Set fan pwm in u-boot

Hi all!
Now playing with the armbian bullseye.
Have a rock5 board with radxa pwm fan attached that is controlled with the fan-control.

Sometimes, the board hangs at reboot and becomes extremely hot. When I power cycle the board, it boots armbian and turns a fan to 100% because of temperature.

The question is how can I enable that fan in u-boot for 75%-100% duty cycle? This will eliminate the risk of overheating in case of freeze at boot.
Then, when the OS will start, the fan will be throttled or completely stopped by the fan-control.