[Buildroot] e500v2 SPE toolchain tuple confuses BR

[Yann E. MORIN]

Dwayne, All,

On Saturday 30 April 2011 00:16:52 Dwayne Fontenot <dwayne.fontenot at att.net> wrote:
> I'm having an issue with buildroot (git HEAD as of 20110428) and a powerpc
> e500v2 toolchain built using the BR crosstool-ng integration.
> 
> The built toolchain has a prefix of powerpc-unknown-linux-gnuspe- yet BR
> assumes it is powerpc-unknown-linux-gnu-

I've add an idea about this. It all boils down to buildroot computing
its own tuple, when it should delegate that to the backend responsible
for building the toolchain.

Indeed, even with a purely external toolchain (ge it from CodeSourcey,
built with crosstool-NG, or any other kind), the tuple can have specifics
that buildroot has no idea about.

In this case, buildroot has no knowledge of the ABI in use by the toolchain
(here the SPE ABI). For ARM, buildroot handles the EABI stuff, but that's
a side effect of buildroot having an internal backend that handles ARM EABI.

So, what I would suggest is that computing the tuple be the responsibility
of the toolchain backend.

For the internal backend, I would be a matter of moving the code along,
out from the package infrastructure. Probably nothing very complex...

For the crosstool-NG backend, that should be fairly trivial; there is
provision for this on crostool-NG, just call ct-ng show-tuple, et voila!

For the external backend, it should not much more complex. gcc is able
to dump the tuple for which it has been built, just call gcc -dumpmachine

Of course, a quick hack to add PPC SPE would be fairly trivial as well,
but it would not scale, doing work that should not ever be done at all. ;-)

Regards,
Yann E. MORIN.

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