I’d like to present some examples of grub configurations, since booting problems are quite common, and they often are quite easy to fix.
You probably know about file /boot/grub/grub.cfg, where grub configurations are generated by the system. It contains boot menu entries that specify how to boot to different entries shown on the boot list when you start your Antergos system. For example, if you dual boot (e.g. Antergos and Windows), then all ways to boot to them are presented in grub.cfg.
So grub.cfg is a generated file, and you should not really make modifications to that file, since they will be overwritten when the system generates the file again (e.g. when kernel is updated).
There is another file, /boot/grub/custom.cfg, that grub boot process will read during boot. It may also contains those boot menu entries as grub.cfg. Those menu entries will be shown in the boot menu list after the menu entries of grub.cfg. File custom.cfg is not generated by the system, so it is up to you to decide its contents!
You could, for example, copy some selected menu entries from grub.cfg to custom.cfg and modify them in custom.cfg if needed. The only restriction is that they must follow the same syntax as in grub.cfg. The syntax resembles bash syntax.
The following posts on this thread will show some examples that I hope will be useful for either fixing problems or just learning more about booting with grub.
And I’m not saying I know (even nearly) everything about this subject, but I have done my share of trial and error with it, as a user, but not a developer.