On Tue, Sep 3, 2024 at 8:32 PM Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx> wrote: > > Ahh thanks for the elaboration. You're welcome! > However, kernel supports many ISA variants that are not defined by any rust target > triple, I'm not really sure if it's appropriate to define them all in upstream. They need to be in upstream Rust somehow, because upstream Rust does not want to stabilize `target.json` since it is too tied to LLVM (as far as we have been told). Whether that is via `-Ctarget-feature`, or a new `-Cglobal-target-feature`, or specific flags like `-Zfixed-x18` (originally `-Ctarget-feature=+reserve-x18`), or (many) new target triples for different combinations, or something else, it depends on the case and what upstream Rust wants to do. That is why we should tell them what is needed, ideally in a new issue in upstream Rust, and link it in https://github.com/Rust-for-Linux/linux/issues/355 (please see that list for similar examples). I hope that explains a bit more the context. Cheers, Miguel