The ConnectCore 8M Mini is shipped without a default operating system loaded. Only U-Boot is flashed in the device. This step demonstrates how to install Digi Embedded Yocto in your ConnectCore 8M Mini.

1. Establish a serial connection with your device

Before you can establish the serial connection, you may need to run a setup script if your ConnectCore 8M Mini Development Kit is revision 4 or higher and you are running Linux. See Run serial console setup script for more information.

Open a serial connection with the device. You can use any serial terminal program such as Tera Term, Minicom, CoolTerm, or HyperTerminal.

PuTTY terminal program is not recommended due to an incompatibility with the USB/serial driver.

Open a serial connection with the following settings:

Parameter Value

Port

Serial port where the device is connected

Baud rate

115200

Data bits

8

Parity

None

Stop bits

1

Flow control

None

2. Download the firmware

Download the firmware images from the following location:

Some promotional ConnectCore 8M Mini development kits include a free Google Coral co-processor. If your kit contains a Google Coral card or you are interested in purchasing one separately, see Google Coral with Digi ConnectCore.

3. Program the firmware

There are multiple methods of programming the firmware to the target:

Program the firmware using UUU

  1. Decompress the zip file in a directory of your choice.

  2. Download the latest Universal Update Utility (UUU) tool, a software tool from NXP.

  3. Place the uuu executable in a directory in your PATH, such as /usr/bin.

  4. Install udev rules to allow any user to run the uuu for accessing the USB port:

    $ sudo sh -c "uuu -udev >> /etc/udev/rules.d/99-uuu.rules"
$ sudo udevadm control --reload-rules

  5. Connect a micro USB cable to your development PC and the other end to the target USB recovery connector.

  6. Reset the device by pressing the reset button on the board and immediately press any key in the serial terminal to stop the auto-boot process. The U-Boot bootloader prompt displays:

    U-Boot SPL dub-2020.04-r3.1-git-00114-g909871f6fff7-dirty (Feb 11 2021 - 16:54:47 +0100)
DDRINFO: start DRAM init
DDRINFO: DRAM rate 3000MTS
DDRINFO:ddrphy calibration done
DDRINFO: ddrmix config done
Normal Boot
Trying to boot from MMC2


U-Boot dub-2020.04-r3.1-git-00114-g909871f6fff7-dirty (Feb 11 2021 - 16:54:47 +0100)

CPU:   i.MX8MMQ rev1.0 1600 MHz (running at 1200 MHz)
CPU:   Industrial temperature grade (-40C to 105C) at 32C
Reset cause: POR
DRAM:  2 GiB
MCA:   HW_VER=1  FW_VER=1.00
MMC:   FSL_SDHC: 1, FSL_SDHC: 0
In:    serial
Out:   serial
Err:   serial
Model: Digi ConnectCore 8M Mini Development Kit
ConnectCore 8M Mini SOM variant 0x03: 2 GiB LPDDR4, Wi-Fi, Bluetooth, MCA, Crypto-auth
  Board version 3, ID undefined
Boot:  MMC2

 BuildInfo:
  - ATF a7f57f3
  - U-Boot dub-2020.04-r3.1-git-00114-g909871f6fff7-dirty

flash target is MMC:0
Net:   eth0: ethernet@30be0000
Fastboot: Normal
Normal Boot
Hit any key to stop autoboot:  0
=>
    Information in the console log may vary.

  7. On the target, in U-Boot, execute the following command:

    => fastboot 0

  8. On your development PC, change to the directory where you extracted the ZIP file:

    $ cd <zip-folder>

  9. Run the install_linux_fw_uuu.sh script with -h parameter to check the syntax:

    $ ./install_linux_fw_uuu.sh -h
############################################################
#           Linux firmware install through USB OTG         #
############################################################
Usage: ./install_linux_fw_uuu.sh [options]

  Options:
   -h                     Show this help.
   -i <dey-image-name>    Image name that prefixes the image filenames, such as 'dey-image-qt',
                          'dey-image-webkit', 'core-image-base'...
                          Defaults to 'dey-image-qt' if not provided.
   -n                     No wait. Skips 10 seconds delay to stop script.
   -u <u-boot-filename>   U-Boot filename.
                          Auto-determined by variant if not provided.

