Hello everyone,

 

First of all, I'm sorry for my English. I'll do my best.

 

Currently armbian is installed in the mmc (although I tried the same test with a sd memory).

 

Now, with lscpu I can see that only cpu0 is enabled; 1-3 are off.

 

When I try: sudo echo '1' | Sudo tee / sys / devices / system / cpu / cpu1 / online to activate cpu1, shell replies with: online: Permission denied

 

I'm looking for options on root permissions or sysfs mount options; For now, I can not find a solution.

 

Thanks in advance for your help.

You have wrong u-boot / boot script combination and you are most likely using not supported developing kernel ?  ... it's not possible to activate cpu's from user space.