# 
# Copyright (C) 2006 OpenWrt.org
#
# This is free software, licensed under the GNU General Public License v2.
# See /LICENSE for more information.
#
KERNEL_BUILD:=1

include $(INCLUDE_DIR)/host.mk
include $(INCLUDE_DIR)/kernel.mk

LINUX_SOURCE:=linux-$(LINUX_VERSION).tar.bz2
LINUX_SITE=http://www.us.kernel.org/pub/linux/kernel/v$(KERNEL) \
           http://www.us.kernel.org/pub/linux/kernel/v$(KERNEL) \
           http://www.kernel.org/pub/linux/kernel/v$(KERNEL) \
           http://www.de.kernel.org/pub/linux/kernel/v$(KERNEL)

ifneq (,$(findstring uml,$(BOARD)))
  LINUX_KARCH:=um
else
  LINUX_KARCH:=$(shell echo $(ARCH) | sed -e 's/i[3-9]86/i386/' \
	-e 's/mipsel/mips/' \
	-e 's/mipseb/mips/' \
	-e 's/powerpc/ppc/' \
	-e 's/sh[234]/sh/' \
	-e 's/armeb/arm/' \
  )
endif

KERNELNAME=
ifneq (,$(findstring x86,$(BOARD)))
  KERNELNAME="bzImage"
endif
ifneq (,$(findstring ppc,$(BOARD)))
  KERNELNAME="uImage"
endif


$(DL_DIR)/$(LINUX_SOURCE):
	-mkdir -p $(DL_DIR)
	$(SCRIPT_DIR)/download.pl $(DL_DIR) $(LINUX_SOURCE) $(LINUX_KERNEL_MD5SUM) $(LINUX_SITE)

$(LINUX_DIR)/.unpacked: $(DL_DIR)/$(LINUX_SOURCE)
	-mkdir -p $(KERNEL_BUILD_DIR)
	bzcat $(DL_DIR)/$(LINUX_SOURCE) | tar -C $(KERNEL_BUILD_DIR) $(TAR_OPTIONS)
	touch $@

ifeq ($(KERNEL),2.4)
$(LINUX_DIR)/.configured: $(LINUX_DIR)/.patched $(LINUX_DIR)/.config
	$(SED) "s,\-mcpu=,\-mtune=,g;" $(LINUX_DIR)/arch/mips/Makefile
	$(MAKE) -C $(LINUX_DIR) CROSS_COMPILE="$(KERNEL_CROSS)" CC="$(KERNEL_CC)" ARCH=$(LINUX_KARCH) oldconfig include/linux/compile.h include/linux/version.h
	touch $@

$(LINUX_DIR)/.depend_done: $(LINUX_DIR)/.configured
	$(MAKE) -C $(LINUX_DIR) CROSS_COMPILE="$(KERNEL_CROSS)" ARCH=$(LINUX_KARCH) dep
	touch $@

$(LINUX_DIR)/vmlinux: $(LINUX_DIR)/.depend_done
else
$(LINUX_DIR)/.configured: $(LINUX_DIR)/.patched
	$(MAKE) -C $(LINUX_DIR) CROSS_COMPILE="$(KERNEL_CROSS)" CC="$(KERNEL_CC)" ARCH=$(LINUX_KARCH) oldconfig prepare scripts
	touch $@
endif

ramdisk-config: $(LINUX_DIR)/.configured FORCE
	mv $(LINUX_DIR)/.config $(LINUX_DIR)/.config.old
	grep -v INITRAMFS $(LINUX_DIR)/.config.old > $(LINUX_DIR)/.config
ifeq ($(CONFIG_TARGET_ROOTFS_INITRAMFS),y)
	echo 'CONFIG_INITRAMFS_SOURCE="../../root"' >> $(LINUX_DIR)/.config
	echo 'CONFIG_INITRAMFS_ROOT_UID=0' >> $(LINUX_DIR)/.config
	echo 'CONFIG_INITRAMFS_ROOT_GID=0' >> $(LINUX_DIR)/.config
	mkdir -p $(BUILD_DIR)/root/etc/init.d
	$(CP) ../generic-2.6/files/init $(BUILD_DIR)/root/
else
	rm -f $(BUILD_DIR)/root/init $(BUILD_DIR)/root/etc/init.d/S00initramfs
	echo 'CONFIG_INITRAMFS_SOURCE=""' >> $(LINUX_DIR)/.config
endif

