There are usually two kinds of Rust crates for a given microcontroller:
- Peripheral Access Crate (PAC): A low-level library, generated from an SVD file by svd2rust.
- Hardware Abstraction Layer (HAL): Higher-level library that provides a safer and more convenient API to work with.
Traditionally, the PAC was named after the microcontroller (e.g. lpc82x, while the HAL had the same name, but with the -hal suffix (e.g. lpc82x-hal). This is somewhat problematic, as end users should almost always use the HAL, but when searching for a given microcontroller, the PAC is what comes up first.
For that reason, parts of the community have started adding the -pac suffix to the PAC's name, so e.g. lpc82x becomes lpc82x-pac.
This creates one new problem: What happens to the, now unused, suffix-less name? It's still the first thing that comes up in search results on crates.io, so the user might accidentally be guided towards a deprecated version.
A solution to this problem is to create a placeholder crate that either fails to build, producing an informative compiler error. This repository contains these placeholder crates for the lpc-rs organization.