> I don't understand why there isn't a special USB-C protocol to recover bios over SDU/CC pins
Not enough of these cases happen under warranty for them to bother (and out of warranty cases are either neutral, or even beneficial to them if they drive sales of new hardware).
Lenovo also just had it happen with their Legion Go. They finally pulled the BIOS from distribution, but doesn't sound like they're doing anything to help the victims whose devices got bricked by a bad update.
> Or some DFU mode you can boot into.
Ironically, Macs do have that, no?
Yep, you can do a DFU recovery on a Mac from another Mac over USB. Same as if it were an iPhone/iPad. Which makes sense since it's basically the same hardware.
In PCs it's usual for a lot of motherboards have a dual bios, so if something fails (eg no POST) in the update, the mobo fall backs to the other one. It's a cheap chip in bulk, that would help a lot in cases like this.
I uploaded a dump of the flash [1] in the bad state and they somehow analyzed it and made a fix. Great for others I guess, but I'm still mindblown that the regular path would have been that this perfectly working laptop to this day become ewaste.
Being an embedded dev, I don't understand why there isn't a special USB-C protocol to recover bios over SDU/CC pins. Or some DFU mode you can boot into.
[1] https://github.com/fwupd/firmware-lenovo/issues/484