# This uses the cross compiler produced by Rob Landley
# Taken from http://landley.net/aboriginal/downloads/binaries/
CROSS_COMPILE	?= 
build_dir       := $(CURDIR)/build-i586
output_dir	:= $(HOME)
rootfs		:= $(HOME)/rootfs-i586.cpio
install_dir     := $(build_dir)/install
config_file     := $(build_dir)/.config
rootfsbase	:= $(shell basename $(rootfs))

make_options := -f Makefile \
                ARCH=i386 \
                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:"
	@echo "make -f i586.mak config"
	@echo "make -f i586.mak build"

.PHONY: have-rootfs
have-rootfs:
	@if [ ! -d $(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

.PHONY: config-base
config-base: FORCE
	@mkdir -p $(build_dir)
	@cp -r $(rootfs) $(build_dir)/$(rootfsbase)
	$(MAKE) $(make_options) i386_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: config-base config-initramfs FORCE
	# Reconfigure a bit
	$(CURDIR)/scripts/config --file $(config_file) \
	--enable X86_32 \
	--enable M586 \
	--disable ACPI \
	--disable SCHED_SMT \
	--disable SCHED_MC \
	--enable MATH_EMULATION \
	--disable VIRTUALIZATION \
	--disable HAMRADIO \
	--disable SMP \
	--disable SUSPEND \
	--disable HIBERNATION \
	--enable INTEL_IDLE \
	--enable NETDEV_1000 \
	--enable E1000 \
	--enable SERIAL_8250 \
	--enable SERIAL_8250_CONSOLE \
	--enable ISA \
	--enable EISA \
	--enable ISA_DMA_API \
	--enable BLK_DEV_XD
	yes "" | make $(make_options) oldconfig

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

saveconfig: config-base FORCE
	yes "" | make $(make_options) oldconfig
	$(MAKE) $(make_options) savedefconfig
	cp $(build_dir)/defconfig arch/x86/configs/i386_defconfig

build: have-crosscompiler FORCE
	$(MAKE) $(make_options) -j 9 bzImage
	$(MAKE) $(make_options) -j 9 modules
	# Copy to output dir
	cp -f $(build_dir)/arch/x86/boot/bzImage $(output_dir)/vmlinuz

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: