ARM Hard Float Support

[Sebastian Huber]

Hello Joel,

On 24/02/2020 02:55, Joel Sherrill wrote:
> Hi
> 
> What's the state of the world on ARM hard float support? I was asked by
> someone about these options:
> 
> -march=armv7-a -mfloat-abi=hard -mfpu=vfpv3-d16
> 
> -march=armv7-a+simd
> 
> When I test build a simple main(), I end up with a library mismatch which
> usually means we are missing a proper multilib variant. I tried this 
> with the
> rtems6 gcc 10 snapshot.
> 
> I looked at our gcc t-rtems versus the main one for elf/eabi and those seem
> to have a LOT more variants.
> 
> Any insight would be appreciated.

GCC 8, 9 and 10 are not supported by the ARM BSPs right now.

You can try this with GCC 10:

-mthumb -march=armv7-a+simd -mfloat-abi=hard

Why do they use -mfpu=vfpv3-d16? This seems to be quite a non-standard 
ARMv7-A chip.

-- 
Sebastian Huber, embedded brains GmbH

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