Hello @taragon
I hope you are doing very well.
It seems that Linux can not control the RTC BBSM directly, and also, the ELE API just have the Enable RTC command:

So, it is recommended to use an external RTC as you can see on EVK or i.MX93 FRDM board:

It is using the PCF2131, and there is a driver in our BSP.
Unfortunately there is not a Linux driver for the RTC on BBSM of i.MX93.
Best regards,
Salas.