I've got an Atomic Pi single board computer that I want to use as a firewall running Sophos XG or Sophos UTM. Neither OS supports booting with UEFI, but the Atomic Pi only supports UEFI booting. I'm hoping it's possible to inject the Compatibility Support Modules for CSM support, which would enable booting non-UEFI operating systems. I've done a fair bit of searching into various options, including modding the firmware myself, but I can't find a suitable BIOS that includes the CSM modules that I can extract.

I've also tried other options like booting from an alternative boot loader like Clover to get it working, but with no luck. I can get pfSense to boot, but don't want to switch from Sophos UTM.

Anyway, I've extracted the firmware using my SPI programmer and have attached it to this thread. I hope this will be sufficient - I can't find the BIOS for download from the manufacturer.

I appreciate any help you can offer

Thanks!

edit: I forgot to include a link to the product page:
https://www.digital-loggers.com/api_faqs.html