[poky] libc configuration of multilib config

[Richard Purdie]

On Thu, 2019-04-11 at 14:05 -0700, Jonathan Richardson wrote:
> Hi,
>  
> We have a cortex-A72 tuning defined as our default tuning based on
> armv8. We also have some bare metal code that runs on a cortex M0.
> Yocto allows you to set a default tune for that multilib config so we
> call it softfp but it’s an armv6 architecture with soft floating
> point:
>  
> MULTILIB_GLOBAL_VARIANTS += "softfp"
> MULTILIBS += "multilib:softfp"
> DEFAULTTUNE_virtclass-multilib-softfp = "armv6t-novfp"
>  
> Since we only have 1 recipe for code running on that processor (the
> SOC contains armv8 and an M0) we compile it as softp-recipe_name, add
> it to EXTRA_IMAGEDEPENDS along with other bootloaders and have
> everything in the same deploy/machine when we create our image.
>                                                 
> Now we want to use newlib instead of glibc for the softfp multilib
> config only. I don’t see a way of configuring this. At this point
> should we put it in a different MACHINE? Should we be defining a
> multilib config for a different architecture or is this overusing the
> feature?

This sounds like you want a separate MACHINE and to use multiconfig
instead of multilib...

Cheers,

Richard