# Copyright 2020 The Android KVM Authors
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

SELF := $(abspath $(lastword $(MAKEFILE_LIST)))

CPUS ?= $(shell nproc)
MAKEFLAGS += --jobs=$(CPUS)

##
## Folders
##
ROOT_DIR := $(CURDIR)

# DIST_DIR might be defined by the CI build (pKVM Busytown)
ifdef DIST_DIR
OUT_DIR := $(DIST_DIR)
else
OUT_DIR := $(ROOT_DIR)/out
endif

LINUX_OUT := $(OUT_DIR)/linux
SCRIPTS_DIR := $(ROOT_DIR)/build

##
## Common options
##
VERBOSE ?= 0
CUSTOM_KERNEL_IMAGE = 0
ARCH = arm64

# 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.gz
endif

##
## Toolchain options and variables
##

# Specifies which toolchain of the prebuilt toolchains to use.
# Can be either clang, gcc-4.9, or gcc-9.2.
TOOLCHAIN ?= clang

# Find the toolchain path for the current OS.
UNNAME_S := $(shell uname -s | tr '[:upper:]' '[:lower:]')
TOOLCHAIN_CLANG := $(ROOT_DIR)/toolchains/$(UNNAME_S)-x86/clang/clang-r383902/
TOOLCHAIN_GCC_49 := $(ROOT_DIR)/toolchains/$(UNNAME_S)-x86/gcc/aarch64-linux-gnu-4.9/
TOOLCHAIN_GCC_92 := $(ROOT_DIR)/toolchains/$(UNNAME_S)-x86/gcc/aarch64-linux-gnu-9.2/

# Set the toolchain build binary paths and prefixes.
ifeq ($(TOOLCHAIN), gcc-4.9)
TOOLCHAIN_BIN := $(TOOLCHAIN_GCC_49)/bin
TARGET = aarch64-linux-gnu
else ifeq ($(TOOLCHAIN), gcc-9.2)
TOOLCHAIN_BIN := $(TOOLCHAIN_GCC_92)/bin
TARGET = aarch64-none-linux-gnu
else ifeq ($(TOOLCHAIN), clang)
TOOLCHAIN_BIN := $(TOOLCHAIN_CLANG)/bin
CC := $(TOOLCHAIN_BIN)/clang
LD := $(TOOLCHAIN_BIN)/ld.lld
OBJCOPY := $(TOOLCHAIN_BIN)/llvm-objcopy
OBJDUMP := $(TOOLCHAIN_BIN)/llvm-objdump
TARGET = aarch64-linux-gnu
# The GCC toolchain is needed when building kvm-unit-tests as well as Linux
# with Clang, because of lack of support for the LLVM integrated assembler.
GCC_TOOLCHAIN_DIR = $(TOOLCHAIN_GCC_49)
GCC_TOOLCHAIN_BIN = $(GCC_TOOLCHAIN_DIR)/bin/
LLVM = "LLVM=1"
# Some targets require additional flags to build with Clang.
COMMON_CFLAGS := -Qunused-arguments --target=$(TARGET) -fno-integrated-as -Wno-asm-operand-widths -fpic --gcc-toolchain=$(GCC_TOOLCHAIN_DIR) --sysroot=$(GCC_TOOLCHAIN_DIR)/$(TARGET)/libc --prefix=$(GCC_TOOLCHAIN_BIN)/$(TARGET)-
else
$(error Unrecognized toolchain: TOOLCHAIN=$(TOOLCHAIN))
endif

# common to all GCC versions
ifneq ($(TOOLCHAIN), clang)
CC := $(TOOLCHAIN_BIN)/$(TARGET)-gcc
LD := $(TOOLCHAIN_BIN)/$(TARGET)-ld
OBJCOPY := $(TOOLCHAIN_BIN)/$(TARGET)-objcopy
OBJDUMP := $(TOOLCHAIN_BIN)/$(TARGET)-objdump
GCC_TOOLCHAIN_BIN := $(TOOLCHAIN_BIN)
endif

##
## Common targets
##

.DEFAULT_GOAL := default

.PHONY: default
default: kvm-unit-tests linux

.PHONY: clean
clean: buildroot_clean kvm-unit-tests_clean linux_clean

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

.PHONY: all
all: buildroot kvm-unit-tests 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 '   kvm-unit-tests       - 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 '   kvm-unit-tests_clean - the kvm-unit-tests'
	@echo '   linux_clean          - the linux kernel'
	@echo ''
	@echo 'Test Targets:'
	@echo '   test                 - runs all tests in qemu-aarch64 simulated environment'
	@echo '   test-kut             - runs all kvm-unit-tests in qemu-aarch64 simulated environment'
	@echo '   test-list            - lists all test targets'
	@echo ''
	@echo 'Misc Targets:'
	@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


##
## kvm-unit-tests
##
KUT_SRC := $(ROOT_DIR)/kvm-unit-tests
KUT_OUT := $(OUT_DIR)/kvm-unit-tests
KUT_STAMP := $(KUT_OUT)/kvm-unit-tests.stamp


