xtensa-esp32-elf-ld
  override OBJCOPY = $(XTENSA_ROOT)/bin/xtensa-esp32-elf-objcopy
  override SIZE = $(XTENSA_ROOT)/bin/xtensa-esp32-elf-size
  CPU      = -mlongcalls -mtext-section-literals -mabi=call0
  CFLAGS   = $(TIER_CFG) $(CPU) -Iinclude -Iports/esp32 -Iports/common -DUOS_GDBSTUB=1
  LDFLAGS  = -T ports/esp32/linker.ld
  QEMU     = echo
  QEMU_MACH = esp32
  QEMU_CPU  = esp32
else ifeq ($(TARGET),esp32s3)
  XTENSA_ROOT = $(HOME)/.espressif/tools/xtensa-esp-elf/esp-14.2.0_20260121/xtensa-esp-elf
  PORT_DIR = ports/esp32
  override CC = $(XTENSA_ROOT)/bin/xtensa-esp32s3-elf-gcc
  override AS = $(XTENSA_ROOT)/bin/xtensa-esp32s3-elf-as
  override LD = $(XTENSA_ROOT)/bin/xtensa-esp32s3-elf-ld
  override OBJCOPY = $(XTENSA_ROOT)/bin/xtensa-esp32s3-elf-objcopy
  override SIZE = $(XTENSA_ROOT)/bin/xtensa-esp32s3-elf-size
  CPU      = -mlongcalls -mtext-section-literals -mabi=call0
  CFLAGS   = $(TIER_CFG) $(CPU) -Iinclude -Iports/esp32 -Iports/common -DUOS_GDBSTUB=1
  LDFLAGS  = -T ports/esp32/linker_s3.ld
  QEMU     = echo
  QEMU_MACH = esp32s3
  QEMU_CPU  = esp32s3

else ifeq ($(TARGET),esp32idf)
  XTENSA_ROOT = $(HOME)/.espressif/tools/xtensa-esp-elf/esp-14.2.0_20260121/xtensa-esp-elf
  PORT_DIR = ports/esp32
  override CC = $(XTENSA_ROOT)/bin/xtensa-esp32-elf-gcc
  override AS = $(XTENSA_ROOT)/bin/xtensa-esp32-elf-as
  override LD = $(XTENSA_ROOT)/bin/xtensa-esp32-elf-ld
  override OBJCOPY = $(XTENSA_ROOT)/bin/xtensa-esp32-elf-objcopy
  override SIZE = $(XTENSA_ROOT)/bin/xtensa-esp32-elf-size
  CPU      = -mlongcalls -mtext-section-literals -mabi=call0
  CFLAGS   = $(TIER_CFG) $(CPU) -Iinclude -Iports/esp32 -Iports/common -DUOS_GDBSTUB=1 -DUOS_FLASH_XIP=1 -DUOS_GDBSTUB=1 -DUOS_SYSTEM_CLOCK=80000000
  LDFLAGS  = -T ports/esp32/linker_idf.ld -N
  QEMU     = qemu-system-xtensa
  QEMU_MACH = esp32
  QEMU_CPU  = esp32

else ifeq ($(TARGET),esp32hw)
  XTENSA_ROOT = $(HOME)/.espressif/tools/xtensa-esp-elf/esp-14.2.0_20260121/xtensa-esp-elf
  PORT_DIR = ports/esp32
  override CC = $(XTENSA_ROOT)/bin/xtensa-esp32-elf-gcc
  override AS = $(XTENSA_ROOT)/bin/xtensa-esp32-elf-as
  override LD = $(XTENSA_ROOT)/bin/xtensa-esp32-elf-ld
  override OBJCOPY = $(XTENSA_ROOT)/bin/xtensa-esp32-elf-objcopy
  override SIZE = $(XTENSA_ROOT)/bin/xtensa-esp32-elf-size
  CPU      = -mlongcalls -mtext-section-literals -mabi=call0
  HAL_ROOT  = $(CURDIR)/../hal/espressif/components
  CFLAGS   = $(TIER_CFG) $(CPU) -Iinclude -Iports/esp32 -Iports/common -DUOS_GDBSTUB=1 \
             -I$(CURDIR)/../hal/espressif \
             -I$(HAL_ROOT)/hal/esp32/include \
             -I$(HAL_ROOT)/hal/include \
             -I$(HAL_ROOT)/hal/platform_port/include \
             -I$(HAL_ROOT)/esp_hal_uart/esp32/include \
             -I$(HAL_ROOT)/esp_hal_uart/include \
             -I$(HAL_ROOT)/esp_hal_wdt/esp32/include \
             -I$(HAL_ROOT)/soc/esp32/include \
             -I$(HAL_ROOT)/soc/esp32/register \
             -I$(HAL_ROOT)/xtensa/esp32/include \
             -I$(HAL_ROOT)/xtensa/include \
             -I$(HAL_ROOT)/esp_common/include \
             -I$(HAL_ROOT)/esp_rom/esp32 \
             -DUOS_SYSTEM_CLOCK=80000000 -DUOS_FLASH_XIP=1 -DUOS_GDBSTUB=1
  LDFLAGS  = -T ports/esp32/linker_flash.ld -N
  QEMU     = qemu-system-xtensa
  QEMU_MACH = esp32
  QEMU_CPU  = esp32

