On embedded devices, how often are you parsing input that came from notepad (or any other text editor)? If your device has a UI or a web server, you’re likely already using something that handles various encoding and line endings. If you’re reading data you included at build time, consider a validator/sanitizer script that can run in your build environment where it can have easy access to off the shelf libraries.

On a side note- as a software engineer who primarily works on things running in a general purpose OS but does occasionally have to make small programs that can function on embedded devices (albeit still usually with an OS, think routers and iot), I’m glad that the Rust community takes no-std development seriously. Large swaths of the rust ecosystem is available even in embedded environments.