I2C RTC clock on the Rock Pi S

I have the Rock Pi S and it works fine. I’m trying to add an I2C hardware RTC clock to it. I can see the clock fine in i2cdetect, but I’m trying to install a boot module for it (i2c-rtc), which is the way you do this for Raspberry Pis, but that overlay doesn’t exist in the Debian Buster image for Rock Pi. Anyone know how to do this?

How do you connects the RTC and on which I2C bus?

You need to enable the overlay of the rtc module, check:

https://wiki.radxa.com/Device-tree-overlays

i2c1-hym8563

Activates hym8563 RTC

Related pins: I2C1(SCL/SDA), nINT(GPIO0_C1)

My RTC clock is a DS3231 on i2c bus 0, how would I connect that?