# Sound Open Firmware
**Wikidata**: [Q116376146](https://www.wikidata.org/wiki/Q116376146)  
**Source**: https://4ort.xyz/entity/sound-open-firmware

## Summary
Sound Open Firmware (SOF) is an open-source firmware designed to provide low-level control for specific device hardware. It is licensed under BSD licenses and utilizes operating systems such as Zephyr and XTOS. The project is publicly accessible via its GitHub repository and website, sofproject.org.

## Key Facts
- **Entity Type:** Firmware (software providing low-level hardware control).
- **Aliases:** SOF.
- **License:** BSD licenses.
- **Operating Systems Used:** Zephyr (a free real-time operating system) and XTOS.
- **Source Code Repository:** `https://github.com/thesofproject/sof`
- **Official Website:** `https://www.sofproject.org/` (English)
- **Developer/Contributor:** Seppo Ingalsuo.
- **Copyright Status:** Copyrighted.
- **Latest Cited Version (from source):** Version 1.6.1 (released December 3, 2020).

## FAQs
### Q: What operating systems does Sound Open Firmware use?
A: Sound Open Firmware utilizes Zephyr, a free real-time operating system, and XTOS. Zephyr was announced by the Linux Foundation in 2016.

### Q: Under what license is Sound Open Firmware distributed?
A: Sound Open Firmware is distributed under the BSD licenses.

### Q: Where can the source code for Sound Open Firmware be found?
A: The source code is hosted on GitHub at `https://github.com/thesofproject/sof`.

## Why It Matters
Sound Open Firmware represents a significant development in the field of hardware control by offering a BSD-licensed solution for audio firmware. By leveraging the Zephyr real-time operating system (RTOS), SOF facilitates low-latency and deterministic audio processing capabilities for devices. This approach moves away from proprietary, closed-source firmware models, allowing for greater transparency, community contribution, and adaptability in hardware support.

The project demonstrates active and consistent development cycles, evidenced by its release history from 2018 through 2020. This regular cadence suggests a robust response to hardware requirements and bug fixes. As audio hardware becomes more complex, the availability of an open firmware stack like SOF is critical for enabling modern audio features and ensuring compatibility across different computing environments without relying solely on vendor-specific binaries.

## Notable For
- **Open Source Audio Firmware:** Distinguished by its use of permissive BSD licensing for low-level hardware control.
- **Zephyr Integration:** Notable for running on Zephyr, a prominent free RTOS managed by the Linux Foundation.
- **Active Development Cycle:** Maintained a frequent release schedule between 2018 and 2020, with multiple point releases (e.g., v1.4.1, v1.4.2) indicating ongoing maintenance.
- **Public Collaboration:** Hosted on GitHub with recorded contributors such as Seppo Ingalsuo.

## Body

### Technical Architecture
Sound Open Firmware is classified as **firmware**, a specific class of computer software responsible for providing low-level control for a device's specific hardware. The project is distinct in its architectural choices, employing **Zephyr** and **XTOS** as its operating environments.
- **Zephyr:** SOF leverages Zephyr, a free real-time operating system (RTOS). Zephyr itself was inception date February 17, 2016.
- **XTOS:** The firmware also supports the XTOS environment.

### Licensing and Development
The project is **copyrighted** but distributed under **BSD licenses**, permitting wide usage and modification within the industry. Development is tracked publicly, with Seppo Ingalsuo cited as a developer/contributor via GitHub records. The source code is accessible at `https://github.com/thesofproject/sof`.

### Release History
The project has maintained a detailed release log with specific versioning and publication dates:

- **v1.2:** Released September 20, 2018.
- **v1.3:** Released June 5, 2019.
- **v1.4:** Released November 12, 2019.
    - **v1.4.1:** Released November 22, 2019.
    - **v1.4.2:** Released January 20, 2020.
    - **v1.4.3:** Released May 12, 2020.
- **v1.5:** Released April 27, 2020.
    - **v1.5.1:** Released June 15, 2020.
- **v1.6:** Released November 17, 2020.
    - **v1.6.1:** Released December 3, 2020.

