GRUB UEFI not detected after GPT setup — need terminal-only fix

[tarik linux]

Hello everyone,

I'm running Linux Lite 5.4 on an HP machine with BIOS Legacy. I've converted my disk to GPT and created a proper EFI partition. I installed GRUB in UEFI mode via terminal (no Live session available), but my firmware does not detect the fallback `bootx64.efi` file. I'm still booting using Legacy mode via F9, and I can't use `efibootmgr` because EFI variables are unavailable in my current session.

What I'm looking for is a way to force UEFI boot using only terminal tools, without removing GRUB Legacy or risking an unbootable system. Ideally, I want to activate a UEFI path that my firmware will recognize, even if it requires copying files manually or testing alternate bootloaders.

System info:
- **Linux Lite Version**: 5.4 (Ubuntu 20.04 base)
- **Memory**: 1.8 GiB
- **Motherboard**: HP 80BF
- **Kernel**: 5.4.0-216-generic
- **Graphics Chip**: Intel HD Graphics (x5-E8000)

Any guidance, script, workaround, or documentation that could help me achieve UEFI boot without a Live USB would be greatly appreciated. Thanks in advance!

[tarik linux]

[Follow-up] Issue resolved – BIOS-only firmware confirmed
Thanks again to the community. Just posting a quick update: After investigating boot issues on Linux Lite (GPT disk, GRUB Legacy, no auto-boot without F9), I discovered that my system firmware is BIOS-only, despite having UEFI menus.
The problem likely came from the missing 

Code:

bios_grub

partition, which BIOS expects when booting from GPT. I almost tried a risky UEFI setup, but thankfully didn't go that route.
The fix ended up being simple: I used Lite Tweaks → Restore Boot Menu, and it immediately restored boot functionality without needing manual F9 input. Everything boots fine now.
Apologies if the original post caused confusion — all is sorted now, and I hope this helps someone else in a similar situation.