.PHONY: kvm-unit-tests
kvm-unit-tests $(KUT_STAMP):
	mkdir -p $(KUT_OUT)
	cd $(KUT_OUT) && \
		$(KUT_SRC)/configure \
			--erratatxt=$(KUT_SRC)/errata.txt \
			--prefix=$(KUT_OUT) --arch=$(ARCH) \
			--cc=$(CC) --ld=$(LD) \
			--objcopy=$(OBJCOPY) --objdump=$(OBJDUMP)
	COMMON_CFLAGS="$(COMMON_CFLAGS)" \
		$(MAKE) -C $(KUT_OUT) standalone
	touch $(KUT_STAMP)

.PHONY: kvm-unit-tests_clean
kvm-unit-tests_clean:
	- rm -f $(KUT_STAMP)
	- $(MAKE) -C $(KUT_OUT) clean


##
## Linux kernel
##
LINUX_DEFCONFIG ?= defconfig
LINUX_VERBOSE ?= $(VERBOSE)
LINUX_SRC ?= $(ROOT_DIR)/linux

LINUX_MAKE := \
	PATH=$(TOOLCHAIN_BIN):$(PATH) \
	ARCH=$(ARCH) \
	CROSS_COMPILE="$(TARGET)-" \
	$(MAKE) \
	$(LLVM) \
	GCC_TOOLCHAIN_DIR="$(GCC_TOOLCHAIN_BIN)" \
	-C $(LINUX_SRC) \
	V=$(LINUX_VERBOSE) \
	O=$(LINUX_OUT)

LINUX_CONFIG := $(LINUX_OUT)/.config

.PHONY: linux_defconfig
linux_defconfig $(LINUX_CONFIG):
	+ $(LINUX_MAKE) $(LINUX_DEFCONFIG)

.PHONY: linux_menuconfig
linux_menuconfig: $(LINUX_CONFIG)
	+ $(LINUX_MAKE) menuconfig

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

.PHONY: linux_image
linux_image: $(LINUX_CONFIG)
	+ $(LINUX_MAKE) Image.gz

# If using own kernel image (KERNEL_IMAGE is set in the environment), then skip.
ifeq ($(CUSTOM_KERNEL_IMAGE), 0)
$(KERNEL_IMAGE): linux_image
endif

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


##
## Generating/Updating prebuilts
##

.PHONY:update-prebuilts
update-prebuilts: \
	prebuilts/linux-aarch64/images/crosvm.ext4 \
	prebuilts/linux-aarch64/images/efi-virtio.rom \
	prebuilts/linux-aarch64/images/rootfs.ext4 \
	prebuilts/linux-x86/qemu

prebuilts/linux-aarch64/images/rootfs.ext4: buildroot
	mkdir -p $(shell dirname $@)
	cp $(BR_OUT)/images/rootfs.ext4 $@

prebuilts/linux-aarch64/images/efi-virtio.rom: buildroot
	mkdir -p $(shell dirname $@)
	cp $(BR_OUT)/per-package/host-qemu/host/share/qemu/efi-virtio.rom $@

CF_DOWNLOAD_AOSP_SH := $(ROOT_DIR)/build/cuttlefish/download-aosp.sh
CROSVM_IMG_SIZE_MB := 1024

prebuilts/linux-aarch64/images/crosvm.ext4: TMP_DIR := $(shell mktemp -d)
prebuilts/linux-aarch64/images/crosvm.ext4: $(CF_DOWNLOAD_AOSP_SH)
	mkdir -p $(shell dirname $@)
	cd $(TMP_DIR) && $(CF_DOWNLOAD_AOSP_SH) -a arm64 -C
	dd if=/dev/zero of=$@.tmp bs=1M count=$(CROSVM_IMG_SIZE_MB)
	mkfs.ext4 -d $(TMP_DIR) $@.tmp
	rm -rf $(TMP_DIR)
	mv $@.tmp $@

# The qemu binary
.PHONY:prebuilts/linux-x86/qemu
prebuilts/linux-x86/qemu:
	- rm -rf $@
	${SCRIPTS_DIR}/aarch64/build_qemu.sh $(OUT_DIR)/qemu ${TOOLCHAIN_BIN}
	mkdir -p $@/bin
	cp $(OUT_DIR)/qemu/qemu-system-aarch64 $@/bin

##
## Run tests
##

# Root test targets. Dynamically generated per-test targets
# will add themselves as dependencies of these.
.PHONY: test test-list
test:
test-list:

#
# kvm-unit-tests
#

KUT_GEN_MAKEFILE := $(SCRIPTS_DIR)/kvm-unit-tests/gen_makefile.sh
KUT_MAKEFILE := $(OUT_DIR)/Makefile.kvm-unit-tests
KUT_TEST_DIR := $(KUT_OUT)/tests
KUT_LOG_DIR := $(OUT_DIR)/test/kvm-unit-tests/

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

# Generate a Makefile with targets per test and configuration.
# Pass in variable/target names from this Makefile that the
# generated Makefile will refer to.
$(KUT_MAKEFILE): $(SELF) $(KUT_GEN_MAKEFILE) $(KUT_STAMP)
	@ mkdir -p $(shell dirname $@)
	@ $(KUT_GEN_MAKEFILE)				\
		$(KUT_TEST_DIR) "$(KUT_EXCLUDE)"	\
		KERNEL_IMAGE KUT_LOG_DIR test test-list	\
		> $@.tmp
	@ mv $@.tmp $@
include $(KUT_MAKEFILE)