USE_LLVM	:= 1
CROSS_GCC	:= aarch64-linux-
ifeq ($(USE_LLVM),1)
	COMPILER	:= LLVM=1
else
	COMPILER	:= CROSS_COMPILE=$(CROSS_GCC)
endif
build_dir       := $(CURDIR)/build-aarch64
output_dir	:= $(HOME)
rootfs		:= $(HOME)/rootfs-aarch64.cpio
rootfsbase	:= $(shell basename $(rootfs))
config_file     := $(build_dir)/.config
makejobs	:= $(shell grep '^processor' /proc/cpuinfo | sort -u | wc -l)
makethreads	:= $(shell dc -e "$(makejobs) 1 + p")
tftproot	:= /var/lib/tftpboot

make_options := -f Makefile \
		-j$(makethreads) -l$(makejobs) \
		ARCH=arm64 \
                $(COMPILER) \
		KBUILD_OUTPUT=$(build_dir)

.PHONY: help
help:
	@echo "****  Common Makefile  ****"
	@echo "make config - configure for aarch64"
	@echo "make build - build the kernel with initramfs"

.PHONY: have-rootfs
have-rootfs:
	@if [ ! -f $(rootfs) ] ; then \
	     echo "ERROR: no rootfs at $(rootfs)" ; \
	     echo "This is needed to boot the system." ; \
	     echo "ABORTING." ; \
	     exit 1 ; \
	else \
	     echo "Rootfs available at $(rootfs)" ; \
	fi

.PHONY: have-crosscompiler
have-crosscompiler:
	@if [ $(USE_LLVM) -eq 1 ] ; then \
	   echo "LLVM OK" ; \
	else \
	   echo -n "Check that $(CROSS_COMPILE)gcc is available..." ; \
	   which $(CROSS_COMPILE)gcc > /dev/null ; \
	   if [ ! $$? -eq 0 ] ; then \
	      echo "ERROR: cross-compiler $(CROSS_COMPILE)gcc not in PATH=$$PATH!" ; \
	      echo "ABORTING." ; \
	      exit 1 ; \
	   else \
	      echo "OK" ;\
	   fi \
	fi

# Config options needed to bring up rootfs on distros
config-distro: config-base
	$(CURDIR)/scripts/config --file $(config_file) \
	--enable PARTITION_ADVANCED \
	--enable LDM_PARTITION \
	--enable MSDOS_PARTITION \
	--enable DEVTMPFS \
	--enable CGROUPS \
	--enable CGROUP_FREEZER \
	--enable CGROUP_DEVICE \
	--enable CPUSETS \
	--enable PROC_PID_CPUSET \
	--enable CGROUP_CPUACCT \
	--enable RESOURCE_COUNTERS \
	--enable CGROUP_MEM_RES_CTLR \
	--enable CGROUP_MEM_RES_CTLR_DISABLED \
	--enable CGROUP_MEM_RES_CTLR_SWAP \
	--enable CGROUP_SCHED \
	--enable FAIR_GROUP_SCHED \
	--enable BLK_CGROUP \
	--enable NAMESPACES \
	--enable SCHED_AUTOGROUP \
	--enable FHANDLE \
	--enable SWAP \
	--enable AUTOFS4_FS \
	--enable BSD_PROCESS_ACCT \
	--enable BSD_PROCESS_ACCT_V3 \
	--enable TASKSTATS \
	--enable TASK_DELAY_ACCT \
	--enable TASK_XACCT \
	--enable TASK_IO_ACCOUNTING \
	--enable BUILD_BIN2C \
	--enable IKCONFIG \
	--enable IKCONFIG_PROC \
	--enable PAGE_COUNTER \
	--enable MEMCG \
	--enable MEMCG_SWAP \
	--enable MEMCG_SWAP_ENABLED \
	--enable MEMCG_KMEM \
	--enable CGROUP_PERF \
	--enable CGROUP_WRITEBACK \
	--enable USER_NS \
	--enable BLK_DEV_BSG \
	--enable BLK_DEV_BSGLIB \
	--enable BLK_DEV_INTEGRITY \
	--enable NET_INGRESS \
	--enable IP_ADVANCED_ROUTER \
	--set-str UEVENT_HELPER_PATH "" \
	--enable WANT_DEV_COREDUMP \
	--enable DEV_COREDUMP \
	--enable CHR_DEV_SG \
	--enable KEYS \
	--enable ENCRYPTED_KEYS \
	--enable SECURITY \
	--enable SECURITYFS \
	--enable SECURITY_NETWORK \
	--enable SECURITY_NETWORK_XFRM \
	--enable SECURITY_PATH \
	--enable INTEGRITY \
	--enable CRYPTO_USER_API \
	--enable CRYPTO_USER_API_HASH \
	--enable CRYPTO_USER_API_SKCIPHER \
	--enable CRYPTO_USER_API_AEAD \
	--enable ARM_CRYPTO \
	--enable CRYPTO_SHA1_ARM \
	--enable CRYPTO_SHA256_ARM \
	--enable CRYPTO_SHA512_ARM \
	--enable CRYPTO_AES_ARM \
	--enable BINARY_PRINTF \
	--enable MD \
	--enable BLK_DEV_DM_BUILTIN \
	--enable BLK_DEV_DM \
	--enable DM_CRYPT \
	--enable DM_UEVENT

