The ConnectCore 8X uses an NXP i.MX8QXP system-on-chip (SOC). NXP released two revisions of the SOC silicon: revision B0 and revision C0.

On i.MX8QXP C0 revision, NXP fixed most of the errata that were reported on B0. For a full list of fixes, see NXP Application Note AN12770.

The Security Controller (SECO) firmware of the SOC is different for each revision. This is a fundamental fix in the security chain that has the following important consequence:

The bootloader for a i.MX8QXP B0 cannot boot on a C0, and vice versa.

Digi Embedded for Android generates different U-Boot artifacts for the different ConnectCore 8X variants for both SOC silicon revisions (B0 and C0). For example, for the default variant of the ConnectCore 8X SBC Pro, Digi Embedded for Android produces:

  • u-boot-ccimx8xsbcpro2GB-B0-flash_all.imx

  • u-boot-ccimx8xsbcpro2GB-B0-flash.imx

  • u-boot-ccimx8xsbcpro2GB-C0-flash_all.imx

  • u-boot-ccimx8xsbcpro2GB-C0-flash.imx

You must select the U-Boot that matches the SOC revision of your ConnectCore 8X SOM.

Identify the SOC revision of your SOM

Visual inspection

The label on the ConnectCore 8X SOM looks like this:

ConnectCore 8X SOM label

The red circle denotes Digi’s revision of the ConnectCore 8X SOM. The following table correlates the ConnectCore 8X SOM revision with the i.MX8QXP SOC revision:

SOM revision Description i.MX8QXP SOC revision

1P, 2P…​

Pre-production series

B0

A, B…​

Mass production series

C0

On the U-Boot console

U-Boot prints the i.MX8QXP SOC revision on the banner, at the CPU line:

U-Boot dub-2018.03-r2.2+g2854efc (Sep 13 2019 - 20:07:29 +0000)

CPU:   Freescale i.MX8QXP revB A35 at 1000 MHz at 37C
DRAM:  2 GiB
MCA:   HW_VER=1  FW_VER=0.16
MMC:   FSL_SDHC: 0, FSL_SDHC: 1
In:    serial
Out:   serial
Err:   serial
Model: Digi International ConnectCore 8X SBC Pro Board.
ConnectCore 8X SOM variant 0x02: Industrial QuadXPlus 1.0GHz, 16GB eMMC, 2GB LPDDR4, -40/+85C, Wireless, Bluetooth
Board: ConnectCore 8X SBC Pro, version 1, ID 135
Boot:  MMC0

BuildInfo:
 - SCFW 494c97f3, SECO-FW d7523fe8, IMX-MKIMAGE abd6ce55, ATF 727cf89
 - U-Boot dub-2018.03-r2.2+g2854efc

Net:   eth0: ethernet@5b040000
Hit any key to stop autoboot:  0
=>

Bootable microSD artifact

Among the many artifacts that a Digi Embedded for Android project produces, there is one with .sdcard extension. You can raw write this file to a microSD card and fully boot the ConnectCore 8X SBC Pro from it.

Digi Embedded for Android only produces one .sdcard file that uses the default U-Boot artifact for the platform. The default U-Boot artifact is the one for the mass production series, that uses the rev C0 silicon.

The default .sdcard artifact cannot boot on a pre-production ConnectCore 8X SOM (with a B0 system-on-chip).