#
# src/kernel/Makefile
#

TARGET = arm-crux-linux-gnueabihf

PWD = $(shell pwd)
WORK = $(PWD)/work
CROSSTOOLS = /devel/crux-arm/toolchain/crosstools

KERNEL_BRANCH = 4.5.y
KERNEL_VERSION = 4.5.4
PATCH_VERSION = 20160513

CONFIG_FILE = config-$(KERNEL_VERSION)-raspberrypi2_$(PATCH_VERSION)
PATCH_FILE = linux-$(KERNEL_BRANCH)-rpi-$(PATCH_VERSION).patch
KERNEL_TARBALL = linux-$(KERNEL_VERSION).tar.xz


.PHONY: all clean config files image map menuconfig modules

all: image modules map dtb

clean: image-clean modules-clean map-clean dtb-clean

distclean: clean image-distclean modules-distclean dtb-distclean map-distclean

$(PWD)/$(KERNEL_TARBALL):
	wget -P $(PWD) https://www.kernel.org/pub/linux/kernel/v4.x/$(KERNEL_TARBALL)
	touch $@

$(PWD)/$(PATCH_FILE):
	wget -P $(PWD) http://stygian.me/crux-arm/distfiles/$(PATCH_FILE)
	touch $@

$(PWD)/$(CONFIG_FILE):
	wget -P $(PWD) http://stygian.me/crux-arm/distfiles/$(CONFIG_FILE)
	touch $@

files: $(PWD)/$(KERNEL_TARBALL) $(PWD)/$(PATCH_FILE) $(PWD)/$(CONFIG_FILE)

$(WORK)/linux-$(KERNEL_VERSION):
	bsdtar -C $(WORK) -xf $(PWD)/$(KERNEL_TARBALL)
	patch -d $(WORK)/linux-$(KERNEL_VERSION) -p1 -i $(PWD)/$(PATCH_FILE)
	sed -e 's|LINUX_COMPILE_BY=.*|LINUX_COMPILE_BY=devel|' \
	    -e 's|LINUX_COMPILE_HOST=.*|LINUX_COMPILE_HOST=crux-arm.nu|' \
	    -i $(WORK)/linux-$(KERNEL_VERSION)/scripts/mkcompile_h
	touch $@

$(WORK)/linux-$(KERNEL_VERSION)/.config: $(WORK)/linux-$(KERNEL_VERSION)
	cp -v $(PWD)/$(CONFIG_FILE) $@
	touch $@

config: files $(WORK)/linux-$(KERNEL_VERSION)/.config

$(WORK)/zImage-$(KERNEL_VERSION): config
	cd $(WORK)/linux-$(KERNEL_VERSION) && \
		export PATH=$(CROSSTOOLS)/bin:$$PATH && \
		export LD_LIBRARY_PATH=$(CROSSTOOLS)/lib:$$LD_LIBRARY_PATH && \
		make ARCH=arm CROSS_COMPILE=$(TARGET)- zImage
	cp -v $(WORK)/linux-$(KERNEL_VERSION)/arch/arm/boot/zImage $@
	touch $@

$(WORK)/kernel7-$(KERNEL_VERSION).img: $(WORK)/zImage-$(KERNEL_VERSION)
	chmod +x $(WORK)/linux-$(KERNEL_VERSION)/scripts/mkknlimg
	cd $(WORK)/linux-$(KERNEL_VERSION) && \
		./scripts/mkknlimg $(WORK)/zImage-$(KERNEL_VERSION) $@
	touch $@

image: $(WORK)/kernel7-$(KERNEL_VERSION).img

image-clean:
	rm -f $(WORK)/zImage-$(KERNEL_VERSION)
	rm -f $(WORK)/kernel7-$(KERNEL_VERSION).img
	if [ -d $(WORK)/linux-$(KERNEL_VERSION)/.config ]; then \
		cd $(WORK)/linux-$(KERNEL_VERSION) && \
			export PATH=$(CROSSTOOLS)/bin:$$PATH && \
			export LD_LIBRARY_PATH=$(CROSSTOOLS)/lib:$$LD_LIBRARY_PATH && \
			make ARCH=arm CROSS_COMPILE=$(TARGET)- clean ; \
	fi

image-distclean: image-clean
	rm -rf $(WORK)/linux-$(KERNEL_VERSION)

