uefi boot kernel upgrade problem. -- Solved.

1clue · Advocate Joined: 05 Feb 2006 Posts: 2569

Hi,

Just installed Gentoo on a router box. I got it working with UEFI boot via these instructions and some others: https://wiki.gentoo.org/wiki/GRUB2#UEFI_with_GPT

I'm not new to Gentoo, not new to hardened and not at all new to Linux. I'm new to UEFI boot.

I used genkernel because I thought it would save time just to get something working, very wrong there but it's over. It boots using the genkernel I installed during initial gentoo installation.

I installed hardened-sources 4.1.6 kernel and installed a new kernel (not genkernel) pretty much like I've been doing for about 2 decades now.

It still boots into 4.0.8 kernel which was built with genkernel.

This is the first time I've really messed with a pure uefi boot system, and I don't know what I'm missing.

I KNOW I have UEFI boot, because it took me a long time to get there from BIOS boot.
I THINK I have grub as boot loader, but I see no evidence that it's actually involved.
I think I'm missing whatever tells the efi system that there's a new kernel.

Thanks.

1clue · Advocate Joined: 05 Feb 2006 Posts: 2569

I now have a system that only boots from system rescue iso or gentoo iso.

I completely removed efibootmgr and grub. I reformatted the /boot and /boot/efi partitions. I rebuilt the kernel and reinstalled it. I reinstalled grub and efibootmgr per the instructions in the handbook: https://wiki.gentoo.org/wiki/Handbook:AMD64/Installation/Bootloader with help from https://wiki.gentoo.org/wiki/GRUB2#UEFI_with_GPT

Somehow during this my network devices changed from the 'new' way back to eth*, which baffles me but whatever. I wish they would stick to one thing.

My partitions are at https://bpaste.net/show/00dab5a52a7c
My mounts are at https://bpaste.net/show/6881cfca1e01
My /boot looks like this: https://bpaste.net/show/efc01effe39f
efibootmgr -v output is https://bpaste.net/show/2838d102aab6
egrep -v '($|!\s*$)' /etc/portage/make.conf: https://bpaste.net/show/63571c78ca1b

Somebody please help.

schorsch_76 · Guru Joined: 19 Jun 2012 Posts: 450

UEFI's boot principle is:

EFI Partition: There are the bootloaders or programms you can start. Basicly you put here grub or the efi kernel. There are Folders like "EFI\Windows" "EFI\gentoo". Each folder contains the bootloader for that system. A *.efi file.

The efi variables are there to let you specify a file from this partiton UEFI should start. BUT: When you name the file EFI/BOOT/bootx64.efi, UEFI will start it even without a UEFI variable. To start my uefi system i dont use the variables, i use the default (fallback) bootx64.efi. In my case i renamed the grubx64.efi to bootx64.efi. The grub.cfg file is at /boot/grub/grub.cfg. on sda2 (ext2).

See:
http://www.rodsbooks.com/refind/
http://homepage.ntlworld.com/jonathan.deboynepollard/FGA/efi-boot-process.html
http://www.rodsbooks.com/linux-uefi/

EDIT:
Your first Partition should be the EFI partiton EF00.
_________________
// valid again: I forgot about the git access. Now 1.2GB big. Start: 2015-06-25
git daily portage tree
Web: https://github.com/schorsch1976/portage
git clone https://github.com/schorsch1976/portage

hurvajs77 · n00b Joined: 05 Apr 2010 Posts: 56

I had similar problem in past - I lost option to boot Windows and still boot with old kernel. So, I found this solution. I wrote small script for compile a new kernel and fix EFI bootmanager

1clue · Advocate Joined: 05 Feb 2006 Posts: 2569

Other than having an unbootable kernel, I'm good now. I'm looking at a kernel panic right now.

So how do you choose a different kernel during boot? That's the thing that gets me here: I'm going to be building a lot of kernels to get the minimum configuration that works for me, I'd like to not have to use system rescue cd in order to get back into my system. All I get is one choice.

I thought you could use grub in conjunction with an EFI boot system. All I ever get is the one kernel.

1clue · Advocate Joined: 05 Feb 2006 Posts: 2569

There is currently nothing but Gentoo on this system. There may be a pfSense distro at some point but I'd prefer that to be on a guest.

My intent is for it to be a kvm host which will handle firewall, routing, vpn and UTM guests. The CPU is an Intel Atom C2758 which has QuickAssist encryption and compression features, so I'm probably going to have to build some proprietary modules for that to take effect, which means even more kernel builds.

1clue · Advocate Joined: 05 Feb 2006 Posts: 2569

I have a working kernel again.

I'm still only getting one kernel listed in grub. I'd like to be able to choose installed kernels like before.

And here's another thing: Using your script as a reference ESP is /boot/efi for me. I have /boot as usual, and /boot/efi for efi kernel. Do I actually need /boot or can I essentially delete it and mount /boot/efi onto my / partition? Or can what's currently /boot/efi be /boot?

I'm very confused right now. Your script helps but I still really don't get how a boot loader works in conjunction with efi. My looking at docs doesn't seem to help, it seems like most of the docs assume BIOS boot and make comments about efi here and there.

1clue · Advocate Joined: 05 Feb 2006 Posts: 2569

Darth Marley · Tux's lil' helper Joined: 25 Jan 2007 Posts: 107

You can mount the efi partition as /boot. I got away with it before I knew more, and now knowing more have seen articles suggesting just mounting it as boot anyway. The bios will boot correctly as long as everything is in its proper place, and Linux doesn't care if /boot has a /efi directory.

1clue · Advocate Joined: 05 Feb 2006 Posts: 2569

I need to put my post count back to 1.

I finally got it right. I reformatted sdb1 and deleted sdb5, and after much ado I got my machine booting off of a unified EF00 /dev/sdb1.

It's almost like my first linux install, back in the 90s.

It's never been the same since lilo.

I'm officially an old fart now. Rather than speeding up I'm slowing down.

Thanks for the help again people.