Re: [PATCH 1/3] xen/arm64: head: Move earlyprintk 'hex' string to .rodata.str

[Michal Orzel <michal.orzel@xxxxxxx>]

On 21/11/2023 18:04, Julien Grall wrote:
> 
> 
> On 21/11/2023 17:00, Michal Orzel wrote:
>> Hi Julien,
> 
> Hi,
> 
>> On 21/11/2023 17:09, Julien Grall wrote:
>>>
>>>
>>> Hi Michal,
>>>
>>> On 21/11/2023 09:45, Michal Orzel wrote:
>>>> At the moment, the 'hex' string is placed right after the 'putn'
>>>> function in the .text section. This is because of the limited range
>>>> (+/- 1MB) of PC relative 'adr' instruction 'putn' uses. Modify it to use
>>>> 'adr_l' instead (range extended to +/- 4GB) and move the string to
>>>> .rodata.str. This way all the earlyprintk messages will be part of .rodata
>>>> and the behavior will be consistent with what we already do on arm32.
>>>
>>> This will be correct today, but I am actually thinking to move 'hex' to
>>> .rodata.idmap so it can be used while we are on the 1:1 mapping and/or
>>> temporary mapping.
>> So you are planning on extending your series to also cover arm64?
> 
> It is not in my soonish plan. But you are arguing that this patch is for
> consistency with arm32. This will not be after my series.
Hmm, consistency was not the only reason for sending this patch. It's a 
beneficial side effect
given that putn implementations are very similar on arm32/arm64. Are you saying 
that
moving a string that is const from .text to .rodata is not a good change?

> 
> And I would not change arm64 just for consistency because I don't view
> it as necessary. The boot code is already not the same.
I don't recall trying to make the entire boot code consistent. But if there are 
parts that
are almost identical, I think symmetry is welcomed. It helps reading the code, 
at least for me.

~Michal