Boot LFS from UEFI, without GRUB

tosaikiran · 12-15-2021, 01:50 AM

Hi,

I am Sai Kiran. I am currently working on installing xen on LFS. I have successfully built the LFS system and installed xen on it. I am trying to boot from UEFI directly, instead of GRUB. The BLFS document talks about booting from GRUB-UEFI, which is not what I want. Could someone throw some light on how to boot from UEFI, bypassing GRUB?

Thanks in advance for your time and support.

Regards,
Sai Kiran.

jmgibson1981 · 12-15-2021, 06:13 PM

I don't think you can. You need some form of bootloader. If there was a way to bypass the need for it it probably would have been done a long time ago. You need something that can be configured for the system. The EFI is built into the motherboard, no different than a bios. It's mostly a read only thing as I understand it.

colorpurple21859 · 12-15-2021, 08:17 PM

You will need to compile efi stub and possibly kernel options into the kernel. It is under processor type and features. Put the kernel on the efi partition and register it with the uefi firmware. Some of it will depend on your system uefi implementation.
Here is some additional information that may be useful
https://www.kernel.org/doc/Documentation/efi-stub.txt
https://wiki.archlinux.org/title/EFISTUB
https://wiki.debian.org/EFIStub
https://github.com/tklengyel/xen-uefi
https://wiki.xenproject.org/wiki/Xen_EFI

hazel · 12-16-2021, 05:54 AM

Is the OP trying to boot Linux directly or via xen? It's not clear from the post. You certainly can boot a kernel directly with efistubs but that may not be what is wanted here.