Having the ability to boot using EFI and patch firmware is a nice feature UEFI adds in comparison to old style BIOS, so updating firmware using it should be quick and simple right?
We’ll not so much when your doing it over IPMI where the standard way to get files on is to mount a ISO image.
From what we found was only the boot image portion on the ISO is visible under EFI meaning you cant just mount any old ISO and see your files.
Next we tried a USB pen drive, again this wasn’t straight forward with the EFI shell refusing to recognise our drive.
It turns out EFI requires a specific partition layout or the drives filesystem won’t be recognised.
This is the process we ended up with:
- Format the USB drive using Rufus with Partition scheme and target system type:
GPT partition scheme for UEFI
- Copy the firmware image to USB drive
- Boot the machine to the EFI shell
- Mount the USB drive from the IPMI storage option
map -rto refresh the device list
- Change to the mounted filesystem device, typically fs0 using:
- Run the EFI firmware update