For this reason rust is currently being proposed to be used for drivers and other code which is already platform or architecture specific, not the core, so as n

For this reason rust is currently being proposed to be used for drivers and other code which is already platform or architecture specific, not the core, so as not to affect the support for these architectures. When rust has a mature enough GCC backend then this won't be an issue and it may be possible for it to move into core (though this would still be a big step and likely quite a while away, for example because it would introduce a hard dependency on a rust compiler).