Also, 10 minute reboot time. And I thought Windows Update was bad!
I've been on trains when they were obviously rebooting due to some sort of fault. It takes forever. What is the train doing during this time, exactly? Does every sub-computer on board boot serially or something?
There are normally a lot of self-tests involved in a reboot.
Every actuator will be energised, de-energised, moved end to end to test limit switches, etc.
It's mostly done serially because some things would be disrupted by other things, and figuring out a dependancy tree is tricky.
Quite a lot of stuff is auto-configured in bootup. For example, it might spend 10 seconds trying to ping a debug console to see if it should enter debug mode. Or 30 seconds with IP addresses configured to the 'lab' setup before switching over to the production networking config when the lab settings won't let it connect to anything.
I've been on trains when they were obviously rebooting due to some sort of fault. It takes forever. What is the train doing during this time, exactly? Does every sub-computer on board boot serially or something?