# `defmt` `defmt` ("de format", short for "deferred formatting") is a highly efficient logging framework that targets resource-constrained devices, like microcontrollers. For more details about the framework check the book at . The git version of the defmt book can be viewed at . ## Setup ### New project The fastest way to get started with `defmt` is to use our [app-template] to set up a new Cortex-M embedded project. [app-template]: https://github.com/knurling-rs/app-template ### Existing project To include `defmt` in your existing project, follow our [Application Setup guide]. [Application Setup guide]: https://defmt.ferrous-systems.com/setup.html ## MSRV `defmt` always compiles on the [latest `stable` rust release](https://github.com/rust-lang/rust/releases/latest). This is enforced by our CI building and testing against this version. It still might work on older rust versions, but this isn't ensured. ## defmt ecosystem The following diagram illustrates the user-facing and internal crates of the defmt framework. ![defmt crates structure](assets/defmt.png) ## Developer Information ### Running Tests Tests are run using `cargo xtask` -- although this is simply an alias (defined in `.cargo/config.toml`) for `cargo run --package xtask --`. To see a list of options, see [`xtask/src/main.rs`](xtask/src/main.rs), or run: ```console $ cargo xtask help ``` For example, to run all the tests, run: ```console $ cargo xtask test-all ``` You will need `qemu-system-arm` installed and in your `$PATH` for some of the tests (e.g. `test-snapshot`). ## Support `defmt` is part of the [Knurling] project, [Ferrous Systems]' effort at improving tooling used to develop for embedded systems. If you think that our work is useful, consider sponsoring it via [GitHub Sponsors]. ## License Licensed under either of - Apache License, Version 2.0 ([LICENSE-APACHE](LICENSE-APACHE) or http://www.apache.org/licenses/LICENSE-2.0) - MIT license ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT) at your option. ### Contribution Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be licensed as above, without any additional terms or conditions. [Knurling]: https://knurling.ferrous-systems.com/ [Ferrous Systems]: https://ferrous-systems.com/ [GitHub Sponsors]: https://github.com/sponsors/knurling-rs