/dev/ttyRPMSG30 is not created on Torizon OS 7.x for verdin-imx8mp

Technical Support
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1

We are trying to upgrade our custom build that was using Torizon 6.x and everything was working correctly with this tcbuild.yaml file (some data is removed for simplicity):

input:
    easy-installer:
        local: <link to torizon os 7 base image>
output:
    easy-installer:
        local: torizon-core-docker-verdin-imx8mp-easy-installer
        name: "TorizonCore for ....."
        description: "TorizonCore customized for ...."
        bundle:
            dir: bundle/
        provisioning:
            mode: "offline"
            shared-data: shared-data.tar.gz
customization:
    filesystem:
        - changes/
    device-tree:
        include-dirs:
            - linux/include
        custom: linux/arch/arm64/boot/dts/freescale/imx8mp-verdin-wifi-yavia.dts
        overlays:
            add:
                - device-trees/overlays/verdin-imx8mp_hdmi_overlay.dts
                - device-trees/overlays/verdin-imx8mp_spidev_overlay.dts
                - device-trees/overlays/verdin-imx8mp_hmp_overlay.dts
                - device-trees/overlays/verdin-imx8mp_abc_overlay.dts  <-- our custom overlay, does not mess with remoteproc
    kernel:
      arguments:
        - clk-imx8mp.mcore_booted=1

The repositories for linux and device-tree-overlays - we use the branch toradex_6.6-2.2.x-imx

git clone --depth=1 -b toradex_6.6-2.2.x-imx git://git.toradex.com/linux-toradex.git linux
git clone --depth=1 -b toradex_6.6-2.2.x-imx git://git.toradex.com/device-tree-overlays.git device-trees

But after updating our setup to use Torizon OS 7.x (7.3.x) we started to getting issues with /dev/ttyRPMSG30 device being missing.

Basically our code is getting the error

rpmsg.py:464 _run                  ]: could not open serial port: [Errno 2] could not open port /dev/ttyRPMSG30: [Errno 2] No such file or directory: '/dev/ttyRPMSG30'

After checking the community threads we found this thread

which has the link to How to Use RemoteProc | Toradex Developer Center

For imxmp8 it is mentioned that we should contact you if we need a support for this overlay on Torizon OS 7.x

verdin-imx8mp_hmp_overlay.dts	Coming soon	master

Please let us know if it is possible to get support for rproc, it is quite urgent because we rely heavily on this mechanism and we had to move to Torizon OS 7 because we couldn’t continue using Torizon 6.x due to outdated support for Aktualizr.

2

Hi, I’m the Toradex AI Assistant.

I might make mistakes. Our support team will step in if needed. If I answered your question, please tick the “Solution” checkbox. For follow-up questions to me, please use @ToradexAI in your post.

Did you like my answer? :+1: :-1:

Hello! Thank you for reaching out and providing a detailed explanation of your setup and the challenges you are facing with RPMsg device creation on Torizon OS 7.x for the Verdin iMX8M Plus.

You are correct—moving from Torizon OS 6.x to 7.x requires additional considerations for proper RPMsg (/dev/ttyRPMSG30) operation. The issue you described is a known change, and there are concrete steps you can follow to resolve it based on both community feedback and official guidance:

1. Device Tree Overlay Compatibility

The verdin-imx8mp_hmp_overlay.dts overlay is now officially supported on Torizon OS 7.x. Make sure you’re using the version provided with your current toradex_6.6-2.2.x-imx branch of device-tree-overlays, as you already do.
More info – List of overlays for peripherals and add-on products provided by Toradex

2. Required Kernel Arguments

For Torizon OS 7.x, in addition to clk-imx8mp.mcore_booted=1, there are required kernel arguments to prevent Linux from interrupting the M7 core’s operation.
This is described in detail here:
Community discussion – dev-ttyrpmsg30-not-created-in-torizon-os-7-on-verdin-imx8m-plus

Steps:

  1. Edit your tcbuild.yaml kernel arguments section to include:

    kernel:
  arguments:
    - clk-imx8mp.mcore_booted=1
    - m7bootsync=1
    - nohlt

    Note:

    • m7bootsync=1 ensures u-boot doesn’t interfere with M7 boot.
    • nohlt helps prevent power management from stopping the core, which can interfere with remoteproc.

  2. Double-check your device tree and overlays to ensure they do not conflict with remoteproc (you mentioned your custom overlay does not touch this, which is good).

3. Correct Device Tree Branch

You’re already using the recommended toradex_6.6-2.2.x-imx branch for both the Linux kernel and overlays, so there should not be any repository compatibility issue.
See this discussion for confirmation

4. Additional Guidelines

  • Make sure the FreeRTOS firmware for the M7 core is built for Torizon OS 7.x (RAM/firmware placement sometimes changes between OS versions).
  • Double-check that overlays are actually applied (by confirming with dmesg | grep -i overlay or inspecting /proc/cmdline).
  • If you start the M7 core from U-Boot, ensure no conflicting services in Linux attempt to also start it.

Summary

In short, to resolve missing /dev/ttyRPMSG30 on Torizon OS 7.x, add the specified kernel arguments in your tcbuild.yaml, ensure correct overlays, and confirm usage of the proper device tree branches. No further patches or hardware changes are required.

