U-Boot Button

The Radxa Cubie A7Z features an onboard U-Boot button for entering FEL mode.

Button Location

For the specific location of the U-Boot button, please refer to the interface description section in the Hardware Interface tutorial!

Usage Guide

FEL is a low-level boot and firmware update mode in Allwinner chips, primarily used for system recovery or debugging when the device cannot boot from conventional storage media.

Entering FEL Mode

To enter FEL mode, press and hold the U-Boot button on the Cubie A7Z before powering on the board, then release the button after power is applied.

1. Press and hold the U-Boot button on the Cubie A7Z

2. Connect the Cubie A7Z's USB Type-C port to your PC's USB Type-A port using a USB Type-A to Type-C cable

3. Release the U-Boot button on the Cubie A7Z

Interface Specifications

Technical Reference

For complete technical specifications and pin definitions, please refer to the Hardware Design: Schematic document in the download section.