If you are unable to boot into RebornOS, this guide will show you how to repair your bootloader using a live ISO.
If you are booted in UEFI mode, when you run the command ls -ld /sys/firmware/efi, you will see an output like:
$ ls -ld /sys/firmware/efi
drwxr-xr-x 5 root root 0 Dec 10 09:52 /sys/firmware/efi/
If you are booted in Legacy mode, when you run the command above, you will see an output like:
$ ls -ld /sys/firmware/efi
ls: cannot access /sys/firmware/efi: No such file or directory
Follow the instructions on this page to chroot into your locally installed RebornOS.
After chrooting, please keep the same terminal window open to perform the below steps.
Based on whether you are booted in UEFI or Legacy mode, you can run the below commands:
UEFI mode
sudo grub-install --target=x86_64-efi --efi-directory=/boot/efi --bootloader-id=RebornOS --recheck
Legacy mode
sudo grub-install --target=i386-pc --bootloader-id=RebornOS --recheck
sudo grub-mkconfig -o /boot/grub/grub.cfg
If the above grub-install and grub-mkconfig steps run successfully, it is safe to reboot!