The ConnectCore 6 Plus platform uses U-Boot (Universal Bootloader) as its primary bootloader. U-Boot is an open-source project. You can find standard documentation about commands, environment variables, Flattened Device Tree support, and more at

About this guide

This guide only describes specific changes made to the standard U-Boot by Digi International.


U-Boot for ConnectCore 6 Plus is based on standard U-Boot v2017.03 plus NXP patches at

Supported interfaces

The U-Boot for ConnectCore 6 Plus supports the following interfaces:

  • UART4 for console (115200/8/N/1)

  • DDR3

  • eMMC for storage (on USDHC4)

  • microSD card (on USDHC2)

  • Gigabit Ethernet on Micrel PHY KSZ9031 (RGMII)

  • I2C multi-port

  • One-Time-Programmable (OTP) bits

U-Boot has not fully implemented device tree support. Although U-Boot source code contains a device tree, not all drivers make use of this information. Changes you make to the U-Boot device tree may not have any effect if the modified nodes and properties are not supported by their corresponding drivers.

Carrier board version and ID

Digi uses non-volatile media to store the carrier board version and ID. See Carrier board version and ID.