ESP32-S31 Linux BSP

⚠️ Espressif Fork: This repository is Espressif's Linux BSP with support for ESP32S31.
⚠️ Developer Preview: This branch (integration/v1.0-esp32s31) is currently in developer preview and is not yet recommended for production use. For branch strategy and maintenance policy, see the Branch Strategy section below.

This repository contains the image layout and packaging tools used by the ESP32-S31 Buildroot integration.

Buildroot packaging

Buildroot installs tools/ and configs/ as a host package. Its post-image hook invokes:

tools/buildroot_post_image.sh esp32s31 nor <images_dir>

The packager wraps the U-Boot SPL in the Espressif image format and merges the SPL, U-Boot FIT, Linux device tree, XIP kernel, and cramfs root filesystem into s31_full_flash.bin.

Set ESP_ESPTOOL when esptool is not available in PATH.

Component verification helpers

• tools/gen_spl_img_esp32s31.sh wraps a standalone U-Boot SPL binary.
• tools/gen_fit_boot0_esp32s31.sh creates a diagnostic U-Boot FIT.

The normal Buildroot flow uses the U-Boot binman-generated u-boot.itb; the FIT helper is intended only for component-level testing.

Branch Strategy

integration/v1.0-esp32s31 - Developer Preview

This branch is currently in developer preview and is not yet recommended for production use.

Purpose

• Quick access to ESP32-S31 BSP support
• Technical validation and feedback collection
• Evaluation and testing purposes only

What to Expect

• Limited chip support: ESP32-S31 only
• Irregular updates: No scheduled release cadence
• Breaking changes: May occur without notice
• Limited feature acceptance: New feature requests may not be accepted during the Developer Preview
• Bug fixes: Bug fixes may be addressed on a best-effort basis during the Developer Preview

Maintenance Policy

• Bug reports are welcome but may be deferred
• Pull requests reviewed on a case-by-case basis
• No API/ABI compatibility guarantees
• Best-effort support only

Recommended For

• Early adopters wanting immediate ESP32-S31 access
• Hardware evaluation and prototyping
• Testing and providing feedback to Espressif

Not Recommended For

• Production deployments
• Long-term projects requiring stability
• Critical systems