Sound Open Firmware Documentation#
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.
Architecture & Key Capabilities#
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.
Documentation Pillars & Navigation#
Explore the documentation portal by selecting one of the core technical pillars below:
Introduction to SOF →
Learn about the SOF project mission, benefits of audio DSP offloading (power, deterministic latency, vertical stack centralization), licensing, and governance.
Read Introduction »Getting Started →
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 »Architecture & System Design →
Deep dive into firmware architecture: audio pipeline execution graphs (DAGs), lockless ring buffers, Zephyr RTOS abstraction, IPC3/IPC4 protocols, and power management.
View Architecture »Supported Platforms Matrix →
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 »Audio Algorithms & Components →
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 »Developer Guides & Runbooks →
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 »C API & Firmware Reference →
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 »Community & Contributing →
Join the SOF open-source community: contributor guidelines, Git patch submission rules, TSC meeting minutes, releases, and frequently asked questions.
Contribute »