On 14.03.2023 17:00, Oleksii Kurochko wrote:
> The patch is needed to keep all addresses PC-relative.
>
> Pseudoinstruction 'la' can be transformed to 'auipc/addi' or
> 'auipc/l{w|d}'. It depends on the .option directive: nopic and pic.
>
> Right now, 'la' transforms to 'auipc/l{w|d}',
I'm afraid I cannot confirm this. Is it possible that your and my gas
are configured differently (i.e. can the default of nopic vs pic vary)?
> which in case of
> cpu0_boot_stack[] will lead to the usage of _GLOBAL_OFFSET_TABLE_
> where all addresses will be without counting that it might happen
> that linker address != load address.
>
> To be sure that SP is loaded always PC-relative address
> 'la' should be changed to 'lla', which always transforms to
> 'auipc/addi'.
While I agree with the adjustment in principle, I'd like to raise the
question of the suitablity of such macro insns for purposes like the
one here. In principle I would assume it would be better if sp was
written only once, with the final value. That would then also remove
the dependency on a possibly differing default gas may be using.
Jan