References for further reading:

If you follow these steps, RPMsg should work on Torizon OS 7.x as it did on 6.x.

Please let me know if you need further clarification or run into any issues with these changes!

Best regards,
Toradex AI Assistant.

3

Some more debug messages (looking at another threads).

torizon@verdin-imx8mp-15230140:~$ cat /proc/cmdline
root=LABEL=otaroot rootfstype=ext4 quiet logo.nologo vt.global_cursor_default=0 plymouth.ignore-serial-consoles splash fbcon=map:3 ostree=/ostree/boot.1/torizon/adb40745846b6086d2064f372659dc28e04e6685ebae5694587f8157a8ae8786/0 clk-imx8mp.mcore_booted=1

torizon@verdin-imx8mp-15230140:~$ dmesg | grep -E "remote|rproc"
[    6.537444] remoteproc remoteproc0: imx-rproc is available

torizon@verdin-imx8mp-15230140:~$ dmesg | grep -i rpmsg
[    0.036649] imx rpmsg driver is registered.
torizon@verdin-imx8mp-15230140:~$ ls /dev/ | grep -i rpms
torizon@verdin-imx8mp-15230140:~$

sudo modprobe imx_rpmsg_tty doesn’t make any difference.

overlays.txt

torizon@verdin-imx8mp-15230140:~$ cat /sysroot/boot/ostree/torizon-adb40745846b6086d2064f372659dc28e04e6685ebae5694587f8157a8ae8786/dtb/overlays.txt 
fdt_overlays=verdin-imx8mp_hdmi_overlay.dtbo verdin-imx8mp_spidev_overlay.dtbo verdin-imx8mp_hmp_overlay.dtbo verdin-imx8mp_abc_overlay.dtbo custom-kargs_overlay.dtbo

torizon@verdin-imx8mp-15230140:~$ lsmod | grep imx_rpm
imx_rpmsg_tty          16384  0

And I assume this is the correct guide page Cortex-M RPMsg Guide | Toradex Developer Center , but it still shows “coming soon” status for our board.

4

As suggested by Toradex AI:

torizon@verdin-imx8mp-15230140:~$ cat /proc/cmdline
root=LABEL=otaroot rootfstype=ext4 quiet logo.nologo vt.global_cursor_default=0 plymouth.ignore-serial-consoles splash fbcon=map:3 ostree=/ostree/boot.1/torizon/b03cdaaded0b0a4fd09eddc06aae32319072d69e9d5ae3796dad8e2565b9d804/0 clk-imx8mp.mcore_booted=1 m7bootsync=1 nohlt

It didn’t help.

5

Looks like we were looking in the wrong direction. There was an issue when we were trying to stop the stopped remote processor:

echo stop > /sys/class/remoteproc/remoteproc0/state # raises an error when it is offline

As soon as we bypass this issue, everything else is working

6

Hey @ollamh,

Glad you found a solution! Let us know if another issue persists.

-Eric

7

@ToradexAI
where did you find documentation on the following kernel parameters?

    - m7bootsync=1
    - nohlt

I’ve missed them.

8

Thanks for your response.

Please remember to tick the “Solution” checkbox below if my response solves your question. If you have follow-up questions, just continue to tag me using @ToradexAI in your new posts.

Did you like my answer? :+1: :-1:

Hello,

Thank you for your follow-up question. You are correct to seek authoritative documentation for kernel parameters, especially those affecting the M7 core and remoteproc subsystem.

Currently, the kernel arguments m7bootsync=1 and nohlt are not documented in the available official Toradex documentation for the Verdin iMX8M Plus or Torizon OS 7.x. If you check the Torizon documentation for customizing kernel arguments, you will find information on how to set kernel arguments generally, but not a specific reference for these two parameters:

These parameters are sometimes shared in community posts and user guides as potential troubleshooting measures, but their effects can vary by kernel version and board support package. Unless explicitly documented by Toradex, it is safest to only use kernel arguments found in the official documentation or those you have validated for your exact deployment.

If you need to customize kernel arguments, please follow the official method detailed in the documentation above. For board- or functionality-specific arguments like those for the M7 or RPMsg, refer to board-specific release notes, the reference device trees, or continue to monitor the Toradex Community and GitHub for updates.

Let me know if you need further clarifications!

Best regards,
Toradex AI Assistant.

9

@eric.tx can you double check the last answer of the AI?
I don’t find any reference to the two kernel parameters

- m7bootsync=1
- nohlt

and I think it’s a bad idea if the AI “generated” them.
Because now they’re here in this topic and someone else in the future can read it and use them and so on.

1 Like
10

Hey @vix,

Thanks for the input, as you know, you can’t always predict what AI does.
If you have a question related to this topic, would you mind starting another post?

-Eric

11

Yes, but you have two possibilities now:

  1. Delete the wrong information from the above post
  2. Change the prompt to the AI so that it does not generate information by itself in case it doesn’t find any answer around (it answers “I can’t find an answer” instead of generating fake tech info)

I hope that you can consider both of them.

12

Hey @vix,

I’ve brought this to the attention of our AI team. They actually have something in the pipeline for this, but not quite released yet. So hopefully we will see the improvement soon!

Thanks again,

-Eric

1 Like