https://github.com/knurling-rs/defmt
Efficient, deferred formatting for logging on embedded systems
https://github.com/knurling-rs/defmt
embedded-systems ferrous-systems logging rust rust-tools
Last synced: 4 months ago
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Efficient, deferred formatting for logging on embedded systems
- Host: GitHub
- URL: https://github.com/knurling-rs/defmt
- Owner: knurling-rs
- License: apache-2.0
- Created: 2020-07-24T16:04:15.000Z (almost 5 years ago)
- Default Branch: main
- Last Pushed: 2025-03-07T14:13:14.000Z (4 months ago)
- Last Synced: 2025-03-07T15:25:31.700Z (4 months ago)
- Topics: embedded-systems, ferrous-systems, logging, rust, rust-tools
- Language: Rust
- Homepage: https://defmt.ferrous-systems.com/
- Size: 2.7 MB
- Stars: 953
- Watchers: 11
- Forks: 94
- Open Issues: 89
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- Funding: .github/FUNDING.yml
- License: LICENSE-APACHE
Awesome Lists containing this project
- rust-embedded - defmt - constrained devices, like microcontrollers. (Tools / Paid and commercially available materials)
- awesome-embedded-rust - defmt - constrained devices, like microcontrollers. (Tools / Paid and commercially available materials)
README
# `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 .
## Components
This repository contains the following packages:
| Name | Path | Description |
| ------------------- | -------------------------------------------------------------- | -------------------------------------------------------------------------- |
| `defmt` | [`./defmt`](./defmt) | On-target code for highly efficient logging |
| `defmt-macros` | [`./macros`](./macros) | Proc Macros for `defmt` |
| `defmt-print` | [`./print`](./print) | CLI utility for decoding and printing `defmt` encoded logs to standard out |
| `defmt-decoder` | [`./decoder`](./decoder) | Host Library for decoding `defmt` log frames |
| `defmt-parser` | [`./parser`](./parser) | Host Library for parsing `defmt` log frames |
| `defmt-rtt` | [`./firmware/defmt-rtt`](./firmware/defmt-rtt) | On-target library for sending `defmt` logs over RTT |
| `defmt-itm` | [`./firmware/defmt-itm`](./firmware/defmt-itm) | On-target library for sending `defmt` logs over ITM |
| `defmt-semihosting` | [`./firmware/defmt-semihosting`](./firmware/defmt-semihosting) | On-target library for sending `defmt` logs over semihosting |
| `panic-probe` | [`./firmware/panic-probe`](./firmware/panic-probe) | On-target library for sending `panic!` over `defmt` |
| `defmt-test` | [`./firmware/defmt-test`](./firmware/defmt-test) | Framework for running tests on-target |
| `defmt-test-macros` | [`./firmware/defmt-test/macros`](./firmware/defmt-test/macros) | Proc Macros for `defmt-test` |
| `defmt-json-schema` | [`./decoder/defmt-json-schema`](./decoder/defmt-json-schema) | Describes the JSON emitted by `defmt-decoder` |
## MSRV
The minimum supported Rust version is 1.76 (or Ferrocene 24.05). `defmt` is tested against the latest stable Rust version and the MSRV.
## 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
)
- MIT license ([LICENSE-MIT](LICENSE-MIT) or )
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