Rocky 9 Linux Booting Notes

This guy (jlehtone) actually sums it up fairly well;

On Rocky 8 [and Rocky 9] the boot process has two options:

Legacy boot loads GRUB from /boot/grub2/ and GRUB reads /boot/grub2/grub.cfg
UEFI boot loads GRUB from /boot/efi/EFI/rocky/ and GRUB reads /boot/efi/EFI/rocky/grub.cfg

On Rocky 9 the same happens, but the /boot/efi/EFI/rocky/grub.cfg is a wrapper that makes the UEFI GRUB read /boot/grub2/grub.cfg.

Either way, you do need only one real grub.cfg

In all cases, the there are two options:

BLS is enabled and the grub.cfg should include /boot/loader/entries/*.conf files as boot entries. This is the default
BLS is disabled and all boot entries are within the grub.cfg

The entries as separate (BLS) files is easier for kernel updates: simply create file for new kernel and remove file of removed kernel. With entries in grub.cfg requires insert/remove lines type edits.

If no BLS entries were found, had they been erased, or did GRUB’s “locate BLS entries” somehow fail?

FROM: https://forums.rockylinux.org/t/grub-empty-after-dnf-upgrade/18132/9

And on this note;

https://bbs.archlinux.org/viewtopic.php?id=258039

set root=(hd0,gpt2)

linux /vmlinuz root=VMe.P3-LV.ROOT ro

initrd /initramfs.img

boot

OR

configfile (hd0,gpt1)/grub2/grub.cfg

NOTE: Some would have you put this, but DON'T: configfile (hd0,gpt1)/boot/grub2/grub.cfg

efi/EFI/WhatEverNamedBootLoaderID/grub.cfg (usually /efi/EFI/rocky/grub.cfg)

grub.cfg "Stub File" that 'points' to /grub2/grub.cfg (that's the path from the "I am the booting OS" perspective, which is of course in /boot/grub2/grub.cfg after Linux has booted.

search --no-floppy --root-dev-only --fs-uuid --set=dev 5603d694-79c2-4c70-9200-2e11ab3c20e8
set prefix=($dev)/grub2
export $prefix
configfile $prefix/grub.cfg