Hi Linus, On 21.03.25 8:24 AM, Linus Walleij wrote: > Hi Christian, > > thanks for your patch! > > Sorry for being late to the show. I missed this very nice patch > that was actually on my personal TODO but I have to much > to do and also I'm not smart with Rust, but I'm a big supporter. > > On Thu, Jan 23, 2025 at 11:40 PM Christian Schrefl > <chrisi.schrefl@xxxxxxxxx> wrote: > >> + select HAVE_RUST if CPU_LITTLE_ENDIAN && CPU_32v7 > > Nothing in the patch series really explains this restriction, so it > should be in the commit message. Arnd mentions some atomics > etc, but we really need to know exactly why this is in the patch. This should probably work with armv6 targets, for v5 or v4 Targets a different target would have to be specified in the KBUILD_RUSTFLAGS. Rust also has some big endian arm targets. > > I'm a bit surprised by this since the rustc LLVM backend nowadays > support all old ARM ISAs. I would have expected: > > select HAVE_RUST if AEABI > > Ideally this should work on any ARM core, but it's fair to require > EABI. > > The big reason: I think we want to be able to use Rust in kernel > core components sooner than ARMv5 goes away from the kernel. > > If testing is the only issue, I can provide testing on ARMv4, v5, > ARMv5 BE etc, just tell me how to test. (But I guess it's more than > that...) The main reason that I only did this for ARMv7 was that I'm not very familiar with older arm versions and that I only have v7 hardware for testing. I currently don't have much time to work on this, but when/if it works in qemu I'll send you a message to test it on HW. Cheers Christian
