[Buildroot] [PATCH 2/5] toolchain/external: fix wrapper by not passing conflicting flags

[Yann E. MORIN <yann.morin.1998@free.fr>]

Maxime, All,

On 2014-01-08 16:57 +0100, Maxime Hadjinlian spake thusly:
> On Wed, Jan 8, 2014 at 4:51 PM, Thomas Petazzoni
> <thomas.petazzoni@free-electrons.com> wrote:
> > Dear Maxime Hadjinlian,
> Hi Thomas,
> >
> > On Wed, 8 Jan 2014 13:45:59 +0100, Maxime Hadjinlian wrote:
> >
> >> Shouldn't we change the different defconfig that exists ? At least the
> >> RaspberryPi so it would sets an example (and maybe add something about
> >> this in the manual ?)
> >
> > Why would the defconfig need some changes following this patch?
> To set a visible example of settings the correct -march/mcpu/mtune options ?
> Also, this would eliminate all the warnings that Yann saw while
> building a kernel for the rpi, so it seems like a good candidate.

There is nothing in that patch that impacts the configuration.
There is no reason to change any defconfig to 'activate' this change.

Rather, the config options BR2_GCC_TARGET_CPU, BR2_GCC_TARGET_ARCH, and
BR2_GCC_TARGET_MTUNE, if any, are pased at the time we build the wrapper
itself.

Those options are set automatically when you choose, in the menuconfig,
the type of CPU your target has. And since that will automatically set
the BR2_GCC_TARGET_{ARCH,CPU,MTUNE} options, they are forcibly set.

And since the raspberrypi_defconfig (as you use that as an example)
already sets BR2_arm1176jzf_s=y, this will set BR2_GCC_TARGET_ARCH and
BR2_GCC_TARGET_CPU.

And this is exactly this situation this patch fixes: our options forcing
the compiler flags, when some are already provided on the command line.

So, there is no need (and no reason) to change any of our defconfigs to
take advantage of this change.

Regards,
Yann E. MORIN.

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