$(WORK)/dtb-$(KERNEL_VERSION): $(WORK)/linux-$(KERNEL_VERSION)
	cd $(WORK)/linux-$(KERNEL_VERSION) && \
		export PATH=$(CROSSTOOLS)/bin:$$PATH && \
		export LD_LIBRARY_PATH=$(CROSSTOOLS):$$LD_LIBRARY_PATH && \
		make ARCH=arm CROSS_COMPILE=$(TARGET)- dtbs
	rm -rf $(WORK)/dtb
	mkdir -p $(WORK)/dtb/overlays
	cp $(WORK)/linux-$(KERNEL_VERSION)/arch/arm/boot/dts/*.dtb $(WORK)/dtb
	cp $(WORK)/linux-$(KERNEL_VERSION)/arch/arm/boot/dts/overlays/*.dtb* $(WORK)/dtb/overlays
	mv $(WORK)/dtb $(WORK)/dtb-$(KERNEL_VERSION)

$(WORK)/dtb-$(KERNEL_VERSION).tar.xz: $(WORK)/dtb-$(KERNEL_VERSION)
	cd $(WORK)/dtb-$(KERNEL_VERSION) && \
		bsdtar --uid 0 --gid 0 -cvJf $(WORK)/dtb-$(KERNEL_VERSION).tar.xz *

dtb: $(WORK)/dtb-$(KERNEL_VERSION).tar.xz

dtb-clean:
	rm -f $(WORK)/dtb-$(KERNEL_VERSION).tar.xz
	rm -rf $(WORK)/dtb-$(KERNEL_VERSION)

dtb-distclean: dtb-clean

$(WORK)/modules-$(KERNEL_VERSION): $(WORK)/linux-$(KERNEL_VERSION)
	cd $(WORK)/linux-$(KERNEL_VERSION) && \
		export PATH=$(CROSSTOOLS)/bin:$$PATH && \
		export LD_LIBRARY_PATH=$(LD_LIBRARY_PATH)/lib:$$LD_LIBRARY_PATH && \
		make ARCH=arm CROSS_COMPILE=$(TARGET)- modules && \
		make ARCH=arm CROSS_COMPILE=$(TARGET)- INSTALL_MOD_PATH=$(WORK)/modules-$(KERNEL_VERSION) modules_install
	rm -f $(WORK)/modules-$(KERNEL_VERSION)/lib/modules/$(KERNEL_VERSION)/{source,build}
	touch $(WORK)/modules-$(KERNEL_VERSION)

$(WORK)/modules-$(KERNEL_VERSION).tar.xz: $(WORK)/modules-$(KERNEL_VERSION)
	cd $(WORK)/modules-$(KERNEL_VERSION) && \
		bsdtar --uid 0 --gid 0 -cvJf $(WORK)/modules-$(KERNEL_VERSION).tar.xz *
	touch $(WORK)/modules-$(KERNEL_VERSION).tar.xz

modules: $(WORK)/modules-$(KERNEL_VERSION).tar.xz

modules-clean:
	rm -f $(WORK)/modules-$(KERNEL_VERSION).tar.xz
	rm -rf $(WORK)/modules-$(KERNEL_VERSION)

modules-distclean: modules-clean

$(WORK)/System.map-$(KERNEL_VERSION): $(WORK)/zImage-$(KERNEL_VERSION)
	cp $(WORK)/linux-$(KERNEL_VERSION)/System.map $(WORK)/System.map-$(KERNEL_VERSION)
	touch $(WORK)/System.map-$(KERNEL_VERSION)

map: $(WORK)/System.map-$(KERNEL_VERSION)

map-clean:
	rm -f $(WORK)/System.map-$(KERNEL_VERSION)

map-distclean: map-clean

menuconfig: $(WORK)/linux-$(KERNEL_VERSION)
	cd $(WORK)/linux-$(KERNEL_VERSION) && \
		export PATH=$(CROSSTOOLS)/bin:$$PATH && \
		export LD_LIBRARY_PATH=$(CROSSTOOLS)/lib:$$LD_LIBRARY_PATH && \
		make ARCH=arm CROSS_COMPILE=$(TARGET)- menuconfig
	touch $(WORK)/linux-$(KERNEL_VERSION)

# End of file