Hi there,
Right now I'm developing i.MX 8M Nano Ultralite DDR3L EVK. I'm planning to use UART3 as RS232 driver. I follow this document to generate yocto project: https://www.nxp.com/docs/en/user-guide/IMX_YOCTO_PROJECT_USERS_GUIDE.pdf
So I have successfully generate core-image-minimal, now I can see that UART3 is available on /dev/ttyxmc2. But, weird things happen when I call stty -F /dev/ttyxmc2, suddenly Linux OS is not responding that I should do hard reset to make Linux working again. There is no problem when I call stty -F /dev/ttyxmc1 (serial console UART), so it's safe to say that stty doesn't have any problem.
Problem still persist when I use core-image-base, but when I generate imx-image-core, suddenly UART3 is working. So my take is, there is nothing wrong with the hardware, it's just something with yocto project configuration. Now, sure I can use imx-image-core, but the image is so big (around 1.6GB), so if possible, I would like to use core-image-minimal as my own base image.
So how to configure core-image-minimal to make UART3 working properly? Any ideas or suggestion is pretty much appreciated. Thank you for your time and assistance.
You can try to build "core-image-full-cmdline". It is small also and more linux commands can be used.