[coreboot] F2A85-V PRO as good target?

Peter Stuge peter at stuge.se
Wed Oct 17 01:02:36 CEST 2012

Rudolf Marek wrote:
> 2) there seems to be some hw way how to unbrick that, but question
> is if it will accept our images
> USB BIOS Flashback - Easy, worry-free USB BIOS
> I suspect it is done by some 8051 controller, possibly some of those chips:
> http://detail.zol.com.cn/picture_index_975/index9747187_0_p336189.shtml
> Looks like independent of any other chips, it could be cool feature
> for coreboot users.

I was curious about what this really was and looked into the manual.

--8<-- Page 2-19, "Onboard switches"
5. BIOS-FLBK switch

The BIOS Flashback buttton offers the most convenient way to update
the BIOS. It allows overclockers to update new BIOS versions without
having to enter their existing BIOS or operating system. Just plug in
a USB storage and press the BIOS Flashback button for 3 seconds, and
the BIOS is automatically flashed using standby power. Hassle-free
updating for the ultimate convenience!

[mainboard drawing showing BIOS_FLBK button location]
F2A85-V PRO BIOS Flashback switch

1. Download the USB BIOS Flashback wizard from the ASUS service
   website (www.asus.com). Save it to a USB portable disk, and place
   it in the root directory.
2. Plug the USB flash drive into the bottom port of ESATA6G_USB3_12
   connector in back I/O.
3. Press the USB BIOS Flashback button for 3 seconds, and the light
   will begin to flash (on the third second).
4. The Flashback function is enabled once the light starts to flash.
5. The flashing rate of the light signal accelerates along with the
   updating speed.
6. BIOS update is complete once the light signal goes out.

[image showing the lower USB 3.0 port marked in red]

* Do not unplug the portable disk, power off the system or press the
  CLR_CMOS button while BIOS update is ongoing, otherwise update will
  be interrupted. In case of interruption, please follow the
  recommended procedures again to complete BIOS update.

* If the light flashes for five seconds and turns into a stable
  light, this means that the USB BIOS Flashback is not operating
  properly. This may be caused by:
  1. Improper installation of the portable disk.
  2. Error in file name or incompatibility in file format. If this is
  the case, please restart the system to turn off the light.

* Updating BIOS may have risks. If the BIOS program is damaged during
  the process causing the system unable to reboot, please contact the
  local service station for help.

The fact that one of the USB 3.0 ports are used for this, and the
fact that they write "If the BIOS program is damaged .. please
contact the local service station" makes me believe that this is
still the same old story, but instead of flashing code being in
the bootblock and running on the CPU the flashing code is maybe in
the IMC firmware instead, running before the CPU.


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