[U-Boot] [PATCH v5] x86: use EFI calling convention for efi_main on x86_64

[Bin Meng]

On Thu, Jun 14, 2018 at 8:27 AM, Ivan Gorinov <ivan.gorinov at intel.com> wrote:
> UEFI specifies the calling convention used in Microsoft compilers;
> first arguments of a function are passed in (%rcx, %rdx, %r8, %r9).
>
> All other compilers use System V ABI by default, passing first integer
> arguments of a function in (%rdi, %rsi, %rdx, %rcx, %r8, %r9).
>
> These ABI also specify different sets of registers that must be preserved
> across function calls (callee-saved).
>
> GCC allows using the Microsoft calling convention by adding the ms_abi
> attribute to a function declaration.
>
> Current EFI implementation in U-Boot specifies EFIAPI for efi_main()
> in the test apps but uses default calling convention in lib/efi.
>
> Save efi_main() arguments in the startup code on x86_64;
> use EFI calling convention for _relocate() on x86_64;
> consistently use EFI calling convention for efi_main() everywhere.
>
> Signed-off-by: Ivan Gorinov <ivan.gorinov at intel.com>
> ---
>  arch/x86/lib/crt0_x86_64_efi.S | 24 +++++++++++++-----------
>  lib/efi/efi_app.c              |  3 ++-
>  lib/efi/efi_stub.c             |  3 ++-
>  3 files changed, 17 insertions(+), 13 deletions(-)
>

Reviewed-by: Bin Meng <bmeng.cn at gmail.com>
Tested-by: Bin Meng <bmeng.cn at gmail.com>