x86: efi: payload: Enforce toolchain to generate 64-bit EFI payload stub codes

Attempting to use a toolchain that is preconfigured to generate code
for the 32-bit architecture (i386), for example, the i386-linux-gcc
toolchain on kernel.org, to compile the 64-bit EFI payload does not
build. This updates the makefile fragments to ensure '-m64' is passed
to toolchain when building the 64-bit EFI payload stub codes.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

arch/x86/cpu/Makefile

@@ -18,7 +18,8 @@ obj-y	+= cpu.o cpu_x86.o
 ifndef CONFIG_$(SPL_)X86_64
 AFLAGS_REMOVE_call32.o := -mregparm=3 \
 	$(if $(CONFIG_EFI_STUB_64BIT),-march=i386 -m32)
-AFLAGS_call32.o := -fpic -fshort-wchar
+AFLAGS_call32.o := -fpic -fshort-wchar \
+	$(if $(CONFIG_EFI_STUB_64BIT),-m64)
 
 extra-y += call32.o
 endif

arch/x86/lib/Makefile

@@ -58,10 +58,10 @@ CFLAGS_reloc_ia32_efi.o += -fpic -fshort-wchar
 
 # When building for 64-bit we must remove the i386-specific flags
 CFLAGS_REMOVE_reloc_x86_64_efi.o += -mregparm=3 -march=i386 -m32
-CFLAGS_reloc_x86_64_efi.o += -fpic -fshort-wchar
+CFLAGS_reloc_x86_64_efi.o += -fpic -fshort-wchar -m64
 
 AFLAGS_REMOVE_crt0_x86_64_efi.o += -mregparm=3 -march=i386 -m32
-AFLAGS_crt0_x86_64_efi.o += -fpic -fshort-wchar
+AFLAGS_crt0_x86_64_efi.o += -fpic -fshort-wchar -m64
 
 extra-$(CONFIG_EFI_STUB_32BIT) += crt0_ia32_efi.o reloc_ia32_efi.o
 extra-$(CONFIG_EFI_STUB_64BIT) += crt0_x86_64_efi.o reloc_x86_64_efi.o

lib/efi/Makefile

@@ -7,9 +7,11 @@ obj-$(CONFIG_EFI_STUB) += efi_info.o
 
 CFLAGS_REMOVE_efi_stub.o := -mregparm=3 \
 	$(if $(CONFIG_EFI_STUB_64BIT),-march=i386 -m32)
-CFLAGS_efi_stub.o := -fpic -fshort-wchar -DEFI_STUB
+CFLAGS_efi_stub.o := -fpic -fshort-wchar -DEFI_STUB \
+	$(if $(CONFIG_EFI_STUB_64BIT),-m64)
 CFLAGS_REMOVE_efi.o := -mregparm=3 \
 	$(if $(CONFIG_EFI_STUB_64BIT),-march=i386 -m32)
-CFLAGS_efi.o := -fpic -fshort-wchar -DEFI_STUB
+CFLAGS_efi.o := -fpic -fshort-wchar -DEFI_STUB \
+	$(if $(CONFIG_EFI_STUB_64BIT),-m64)
 
 extra-$(CONFIG_EFI_STUB) += efi_stub.o efi.o