include/efi: Override EFIAPI macro for x86_64

This commit overrides the EFIAPI macro definition when using FSP on
x86_64 to ensure the correct calling convention is used.

On i386, there is no side-effect since the C calling convention used
by coreboot and FSP are the same. However, on x86_64, FSP/UEFI uses
the Microsoft x64 calling convention while coreboot uses the System
V AMD64 ABI.

This change resolves this incompatibility by setting EFIAPI to
attribute((ms_abi)) on x86_64 when using FSP.

TEST=Able to build google/rex0 in 32-bit and 64-bit mode.

Change-Id: Ifae910be66d550af04cce5136d186a7e9dd085b3
Signed-off-by: Subrata Banik <subratabanik@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/82266
Reviewed-by: Ronak Kanabar <ronak.kanabar@intel.com>
Reviewed-by: Eric Lai <ericllai@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

0 files changed, 0 insertions, 0 deletions