getting second serial port available - Printable Version

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getting second serial port available - gadgetguy - 11-10-2023

I'm trying to get the second serial port working (/dev/ttyS2) on a PINE64-LTS board.

I created and edited the DTS file as @martinayotte  posted a while back (
But it didn't seem to work. I am using a logic analyzer to monitor the signals and getting NO data. I am using a simple C program to open and write to the port. the write reports its writing data.

in /boot/dtb/allwinner I modified the "-lts.dtb" file
-rw-r--r-- 1 root root 41859 Feb 17  2023 sun50i-a64-pine64.dtb
-rw-rw-r-- 1 root root 41973 Nov  1 13:20 sun50i-a64-pine64-lts.dtb
-rw-r--r-- 1 root root 41909 Feb 17  2023 sun50i-a64-pine64-lts-dtb-backup
-rw-r--r-- 1 root root 41981 Feb 17  2023 sun50i-a64-pine64-plus.dtb

Is there a way to confirm 
a) which DTB file the system is actually using, or
b) that the "okay" on that serial port is enabling the mux mapping for those pins?

Thanks in advance.

RE: getting second serial port available - gadgetguy - 11-26-2023

So I never did get an answer to this question, but it because un-necessary. I went into armbian-config on the root login and you can manage additional devices there. Turning on UART2 (in hardware section) and rebooting enabled the UART2 pin mux's so that it works on Pi connector Pins 8 and 10.