Kontron AM5030 uEFI - Manual (Page 71)

AM5030 uEFI BIOS Updating the uEFI BIOS
ID 1037-1209, Rev. 1.0 Page 65
P R E L I M I N A R Y
9. Updating the uEFI BIOS
BIOS updates are typically delivered as an update CD ISO image. This ISO image needs just
to be burned to a CD and booted. Follow the menu for updating the uEFI BIOS. For further in-
formation refer to the update CD documentation.
9.1 BIOS Redundancy Strategy
The AM5030 has two sets of EFI Flash chips to form an EFI redundancy strategy. Basic idea
behind that is to always have at least one working EFI available regardless if there have been
any flashing errors or not.
9.2 Updating Strategy
To always maintain at least one EFI Flash correct, the update CD uses the following update
procedure:
1. Switch to the second Flash.
Since the update CD always changes the Flash chip prior to doing any updates, the uEFI
BIOS that was used to actually boot the board and is therefore known to be good is pre-
served for backup.
2. Update the second Flash.
This flash is now selected as active boot Flash.
The update CD will not allow to flash both chips at a time. Flashing both chips would destroy
the backup version and therefore break the redundancy.
If you want to have the same BIOS version on both Flash chips, then simply run the update CD
twice.
9.3 Fallback Mechanism
In case of one EFI being corrupted and therefore the board not starting up, the IPMI controller
automatically switches to the other Flash and resets the board. The board should now come
up successfully from the other not corrupted image. The flashing procedure can now be restart-
ed to restore the broken image.
9.4 Flash Selection by IPMI Command
Usually the active Flash is selected by the IPMI controller. The Flash bank can be switched via
an IPMI OEM command. This command is used by the update CD. See the IPMI manual for
further information.