$(LINUX_DIR)/vmlinux: ramdisk-config
	$(MAKE) -j$(CONFIG_JLEVEL) -C $(LINUX_DIR) CROSS_COMPILE="$(KERNEL_CROSS)" CC="$(KERNEL_CC)" ARCH=$(LINUX_KARCH) $(KERNELNAME)

$(LINUX_KERNEL): $(LINUX_DIR)/vmlinux
	$(KERNEL_CROSS)objcopy -O binary -R .reginfo -R .note -R .comment -R .mdebug -S $< $@
	touch -c $(LINUX_KERNEL)

$(LINUX_DIR)/.modules_done: $(LINUX_DIR)/.config
	rm -rf $(KERNEL_BUILD_DIR)/modules
	$(MAKE) -j$(CONFIG_JLEVEL) -C "$(LINUX_DIR)" CROSS_COMPILE="$(KERNEL_CROSS)" CC="$(KERNEL_CC)" ARCH=$(LINUX_KARCH) modules
	$(MAKE) -C "$(LINUX_DIR)" CROSS_COMPILE="$(KERNEL_CROSS)" CC="$(KERNEL_CC)" ARCH=$(LINUX_KARCH) DEPMOD=true INSTALL_MOD_PATH=$(KERNEL_BUILD_DIR)/modules modules_install
	touch $(LINUX_DIR)/.modules_done

$(LINUX_DIR)/.linux-compile: $(LINUX_DIR)/.modules_done
	@rm -f $(BUILD_DIR)/linux
	ln -sf $(KERNEL_BUILD_DIR)/linux-$(LINUX_VERSION) $(BUILD_DIR)/linux
	touch $@

$(TOPDIR)/.kernel.mk: $(TOPDIR)/target/linux/$(BOARD)-$(KERNEL)/Makefile
	echo "CONFIG_BOARD:=$(BOARD)" > $@
	echo "CONFIG_KERNEL:=$(KERNEL)" >> $@
	echo "CONFIG_LINUX_VERSION:=$(LINUX_VERSION)" >> $@
	echo "CONFIG_LINUX_RELEASE:=$(LINUX_RELEASE)" >> $@
	echo "CONFIG_LINUX_KARCH:=$(LINUX_KARCH)" >> $@

download: $(DL_DIR)/$(LINUX_SOURCE)
prepare: $(LINUX_DIR)/.configured
	@mkdir -p $(LINUX_DIR)

compile: prepare $(LINUX_DIR)/.linux-compile
install: compile $(LINUX_KERNEL)

mostlyclean: FORCE
	rm -f $(LINUX_DIR)/.linux-compile
	rm -f $(KERNEL_BUILD_DIR)/linux-$(LINUX_VERSION)/.modules_done
	rm -f $(KERNEL_BUILD_DIR)/linux-$(LINUX_VERSION)/.drivers-unpacked
	$(MAKE) -C $(KERNEL_BUILD_DIR)/linux-$(LINUX_VERSION) clean
	rm -f $(LINUX_KERNEL)

rebuild: FORCE
	-$(MAKE) mostlyclean
	if [ -f $(LINUX_KERNEL) ]; then \
		$(MAKE) clean; \
	fi
	$(MAKE) compile $(MAKE_TRACE)

clean: FORCE
	rm -f $(STAMP_DIR)/.linux-compile
	rm -rf $(KERNEL_BUILD_DIR)