RTC pins

[CounterPillow]

Your wiring sounds correct, what I suspect may be going on here is that the EDK II port is not configuring the RK817 PMIC right. In such a case, the RK817 PMIC might think it's running into some dangerous condition and resets the board. I tried checking the EDK II repo for anything relating to RK8xx but it doesn't seem to be doing anything from what a quick GitHub search revealed, which means the PMIC is using factory pre-programmed values for its config registers. For what it's worth, u-boot doesn't seem to be setting anything immediately obvious either; it enables under-voltage protection on LDO3 but that seems to be the opposite of what I'd suspect the problem to be. It's possible this is a red herring, but the board resetting itself after a few seconds does smell like a PMIC problem.

Here's the RK817 datasheet with all its register descriptions and such, maybe it's helpful in figuring out what's going on.

By the way, it's also definitely not a battery voltage issue, the PMIC only hard powers down the system in such a case at a battery voltage of like 2.9 last I checked, and it shouldn't be doing that when the board is getting power from the wall.