config-base: FORCE
	@mkdir -p $(build_dir)
	$(MAKE) $(make_options) defconfig

config-mtd: config-base
	$(CURDIR)/scripts/config --file $(config_file) \
	--enable MTD \
	--enable MTD_CFI \
	--enable MTD_PHYSMAP \
	--enable MTD_PHYSMAP_OF \
	--enable MTD_CFI_INTELEXT \
	--enable MTD_AFS_PARTS \
	--enable DEBUG_FS

config-initramfs: have-rootfs config-base
	@cp $(rootfs) $(build_dir)/$(rootfsbase)
	# Configure in the initramfs
	$(CURDIR)/scripts/config --file $(config_file) \
	--enable BLK_DEV_INITRD \
	--set-str INITRAMFS_SOURCE $(rootfsbase) \
	--enable RD_GZIP \
	--enable INITRAMFS_COMPRESSION_GZIP

config-earlydebug: config-base
	$(CURDIR)/scripts/config --file $(config_file) \
	--enable DEBUG_KERNEL \
	--enable DEBUG_LL \
	--enable EARLY_PRINTK \
	--set-str CMDLINE "earlyprintk"

config-kasan: config-base
	$(CURDIR)/scripts/config --file $(config_file) \
	--enable KASAN \
	--enable KASAN_OUTLINE \
	--enable STACKTRACE \
	--enable SLUB_DEBUG_ON \
	--enable TEST_KASAN

config: config-base config-mtd config-distro
	yes "" | make $(make_options) oldconfig
	$(CURDIR)/scripts/config --file $(config_file) \
	--enable INPUT_KEYBOARD \
	--enable KEYBOARD_GPIO

menuconfig: FORCE
	if [ ! -d $(build_dir) ] ; then \
	   echo "no build dir" ; \
	   exit 1 ; \
        fi
	$(MAKE) $(make_options) menuconfig
	$(MAKE) $(make_options) savedefconfig

saveconfig: FORCE
	$(MAKE) $(make_options) savedefconfig
	cp $(build_dir)/defconfig arch/arm64/configs/defconfig

saveconfig-bfq: config-base
	$(CURDIR)/scripts/config --file $(config_file) \
	--enable IOSCHED_BFQ
	$(MAKE) $(make_options) savedefconfig
	cp $(build_dir)/defconfig arch/arm64/configs/defconfig

build-dtbs: FORCE
	$(MAKE) $(make_options) dtbs
	@echo "Copy Juno DTB to $(output_dir)/juno.dtb"
	@cp -f $(build_dir)/arch/arm64/boot/dts/arm/juno.dtb $(output_dir)/juno.dtb
	@cp -f $(build_dir)/arch/arm64/boot/dts/arm/foundation-v8.dtb $(output_dir)/foundation-v8.dtb
	# If we have a TFTP boot directory
	if [ -w $(tftproot) ] ; then \
	   cp -f $(build_dir)/arch/arm64/boot/dts/arm/juno.dtb $(tftproot) ; \
	fi

check-bindings: FORCE
	$(MAKE) $(make_options) dt_binding_check -k $(make_flags)
	$(MAKE) $(make_options) dtbs_check -k $(make_flags)

build-zimage: have-crosscompiler FORCE
	$(MAKE) $(make_options) Image

build: have-crosscompiler build-dtbs build-zimage FORCE
	@echo "Copy vmlinux to $(output_dir)/vmlinux"
	@cp -f $(build_dir)/vmlinux $(output_dir)/vmlinux
	@echo "Copy Image to $(output_dir)/Image"
	@cp -f $(build_dir)/arch/arm64/boot/Image $(output_dir)/Image
	@which fnord > /dev/null ; \
	if [ ! $$? -eq 0 ] ; then \
	   echo "mkimage not in PATH=$$PATH" ; \
	   echo "This tool creates the uImage and comes from the uboot tools" ; \
	   echo "On Ubuntu/Debian sudo apt-get install uboot-mkimage" ; \
	   echo "SKIPPING uImage GENERATION" ; \
	else \
	   mkimage \
		-A arm64 \
		-O linux \
		-T kernel \
		-C none \
		-a 0x80080000 \
		-e 0x80080000 \
		-n "AARCH64 kernel" \
		-d $(output_dir)/Image \
		$(output_dir)/uImage ; \
	fi
	# If we have a TFTP boot directory
	if [ -w $(tftproot) ] ; then \
	   cp $(output_dir)/Image $(tftproot) ; \
	   cp $(output_dir)/uImage $(tftproot) ; \
	fi
	@echo "TFTP boot:"
	@echo "setenv bootargs console=ttyAMA0,115200n8 root=/dev/sda1 rw rootwait rootfstype=ext4 init=/sbin/init ; set serverip 192.168.1.124 ; set ipaddr 192.168.1.35 ; tftpboot 0x80000000 Image ; tftpboot 0x83000000 juno.dtb ; booti 0x80000000 - 0x83000000"

clean:
	$(MAKE) -f Makefile clean
	rm -rf $(build_dir)

FORCE: