Their low-level design is much closer to an embedded device like a Raspberry Pi, minus the SD card slot.
...or like a iPhone.
From that article you linked:
Some PC motherboards implement a similar feature as part of a separate chip, which can flash the UEFI firmware from a USB stick without actually turning on the motherboard normally, but this is only common in higher-end stand alone motherboards.
That might be referring to boot-block recovery, and I haven't seen any with a "separate chip" besides the dual-BIOS type; it's in the same flash (just a normally write-protected part) as the rest of the BIOS. The older ones will look for a flashable ROM image on the first floppy drive, but I'm not surprised if the newer ones will do it with USB instead.
BIOS firmware has been flashable from the OS since, what, the Windows 98 days? I'm sure I remember updating the BIOS on an old Pentium III ThinkPad in this manner.
I believe they're using BIOS in a more general sense. You're right that UEFI replaces the old BIOS APIs that bootloaders used, but there's still firmware (e.g. coreboot) below or part of its newer APIs.
What are you talking about? The BIOS has very little to do with the OS. Sure the flasher may be OS specific, but there are often alternative methods for eg. for Linux.
Yay. Now we have an OS hard-coded into the BIOS. Why is this a good thing?
What does this buy over simply putting a flash chip on the motherboard and letting the OS treat it like another peripheral, perhaps with a pre-installed slimmed linux distro?
That is pretty weird, yeah. At a guess, I'd say it has the OS as firmware to make the bootup really fast, and you'd be replacing that firmware board with a BIOS board.
> It does that with a UEFI which lives... where? Oh right, on the chip.
No, UEFI is firmware stored on a flash chip on the motherboard, usually connected to the CPU through the LPC bus. CPUs do not have any nonvolatile storage onboard (unless you count eFuses).
> Below UEFI is the BIOS, or the firmware formerly known as the BIOS. There is a project to make an open source firmware for PCs: https://www.coreboot.org. It works on a selection of newish motherboards.
This simply isn't true - while UEFI firmwares do offer BIOS emulation, there's no "BIOS" underneath them on most modern boards.
A slightly off-topic question: many modern motherboard have a function to flash a BIOS even without CPU present (e.g. Gigabyte markets it as Q-Flash). Any idea how does that technically work? Do they put a separate CPU on the motherboard?
> This all makes me think there is some other microcontroller somewhere that controls the bios flashback process, which would almost certainly be an extra chip.
I believe they just have some sort of extra microcontroller wired to a USB port and the SPI flash chip that stores the BIOS, probably with some sort of switch to ensure the host can't touch the SPI flash when the external microcontroller is attempting to flash it.
OSes tickling the BIOS is nothing new. Vendors have been providing Windows-based flashing utilities for a long time. Even most of the special bootable flashing disks run freedos.
Supposedly even the original PC had a BASIC boot option.
And frankly, its design is not that far from the other micros (ISA cards can extend the BIOS by responding to specific memory address ranges, much like a ROM cart on a C64). Its just so damn well wallpapered over these days.
We've been living in a world where you couldn't brick the firmware from the OS for a long time, and it's been terrible. I'm perfectly happy to take the risk of being able to brick a board from the OS if it means I never again have to try boot to a dos disk and run a proprietary exe to update the BIOS.
Some boards do have something of a "factory reset" in the form of dual bios so that if one is bricked, the backup can still be booted. But it's not a bug that not every motherboard has this feature.
...or like a iPhone.
From that article you linked:
Some PC motherboards implement a similar feature as part of a separate chip, which can flash the UEFI firmware from a USB stick without actually turning on the motherboard normally, but this is only common in higher-end stand alone motherboards.
That might be referring to boot-block recovery, and I haven't seen any with a "separate chip" besides the dual-BIOS type; it's in the same flash (just a normally write-protected part) as the rest of the BIOS. The older ones will look for a flashable ROM image on the first floppy drive, but I'm not surprised if the newer ones will do it with USB instead.
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