Custom operating-system

[ukrolelo]

Greetings,
i would like to ask regarding the update operating system process when you press update in GUI.
What is going on, where it check the update and were from it is downloading?
Is it possible to somehow point to other than original(yours) repository?
For example fork ? But to still be able to check for updates.

The problem i have with remote NAS mount, i am looking for other solution to do that.
Because my PR was not taken it was not correct for HASS specifications.

P.S. If somebody can point me to files where the settings for update are.

Thank you

Reference:
https://community.home-assistant.io/t/nas-mount-on-hass-os/320218