# Pactor64 Makefile — x86-64 kernel build system
# Uses GRUB2 as bootloader with multiboot2 protocol

ASM         = nasm
CC          = gcc
LD          = ld

# === Kernel flags ===
ASM_FLAGS   = -f elf64
CC_FLAGS    = -std=gnu11 -ffreestanding -fno-builtin -fno-stack-protector \
              -fno-pic -fno-pie -O2 -Wall -Wextra -mcmodel=kernel \
              -mno-red-zone -mno-sse -mno-sse2 -mgeneral-regs-only \
              -nostdlib -nostdinc -Iinclude
LD_FLAGS    = -T linker.ld -nostdlib -z max-page-size=0x1000

# === Userspace flags ===
UCC_FLAGS   = -std=gnu11 -ffreestanding -fno-builtin -fno-stack-protector \
              -no-pie -O2 -Wall -Wextra -mcmodel=small \
              -mno-sse -mno-sse2 -mgeneral-regs-only \
              -nostdlib -nostdinc -Ilibc
ULD_FLAGS   = -T userspace.ld -nostdlib --allow-multiple-definition -z max-page-size=0x1000

BUILD_DIR   = build
ISO_DIR     = $(BUILD_DIR)/iso
KERNEL_ELF  = $(BUILD_DIR)/pactor64.kernel
ISO_IMAGE   = $(BUILD_DIR)/pactor64.iso
DISK_IMG    = $(BUILD_DIR)/pactor64.disk

# Kernel objects
KERNEL_OBJS = $(BUILD_DIR)/entry.o \
              $(BUILD_DIR)/isr.o \
              $(BUILD_DIR)/main.o \
              $(BUILD_DIR)/idt.o \
              $(BUILD_DIR)/timer.o \
              $(BUILD_DIR)/keyboard.o \
              $(BUILD_DIR)/pmm.o \
              $(BUILD_DIR)/heap.o \
              $(BUILD_DIR)/vga.o \
              $(BUILD_DIR)/shell.o \
              $(BUILD_DIR)/ext2.o \
              $(BUILD_DIR)/ata.o \
              $(BUILD_DIR)/elf.o \
              $(BUILD_DIR)/syscall.o \
              $(BUILD_DIR)/syscall_entry.o

# Userspace
LIBC_OBJS   = $(BUILD_DIR)/start_entry.o $(BUILD_DIR)/libc_start.o
PROG_ELF    = $(BUILD_DIR)/programs/hello.elf

.PHONY: all clean run run-disk debug disk iso programs verify

all: $(ISO_IMAGE)
	@echo "========================================="
	@echo "  Pactor64 ISO built: $(ISO_IMAGE)"
	@echo "  Kernel: $(KERNEL_ELF)"
	@echo "  Programs: $(PROG_ELF)"
	@echo "========================================="

$(ISO_IMAGE): $(KERNEL_ELF) $(PROG_ELF) boot/grub.cfg
	@mkdir -p $(ISO_DIR)/boot/grub $(ISO_DIR)/programs
	@cp $(KERNEL_ELF) $(ISO_DIR)/boot/pactor64.kernel
	@cp boot/grub.cfg $(ISO_DIR)/boot/grub/grub.cfg
	@cp $(PROG_ELF) $(ISO_DIR)/programs/hello.elf 2>/dev/null || true
	@grub-mkrescue -o $@ $(ISO_DIR) 2>/dev/null

# === Kernel linking ===
$(KERNEL_ELF): $(KERNEL_OBJS)
	$(LD) $(LD_FLAGS) $^ -o $@

# === Kernel ASM objects ===
$(BUILD_DIR)/entry.o: kernel/entry.asm | $(BUILD_DIR)
	$(ASM) $(ASM_FLAGS) $< -o $@

$(BUILD_DIR)/isr.o: kernel/isr.asm | $(BUILD_DIR)
	$(ASM) $(ASM_FLAGS) $< -o $@

$(BUILD_DIR)/syscall_entry.o: kernel/syscall_entry.asm | $(BUILD_DIR)
	$(ASM) $(ASM_FLAGS) $< -o $@

# === Kernel C objects ===
$(BUILD_DIR)/main.o: kernel/main.c include/pactor64.h | $(BUILD_DIR)
	$(CC) $(CC_FLAGS) -c $< -o $@

