HOST ?= $(shell uname -s | tr '[:upper:]' '[:lower:]')
ARCH ?= ##DEFAULT_ARCH##
MODE ?= debug
SMP ?= 4

QEMU ?= ##QEMU##
GDB ?= ##GDB##
FDISK ?= ##FDISK##

IMG ?= ##IMAGE##

COMMA := ,

PROFILE = $(MODE)
ifeq ($(MODE),debug)
PROFILE := dev
endif

USER_PROGRAMS = $(shell find user-programs -type f)
KERNEL_SOURCES := $(shell find src macros crates -name '*.rs' -type f)
KERNEL_CARGO_MANIFESTS += $(shell find src macros crates -name Cargo.toml -type f)
KERNEL_DEPS := $(KERNEL_SOURCES) $(KERNEL_CARGO_MANIFESTS)

QEMU_ARGS ?= -no-reboot
CARGO_FLAGS := --profile $(PROFILE)

ifneq ($(SMP),)
CARGO_FLAGS += --features smp
endif

ifneq ($(FEATURES),)
CARGO_FLAGS += --features $(FEATURES)
endif

ifeq ($(HOST),darwin)
QEMU_ACCEL ?= -accel tcg
else ifeq ($(HOST),linux)

ifeq ($(shell ls /dev/kvm),/dev/kvm)
QEMU_ACCEL ?= -accel kvm
endif

endif

QEMU_ARGS += $(QEMU_ACCEL)

ifneq ($(DEBUG_TRAPS),)
QEMU_ARGS += -d cpu_reset,int,guest_errors -D build/qemu.log
endif

ifneq ($(SMP),)
QEMU_ARGS += -smp $(SMP)
endif

ifeq ($(ARCH),riscv64)

BINARY_DIR_BASE := build/riscv64gc-unknown-none-elf
BINARY_DIR := $(BINARY_DIR_BASE)/$(MODE)

QEMU_ARGS += \
	-machine virt -kernel $(BINARY_DIR)/eonix_kernel \
	-device virtio-blk-device,drive=disk0,bus=virtio-mmio-bus.0 \
	-device virtio-net-device,netdev=mynet0 \
	-drive id=disk0,file=build/boot-riscv64.img,format=raw,if=none \
	-netdev user,id=mynet0 \
	-rtc base=utc

ifneq ($(IMG),)
QEMU_ARGS += \
	-drive id=disk1,file=$(IMG),format=raw,if=none \
	-device virtio-blk-device,drive=disk1,bus=virtio-mmio-bus.1
endif

CARGO_FLAGS += --target riscv64gc-unknown-none-elf

.PHONY: build
build: $(BINARY_DIR)/eonix_kernel build/boot-riscv64.img

else ifeq ($(ARCH),loongarch64)

BINARY_DIR_BASE := build/loongarch64-unknown-none-softfloat
BINARY_DIR := $(BINARY_DIR_BASE)/$(MODE)

QEMU_ARGS += \
	-machine virt -kernel $(BINARY_DIR)/eonix_kernel -m 1G \
	-device virtio-blk-pci,drive=disk0 \
	-device virtio-net-pci,netdev=mynet0 \
	-drive id=disk0,file=build/boot-loongarch64.img,format=raw,if=none \
	-netdev user,id=mynet0,hostfwd=tcp::5555-:5555,hostfwd=udp::5555-:5555 \
	-rtc base=utc

ifneq ($(IMG),)
QEMU_ARGS += \
	-drive id=disk1,file=$(IMG),format=raw,if=none \
	-device virtio-blk-pci,drive=disk1
endif

CARGO_FLAGS += --target loongarch64-unknown-none-softfloat

.PHONY: build
build: $(BINARY_DIR)/eonix_kernel build/boot-loongarch64.img

else ifeq ($(ARCH),x86_64)

BINARY_DIR_BASE := build/x86_64-unknown-none
BINARY_DIR := $(BINARY_DIR_BASE)/$(MODE)

QEMU_ARGS += \
	-machine q35 \
	-device ahci,id=ahci \
	-device ide-hd,drive=disk0,bus=ahci.0 \
	-device e1000e,netdev=mynet0 \
	-drive id=disk0,file=build/boot-x86_64.img,format=raw,if=none \
	-netdev user,id=mynet0

ifneq ($(IMG),)
QEMU_ARGS += \
	-drive id=disk1,file=$(IMG),format=raw,if=none \
	-device ide-hd,drive=disk1,bus=ahci.1
endif

