LINUX_SERIES = 2.6
LINUX_VER    = 2.6.18

EXTRAVERSION ?= xen

LINUX_SRCDIR = linux-$(LINUX_VER)-xen
LINUX_DIR    = build-linux-$(LINUX_VER)-$(EXTRAVERSION)_$(XEN_TARGET_ARCH)

IMAGE_TARGET ?= vmlinuz
INSTALL_BOOT_PATH ?= $(DESTDIR)

ifeq ($(XEN_TARGET_ARCH),ia64)
INSTALL_BOOT_PATH := $(DESTDIR)/boot
endif

LINUX_VER3  := $(LINUX_SERIES).$(word 3, $(subst ., ,$(LINUX_VER)))

include buildconfigs/Rules.mk

# The real action starts here!
.PHONY: build
build: $(LINUX_DIR)/include/linux/autoconf.h
	if grep "^CONFIG_MODULES=" $(LINUX_DIR)/.config ; then \
	    $(MAKE) -C $(LINUX_DIR) ARCH=$(LINUX_ARCH) modules ; \
	    $(MAKE) -C $(LINUX_DIR) ARCH=$(LINUX_ARCH) INSTALL_MOD_PATH=$(DESTDIR) modules_install ; \
	fi
	$(MAKE) -C $(LINUX_DIR) ARCH=$(LINUX_ARCH) INSTALL_PATH=$(DESTDIR) $(IMAGE_TARGET)
	mkdir -p $(INSTALL_BOOT_PATH)
	$(MAKE) -C $(LINUX_DIR) ARCH=$(LINUX_ARCH) INSTALL_PATH=$(INSTALL_BOOT_PATH) install

$(LINUX_SRCDIR)/.valid-src: ref-linux-$(LINUX_VER)/.valid-ref
	rm -rf $(LINUX_SRCDIR)
	cp -al $(<D) $(LINUX_SRCDIR)
	# Apply arch-xen patches
	( cd linux-$(LINUX_SERIES)-xen-sparse && \
          LINUX_ARCH=$(LINUX_ARCH) bash ./mkbuildtree ../$(LINUX_SRCDIR) )
	# Patch kernel Makefile to set EXTRAVERSION
	( cd $(LINUX_SRCDIR) ; \
	  sed -e 's,^EXTRAVERSION.*,&$$(XENGUEST),' \
	      -e 's,^KERNELRELEASE,XENGUEST := $$(shell [ -r $$(objtree)/.xenguest ] \&\& cat $$(objtree)/.xenguest)\n&,' Makefile >Mk.tmp ; \
	  rm -f Makefile ; mv Mk.tmp Makefile )
	touch $@

$(LINUX_DIR)/include/linux/autoconf.h: $(LINUX_SRCDIR)/.valid-src
	rm -rf $(LINUX_DIR)
	mkdir -p $(LINUX_DIR)
	# Re-use config from install dir if one exits else use default config
	CONFIG_VERSION=$$(sed -ne 's/$$(XENGUEST)//; s/^EXTRAVERSION = //p' $(LINUX_SRCDIR)/Makefile); \
	[ -r $(DESTDIR)/boot/config-$(LINUX_VER3)$$CONFIG_VERSION-$(EXTRAVERSION) ] && \
	  cp $(DESTDIR)/boot/config-$(LINUX_VER3)$$CONFIG_VERSION-$(EXTRAVERSION) $(LINUX_DIR)/.config \
	  || sh buildconfigs/create_config.sh $(LINUX_DIR)/.config $(EXTRAVERSION) $(XEN_TARGET_ARCH) $(XEN_SYSTYPE)
	# See if we need to munge config to enable PAE
	$(MAKE) CONFIG_FILE=$(LINUX_DIR)/.config -f buildconfigs/Rules.mk config-update-pae
	echo "-$(EXTRAVERSION)" >$(LINUX_DIR)/.xenguest
	$(MAKE) -C $(LINUX_SRCDIR) ARCH=$(LINUX_ARCH) oldconfig O=$$(/bin/pwd)/$(LINUX_DIR)

.PHONY: prep
prep: $(LINUX_DIR)/include/linux/autoconf.h

.PHONY: config
config: CONFIGMODE = menuconfig
config: $(LINUX_DIR)/include/linux/autoconf.h
	$(MAKE) -C $(LINUX_DIR) ARCH=$(LINUX_ARCH) $(CONFIGMODE)

.PHONY: clean
clean::
	[ ! -d $(LINUX_DIR) ] || \
		$(MAKE) -C $(LINUX_DIR) ARCH=$(LINUX_ARCH) clean


.PHONY: delete
delete: 
	rm -rf tmp-linux-$(LINUX_VER) $(LINUX_DIR) 

.PHONY: mrpropper
mrpropper:
	rm -rf $(LINUX_SRCDIR)
	rm -f linux-$(LINUX_VER).tar.bz2