Here, Our question like is it possible to access UART to read data when you are accessing same UART through Terminal? Theoretically, It is not possible because you are accessing same UART from Process and Terminal which may conflict.
But, We just want to get confirmation from your end.
Because we have another option to disable it from Boot Loader and it can be then accessible from process whenever required.
As you have provided Terminate UART console utility which is kind of utility to disable UART console.
Here, We have question like can we use same UART from application process while you are accessing UART console from any utility?
I think it won't be possible because we can't access UART console from both end at a time...so either packet will be missed or dropped which we are facing right now..
Let me explain overall scenario like what we are doing over here.
Board Boot and access UART console using Teraterm or Putty UART Terminal
Then execute one process in which same UART is opened and waiting to get data over same UART
Now, We are sending any command input over UART terminal and at the same time we are reading UART data in which some of packets or characters will be missed
So the main reason to drop or discard packets like same UART we are accessing from UART Terminal and out process running into OpenWRT
Hope above explanation will be sufficient regarding the issue which we are facing at our end.
Initially we have thought exactly like that but we can have option to disable UART from boot loader because into closed product there is no any usage of UART Terminal to be enabled once it will be boot successfully
After SSH serial connected, we can upload SystemUpgrade.bin file into openwrt, reliable.
Suggest your App could get all parameters/configs/commands from a file, and upload the file by SSH terminal.