APU2 APU3 APU4 BIOS upgrade

PC Engines published new BIOS for the APU, every 4-8 weeks. Some recent BIOS versions added better suppoer for ECC Ram, therefore it's worth to upgrade.

Download the latest BIOS versions here: https://pcengines.github.io/


Step 1: create a bootable USB stick

You can create a bootable debian stick, like described here: Debian installation instructions or another linux distribution of your choosing. The important step is to be able to boot linux that has flashrom utility.


Step 2: install flashrom

If you have a bootable debian, you can simply install flashrom from the repository

sudo apt-get install flashrom

otherwise, install flashrom some other way.


Step 3: download BIOS version for your board

Download the latest BIOS versions here: https://pcengines.github.io/

Make sure you download the correct version. If you have APU3, make sure you download APU3 image.

wget http://pcengines.ch/file/apu3_v4.8.0.5.rom.tar.gz

gunzip apu3_v4.8.0.5.rom.tar.gz

ls -l apu3_v4.8.0.5.rom

Make sure you unpack the image like shown above. You need a file with .rom extension.


Step 4: write the new BIOS to the chip

Use the below command, make sure you replace the image name with the image you downloaded.

flashrom -w apu3_v4.8.0.5.rom -p internal:boardmismatch=force

Here's how it should look like, if you have done it correctly. 

root@debian:~# flashrom -w apu3_v4.8.0.5.rom -p internal:boardmismatch=force
flashrom v0.9.9-r1954 on Linux 4.9.0-6-amd64 (x86_64)
flashrom is free software, get the source code at https://flashrom.org

Calibrating delay loop... OK.
coreboot table found at 0xcfed1000.
Found chipset "AMD FCH".
Enabling flash write... OK.
Found Winbond flash chip "W25Q64.V" (8192 kB, SPI) mapped at physical address 0x00000000ff800000.
Reading old flash chip contents... done.
Erasing and writing flash chip... Erase/write done.
Verifying flash... VERIFIED.



All ready! Reboot and enjoy new BIOS!



If, somehow, you managed to write a wrong BIOS to the board, or you lost electricity during the upgrade, you can recover with the BIOS flash recovery module.

We have flashed hundreds of BIOSes on these boards and never needed this module. Don't buy it ahead of time :-)