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

[Jan Beulich <jbeulich@xxxxxxxx>]

On 30.03.2022 15:24, 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
> usage in this header."

This reads okay to me (perhaps with "the" inserted before "EFI macro").

Jan