  10. To program the default image files (dey-image-qt):

    $ ./install_linux_fw_uuu.sh

  11. Once the firmware is installed, the device boots automatically. The default username is root with no password.

    Remove the micro USB cable from the recovery connector of the ConnectCore 8M Mini Development Kit. The USB port will not connect if a cable is connected to the recovery of the ConnectCore 8M Mini Development Kit. See USB interfaces on the ConnectCore 8M Mini.

Program the firmware using uSD card

  1. Decompress the zip file.

  2. Place the decompressed files in the root of a FAT-formatted microSD card and insert it in the microSD socket of the board.

  3. Reset the device by pressing the reset button on the board and immediately press any key in the serial terminal to stop the auto-boot process. The U-Boot bootloader prompt displays:

    U-Boot SPL dub-2020.04-r3.1-git-00114-g909871f6fff7-dirty (Feb 11 2021 - 16:54:47 +0100)
DDRINFO: start DRAM init
DDRINFO: DRAM rate 3000MTS
DDRINFO:ddrphy calibration done
DDRINFO: ddrmix config done
Normal Boot
Trying to boot from MMC2


U-Boot dub-2020.04-r3.1-git-00114-g909871f6fff7-dirty (Feb 11 2021 - 16:54:47 +0100)

CPU:   i.MX8MMQ rev1.0 1600 MHz (running at 1200 MHz)
CPU:   Industrial temperature grade (-40C to 105C) at 32C
Reset cause: POR
DRAM:  2 GiB
MCA:   HW_VER=1  FW_VER=1.00
MMC:   FSL_SDHC: 1, FSL_SDHC: 0
In:    serial
Out:   serial
Err:   serial
Model: Digi ConnectCore 8M Mini Development Kit
ConnectCore 8M Mini SOM variant 0x03: 2 GiB LPDDR4, Wi-Fi, Bluetooth, MCA, Crypto-auth
  Board version 3, ID undefined
Boot:  MMC2

 BuildInfo:
  - ATF a7f57f3
  - U-Boot dub-2020.04-r3.1-git-00114-g909871f6fff7-dirty

flash target is MMC:0
Net:   eth0: ethernet@30be0000
Fastboot: Normal
Normal Boot
Hit any key to stop autoboot:  0
=>
    Information in the console log may vary.

  4. To install the default firmware images (dey-image-qt) into the internal eMMC, run the following command:

    => run install_linux_fw_sd

    To program other images, set the variable image-name to the DEY image name (such as dey-image-webkit or core-image-base) before running the script.

    => setenv image-name core-image-base
=> run install_linux_fw_sd

  5. Once the firmware is installed, the device boots automatically. The default username is root with no password.

    During installation, error messages appear when the installation process attempts to override MAC addresses. These messages are expected.

    ## Resetting to default environment
oldval: 00:40:9D:7D:17:9A  defval: 00:04:f3:ff:ff:fa
## Error: Can't overwrite "ethaddr"
himport_r: can't insert "ethaddr=00:04:f3:ff:ff:fa" into hash table
oldval: 00:40:9D:7D:17:9B  defval: 00:04:f3:ff:ff:fb
## Error: Can't overwrite "eth1addr"
himport_r: can't insert "eth1addr=00:04:f3:ff:ff:fb" into hash table
oldval: 00:40:9D:7D:17:9C  defval: 00:04:f3:ff:ff:fc
## Error: Can't overwrite "wlanaddr"
himport_r: can't insert "wlanaddr=00:04:f3:ff:ff:fc" into hash table
oldval: 00:40:9D:7D:17:9D  defval: 00:04:f3:ff:ff:fd
## Error: Can't overwrite "btaddr"
himport_r: can't insert "btaddr=00:04:f3:ff:ff:fd" into hash table