Can't use a usb rs232 cable

[aliafshar]

Hi everyone!

I got given one of these Coral boards to play with and I have to say I am quite impressed. I have a problem though. I need to connect a USB RS232 cable (PL2303). In every other linux I have used (including rpi) this detects normally using the usbserial kernel module, but not in Mendel linux. Mendel has usbserial as a kernel builtin (probably for the serial console), so I can't remove the module and reload with vendor/product parameters and I can't seem to correctly pass them on the boot line. I haven't tried to rebuild the kernel yet.

I'd appreciate any help here.

1. How can I pass boot parameters or modify the boot line?
2. How can I rebuild the kernel only? I have the source code, but don't know the default kernel config.
3. Is there any other distro that I can run on this machine? Stock debian would be great, but not sure how to accomplish it with fastboot.

Thanks a lot!

[aliafshar]

Since I (fortunately) work at Google, I got in touch with one of the Mendel engineers, who taught me how to rebuild the kernel with the extra module I need. And this issue is now closed.

[aliafshar]

If anyone is reading, and needs to recompile the kernel, first follow the instructions to get the source code, here: https://coral.googlesource.com/docs/+/refs/heads/master/GettingStarted.md

1. Edit packages/linux-imx/debian/defconfig to add the config options you want to the kernel. In my case add the missing kernel option. CONFIG_USB_SERIAL_PL2303=y

2. Rebuild the kernel m docker-linux-imx

3. Install the new kernel

   j product
   cd packages/bsp/
   mdt install ./linux-image-4.14.98-imx_11-4_arm64.deb

4. Reboot Hope that helps anyone

[aliafshar]

And I documented it in this blog post: https://medium.com/@aliafshar/recompiling-the-coral-dev-board-mendel-linux-kernel-1319c911bcad