Good morning.
I have an stm32mp1 lime board connected to a lime overlay. It works just fine and I can easily control a MOD-IO2 board, but I can't find what tty devices map the uart/usart on uext1 and uext2 connector on the overlay.
Regards.
Edo
This can be seen in the sources for the SHIELD overlay. Check here:
https://github.com/OLIMEX/olinuxino-overlays/blob/master/stm32mp1/stm32mp1-shield.dts