How to set powersave governor?

Hardware
1

Hi, I am trying to set powersave governor on my Odroid m1 8GB and I am running homeassistant OS,
I have access to the command line through the web interface.
I installed cpupower and tried to set governor (cpupower frequency-set -g powersave) and that failed due to what I think is a permission problem. I then tried much lower level echo ondemand > /sys/devices/system/cpu/cpufreq/policy0/scaling_governor that failed on “/sys/devices/system/cpu/cpufreq/policy0/scaling_governor is readonly filesystem”.
I then found this post How to set up an Odroid with Home Assistant (cpufreq) - #4 by specs but I cannot do even the first command mount -t sysfs none sys -n -o r (even tho I am root and user hassio doesnt exist) due to “permission denied”. What should I do next?

2

The complete script I have in config:

#!/bin/sh
 mkdir /root/sys
 mount -t sysfs none /root/sys -n -o rw
 echo conservative   > /root/sys/devices/system/cpu/cpufreq/policy0/scaling_governor
 echo powersupersave > /root/sys/module/pcie_aspm/parameters/policy 
 echo 200000000 >  sys/devices/platform/fde60000.gpu/devfreq/fde60000.gpu/max_freq
 umount /root/sys
 rm -rf /root/sys

And this needs to be run as root.

After the script works you can try to start the script at boot.