Most of the ALIX boards use something called TinyBIOS[1][2]. Browsing through the source tree from the pcengines site, it doesn't seem to share any relation with this project here.

The current APU boards use Coreboot[3]

[1] https://www.pcengines.ch/alix.htm

[2] https://www.pcengines.ch/tinybios.htm

[3] https://www.pcengines.ch/apu2.htm