##
## Folders
##
ROOT_DIR := $(CURDIR)
OUT_DIR := $(ROOT_DIR)/out
LINUX_OUT := $(OUT_DIR)/linux
CCACHE_DIR := $(OUT_DIR)/.ccache
TEST_SCRIPTS_DIR := $(ROOT_DIR)/build/aarch64-unit-tests

##
## Common options
##
VERBOSE ?= 0
CCACHE ?= ""

# Find toolchain for current OS
UNNAME_S := $(shell uname -s | tr '[:upper:]' '[:lower:]')
TOOLCHAIN_CLANG := $(ROOT_DIR)/toolchains/$(UNNAME_S)-x86/clang/clang-r383902
TOOLCHAIN_BINUTILS := $(ROOT_DIR)/toolchains/$(UNNAME_S)-x86/gcc/aarch64-linux-android

CUSTOM_KERNEL_IMAGE=0

# KERNEL_IMAGE can be set to use own custom kernel image.
ifdef KERNEL_IMAGE
CUSTOM_KERNEL_IMAGE=1
else
KERNEL_IMAGE := $(LINUX_OUT)/arch/arm64/boot/Image
endif

##
## Common targets
##

.DEFAULT_GOAL := default

.PHONY: default
default: kvmunittests linux

.PHONY: clean
clean: buildroot_clean kvmunittests_clean linux_clean

.PHONY: distclean
distclean: kvmunittests_clean
	- rm -rf $(OUT_DIR)

.PHONY: all
all: buildroot kvmunittests linux

.PHONY: help
help:
	@echo 'Generic Targets:'
	@echo '   default              - builds all generic targets except for buildroot'
	@echo '   all                  - builds all generic targets'
	@echo '   buildroot            - the buildroot rootfs image as well as the host qemu'
	@echo '   kvmunittests         - the kvm-unit-tests'
	@echo '   linux                - the linux kernel'
	@echo ''
	@echo 'Clean Targets:'
	@echo '   clean                - cleans all, but keeps the prebuilts'
	@echo '   distclean            - distclean for all targets'
	@echo '   buildroot_clean      - the buildroot rootfs image as well as the host qemu'
	@echo '   kvmunittests_clean   - the kvm-unit-tests'
	@echo '   linux_clean          - the linux kernel'
	@echo ''
	@echo 'Misc Targets:'
	@echo '   test                 - runs the kvm unit tests in the qemu-aarch64 simulated environment'
	@echo '   update-prebuilts     - generates/update the prebuilt rootfs image (aarch64) and the qemu host (aarch64)'


##
## Buildroot
##

BR_DEFCONFIG ?= qemu_aarch64_virt_kvmunittests_defconfig
BR_VERBOSE ?= $(VERBOSE)

BR_SRC := $(ROOT_DIR)/buildroot
BR_OUT := $(OUT_DIR)/buildroot
BR_MAKE := $(MAKE) -C $(BR_SRC) V=$(BR_VERBOSE) O=$(BR_OUT)

.PHONY: buildroot
buildroot:
	+ $(BR_MAKE) $(BR_DEFCONFIG)
	+ $(BR_MAKE) all

.PHONY: buildroot_clean
buildroot_clean:
	+ $(BR_MAKE) clean


##
## kvmunittests
##
KUT_CROSS_PREFIX ?= "aarch64-linux-android-"

KUT_ARCH := "arm64"
KUT_SRC := $(ROOT_DIR)/kvm-unit-tests
KUT_OUT := $(OUT_DIR)/kvm-unit-tests
KUT_CC := $(TOOLCHAIN_CLANG)/bin/clang
KUT_LD := $(TOOLCHAIN_CLANG)/bin/ld.lld
KUT_OBJCOPY := $(TOOLCHAIN_CLANG)/bin/llvm-objcopy
KUT_OBJDUMP := $(TOOLCHAIN_CLANG)/bin/llvm-objdump
KUT_COMMON_CFLAGS := "-Qunused-arguments -target aarch64-linux-gnueabi -fno-integrated-as -Wno-asm-operand-widths -fpic --gcc-toolchain=$(TOOLCHAIN_BINUTILS)"
KUT_PATH := $(TOOLCHAIN_CLANG)/bin:$(TOOLCHAIN_BINUTILS)/bin:$(PATH)


