If an update goes really wrong (ie. battery died in middle of an update), the Mac may need to go into DFU mode and get a firmware write over USB.
I don't know if this is the actual format the firmware update uses, but the ports listed in the official documents match the "special" ports in the wiki there.
https://support.apple.com/guide/apple-configurator-mac/reviv...
If an update goes really wrong (ie. battery died in middle of an update), the Mac may need to go into DFU mode and get a firmware write over USB.
I don't know if this is the actual format the firmware update uses, but the ports listed in the official documents match the "special" ports in the wiki there.