Welcome to the Sound Open Firmware (SOF) technical documentation portal.
Sound Open Firmware is a permissively licensed, open-source audio Digital Signal Processing (DSP) firmware infrastructure, SDK, and real-time execution framework governed under the Linux Foundation and directed by the SOF Technical Steering Committee (TSC).
SOF provides transparent, deterministic, low-latency audio processing infrastructure for modern computing architectures ranging from embedded microcontrollers and IoT devices to multi-core client PCs and servers.
Sound Open Firmware delivers a unified, cross-platform audio software stack across two foundational deployment paradigms:
- Host-Based Client Architecture: Where the DSP operates as an accelerator coupled to a host application processor running Linux, ChromeOS, Android, or Windows. The mainline Linux kernel driver subsystem (
sound/soc/sof/) manages firmware lifecycle, dynamic ALSA topology parsing, and aggressive power gating (D0ix runtime idle, D3 cold suspend), while real-time audio streams exchange through mailbox IPC protocols (IPC4 and IPC3) and host DMA memory windows. - Hostless & Standalone Architecture: Where SOF executes autonomously on microcontrollers and embedded DSPs (such as the Espressif ESP32-P4 or PJRC Teensy 4.1 / i.MX RT1062) atop the Zephyr RTOS. Standalone topologies process audio directly between hardware peripherals (I2S/TDM, SoundWire, PDM microphones, and S/PDIF) without requiring a host OS.
Explore the documentation portal by selecting one of the core technical pillars below:
Learn about the SOF project mission, benefits of audio DSP offloading (power, deterministic latency, vertical stack centralization), licensing, and governance.
Read Introduction »Set up your build host, configure the LLVM/Clang Xtensa cross-compiler toolchain, compile firmware images for target platforms, and run simulation in QEMU.
Explore Quickstart »Deep dive into firmware architecture: audio pipeline execution graphs (DAGs), lockless ring buffers, Zephyr RTOS abstraction, IPC3/IPC4 protocols, and power management.
View Architecture »Hardware compatibility specifications across Intel CAVS & ACE (PTL, ARL, MTL, TGL), AMD, NXP i.MX, MediaTek, Espressif ESP32-P4, and PJRC Teensy 4.1.
Browse Platforms »Comprehensive catalog of built-in audio signal processing modules: Volume, Mixer, Parametric EQ (FIR/IIR), DRC, SRC, ASRC, Crossover, DCBlock, and Wake-on-Voice.
Inspect Algorithms »Step-by-step developer runbooks: ALSA Topology 2 creation, UCM2 configuration and debugging, LLEXT dynamic module integration, CMake workflows, and real-time DSP probes.
Read Guides »Interactive Doxygen API documentation and Sphinx Breathe subsystem reference for IPC4, LLEXT modules, pipeline scheduling, audio components, RTOS abstraction, and DSP math.
Explore C API »Join the SOF open-source community: contributor guidelines, Git patch submission rules, TSC meeting minutes, releases, and frequently asked questions.
Contribute ».. toctree:: :hidden: SOF Project Website <https://sofproject.org> introduction/index.rst getting_started/index.rst architectures/index.rst platforms/index.rst algos/index.rst developer_guides/index.rst release.rst contribute/index.rst tsc/index.rst api/index.rst presentations/index.rst faq/index.rst