else
  $(error Unknown target: $(TARGET). Valid: lm3s6965evb stm32f0 stm32g0 stm32l0 nxp_kl nxp_lpc nuvoton_nano)
endif

# === Build configuration ===
CC      = arm-none-eabi-gcc
AS      = arm-none-eabi-gcc
LD      = arm-none-eabi-gcc
OBJCOPY = arm-none-eabi-objcopy
SIZE     ?= arm-none-eabi-size

INCLUDES = -Iinclude -I$(PORT_DIR) -Iports/common
TIER_CFG ?=
ifeq ($(filter esp32 esp32s3 esp32hw esp32idf,$(TARGET)),)
CFLAGS   = $(TIER_CFG) $(CPU) -std=c99 -Os -Wall -Wextra -Werror \
           -ffreestanding -fno-builtin -fno-exceptions \
           -ffunction-sections -fdata-sections $(INCLUDES)
endif
ASFLAGS  = -mabi=call0 $(INCLUDES)

LIBGCC   = $(shell $(CC) $(CPU) -print-libgcc-file-name)
ifeq ($(filter esp32 esp32s3 esp32hw esp32idf,$(TARGET)),)
  LDFLAGS = $(CPU) -nostartfiles -Wl,--gc-sections -T $(PORT_DIR)/linker.ld
endif

BUILD_DIR = build/$(TARGET)

# === Source files ===
CORE_DIR  = src/core
PERSONALITY_DIR = src/personality
TEST_DIR  = test

# Architecture directory: PikeOS-style, one dir per ISA
ifeq ($(filter esp32 esp32s3 esp32hw esp32idf,$(TARGET)),)
  ARCH_DIR  = arch/arm
else
  ARCH_DIR  = arch/xtensa
endif

CORE_SRC  = $(wildcard $(CORE_DIR)/*.c)
PERSONALITY_SRC = $(wildcard $(PERSONALITY_DIR)/*.c)
PORT_SRC  = $(wildcard $(PORT_DIR)/*.c)
PORT_ASM  = $(wildcard $(PORT_DIR)/*.S)
ARCH_SRC  = $(wildcard $(ARCH_DIR)/src/*.c)
ARCH_ASM  = $(wildcard $(ARCH_DIR)/src/*.S)
TEST_SRC  = test/test_uos_esp32.c

CORE_OBJ  = $(patsubst $(CORE_DIR)/%.c,$(BUILD_DIR)/core/%.o,$(CORE_SRC))
PERSONALITY_OBJ = $(patsubst $(PERSONALITY_DIR)/%.c,$(BUILD_DIR)/pers/%.o,$(PERSONALITY_SRC))
PORT_OBJ  = $(patsubst $(PORT_DIR)/%.c,$(BUILD_DIR)/port/%.o,$(PORT_SRC))
PORT_AOBJ = $(patsubst $(PORT_DIR)/%.S,$(BUILD_DIR)/port/%.o,$(PORT_ASM))
ARCH_OBJ  = $(patsubst $(ARCH_DIR)/src/%.c,$(BUILD_DIR)/arch/%.o,$(ARCH_SRC))
ARCH_AOBJ = $(patsubst $(ARCH_DIR)/src/%.S,$(BUILD_DIR)/arch/%.o,$(ARCH_ASM))
TEST_OBJ  = $(patsubst $(TEST_DIR)/%.c,$(BUILD_DIR)/test/%.o,$(TEST_SRC))

