Re: [PATCH v2 2/2] xen: Populate xen.lds.h and make use of its macros

[Jan Beulich <jbeulich@xxxxxxxx>]

On 30.03.2022 15:30, Julien Grall wrote:
> Hi,
> 
> On 30/03/2022 14:24, Michal Orzel wrote:
>>
>>
>> On 30.03.2022 14:53, Jan Beulich wrote:
>>> On 30.03.2022 14:13, Michal Orzel wrote:
>>>> On 30.03.2022 13:57, Jan Beulich wrote:
>>>>> On 30.03.2022 13:04, Michal Orzel wrote:
>>>>>> On 30.03.2022 12:42, Jan Beulich wrote:
>>>>>>> On 30.03.2022 12:32, Julien Grall wrote:
>>>>>>>> Renaming to PE_COFF may help to avoid the confusion with CONFIG_EFI.
>>>>>>>> That said, it would possibly make more difficult to associate the flag
>>>>>>>> with "linking an EFI binary".
>>>>>>>
>>>>>>> Indeed. And EFI_PE_COFF is getting a little unwieldy for my taste.
>>>>>>>
>>>>>>>> I think some documentaion about the define EFI would be help so there
>>>>>>>> are no more confusion between CONFIG_EFI/EFI. But I am not sure where 
>>>>>>>> to
>>>>>>>> put it. Maybe at the top of the header?
>>>>>>>
>>>>>>> That's perhaps the best place, yes.
>>>>>>>
>>>>>> In this case how about the following comment at the top of xen.lds.h:
>>>>>>
>>>>>> "To avoid any confusion about EFI macro used in this header vs EFI 
>>>>>> support,
>>>>>> the former is used when linking a native EFI (i.e. PE/COFF) binary, 
>>>>>> whereas
>>>>>> the latter means support for generating EFI binary.
>>>>>
>>>>> No, that's the case on Arm only. As Julien suggested, it is perhaps best
>>>>> to explain the difference between EFI and CONFIG_EFI, without going into
>>>>> arch specifics.
>>>> Could you please tell me what you are reffering to as there is no such 
>>>> identifier
>>>> in Xen (as opposed to Linux) like CONFIG_EFI ?
>>>
>>> Let's call it a "virtual" CONFIG_EFI then; I think we really should have
>>> such an option. But yes, if you don't like referring to such a virtual
>>> option, then describing what is meant verbally is certainly going to be
>>> fine.
>>>
>> FWICS, there was an attempt done by Wei in his NUMA series to define 
>> CONFIG_EFI.
>> However as this is not yet merged and agreed, I would like not to refer to 
>> identifiers
>> not existing in the code, even though most people are familiar with this 
>> option from Linux.
>>
>> So by taking an example from Linux I would verbally explain it like that:
>> "To avoid any confusion, please note that EFI macro does not correspond to 
>> EFI
>> runtime support and is used when linking a native EFI (i.e. PE/COFF) binary, 
>> hence its
> 
> "EFI runtime support" can be mistakenly associated to EFI runtime 
> services (which BTW not supported on Arm). So I would suggest to 
> s/runtime/boot/.

Or simply just "EFI support"?

Jan