From the looks of it, Rust is usable un a tiny embedded system but it is not "great". I think that out of the recent, trendy languages, Zig is the best suited for this task, but in practice C is still king.
The big thing is memory allocation, sometimes, on tiny systems, you can't malloc() at all, you also have to be careful about your stack, which is often no more than a few kB. Rust, like modern C++ tend to abstract away these things, which is perfectly fine on Linux and a good thing when you have a lot of dynamic structures, but one a tiny system, you usually want full control. Rust can do that, I think, like C++, it is just not what it does best. C works well because it does nothing unless you explicitly ask for it, and Zig took that philosophy and ran away with it, making memory allocation even more explicit.
Rust has no malloc in the language whatsoever. In embedded, you don't even include the libraries for dynamic allocation in the first place, unless you want to. And it's very normal not to.
It probably depends how tiny you mean. If the reason you can't allocate memory is because the only 1024 bytes of static RAM is all stack, then, yeah, Rust won't be very comfortable on that hardware. On the other hand C isn't exactly a barrel of laughs either. In my mind if I can sensibly chart what each byte of RAM is used for on a whiteboard then we should write machine code by hand and skip "high level" languages entirely.
I don't know where I've lied about this, supposedly. Unless you say that, because of this implementation exception (which is based on target, not std vs no_std by the way) as meaning that "there's no UB in safe Rust" to be a lie.
I would still stand by that statement generally. Implementation issues on specific platforms are generally not considered to be what's being discussed when talking about things like this. It's similar to how cvs-rs doesn't make this a lie; a bug isn't in scope to what we're talking about 99% of the time.
In context, I'd have no reason to deny that this is something you'd want to watch out for.
> For an example, if a function in no_std overflows, it can result in undefined behavior, no unsafe required. And stack overflows are easy in Rust, like they are easy in most other systems languages.
This is true, no_std has no Rust runtime so it doesn't provide stack protection. I am aware of efforts to address this for embedded, but they're not available at the moment.
> Steve Klabnik has lied about that in the past, as he is wont to do.
1) I don't know what Steve has to do with anything I asked so it is bizarre to bring up and 2) I find this is to be a ridiculous statement.
