http://uncensored.i2p/readfwd?go=Hardware?start_reading_at=2099315621
Most devices do this early on in the boot process,perhaps the very first thing, ( its inside UBoot if its ARM ), and if you are stupid and put this into the kernel, by the time you get there the power supply has already given up. I think this is inaccurate. USB-C defaults to 5V power
supply, same as USB-A. Consumers can negotiate higher.