Re: [PATCH 2/2] ArmVirtPkg: enable EBC interpreter for AArch64 QEMU

[Laszlo Ersek <lersek@redhat.com>]

On 08/17/16 16:04, Ard Biesheuvel wrote:
> On 17 August 2016 at 15:55, Laszlo Ersek <lersek@redhat.com> wrote:
>> On 08/17/16 15:47, Ard Biesheuvel wrote:
>>> On 17 August 2016 at 15:45, Leif Lindholm <leif.lindholm@linaro.org> wrote:
>>>> Since we now have EBC support for AArch64, enable it by default
>>>> on the QEMU platform.
>>>>
>>>> Contributed-under: TianoCore Contribution Agreement 1.0
>>>> Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
>>>> ---
>>>>  ArmVirtPkg/ArmVirtQemu.dsc           | 1 +
>>>>  ArmVirtPkg/ArmVirtQemuFvMain.fdf.inc | 5 +++++
>>>>  2 files changed, 6 insertions(+)
>>>>
>>>> diff --git a/ArmVirtPkg/ArmVirtQemu.dsc b/ArmVirtPkg/ArmVirtQemu.dsc
>>>> index 9f88786..fb851e7 100644
>>>> --- a/ArmVirtPkg/ArmVirtQemu.dsc
>>>> +++ b/ArmVirtPkg/ArmVirtQemu.dsc
>>>> @@ -401,3 +401,4 @@ [Components.AARCH64]
>>>>      <LibraryClasses>
>>>>        NULL|ArmVirtPkg/Library/FdtPciPcdProducerLib/FdtPciPcdProducerLib.inf
>>>>    }
>>>> +  MdeModulePkg/Universal/EbcDxe/EbcDxe.inf
>>>
>>> Please add it to ArmVirtPkg/ArmVirtQemuKernel.dsc as well:
>>> ArmVirtQemuFvMain.fdf.inc is shared between them.
>>>
>>> With that,
>>>
>>> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
>>
>> Any reason for not adding it to the Xen platform as well?
>>
>> What kind of modules do we expect to come in EBC? Option ROMs perhaps?
> 
> Yes, that is the primary purpose, although any DXE/UEFI driver could
> be distributed as an EBC module, I suppose (and we have an EBC version
> of fat.efi in FatBinPkg)
> 
>> In that case, Xen may indeed be irrelevant here (I have no clue about
>> adding oproms to emulated or assigned devices under Xen, so I can't make
>> an argument either way.) If we expect general stuff (for example, even
>> UEFI_APPLICATION modules) to arrive in EBC, then I think Xen would be a
>> justified addition.
>>
> 
> I remember reading somewhere that EBC was strictly for drivers, not
> applications, but I cannot find a reference anymore in the spec.
> 
> I wouldn't mind adding it to Xen, but I don't see the point tbh

I don't insist, I'd just like to avoid the Qemu <-> Xen platform
divergence getting out of hand :) At some point we'll compare those
files in the future, and ask ourselves why EBC (and the rest :)) are
only in Qemu.

Anyway, this should not block the patch; I just figured I'd raise it.

Thanks
Laszlo