Since they contain copyrighted material, you won't find them on official GitHub pages, but the community maintains them on several reputable archival sites:

It tells EmuELEC how to behave like a PlayStation or a Dreamcast.

His journey took him into the sprawling archives of the internet. He sought the "EmuELEC BIOS Pack," a legendary digital bundle whispered about in Reddit forums Discord channels

If you’ve recently set up a retro gaming handheld or an Android TV box with EmuELEC, you’ve likely encountered a frustrating hurdle: a game simply refuses to launch, or you’re greeted with a black screen and a cryptic error message.