[U-Boot] ARM relocation, question to Heiko

Albert ARIBAUD
2010-10-03T18:34:41Z

Le 03/10/2010 20:03, Wolfgang Denk a ?crit :

> Dear Reinhard Meyer,
>
> In message<4CA6E8E5.2090605@emk-elektronik.de> you wrote:
>>
>>> And yes, this means the content arrays of pointers such as init_sequence
>>> is not relocated. Been there, done that, can give you one of the
>>> tee-shirts I got :)
>
> It should work.
>
> Eventually we need to find out which sort of tweaking of compiler
> and/or linker options is needed on ARM.

While looking for enhancements to Heiko's arm relocation patches, I have
gone through all relocation related compiler and linker options, and
then some. -fPIC / -fPIE will not generate GOT fixups for data
containing pointers, and I have found no additional option that will.

OTOH, -pie will generate this kind of fixup (and all others needed) in
the form of .rel.dyn relocations, as Bill describes.

> Well, please keep in mind that all this code is working find on
> PowerPC, which has been using relocation right from the beginning.

I don't mean to say that PPC relocation does not work; I mean to say
that a mechanism intended for one architecture may not be the optimal
one for another, and if two mechanisms exist which provide relocation
and one of them does not require specific tricks in the code, then I
would choose this one.

> Best regards,
>
> Wolfgang Denk

Amicalement,
--
Albert.