Little File System (LittleFS)#

Overview#

The Little File System (LittleFS) is a fail-safe file system designed for embedded systems, particularly for microcontrollers that use flash storage. It provides reliable file storage while addressing key challenges in embedded environments, such as power loss, flash wear, and limited system memory.

LittleFS is integrated into the Silicon Labs SiWx917 platform and is available through the WiSeConnect SDK and Simplicity Studio.

  • Bounded RAM/ROM: LittleFS operates within strict memory limits by avoiding recursion and minimizing dynamic memory allocations.

    It uses static, configurable buffers to maintain a predictable memory footprint.

  • Power-loss resilience: Many embedded operating systems may experience unexpected power failures. LittleFS uses copy-on-write and transactional commit mechanisms to maintain a valid state on disk, ensuring data consistency even after sudden outages.

  • Wear leveling: Flash memory degrades with repeated erase/write cycles.

    LittleFS distributes writes evenly across available sectors, extending flash lifetime even in systems without a full flash translation layer (FTL).

On the SiWG917 platform, LittleFS is integrated as a third-party component to provide a robust file storage option for applications requiring file system access.

It operates over the QSPI flash interface (either internal or external) managed by the SiWx917’s high-performance (HP) domain. The QSPI controller is available only in PS4 and PS3 power states.

Typical use cases include:

  • Storing logs, diagnostic data, or firmware metadata

  • Managing user-generated files or configuration exports

  • Supporting file-based interfaces in Matter or Wi-Fi provisioning flows

Note: LittleFS can coexist with NVM3 on SiWx917. Use NVM3 for structured key-value data, and LittleFS for general file-based storage.

Audience#

This guide is intended for professionals developing and maintaining embedded applications using the SiWx917 platform, and are interested in having persistent data storage through a file system.