New comment by aisecat on void-packages repository

https://github.com/void-linux/void-packages/pull/23541#issuecomment-678682619

Comment:
@MGlolenstine @PaperMountainStudio Some time back you had to have "arm_64bit=1" in config.txt to get past the rainbow screen on a 64bit kernel. The instructions worked for my pi4 even without the option, but my guess is maybe you have an older bootloader firmware, which can be updated on rpi4. 

Anyway try setting this option in your config.txt