The ConnectCore 6UL 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 www.denx.de/wiki/U-Boot/Documentation.

About this guide

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

Version

U-Boot for ConnectCore 6UL is based on standard U-Boot v2017.03 plus NXP patches at http://git.freescale.com/git/cgit.cgi/imx/uboot-imx.git.

Supported interfaces

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

  • UART5 for console (115200/8/N/1)

  • DDR3

  • NAND Flash

  • uSD card (on USDHC2)

  • 10/100Mbps Ethernet on SMSC LAN8720 PHY (RMII)

  • 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.