.PHONY: kvmunittests
kvmunittests:
	cd $(KUT_SRC) && \
		./configure --prefix=$(KUT_OUT) --arch=$(KUT_ARCH) \
			--cc=$(KUT_CC) --ld=$(KUT_LD) \
			--objcopy=$(KUT_OBJCOPY) --objdump=$(KUT_OBJDUMP)
	PATH=$(KUT_PATH) COMMON_CFLAGS=$(KUT_COMMON_CFLAGS) $(MAKE) -C $(KUT_SRC) install

.PHONY: kvmunittests_clean
kvmunittests_clean:
	- $(MAKE) -C $(KUT_SRC) clean


##
## Linux kernel
##
LINUX_DEFCONFIG ?= defconfig
LINUX_VERBOSE ?= $(VERBOSE)
LINUX_CROSS_COMPILE ?= "aarch64-linux-gnu-"
LINUX_SRC ?= $(ROOT_DIR)/linux

LINUX_ARCH := arm64
LINUX_PATH := $(TOOLCHAIN_CLANG)/bin:$(PATH)
LINUX_MAKE := \
	PATH=$(LINUX_PATH) \
	ARCH=$(LINUX_ARCH) \
	CROSS_COMPILE=$(LINUX_CROSS_COMPILE) \
	$(MAKE) \
	LLVM=1 \
	GCC_TOOLCHAIN_DIR=$(TOOLCHAIN_BINUTILS)/bin \
	-C $(LINUX_SRC) \
	V=$(LINUX_VERBOSE) \
	O=$(LINUX_OUT)

.PHONY: linux
linux:
	+ $(LINUX_MAKE) $(LINUX_DEFCONFIG)
	+ $(LINUX_MAKE)

.PHONY: linux_image
linux_image:
# If using own kernel image (KERNEL_IMAGE is set in the environment), then skip.
ifeq ($(CUSTOM_KERNEL_IMAGE), 0)
	echo $(CUSTOM_KERNEL_IMAGE)
	+ $(LINUX_MAKE) $(LINUX_DEFCONFIG)
	+ $(LINUX_MAKE) Image.gz
endif

.PHONY: linux_clean
linux_clean:
	+ $(LINUX_MAKE) clean
	+ $(LINUX_MAKE) mrproper


##
## Generating/Updating prebuilts
##

update-prebuilts: \
	prebuilts/linux-aarch64/images \
	prebuilts/linux-x86/qemu

# The rootfs and rom images for qemu
prebuilts/linux-aarch64/images: buildroot
	- rm -rf $@
	mkdir -p $@
	cp $(BR_OUT)/images/rootfs.ext4 $@
	cp $(BR_OUT)/per-package/host-qemu/host/share/qemu/efi-virtio.rom $@

# The qemu binary and the libraries it requires
prebuilts/linux-x86/qemu: buildroot
	- rm -rf $@
	mkdir -p $@/bin
	cp $(BR_OUT)/host/bin/qemu-system-aarch64 $@/bin
	mkdir -p $@/lib
	cp $(BR_OUT)/host/lib/lib* $@/lib


##
## Run unit tests
##

MAKE_PID := $(shell echo $$PPID)
JOB_FLAG := $(filter -j%, $(subst -j ,-j,$(shell ps T | grep "^\s*$(MAKE_PID).*$(MAKE)")))
JOBS     := $(subst -j,,$(JOB_FLAG))
ifeq ($(JOBS),)
	JOBS := "1"
endif

KUT_QEMU_BIN := $(ROOT_DIR)/prebuilts/linux-x86/qemu/bin/qemu-system-aarch64
KUT_QEMU_LIB := $(ROOT_DIR)/prebuilts/linux-x86/qemu/lib
KUT_ROOTFS_IMAGE := $(ROOT_DIR)/prebuilts/linux-aarch64/images/rootfs.ext4

# Exclude tests that require user interaction or are known to fail.
KUT_EXCLUDE := "(.+migrat.+)|(gicv2-.+)|(pmu-event-introspection)|(micro-bench)"

.PHONY: test
test: kvmunittests linux_image
	@LD_LIBRARY_PATH=$(KUT_QEMU_LIB):$(LD_LIBRARY_PATH) VERBOSE=$(VERBOSE) \
		$(TEST_SCRIPTS_DIR)/run_tests.sh \
			-j $(JOBS) \
			-t $(KUT_OUT)/share/kvm-unit-tests/ \
			-x $(KUT_EXCLUDE) \
			-l $(KERNEL_IMAGE) \
			-r $(KUT_ROOTFS_IMAGE) \
			-e $(KUT_QEMU_BIN)