$(BUILD_DIR)/idt.o: kernel/idt.c include/pactor64.h | $(BUILD_DIR)
	$(CC) $(CC_FLAGS) -c $< -o $@

$(BUILD_DIR)/timer.o: kernel/timer.c include/pactor64.h | $(BUILD_DIR)
	$(CC) $(CC_FLAGS) -c $< -o $@

$(BUILD_DIR)/keyboard.o: kernel/keyboard.c include/pactor64.h | $(BUILD_DIR)
	$(CC) $(CC_FLAGS) -c $< -o $@

$(BUILD_DIR)/pmm.o: kernel/pmm.c include/pactor64.h | $(BUILD_DIR)
	$(CC) $(CC_FLAGS) -c $< -o $@

$(BUILD_DIR)/heap.o: kernel/heap.c include/pactor64.h | $(BUILD_DIR)
	$(CC) $(CC_FLAGS) -c $< -o $@

$(BUILD_DIR)/vga.o: kernel/vga.c include/pactor64.h | $(BUILD_DIR)
	$(CC) $(CC_FLAGS) -c $< -o $@

$(BUILD_DIR)/shell.o: kernel/shell.c include/pactor64.h kernel/ata.h kernel/ext2.h kernel/elf.h kernel/hello_elf.h | $(BUILD_DIR)
	$(CC) $(CC_FLAGS) -c $< -o $@

$(BUILD_DIR)/ata.o: kernel/ata.c kernel/ata.h include/pactor64.h | $(BUILD_DIR)
	$(CC) $(CC_FLAGS) -c $< -o $@

$(BUILD_DIR)/ext2.o: kernel/ext2.c kernel/ext2.h kernel/ata.h include/pactor64.h | $(BUILD_DIR)
	$(CC) $(CC_FLAGS) -c $< -o $@

$(BUILD_DIR)/elf.o: kernel/elf.c kernel/elf.h include/pactor64.h | $(BUILD_DIR)
	$(CC) $(CC_FLAGS) -c $< -o $@

$(BUILD_DIR)/syscall.o: kernel/syscall.c kernel/syscall.h include/pactor64.h | $(BUILD_DIR)
	$(CC) $(CC_FLAGS) -c $< -o $@

# === Userspace libc ===
$(BUILD_DIR)/start_entry.o: /tmp/start_entry.asm | $(BUILD_DIR)
	$(ASM) $(ASM_FLAGS) $< -o $@

$(BUILD_DIR)/libc_start.o: libc/start.c libc/libc.h | $(BUILD_DIR)
	$(CC) $(UCC_FLAGS) -c $< -o $@

# === Userspace programs ===
programs: $(PROG_ELF)

$(BUILD_DIR)/programs/hello.elf: $(BUILD_DIR)/programs/hello.o $(LIBC_OBJS) userspace.ld
	@mkdir -p $(BUILD_DIR)/programs
	$(LD) $(ULD_FLAGS) $(BUILD_DIR)/programs/hello.o $(LIBC_OBJS) -o $@

$(BUILD_DIR)/programs/hello.o: programs/hello.c libc/libc.h | $(BUILD_DIR)/programs
	$(CC) $(UCC_FLAGS) -c $< -o $@

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

$(BUILD_DIR):
	@mkdir -p $@

clean:
	rm -rf $(BUILD_DIR)

run: $(ISO_IMAGE)
	qemu-system-x86_64 -cdrom $(ISO_IMAGE) -m 512 \
		-serial mon:stdio -display none -no-reboot

debug: $(ISO_IMAGE)
	qemu-system-x86_64 -cdrom $(ISO_IMAGE) -m 512 \
		-serial mon:stdio -display none -no-reboot -s -S

# === Disk image ===
disk: $(KERNEL_ELF) $(PROG_ELF)
	@bash scripts/mkdisk.sh

# === Boot from disk image ===
run-disk: disk
	qemu-system-x86_64 -drive file=$(DISK_IMG),format=raw,if=ide -m 512 \
		-serial mon:stdio -display none -no-reboot

run-disk-gui: disk
	qemu-system-x86_64 -drive file=$(DISK_IMG),format=raw,if=ide -m 512 \
		-serial mon:stdio -no-reboot

verify: $(KERNEL_ELF)
	@grub-file --is-x86-multiboot2 $(KERNEL_ELF) && echo "VALID multiboot2" || echo "INVALID"