Fix out of source tree build bugs:
	- add (srctree)/include/asm-xen to include list
	- fix include2/asm link to reference asm-XENARCH
	- fix install target for public headeres This fix enables the complication of several configurations from the same (read-only) source tree.

Signed-off-by: Shahar Frank <shaharf@xxxxxxxxxxxx>

Index: arch/xen/Makefile
===================================================================
--- arch/xen/Makefile	(revision 112)
+++ arch/xen/Makefile	(working copy)
@@ -16,12 +16,22 @@
 
 # pick up headers from include/asm-xen/asm in preference over include/asm  NOSTDINC_FLAGS  = -nostdinc -iwithprefix include/asm-xen -Iinclude/asm-xen -iwithprefix include
+ifneq ($(KBUILD_SRC),)
+NOSTDINC_FLAGS += -I$(srctree)/include/asm-xen endif
 
 # make uname return the processor arch
 UTS_MACHINE := $(XENARCH)
 
 core-y	+= arch/xen/kernel/
 
+.PHONY: include2/asm
+include2/asm:
+ifneq ($(KBUILD_SRC),)
+	@echo '  SYMLINK ../include/asm-$(XENARCH) -> include2/asm'
+	$(Q)ln -fsn ../include/asm-$(XENARCH) include2/asm endif
+
 include/.asm-ignore: include/asm
 	@rm -f include/.asm-ignore
 	@mv include/asm include/.asm-ignore
@@ -40,7 +50,7 @@
 	@ln -fsn $(srctree)/arch/xen/$(XENARCH) $@
 
 prepare: include/.asm-ignore include/asm-xen/asm \
-	arch/xen/arch ;
+	arch/xen/arch include2/asm
 
 all: vmlinuz
 
@@ -58,7 +68,7 @@
 	install -m0664 .config $(INSTALL_PATH)/boot/config-$(XINSTALL_NAME)$(INSTALL_SUFFIX)
 	install -m0664 System.map $(INSTALL_PATH)/boot/System.map-$(XINSTALL_NAME)$(INSTALL_SUFFIX)
 	mkdir -p $(INSTALL_PATH)/usr/include/xen/linux
-	install -m0644 include/asm-xen/linux-public/*.h $(INSTALL_PATH)/usr/include/xen/linux
+	install -m0644 $(srctree)/include/asm-xen/linux-public/*.h 
+$(INSTALL_PATH)/usr/include/xen/linux
 
 archclean:
 	@if [ -e arch/xen/arch ]; then $(MAKE) $(clean)=arch/xen/arch; fi;