USE_LLVM	:= 1
CROSS_GCC	:= arm-none-eabi-
ifeq ($(USE_LLVM),1)
	COMPILER	:= LLVM=1
else
	COMPILER	:= CROSS_COMPILE=$(CROSS_GCC)
endif
ARMMACHINE	?= multi_v7
CROSS_COMPILE	?= arm-none-eabi-
PATCHDIR	:= ${HOME}/linux-stericsson
build_dir       := $(CURDIR)/build-$(ARMMACHINE)
output_dir	:= $(HOME)
#rootfs		:= $(HOME)/rootfs-msm8660.cpio
rootfs		:= $(HOME)/rootfs-vexpress.cpio
rootfsbase	:= $(shell basename $(rootfs))
install_dir     := $(build_dir)/install
config_file     := $(build_dir)/.config
strip		:= $(CROSS_COMPILE)strip
objcopy		:= $(CROSS_COMPILE)objcopy
makejobs	:= $(shell grep '^processor' /proc/cpuinfo | sort -u | wc -l)
makethreads	:= $(shell dc -e "$(makejobs) 1 + p")
tftproot	:= /var/lib/tftpboot
ifeq ($(ARMMACHINE),stm32)
kernelobject	:= xipImage
else
kernelobject	:= zImage
endif

make_options := -f Makefile \
		-j$(makethreads) -l$(makejobs) \
		ARCH=arm \
		$(COMPILER) \
		KBUILD_OUTPUT=$(build_dir)
#make_flags	:= CONFIG_DEBUG_SECTION_MISMATCH=y

.PHONY: help
help:
	@echo "****  Common Makefile  ****"
	@echo "make config [ARMMACHINE=foo] - configure for platform \"foo\""
	@echo "make build - build the kernel and produce a RAMdisk image"
	@echo
	@echo "example:"
	@echo "make -f $(ARMMACHINE).mak ARMMACHINE=foo config"
	@echo "make -f $(ARMMACHINE).mak ARMMACHINE=foo build"

.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-base: FORCE
	@mkdir -p $(build_dir)
	$(MAKE) $(make_options) $(ARMMACHINE)_defconfig
	$(CURDIR)/scripts/config --file $(config_file) \
	--enable PREEMPT \
	--enable DEBUG_FS

config-initramfs: 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 \
	--enable DEBUG_VEXPRESS_UART0_RS1 \
	--enable DEBUG_UNCOMPRESS \
	--set-str CMDLINE "earlyprintk"

config-cfi: config-base
	$(CURDIR)/scripts/config --file $(config_file) \
	--enable CFI_CLANG \
	--enable CFI_PERMISSIVE \
	--enable FTRACE \
	--enable FUNCTION_TRACER \
	--enable LKDTM

config: have-rootfs config-base config-initramfs config-cfi
	yes "" | make $(make_options) oldconfig

allmodconfig: config
	make $(make_options) allmodconfig

allyesconfig: config
	make $(make_options) allyesconfig

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

saveconfig: FORCE
	# yes "" | make $(make_options) oldconfig
	# $(CURDIR)/scripts/config --file $(config_file) \
	# --enable PREEMPT
	$(MAKE) $(make_options) savedefconfig
	cp $(build_dir)/defconfig arch/arm/configs/$(ARMMACHINE)_defconfig

build-dtbs: FORCE
	$(MAKE) $(make_options) dtbs $(make_flags)

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

build-kernelobject: have-crosscompiler
	$(MAKE) $(make_options) $(kernelobject) $(make_flags)

build-modules: build-kernelobject
	$(MAKE) $(make_options) modules $(make_flags)

build: have-rootfs have-crosscompiler build-kernelobject
	@echo "Copy vmlinux to $(output_dir)/vmlinux"
	@cp -f $(build_dir)/vmlinux $(output_dir)/vmlinux
ifeq ($(ARMMACHINE),stm32)
	@echo "Copy xipImage to $(output_dir)/xipImage"
	@cp -f $(build_dir)/arch/arm/boot/xipImage $(output_dir)/xipImage
else
	@echo "Copy zImage to $(output_dir)/zImage"
	@cp -f $(build_dir)/arch/arm/boot/zImage $(output_dir)/zImage
endif
	@which mkimage > /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 arm \
		-O linux \
		-T kernel \
		-C none \
		-a 0x00008000 \
		-e 0x00008000 \
		-n "$(ARMMACHINE) kernel" \
		-d $(output_dir)/zImage \
		$(output_dir)/uImage ; \
	fi
	# If we have a TFTP boot directory
	if [ -w $(tftproot) ] ; then \
	   cp $(output_dir)/vmlinux $(tftproot) ; \
	   cp $(output_dir)/$(kernelobject) $(tftproot) ; \
	fi

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

# Rules without commands or prerequisites that do not match a file name
# are considered to always change when make runs. This means that any rule
# that depends on FORCE will always be remade also.
FORCE: