Another quick question:
Is there anyway that we can use the second UART port in P9 connector? I know something need to change to generate new dtb file to enable that. Is there any easy way to download or generate this file?
Thanks a lot.
p.s. digging on the internet and found this:
https://patchwork.kernel.org/patch/9988925/
The reason why UART is not enabled: "... because both headers are dedicated to expose general purpose pins and remapping some of them to use the second UART would break existing users."
However, after checking the GPIO mapping, I found PIN 24&26 on P9 header are used for UART only, not possibly messing around with other GPIO pins. It should be opened at the beginning.
Can we have a dts file with this option on? Maybe I have to learn how to compile the dts file myself.