x86/efi: split compiler vs linker support

So that an ELF binary with support for EFI services will be built when
the compiler supports the MS ABI, regardless of the linker support for
PE.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Tested-by: Daniel Kiper <daniel.kiper@oracle.com>

xen/arch/x86/Makefile

@@ -163,10 +163,11 @@ EFI_LDFLAGS += --minor-image-version=$(XEN_SUBVERSION)
 EFI_LDFLAGS += --major-os-version=2 --minor-os-version=0
 EFI_LDFLAGS += --major-subsystem-version=2 --minor-subsystem-version=0
 
-# Check if the build system supports PE.
-XEN_BUILD_PE := $(shell $(CC) $(filter-out $(CFLAGS-y) .%.d,$(CFLAGS)) -c efi/check.c -o efi/check.o 2>/dev/null && echo y)
-export XEN_BUILD_PE := $(if $(XEN_BUILD_PE),$(shell $(LD) -mi386pep --subsystem=10 -o efi/check.efi efi/check.o 2>/dev/null && echo y))
-CFLAGS-$(XEN_BUILD_PE) += -DXEN_BUILD_PE
+# Check if the compiler supports the MS ABI.
+export XEN_BUILD_EFI := $(shell $(CC) $(filter-out $(CFLAGS-y) .%.d,$(CFLAGS)) -c efi/check.c -o efi/check.o 2>/dev/null && echo y)
+# Check if the linker supports PE.
+XEN_BUILD_PE := $(if $(XEN_BUILD_EFI),$(shell $(LD) -mi386pep --subsystem=10 -o efi/check.efi efi/check.o 2>/dev/null && echo y))
+CFLAGS-$(XEN_BUILD_EFI) += -DXEN_BUILD_EFI
 
 $(TARGET).efi: VIRT_BASE = 0x$(shell $(NM) efi/relocs-dummy.o | sed -n 's, A VIRT_START$$,,p')
 $(TARGET).efi: ALT_BASE = 0x$(shell $(NM) efi/relocs-dummy.o | sed -n 's, A ALT_START$$,,p')

xen/arch/x86/efi/Makefile

@@ -6,6 +6,6 @@ CFLAGS += -fshort-wchar
 boot.init.o: buildid.o
 
 obj-y := stub.o
-obj-$(XEN_BUILD_PE) := boot.init.o compat.o relocs-dummy.o runtime.o
-extra-$(XEN_BUILD_PE) += buildid.o
-nocov-$(XEN_BUILD_PE) += stub.o
+obj-$(XEN_BUILD_EFI) := boot.init.o compat.o relocs-dummy.o runtime.o
+extra-$(XEN_BUILD_EFI) += buildid.o
+nocov-$(XEN_BUILD_EFI) += stub.o

xen/arch/x86/xen.lds.S

@@ -304,7 +304,7 @@ SECTIONS
   } :text
 #endif
 
-#ifndef XEN_BUILD_PE
+#ifndef XEN_BUILD_EFI
   efi = .;
 #endif