[OE-core] [OE-Core][PATCH 05/13] arch-powerpc64.inc: Use elfv2 ABI when building with musl

[Khem Raj]

On Fri, Dec 14, 2018 at 9:56 AM Serhey Popovych
<serhe.popovych at gmail.com> wrote:
>
> Historically first PowerPC ABI was big-endian only (elfv1 currently). It
> is standard ABI for both 32-bit ppc and 64-bit ppc64 architectures.
>
> With PowerPC little-endian support new ABI was introduced (elfv2) and it
> is used primarily with ppc64le target only. While it has support for
> big-endian it is not commonly used and elfv1 still preferred.
>
> Musl does support only elfv2 ABI for both LE and BE and does not have
> any plans to support elfv1.
>
> Since then to build for powerpc64 with musl new ABI should be used. As
> expected it is not compatible with elfv1 but that isn't problem as long
> as there is no binary distributed software or assembly code written for
> elfv1 ABI.
>
> Signed-off-by: Serhey Popovych <serhe.popovych at gmail.com>
> ---
>  meta/conf/machine/include/powerpc/arch-powerpc64.inc | 3 +++
>  1 file changed, 3 insertions(+)
>
> diff --git a/meta/conf/machine/include/powerpc/arch-powerpc64.inc b/meta/conf/machine/include/powerpc/arch-powerpc64.inc
> index f751c6b..d9916d4 100644
> --- a/meta/conf/machine/include/powerpc/arch-powerpc64.inc
> +++ b/meta/conf/machine/include/powerpc/arch-powerpc64.inc
> @@ -7,6 +7,9 @@ TUNECONFLICTS[m64] = "m32 nf"
>  TUNE_CCARGS .= "${@bb.utils.contains('TUNE_FEATURES', 'm64', ' -m64', '', d)}"
>  TUNE_ARCH .= "${@bb.utils.contains('TUNE_FEATURES', [ 'm64' ], 'powerpc64', '', d)}"
>
> +# musl only supports elfv2 ABI for ppc64
> +TUNE_CCARGS .= "${@['', ' -mabi=elfv2']['libc-musl' in d.getVar('OVERRIDES').split(':')]}"
> +

I wonder if we should change gcc to use this ABI by default when
configured for ppc64/musl ?
This would avoid us adding compiler options here, in bad cases it may
be that other compilers
call it out differently.

>  # user mode qemu doesn't support ppc64
>  MACHINE_FEATURES_BACKFILL_CONSIDERED_append = " ${@bb.utils.contains('TUNE_FEATURES', 'm64', 'qemu-usermode', '', d)}"
>
> --
> 2.7.4
>
> --
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