CARGO_FLAGS += --target x86_64-unknown-none.json

.PHONY: build
build: $(BINARY_DIR)/eonix_kernel build/boot-x86_64.img

endif

.PHONY: run
run: build build/kernel.sym
	$(QEMU) $(QEMU_ARGS) -display none -serial mon:stdio

.PHONY: srun
srun: build build/kernel.sym
	$(QEMU) $(QEMU_ARGS) -display none -S -s -serial mon:stdio

.PHONY: test-run
test-run: build
	$(QEMU) $(QEMU_ARGS) -display none -serial stdio

.PHONY: clean
clean:
	-rm -rf build
	-mkdir build

.PHONY: clean-all
clean-all: clean
	-rm Makefile

.PHONY: debug
debug: build/kernel.sym
	-RUST_GDB=$(GDB) rust-gdb --symbols=build/kernel.sym \
		-iex 'source pretty-print.py' \
		-iex 'set pagination off' \
		-iex 'set output-radix 16' \
		-iex 'set print asm-demangle on' \
		-iex 'set print pretty on' \
		-iex 'target remote:1234'
	-killall $(QEMU)

.PHONY: tmux-debug
tmux-debug:
	tmux new-session -s gbos-debug -d
	-tmux split-window -t gbos-debug -hf
	-tmux send-keys -t gbos-debug:1.1 'make srun' C-m
	-tmux send-keys -t gbos-debug:1.2 'make debug' C-m C-m
	-tmux attach -t gbos-debug
	tmux kill-session -t gbos-debug

$(BINARY_DIR)/eonix_kernel: $(KERNEL_DEPS)
	CARGO_TARGET_DIR=build cargo build $(CARGO_FLAGS)

build/kernel.sym: $(BINARY_DIR)/eonix_kernel
	CARGO_TARGET_DIR=build cargo objcopy -q $(CARGO_FLAGS) -- --only-keep-debug build/kernel.sym

build/fs-%.img: user-programs/init_script_%.sh script/build-img.sh $(USER_PROGRAMS)
	ARCH=$* OUTPUT=$@ sh script/build-img.sh

build/mbr.bin: $(BINARY_DIR)/eonix_kernel
	CARGO_TARGET_DIR=build cargo objcopy -q $(CARGO_FLAGS) -- -O binary -j .mbr build/mbr.bin

build/stage1.bin: $(BINARY_DIR)/eonix_kernel
	CARGO_TARGET_DIR=build cargo objcopy -q $(CARGO_FLAGS) -- -O binary -j .stage1 build/stage1.bin

build/kernel.bin: $(BINARY_DIR)/eonix_kernel
	CARGO_TARGET_DIR=build cargo objcopy -q $(CARGO_FLAGS) -- -O binary --strip-debug \
		-R .mbr -R .stage1 build/kernel.bin

build/boot-x86_64.img: build/fs-x86_64.img build/mbr.bin build/stage1.bin build/kernel.bin
	dd if=build/mbr.bin of=$@ bs=512 count=1 conv=notrunc 2> /dev/null
	dd if=build/stage1.bin of=$@ bs=512 seek=1 conv=notrunc 2> /dev/null
	dd if=build/kernel.bin of=$@ bs=4096 seek=1 conv=notrunc 2> /dev/null
	dd if=$< of=$@ bs=$(shell expr 4 \* 1024 \* 1024) \
		seek=1 conv=notrunc 2> /dev/null
	sh -c 'echo n; echo; echo; echo 8192; echo; echo a; echo w' \
		| $(FDISK) $@ 2> /dev/null > /dev/null

build/boot-riscv64.img: build/fs-riscv64.img
	dd if=$< of=$@ bs=$(shell expr 4 \* 1024 \* 1024) \
		seek=1 conv=notrunc 2> /dev/null
	sh -c 'echo n; echo; echo; echo 8192; echo; echo a; echo w' \
		| $(FDISK) $@ 2> /dev/null > /dev/null

build/boot-loongarch64.img: build/fs-loongarch64.img
	dd if=$< of=$@ bs=$(shell expr 4 \* 1024 \* 1024) \
		seek=1 conv=notrunc 2> /dev/null
	sh -c 'echo n; echo; echo; echo 8192; echo; echo a; echo w' \
		| $(FDISK) $@ 2> /dev/null > /dev/null

.DEFAULT_GOAL := build