How is the factory BIOS flashed?

[MikalE]

What I mean is, what is the physical process?

Are the BIOS chips flashed as a batch is some sort of caddie and then soldered in, or are they all individually flashed one machine at a time after the chip is already installed on the MB?

Inquiring minds want to know...

[flolic]

They are almost certainly programmed right at (memory IC) factory. When you order larger batches of flash/eeprom chips you can get them preprogrammed for very little extra cost.

[MikalE]

Thanks for the reply, but "almost certainly" doesn't give me a definite answer.

I guess it shall remain a mystery of the cosmos. We don't need to know what they do in those sealed off clean rooms...

[dr_st]

There may not necessarily be a single approach. Also, regardless of the process used to flash the general BIOS, certain unique parts (such as the serial numbers and the MAC addresses) must be introduced through a special per-machine procedure.

[flolic]

Few days ago I replaced motherboard of the HP ZBook 15 G1 laptop. New motherboard needs initialization when you start the machine. There is a program that is used to input serial number, product id and some other identifiers.
I guess bios chips arrive at factory preprogrammed and final configuration is written after the motherboard (or laptop) is assembled, via the automated process.

IMHO, there is no fuc*ing way they program bios chips before board assembly, that would be VERY uneconomical. Full programming after assembly is easier, but that would be waste of time. But configuring preprogrammed board only takes part of a second.