--- xen/arch/x86/Makefile_ORIGINAL	2016-12-09 08:00:35.187413472 -0800
+++ xen/arch/x86/Makefile	2016-12-09 08:05:26.275430987 -0800
@@ -174,20 +174,20 @@
 $(TARGET).efi: prelink-efi.o $(note_file) efi.lds efi/relocs-dummy.o $(BASEDIR)/common/symbols-dummy.o efi/mkreloc
 	$(foreach base, $(VIRT_BASE) $(ALT_BASE), \
 	          $(guard) $(LD) $(call EFI_LDFLAGS,$(base)) -T efi.lds -N $< efi/relocs-dummy.o \
-	                $(BASEDIR)/common/symbols-dummy.o $(note_file) -o $(@D)/.$(@F).$(base).0 &&) :
+	                $(BASEDIR)/common/symbols-dummy.o  -b coff-x86-64 $(note_file) -o $(@D)/.$(@F).$(base).0 &&) :
 	$(guard) efi/mkreloc $(foreach base,$(VIRT_BASE) $(ALT_BASE),$(@D)/.$(@F).$(base).0) >$(@D)/.$(@F).0r.S
 	$(guard) $(NM) -pa --format=sysv $(@D)/.$(@F).$(VIRT_BASE).0 \
 		| $(guard) $(BASEDIR)/tools/symbols $(all_symbols) --sysv --sort >$(@D)/.$(@F).0s.S
 	$(guard) $(MAKE) -f $(BASEDIR)/Rules.mk $(@D)/.$(@F).0r.o $(@D)/.$(@F).0s.o
 	$(foreach base, $(VIRT_BASE) $(ALT_BASE), \
 	          $(guard) $(LD) $(call EFI_LDFLAGS,$(base)) -T efi.lds -N $< \
-	                $(@D)/.$(@F).0r.o $(@D)/.$(@F).0s.o $(note_file) -o $(@D)/.$(@F).$(base).1 &&) :
+	                $(@D)/.$(@F).0r.o $(@D)/.$(@F).0s.o  -b coff-x86-64 $(note_file) -o $(@D)/.$(@F).$(base).1 &&) :
 	$(guard) efi/mkreloc $(foreach base,$(VIRT_BASE) $(ALT_BASE),$(@D)/.$(@F).$(base).1) >$(@D)/.$(@F).1r.S
 	$(guard) $(NM) -pa --format=sysv $(@D)/.$(@F).$(VIRT_BASE).1 \
 		| $(guard) $(BASEDIR)/tools/symbols $(all_symbols) --sysv --sort >$(@D)/.$(@F).1s.S
 	$(guard) $(MAKE) -f $(BASEDIR)/Rules.mk $(@D)/.$(@F).1r.o $(@D)/.$(@F).1s.o
 	$(guard) $(LD) $(call EFI_LDFLAGS,$(VIRT_BASE)) -T efi.lds -N $< \
-	                $(@D)/.$(@F).1r.o $(@D)/.$(@F).1s.o $(note_file) -o $@
+	                $(@D)/.$(@F).1r.o $(@D)/.$(@F).1s.o  -b coff-x86-64 $(note_file) -o $@
 	if $(guard) false; then rm -f $@; echo 'EFI support disabled'; \
 	else $(NM) -pa --format=sysv $(@D)/$(@F) \
 		| $(BASEDIR)/tools/symbols --xensyms --sysv --sort >$(@D)/$(@F).map; fi