CDC ACM kernel module missing

[tillkamppeter]

I have connected an SBC's power supply USB-C port with one of the USB-C ports (lower left, with USB-C module) of the RISC-V board, running V1.1 of the Ubuntu 24.04 image.

The SBC is running and on can access the web interface of the server software running on it. So it gets powered by the same power supply which powers the RISC-V board.

Now, the documentation of the SBC tells that on this USB-C port there is also a serial console for monitoring the boot process. And, indeed, the SBC shows as a USB->serial adapter (of CDC ACM type) in lsusb -v, run on the RISC-V board, but I cannot access it.

With a regular (Ubuntu on amd64) laptop I can access the SBC's serial console with sudo minicom -s and choosing a device /dev/ttyACM0, /dev/ttyACM1, ...

I did some investigation and on the amd64 laptop there is a kernel module cdc_acm but it is missing on the RISC-V system. Could this module be supplied with an upcoming update?

[DC-DeepComputing]

I have connected an SBC's power supply USB-C port with one of the USB-C ports (lower left, with USB-C module) of the RISC-V board, running V1.1 of the Ubuntu 24.04 image.

The SBC is running and on can access the web interface of the server software running on it. So it gets powered by the same power supply which powers the RISC-V board.

Now, the documentation of the SBC tells that on this USB-C port there is also a serial console for monitoring the boot process. And, indeed, the SBC shows as a USB->serial adapter (of CDC ACM type) in lsusb -c, run on the RISC-V board, but I cannot access it.

With a regular (Ubuntu on amd64) laptop I can access the SBC's serial console with sudo minicom -s and choosing a device /dev/ttyACM0, /dev/ttyACM1, ...

I did some investigation and on the amd64 laptop there is a kernel module cdc_acm but it is missing on the RISC-V system. Could this module be supplied with an upcoming update?

First of all, our serial port is a monitored serial port, directly connected to the computer can be used, do not need to install CDC ACM module. If you need to install the CDC ACM module, you can insert the USB serial port module to debug other devices. We have developed the kernel and code, you can add it yourself.
https://github.com/[DC-DeepComputing/DC-linux](https://github.com/DC-DeepComputing/DC-linux)

[tillkamppeter]

Note that this is not about the serial port which the RISC-V board has for monitoring its boot process.

The scenario is that the RISC-V board is in a developer's or administrator's laptop and they are using the SBC I mentioned. For administration of the SBC and/or developing on it they want to monitor the SBC's boot process. The implementation of a serial port over USB on the SBC is of the CDC ACM type, and therefore a client which wants to access the SBC's serial port needs a CDC ACM driver, which is implemented as the cdc_acm kernel module. Once, as Ubuntu comes with this module by default, and second, as a Framework RISC-V laptop is probably mostly used by developers it would make a lot of sense to include this kernel module.