starting with cargo (rust)

Rust is a curly-brace, block-structured expression language. It visually resembles the C language family, but differs significantly in syntactic and semantic details. Its design is oriented toward concerns of "programming in the large", that is, of creating and maintaining boundaries - both abstract and operational - that preserve large-system integrity, availability and concurrency.

It supports a mixture of imperative procedural, concurrent actor, object-oriented and pure functional styles. Rust also supports generic programming and meta-programming, in both static and dynamic styles.

remember to update rustc with 'rustup update'

comprehensive rust/bare-metal
starting with cargo (rust)
Then : Cargo build
and
Then : Cargo run

OR
Embedded Rust

A recently discovered file on BBC Micro-bit:
# Behavior configuration file
# Reset can be hard or auto
# hard - user must disconnect power, press reset button or send a serial break command
# auto - upon programming completion the target MCU automatically resets
# and starts running
#
# The filename indicates how your board will reset the target
# Delete this file to toggle the behavior
# This setting can only be changed in maintenance mode

Also
nightly rust