OBJS      = $(CORE_OBJ) $(PERSONALITY_OBJ) $(PORT_OBJ) $(PORT_AOBJ) $(ARCH_OBJ) $(ARCH_AOBJ) $(TEST_OBJ)
TARGET_ELF = $(BUILD_DIR)/universalisos.elf
TARGET_BIN = $(BUILD_DIR)/universalisos.bin

# === Rules ===
.PHONY: all clean run size

all: $(TARGET_ELF) size

$(TARGET_ELF): $(OBJS)
	$(LD) $(LDFLAGS) $(OBJS) $(LIBGCC) -o $@
	$(OBJCOPY) -O binary $@ $(TARGET_BIN)

$(BUILD_DIR)/core/%.o: $(CORE_DIR)/%.c
	@mkdir -p $(dir $@)
	$(CC) $(CFLAGS) -c $< -o $@

$(BUILD_DIR)/port/%.o: $(PORT_DIR)/%.c
	@mkdir -p $(dir $@)
	$(CC) $(CFLAGS) -c $< -o $@

$(BUILD_DIR)/pers/%.o: $(PERSONALITY_DIR)/%.c
	@mkdir -p $(dir $@)
	$(CC) $(CFLAGS) -c $< -o $@

$(BUILD_DIR)/port/%.o: $(PORT_DIR)/%.S
	@mkdir -p $(dir $@)
	$(CC) $(CFLAGS) -c $< -o $@

$(BUILD_DIR)/arch/%.o: $(ARCH_DIR)/src/%.c
	@mkdir -p $(dir $@)
	$(CC) $(CFLAGS) -c $< -o $@

$(BUILD_DIR)/arch/%.o: $(ARCH_DIR)/src/%.S
	@mkdir -p $(dir $@)
	$(CC) $(CFLAGS) -c $< -o $@

$(BUILD_DIR)/test/%.o: $(TEST_DIR)/%.c
	@mkdir -p $(dir $@)
	$(CC) $(CFLAGS) -c $< -o $@

size: $(TARGET_ELF)
	@$(SIZE) $(TARGET_ELF)

# esp32hw: generate ESP32 flash image (requires esptool --chip esp32)
ifeq ($(TARGET),esp32hw)
flash-hw: $(TARGET_ELF)
	esptool --chip esp32 elf2image --flash-mode dio --flash-size 2MB --flash-freq 40m \
		$(TARGET_ELF) -o $(BUILD_DIR)/uos_hw.bin
	@echo "ESP32 image: $(BUILD_DIR)/uos_hw.bin"
	@echo "Flash: esptool --chip esp32 --port /dev/ttyACM0 --baud 460800 write_flash 0x10000 $(BUILD_DIR)/uos_hw.bin"
endif

# === Debug / GDB ===
GDB      ?= xtensa-esp32-elf-gdb
GDB_BIN   = $(HOME)/.espressif/tools/xtensa-esp-elf-gdb/16.3_20250913/xtensa-esp-elf-gdb/bin/xtensa-esp32-elf-gdb

# QEMU with GDB stub (port 1234, halt at startup)
debug-qemu: $(TARGET_ELF)
	$(QEMU) -M $(QEMU_MACH) -cpu $(QEMU_CPU) -m $(QEMU_MEM) \
		-nographic -s -S -kernel $(TARGET_ELF)

# GDB session against running QEMU stub
debug: $(TARGET_ELF)
	$(GDB_BIN) -ex "target remote :1234" \
		-ex "set confirm off" \
		-ex "file $(TARGET_ELF)" \
		-ex "symbol-file $(TARGET_ELF)" \
		-ex "hb _start" \
		-ex "c" $(TARGET_ELF)

run: $(TARGET_ELF)
	$(QEMU) -M $(QEMU_MACH) -cpu $(QEMU_CPU) -m $(QEMU_MEM) \
		-nographic -kernel $(TARGET_ELF)

clean:
	rm -rf build