Omega RTC Integration
I will be using some Omegas where there is no connectivity at times and so will be installing an RTC. Reading and writing from/to the RTC is no problem however I am wondering what the exact mechanism is that the Onion uses to sync network time. Ideally I would like to see if a network time server is available and if so sync the system time and then update the RTC. If no server is available then have the system time set from the RTC. Failing that I would be happy to just turn off the network time sync and have the Omega just use the RTC as the source.
IIRC, the standard RTC package implements an init script which will read the data from the RTC device on boot and set the clock accordingly.
On shutdown it updates the RTC device with the current clock value.
In between those states, if a network connection is established, the Omega will query NTP servers and sync the clock with that.
So, as long as you build your firmware with the requisite packages (the one with the driver for your RTC device and the standard RTC package together with any dependencies either require) and ensure that the RTC device is accessible during boot up, your needs should be accommodated.