Flashing new Coral Dev Board 4GB


Following the flashing steps with a new 4GB Coral Dev Board, that should be similar to the original 1GB Dev Board, device never shuts down for the flashing process…


Any ideas?


Hello @rlomascolo

Welcome to our forums! Are you able to try the same SD card into another (1GB version ideally) board? Even trying a different SD card would help.

It would also be helpful if you could connect to the serial console and/or plug a screen so we can extract some more information.


Sadly the 1GB devboard I had is not at the office at the moment and will take some days to be back.
Tried another SD card , 16GB and same problem.
In SD boot mode: No screen output, serial output gets the output from U-boot as copied below

U-Boot SPL 2019.04.1 (Apr 29 2020 - 18:40:05 +0000)
Board id: 0
DDRINFO: start DRAM init
DDRINFO:ddrphy calibration done
DDRINFO: ddrmix config done
Normal Boot
Trying to boot from MMC1
hdr read sector 300, count=1
U-Boot 2019.04.1 (Apr 29 2020 - 18:40:05 +0000)
CPU: Freescale i.MX8MQ rev2.1 1500 MHz (running at 1000 MHz)
CPU: Commercial temperature grade (0C to 95C) at 32C
Reset cause: POR
Model: Freescale i.MX8MQ Phanbell
Loading Environment from MMC… *** Warning - bad CRC, using default environment
In: serial
Out: serial
Err: serial

  • ATF
  • U-Boot 2019.04.1
    flash target is MMC:0
    Warning: ethernet@30be0000 using MAC address from ROM
    eth0: ethernet@30be0000
    Fastboot: Normal
    Normal Boot
    Hit any key to stop autoboot: 0

Welcome to your new Coral EdgeTPU Development Board!

To get started, you need to download and flash the latest firmware.
Please follow the instructions at g.co/coral/setup.
Configured USB Switch for UFP
In fastboot mode. Press Control-C to exit.
In fastboot mode. Press Control-C to exit

Hi there, are you able to catch/post the log/screen output during the flashing process on the 4GB model?

Hi , the logs only come from serial connection, no screen output.
The messages are in a previous post up in this post.

OK thank you. I’ll raise this internally to see if we can replicate and advise in due course.

Hi @rlomascolo,

I don’t have the 4GB version to test, but from the logs you pasted it appears that u-boot is loaded from the eMMC and not from the BalenaOS sd-card. Can you please confirm if all the boot switches were in sd-card boot mode (all switches are in off position) when booting from the BalenaOS card? You can re-try moving the first switch to off, to rule out imperfect contact, and check if you still see “U-Boot 2019.04.1 (Apr 29 2020…”

Another way to check if the switches are in sd-card mode is to boot with no card is inserted, and no u-boot logs should be visible on the serial.

Problem solved changing switches but there is an inconsistency somewhere here.
I tried many times with the ON OFF ON ON configuration for booting from SD Card, but could not get it booting from the SD. (balena+coral docs and Google Coral docs)
According to your post i tried the OFF OFF OFF OFF and it worked… now my Coral is running balena without the SD

Many thanks !!

Glad that it worked for you.
Thanks for letting us know, I will pass this internally to investigate and double check whether we need to change our docs.

Kind regards,