## References

1. [Source](https://github.com/thesofproject/sof/graphs/contributors)
2. [Release 1.2. 2018](https://github.com/thesofproject/sof/releases/tag/v1.2)
3. [Release 1.3. 2019](https://github.com/thesofproject/sof/releases/tag/v1.3)
4. [Release 1.4. 2019](https://github.com/thesofproject/sof/releases/tag/v1.4)
5. [Release 1.4.1. 2019](https://github.com/thesofproject/sof/releases/tag/v1.4.1)
6. [Release 1.4.2. 2020](https://github.com/thesofproject/sof/releases/tag/v1.4.2)
7. [Release 1.4.3. 2020](https://github.com/thesofproject/sof/releases/tag/v1.4.3)
8. [Release 1.5. 2020](https://github.com/thesofproject/sof/releases/tag/v1.5)
9. [Release 1.5.1. 2020](https://github.com/thesofproject/sof/releases/tag/v1.5.1)
10. [Release 1.6. 2020](https://github.com/thesofproject/sof/releases/tag/v1.6)
11. [Release 1.6.1. 2020](https://github.com/thesofproject/sof/releases/tag/v1.6.1)
12. [Release 1.7. 2021](https://github.com/thesofproject/sof/releases/tag/v1.7)
13. [Release 1.8. 2021](https://github.com/thesofproject/sof/releases/tag/v1.8)
14. [Release 1.9. 2021](https://github.com/thesofproject/sof/releases/tag/v1.9)
15. [Release 1.9.2. 2021](https://github.com/thesofproject/sof/releases/tag/v1.9.2)
16. [Release 1.9.3. 2021](https://github.com/thesofproject/sof/releases/tag/v1.9.3)
17. [Release 2.0. 2021](https://github.com/thesofproject/sof/releases/tag/v2.0)
18. [Release 2.1. 2022](https://github.com/thesofproject/sof/releases/tag/v2.1)
19. [Release 2.1.1a. 2022](https://github.com/thesofproject/sof/releases/tag/v2.1.1a)
20. [Release 2.1.1. 2022](https://github.com/thesofproject/sof/releases/tag/v2.1.1)
21. [Release 2.2. 2022](https://github.com/thesofproject/sof/releases/tag/v2.2)
22. [Release 2.2.1. 2022](https://github.com/thesofproject/sof/releases/tag/v2.2.1)
23. [Release 2.2.2. 2022](https://github.com/thesofproject/sof/releases/tag/v2.2.2)
24. [Release 2.2.3. 2022](https://github.com/thesofproject/sof/releases/tag/v2.2.3)
25. [Release 2.2.4. 2023](https://github.com/thesofproject/sof/releases/tag/v2.2.4)
26. [Release 2.3. 2022](https://github.com/thesofproject/sof/releases/tag/v2.3)
27. [Release 2.4.1. 2023](https://github.com/thesofproject/sof/releases/tag/v2.4.1)
28. [v2.5-rc1. 2023](https://github.com/thesofproject/sof/releases/tag/v2.5-rc1)
29. [v2.5. 2023](https://github.com/thesofproject/sof/releases/tag/v2.5)
30. [Release 2.2.5. 2023](https://github.com/thesofproject/sof/releases/tag/v2.2.5)
31. [Release 2.6. 2023](https://github.com/thesofproject/sof/releases/tag/v2.6)
32. [Release 2.2.6. 2023](https://github.com/thesofproject/sof/releases/tag/v2.2.6)
33. [Release 2.6.1. 2023](https://github.com/thesofproject/sof/releases/tag/v2.6.1)
34. [Release 2.7. 2023](https://github.com/thesofproject/sof/releases/tag/v2.7)
35. [Release 2.7.1. 2023](https://github.com/thesofproject/sof/releases/tag/v2.7.1)
36. [Release 2.7.2. 2023](https://github.com/thesofproject/sof/releases/tag/v2.7.2)
37. [SOF 2.8.0 is here. 2023](https://www.sofproject.org/blog/2023/12/18/sof-2-8-0-is-here/)
38. [Release 2.8. 2023](https://github.com/thesofproject/sof/releases/tag/v2.8)
39. [Release 2.8.1. 2024](https://github.com/thesofproject/sof/releases/tag/v2.8.1)
40. [Release 2.9. 2024](https://github.com/thesofproject/sof/releases/tag/v2.9)
41. [SOF 2.10.0 is here. 2024](https://www.sofproject.org/blog/2024/07/17/sof-2-10-0-is-here/)
42. [Release 2.10. 2024](https://github.com/thesofproject/sof/releases/tag/v2.10)
43. [Release 2.11. 2024](https://github.com/thesofproject/sof/releases/tag/v2.11)
44. [Release 2.11.2. 2024](https://github.com/thesofproject/sof/releases/tag/v2.11.2)
45. [Release 2.11.3. 2024](https://github.com/thesofproject/sof/releases/tag/v2.11.3)
46. [Release 2.12. 2025](https://github.com/thesofproject/sof/releases/tag/v2.12)
47. [Release 2.12.1. 2025](https://github.com/thesofproject/sof/releases/tag/v2.12.1)
48. [v2.13. 2025](https://github.com/thesofproject/sof/releases/tag/v2.13)
49. [Release 2.13.1. 2025](https://github.com/thesofproject/sof/releases/tag/v2.13.1)
50. [Release 2.14. 2025](https://github.com/thesofproject/sof/releases/tag/v2.14)