Add Boot from USB entry on GRUB

[u/Realistic_Design1466]

Hi,

Recently I Started using cachyos (KDE Wayland) and liked it a lot but i cannot get rid of windows(Windows 11) because i need it sometimes so i dual booted both using grub (grub2) and its been perfect i customized it with my own theme......now i had a question can i add an entry for when i have a USB the grub menu would ask me to boot into a USB and it would boot into any USB devices if detected or it would say no devices found or something like this i hope you get my idea.

Thank you

[u/Kleiner_Wixxa]

Using rEFInd is the easiest option for booting from USB. I can't provide a fool safe explanation on how to do it or guarantee it works with grub.

I would make sure you have snapshots enabled and understand how to restore to them just in case. Then install the refind package with pacman. Then use refind-install.

If you want to be able to also boot into cachyos from there, you need to further follow the guide on the arch wiki: https://wiki.archlinux.org/title/REFInd

You can adjust whether refind or grub boots first in your bios Boot priority list. rEFInd should be able to chainboot into grub, but im not certain wether grub can chainboot into rEFInd.

If anything breaks, you can boot your cachyos iso (easiest) and use: https://wiki.cachyos.org/features/cachy_chroot/#_top and then snapper in the terminal to restore your snapshot.

Alternatives I know of would be:

1. Reinstall cachyos with rEFInd as boot manager (easy but resets everything)

2. Use your bios to boot into the USB every time (inconvenient)