ITCM init

[jordens]

stabilizer/src/hardware/setup.rs

Line 183 in 3ef00cb

let dst = slice::from_raw_parts_mut(sitcm, len);

That destination slice is uninitialized, thus insta-UB. Needs to be MaybeUninit.

[ryan-summers]

Not only that, but the pointer provenance of the sitcm pointer only permits us to technically write 4 bytes (because the static mut __sitcm: u32.

[ryan-summers]

Ref rust-embedded/wg#771, it might be the case that pointer provenance is not actually an issue

[jordens]

Way back I had argued that this is like an FFI interface where one crates slices from addresses and lengths in a similar way without virtual machine knowing much about them.
I.e. specifically the src slice must be fine to create like this. How else would one do it?
And if the src slice is fine (initialized, doesn't break aliasing rules), so is the dst slice.

[jordens]

Closing as "not a problem".

[jordens]

As per rust-lang/unsafe-code-guidelines#259 we may want to try using ZSTs for the symbols though.