CROSS_COMPILE	?= arm-linux-gnueabihf-
build_dir       := $(CURDIR)/build-u300
output_dir	:= $(HOME)
rootfs		:= $(HOME)/rootfs-u300.cpio
install_dir     := $(build_dir)/install
config_file     := $(build_dir)/.config
strip		:= $(CROSS_COMPILE)strip
objcopy		:= $(CROSS_COMPILE)objcopy
rootfsbase	:= $(shell basename $(rootfs))
dtb		:= $(build_dir)/arch/arm/boot/dts/ste-u300.dtb


make_options := -f Makefile \
                ARCH=arm \
                CROSS_COMPILE=$(CROSS_COMPILE) \
                KBUILD_OUTPUT=$(build_dir)

.PHONY: help
help:
	@echo "****  Common Makefile  ****"
	@echo "make config [PLATFORM=foo] - configure for platform \"foo\""
	@echo "make build - build the kernel and produce a RAMdisk image"
	@echo
	@echo "example for ATAG boot:"
	@echo "make -f u300.mak config && make -f u300.mak build"
	@echo "example for appended devicetree boot:"
	@echo "make -f u300.mak config-dt && make -f u300.mak build-dt"

.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
	@if [ ! -r $(rootfs) ] ; then \
	     echo "ERROR: rootfs at $(rootfs) not readable" ; \
	     echo "ABORTING." ; \
	     exit 1 ; \
	fi

.PHONY: have-crosscompiler
have-crosscompiler:
	@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

config-base: have-rootfs FORCE
	@mkdir -p $(build_dir)
	@cp $(rootfs) $(build_dir)/$(rootfsbase)
	$(MAKE) $(make_options) u300_defconfig

config-initramfs: config-base FORCE
	# 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-mainlined-features: config-base FORCE
	$(CURDIR)/scripts/config --file $(config_file) \
	--enable PM \
	--enable DEBUG_FS \
	--enable MMC_CLKGATE \
	--disable MMC_DEBUG \
	--enable MTD \
	--enable MTD_PARTITIONS \
	--enable MTD_CMDLINE_PARTS \
	--enable MTD_NAND \
	--enable MTD_NAND_FSMC \
	--disable ARCH_MULTI_V7

config-common: have-rootfs config-base config-initramfs FORCE
	# Reconfigure a bit
	$(CURDIR)/scripts/config --file $(config_file) \
	--set-str CMDLINE "root=/dev/ram0 console=ttyAMA0,115200n8 lpj=515072 earlyprintk" \
	--enable DEBUG_LL \
	--enable EARLY_PRINTK \
	--enable COMMON_CLK_DEBUG \
	--enable ARM_TEST \
	--enable ARM_TCM_TEST

config: config-common FORCE
	yes "" | make $(make_options) oldconfig

config-dt: config-common FORCE
	$(CURDIR)/scripts/config --file $(config_file) \
	--enable USE_OF \
	--enable OF_GPIO \
	--enable ARM_APPENDED_DTB \
	--enable ARM_ATAG_DTB_COMPAT \
	--enable PROC_DEVICETREE
	yes "" | make $(make_options) oldconfig

menuconfig: FORCE
	$(MAKE) $(make_options) menuconfig

saveconfig: config-base config-mainlined-features FORCE
	yes "" | make $(make_options) oldconfig
	$(MAKE) $(make_options) savedefconfig
	cp $(build_dir)/defconfig arch/arm/configs/u300_defconfig

build-zimage: have-crosscompiler FORCE
	$(MAKE) $(make_options) -j 4 zImage CONFIG_DEBUG_SECTION_MISMATCH=y
	@echo "Copy zImage to $(output_dir)/vmlinux.bin"
	@cp -f $(build_dir)/arch/arm/boot/zImage $(output_dir)/vmlinux.bin

build-dtbs: FORCE
	$(MAKE) $(make_options) -j 4 dtbs CONFIG_DEBUG_SECTION_MISMATCH=y

build: build-zimage build-dtbs FORCE
	@if [ ! -r $(dtb) ] ; then \
	   echo "NO DTB in $(dtb)!" ; \
	   exit 1 ; \
	fi
	@echo "Catenate DTB onto zImage $(output_dir)/vmlinux.bin"
	cat $(dtb) >> $(output_dir)/vmlinux.bin
	@echo "DONE"

clean:
	$(MAKE) -f Makefile mrproper
	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: