Serial ports on Apalis imx6/Eagle Board from Diamond System


I am working with the Eagle board from Diamond Systems that has apalis imx6 on it. After updating it with a previous image of my work I cannot write or read from ports /dev/ttyS0 /dev/ttyS1 /dev/ttyS2 /dev/ttyS3 but I can from /dev/ttymxc3 /dev/ttymxc4.

Do you have any idea what I should do to regain access to those ports ?

Best regards,


uname -a info: Linux apalis-imx6 3.14.52-00009-g786c368 #20 SMP Sat Jun 17 11:27:18 IST 2017 armv7l GNU/Linux

hardware: The board I’m working with is EGL-MX6-Q2G-XT from Diamond System. It’s an ARM SBC using Toradex Apalis iMX6.

I used this How to Clone Embedded Linux on eMMC Based Toradex Modules section BSP 2.7 and older. For the restore I used Direct restore using UMS again (A). In part A.2.3, what is the “target reset” ? Is it just an OFF/ON of the board ?

Hi @JG2!

I have some comments about what you have:

  1. Your Linux version is very old… if you take a look at the Embedded Linux Release Matrix article, you can see that the oldest Linux version for an LTS BSP is 4.9 (for BSP 2.8.7)

  2. I strongly advise you to upgrade to the newest possible BSP version

  3. About the serial devices, you can take a look in the UART (Linux) article, which lists the UART ports for each module

Also, could you elaborate on your specific need of the /dev/ttyS[0-3] devices?

Best regards,

Hi @JG2!

what is the “target reset” ? Is it just an OFF/ON of the board ?

When talking about embedded systems, they are commonly referenced as target and the computer where you do the development is commonly referenced as host. So, a target reset is indeed a reset or an off → on

Best regards,


Thanks for your answer. I’m not sure I can update the linux version? Is there a risk I would lose the drivers installed by Diamond Systems on it? It was sold to us in 2017. There are specific drivers on this Eagle Board (that has apalis imx6) to be able to choose modes RS232/422/485 on /dev/ttymxc3 mxc4 ttyS0 ttyS1 ttyS2 ttyS3 (and others that I don’t use).

I used to be able to use the /dev/ttyS[0-3] devices. I still can on the other board I have. I did a clone on that second board and updated the first board with it.

Best regards,


Here is the manual to the board:

Hi @JG2 !

If you update, you’ll certainly lose your current software setup.

From what I understood, you got this software setup from Diamond System. So, if you need support to use it or maintain/upgrade, you will need to get support from them.

On the other hand, if you make use of Toradex software, we will be happy to help you.

Best regards,