# AsterOS build systém

ARCH := x86_64
# Prefer dedicated cross toolchain, fallback to host toolchain when unavailable.
CROSS ?= $(shell if command -v x86_64-elf-gcc >/dev/null 2>&1; then echo x86_64-elf-; else echo; fi)
CC := $(CROSS)gcc
LD := $(CROSS)ld
OBJCOPY := $(CROSS)objcopy
AS := nasm

CFLAGS := -std=gnu11 -ffreestanding -fno-stack-protector -fno-pic -m64 -Wall -Wextra -Iinclude
LDFLAGS := -nostdlib -T linker.ld

BUILD := build
IMG := $(BUILD)/aster.img
DATA_DISK := asterfs.img
BRIDGE_IF ?= br0

SYSAPP_SRCS := $(wildcard sysapps/*.c)
SYSAPP_OBJS := $(patsubst sysapps/%.c,$(BUILD)/sysapps/%.o,$(SYSAPP_SRCS))
SYSAPP_REGISTRY_SRC := $(BUILD)/kernel/sysapps_registry.c
SYSAPP_REGISTRY_OBJ := $(BUILD)/kernel/sysapps_registry.o

KERNEL_OBJS := \
	$(BUILD)/arch/x86_64/entry.o \
	$(BUILD)/arch/x86_64/gdt.o \
	$(BUILD)/arch/x86_64/idt.o \
	$(BUILD)/arch/x86_64/interrupts.o \
	$(BUILD)/arch/x86_64/cpu.o \
	$(BUILD)/kernel/main.o \
	$(BUILD)/kernel/bootlog.o \
	$(BUILD)/kernel/panic.o \
	$(BUILD)/kernel/printk.o \
	$(BUILD)/kernel/memory.o \
	$(BUILD)/kernel/process.o \
	$(BUILD)/kernel/scheduler.o \
	$(BUILD)/kernel/syscall.o \
	$(BUILD)/kernel/aster_api.o \
	$(BUILD)/kernel/string.o \
	$(BUILD)/drivers/display.o \
	$(BUILD)/drivers/keyboard.o \
	$(BUILD)/drivers/serial.o \
	$(BUILD)/drivers/timer.o \
	$(BUILD)/drivers/storage.o \
	$(BUILD)/apps/calc_app.o \
	$(BUILD)/apps/tetris_app.o \
	$(SYSAPP_REGISTRY_OBJ) \
	$(SYSAPP_OBJS)

all: $(IMG)

$(BUILD):
	mkdir -p $(BUILD)/boot $(BUILD)/kernel $(BUILD)/arch/x86_64 $(BUILD)/drivers $(BUILD)/apps $(BUILD)/sysapps

$(BUILD)/boot/boot.bin: boot/boot.asm | $(BUILD)
	$(AS) -f bin $< -o $@

$(BUILD)/boot/kernel_sectors.inc: $(BUILD)/kernel.bin | $(BUILD)
	mkdir -p $(dir $@)
	@size=$$(wc -c < $(BUILD)/kernel.bin); \
	sectors=$$(( (size + 511) / 512 )); \
	if [ $$sectors -lt 1 ]; then sectors=1; fi; \
	echo "; auto-generated from build/kernel.bin" > $@; \
	echo "KERNEL_SECTORS     equ $$sectors" >> $@

$(BUILD)/boot/stage2.bin: boot/stage2.asm boot/disk.asm $(BUILD)/boot/kernel_sectors.inc | $(BUILD)
	$(AS) -I boot/ -I $(BUILD)/boot/ -f bin $< -o $@

$(BUILD)/arch/x86_64/%.o: arch/x86_64/%.asm | $(BUILD)
	$(AS) -f elf64 $< -o $@

$(BUILD)/arch/x86_64/%.o: arch/x86_64/%.c | $(BUILD)
	$(CC) $(CFLAGS) -c $< -o $@

$(BUILD)/kernel/%.o: kernel/%.c | $(BUILD)
	$(CC) $(CFLAGS) -c $< -o $@

$(BUILD)/drivers/%.o: drivers/%.c | $(BUILD)
	$(CC) $(CFLAGS) -c $< -o $@

$(BUILD)/apps/%.o: apps/%.c | $(BUILD)
	$(CC) $(CFLAGS) -c $< -o $@

$(BUILD)/sysapps/%.o: sysapps/%.c | $(BUILD)
	mkdir -p $(dir $@)
	$(CC) $(CFLAGS) -Dinit=sysapp_init_$* -c $< -o $@

$(SYSAPP_REGISTRY_SRC): $(SYSAPP_SRCS) | $(BUILD)
	mkdir -p $(dir $@)
	@{ \
		echo '#include "sysapps_runtime.h"'; \
		for f in $(SYSAPP_SRCS); do \
			n=$${f##*/}; n=$${n%.c}; \
			echo "extern void sysapp_init_$${n}(void);"; \
		done; \
		echo 'const sysapp_entry_t g_sysapps[] = {'; \
		for f in $(SYSAPP_SRCS); do \
			n=$${f##*/}; n=$${n%.c}; \
			echo "    {\"$${n}\", sysapp_init_$${n}},"; \
		done; \
		echo '    {0, 0}'; \
		echo '};'; \
	} > $@

$(SYSAPP_REGISTRY_OBJ): $(SYSAPP_REGISTRY_SRC)
	$(CC) $(CFLAGS) -c $< -o $@

$(BUILD)/kernel.elf: $(KERNEL_OBJS) linker.ld
	$(LD) $(LDFLAGS) -o $@ $(KERNEL_OBJS)

$(BUILD)/kernel.bin: $(BUILD)/kernel.elf
	$(OBJCOPY) -O binary $< $@

$(IMG): $(BUILD)/boot/boot.bin $(BUILD)/boot/stage2.bin $(BUILD)/kernel.bin
	dd if=/dev/zero of=$(IMG) bs=512 count=2880
	dd if=$(BUILD)/boot/boot.bin of=$(IMG) conv=notrunc
	dd if=$(BUILD)/boot/stage2.bin of=$(IMG) bs=512 seek=1 conv=notrunc
	dd if=$(BUILD)/kernel.bin of=$(IMG) bs=512 seek=17 conv=notrunc

$(DATA_DISK):
	if [ -f $(BUILD)/asterfs.img ] && [ ! -f $(DATA_DISK) ]; then cp $(BUILD)/asterfs.img $(DATA_DISK); fi
	test -f $(DATA_DISK) || dd if=/dev/zero of=$(DATA_DISK) bs=512 count=8192

run: $(IMG) $(DATA_DISK)
	qemu-system-x86_64 -drive format=raw,file=$(IMG),if=ide,index=0 -drive format=raw,file=$(DATA_DISK),if=ide,index=1

clean:
	rm -rf $(BUILD)

.PHONY: all run clean