Re: edk2 and gnu-efi calling schemes

["Knop, Ryszard" <ryszard.knop@intel.com>]

Hi Laszlo,
Regarding "functions that take variable arguments must be EFIAPI, even if they are STATIC (long story)" - what's the story? :)
Thanks, Richard.

-----Original Message-----
From: edk2-devel [mailto:edk2-devel-bounces@lists.01.org] On Behalf Of Laszlo Ersek
Sent: Friday, December 7, 2018 14:07
To: Peter Wiehe <peter.wiehe2@gmail.com>
Cc: edk2-devel@lists.01.org; Bill Paul <wpaul@windriver.com>
Subject: Re: [edk2] edk2 and gnu-efi calling schemes

On 12/06/18 23:46, Bill Paul wrote:
> Of all the gin joints in all the towns in all the world, Peter Wiehe 
> had to walk into mine at 14:34 on Thursday 06 December 2018 and say:
> 
>> OK, another question:
>>
>> when writing an UEFI application, edk2 and gnu-efi have different 
>> 64bit calling schemes. Does that only apply to calling the 
>> runtime-library/object file (and inside of the UEFI-application, of 
>> course)? Or does the call from application to UEFI differ in both 
>> toolkits, too? (If it is the latter, it would mean that the UEFI 
>> standard is unprecise!)
> 
> Both the EDK and GNU EFI obey the same standards when calling UEFI 
> APIs. Their exact implementations may differ depending on the 
> circumstances. For example, GNU EFI may use the 
> __attribute__((ms_abi)) tag to tell the compiler what ABI to use, or 
> if the compiler doesn't support this it can fall back to using some 
> compatibility wrapper macros (see lib/x86_64/efi_stub.S). Either way, you end up with the same behavior.
> 
> Within a given FOO.EFI application, the application code itself can 
> get away with using whatever calling convention it wants, right up 
> until it needs to call a UEFI firmware routine. At that point, it has 
> to follow the conventions spelled out in the UEFI spec.

I'd like to add:

- in edk2, functions declared in lib class headers have to be EFIAPI;

- functions that take variable arguments must be EFIAPI, even if they
  are STATIC (long story).

Thanks
Laszlo
_______________________________________________
edk2-devel mailing list
edk2-devel@lists.01.org
https://lists.01.org/mailman/listinfo/edk2-devel
--------------------------------------------------------------------

Intel Technology Poland sp. z o.o.
ul. Slowackiego 173 | 80-298 Gdansk | Sad Rejonowy Gdansk Polnoc | VII Wydzial Gospodarczy Krajowego Rejestru Sadowego - KRS 101882 | NIP 957-07-52-316 | Kapital zakladowy 200.000 PLN.

Ta wiadomosc wraz z zalacznikami jest przeznaczona dla okreslonego adresata i moze zawierac informacje poufne. W razie przypadkowego otrzymania tej wiadomosci, prosimy o powiadomienie nadawcy oraz trwale jej usuniecie; jakiekolwiek
przegladanie lub rozpowszechnianie jest zabronione.
This e-mail and any attachments may contain confidential material for the sole use of the intended recipient(s). If you are not the intended recipient, please contact the sender and delete all copies; any review or distribution by
others is strictly prohibited.