The ConnectCore 93 uses an NXP i.MX93 system-on-chip (SOC). NXP released two revisions of the SOC silicon: revision A0 and revision A1.

On i.MX93 A1 revision, NXP fixed some of the errata reported on A0. For a list of fixes, see NXP Application Note AN13997. Note that you will need to register with the NXP website.

The EdgeLock<sup>®</sup> Secure Enclave (ELE) firmware is different for each revision. It is a fundamental fix in the security chain that has the following consequence:

The bootloader for an i.MX93 A0 cannot boot on an A1, and vice versa.

Digi Embedded Yocto generates different U-Boot artifacts for the different ConnectCore 93 variants for both SOC silicon revisions. For example, for the default variant of the ConnectCore 93 Development Kit, Digi Embedded Yocto produces:

  • imx-boot-ccimx93-dvk.bin-flash_singleboot_a0

  • imx-boot-ccimx93-dvk.bin-flash_singleboot

You must select the U-Boot that matches the SOC revision of your ConnectCore 93 SOM.

Identify the SOC revision of your SOM

Visual inspection

The i.MX93 part number’s last letter indicates the silicon revision. For example, 93xxxxA is an i.MX93 A0 SOC revision, whereas 93xxxxB is an i.MX93 A1 SOC revision.

On the U-Boot console

U-Boot prints the i.MX93 SOC revision on the banner at the SOC and CPU lines:

U-Boot SPL dub-2023.04-r3.2 (Jan 30 2024 - 10:57:23 +0000)
SOC: 0xa1009300
LC: 0x2040010
PMIC: Over Drive Voltage Mode
M33 prepare ok
Normal Boot
Trying to boot from BOOTROM
Boot Stage: Primary boot
image offset 0x0, pagesize 0x200, ivt offset 0x0
Load image from 0x4f400 by ROM_API
NOTICE:  BL31: v2.8(release):lf-6.1.55-2.2.0-0-g08e9d4eef226-dirty
NOTICE:  BL31: Built : 16:47:44, Jan 30 2024

U-Boot dub-2023.04-r3.2 (Jan 30 2024 - 10:57:23 +0000)

CPU:   i.MX93(52) rev1.1 1700 MHz (running at 1692 MHz)
CPU:   Industrial temperature grade (-40C to 105C) at 42C
Reset cause: POR (0x1)
DRAM:  992 MiB
Core:  202 devices, 29 uclasses, devicetree: separate
In:    serial
Out:   serial
Err:   serial
Model: Digi ConnectCore 93 Development Kit
ConnectCore 93 SOM variant 0x01: 992 MiB LPDDR4, Wi-Fi, Bluetooth
Boot:  MMC0

  - ELE firmware version 0.1.0-44880904

flash target is MMC:0
Net:   eth0: ethernet@428a0000 [PRIME]
Fastboot: Normal
Normal Boot
Hit any key to stop autoboot:  0

Bootable microSD artifact

Among the many artifacts that a Digi Embedded Yocto project produces, there is one with .sdcard extension. You can raw write this file to a microSD card and fully boot the ConnectCore 93 Development Kit from it.

Digi Embedded Yocto 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, which uses the rev A1 silicon. See Boot the system#substitute-the-bootloader for information on how to change the bootloader on the sdcard image.

The default .sdcard artifact cannot boot on a pre-production ConnectCore 93 SOM (with an A0 system-on-chip).