[U-Boot] [PATCH v4 1/4] x86: use EFI calling convention for efi_main on x86_64

Bin Meng bmeng.cn at gmail.com
Fri Jun 22 01:44:38 UTC 2018


Hi Ivan,

On Wed, Jun 13, 2018 at 9:36 AM, Bin Meng <bmeng.cn at gmail.com> wrote:
> Hi Ivan,
>
> On Wed, Jun 13, 2018 at 1:52 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.
>> The arguments of efi_main() are also passed as unused arguments to the
>> _relocate() function.
>>
>> Save efi_main() arguments in the startup code on x86_64;
>> use EFI calling convention for _relocate() on x86_64;
>> remove unused _relocate() arguments;
>
> Thanks for working on this. But as I mentioned previously, the removal
> of _relocate() arguments should be in a separate patch. This patch
> should only deal with the calling convention changes.
>
> So we should have 4 patches:
> [1/4]: efi: calling convention changes for x86_64
> [2/4]: x86: remove unused _relocate() arguments
> [3/4]: arm: remove unused _relocate() arguments
> [4/4]: riscv: remove unused _relocate() arguments
>

So far I did not see you posted a newer version of patch series to
remove unused _relocate() arguments for x86/arm/riscv. Will you do
that?

>> 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  | 21 ++++++++++-----------
>>  arch/x86/lib/reloc_x86_64_efi.c |  3 +--
>>  lib/efi/efi_app.c               |  3 ++-
>>  lib/efi/efi_stub.c              |  3 ++-
>>  4 files changed, 15 insertions(+), 15 deletions(-)
>>

Regards,
Bin


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