[RFC][PATCH] powerpc/64be: use ELFv2 ABI for big endian kernels

[Michael Ellerman]

Segher Boessenkool <segher at kernel.crashing.org> writes:

> On Thu, Nov 24, 2016 at 04:37:50PM +1100, Oliver O'Halloran wrote:
>> On Thu, Nov 24, 2016 at 1:38 AM, Segher Boessenkool
>> <segher at kernel.crashing.org> wrote:
>> > On Thu, Nov 24, 2016 at 12:08:40AM +1100, Nicholas Piggin wrote:
>> >> Question, are there any fundamental reasons we shouldn't use the ELFv2
>> >> ABI to build big endian kernels if the compiler supports it?
>> >
>> > No one uses ELFv2 for BE in production, and it isn't thoroughly tested
>> > at all, not even regularly tested.  "Not supported", as far as GCC is
>> > concerned (or any of the distros AFAIK).
>> 
>> Is this actually unsupported by gcc?
>
> It may or may not work.  We of course try to keep it working, or make
> it work if it doesn't now.  But it isn't regularly tested, and it isn't
> a target that is considered for the release criteria (see
> https://gcc.gnu.org/gcc-7/criteria.html -- powerpc64{,le}-linux, i.e.
> ABIv1 for BE, ABIv2 for LE).

It doesn't actually say that though. It just says
powerpc64-unknown-linux-gnu. So how is someone, say the musl folks,
supposed to know that BE ABIv2 is not supported?

cheers