GRUB 2 error – "fb: switching to radeondrmfb from EFI VGA"

Whenever I try to boot Arch, Mint or Debian Linux from a USB stick using GRUB 2 on my Mac with compatibility mode, it freezes on this error (given in the question title). I've tried every available, up to date, method on the web. Any help is appreciated. I have managed to get into the GRUB 2 commandline. Is there an option to set or something else?