Does that HassIO operating system give the ability to update the firmware on a Raspberry Pi, the way the Raspberry Pi OS does, or do I need to boot off a Raspberry Pi OS card to do that.
The Pi 4 has had a number of firmware udpates since release to help keep it cool.
Kernel yes, but firmware no. You’ll be a second card, or you’ll need to backup, nuke the assistant setup and flash raspberry pi OS, update firmware then go back and reinstall and restore assistant.
I don’t use a RasPi, so I’m not sure of the terminology, but is the Firmware the same as EEPROM?
If so, then yes, HAOS has the ability to upgrade this:
However it looks like it’s been disabled for the time-being due to compatability issues and your instruction are correct that the user should do this themselves if needed (and if it won’t break anything):