No efivars on gentoo install media

huttuded · n00b Joined: 27 Jan 2019 Posts: 15

Greetings to you, Gentoo community.

Yesterday I decided to install Gentoo on my main rig after using it a bit over month on both of my laptops. Everything went well with the installation, except when I was configuring GRUB and it threw a bunch of errors. I noticed that the /sys/firmware/efi partition was missing. I read that the installation media has to be booted in UEFI -mode, but for some reason my motherboard's UEFI/BIOS won't allow that on the gentoo USB-stick. I tried various different options from my mobo's (ASUS Prime B350 Plus) BIOS settings. I tried disabling secure boot, disabling CSM and someone had got it working from a different menu called "boot override". But it just won't boot, the screen just flashes and goes back to the boot menu. The only way I seem to be able to boot it is in the non-UEFI legacy mode. I've also tried creating the minimal CD with different software, like Rufus and Universal USB Installer (or something like that).

This might not be the right place to ask this question, since I think it's more of my motherboards's UEFI/BIOS -kind of issue.

Every time I try to install something manually witth GPT/UEFI, I fail horribly. I'm considering to go and install it with ye olde BIOS/MBR, since I currently only have < 2 TB of storage. Are there any other drawbacks or limits if I use LILO+MBR than the 4 primary partitions & 2 TB maximum supported storage? After all this (fun) I'm feeling impatient.

nick_gentoo · Tux's lil' helper Joined: 07 Jan 2019 Posts: 140

huttuded, have a look at this section: https://wiki.gentoo.org/wiki/Handbook:AMD64/Installation/Bootloader#Install, it mentions mounting the efivars partition:

huttuded · n00b Joined: 27 Jan 2019 Posts: 15

Yes, I followed that part of the handbook too and the output is:

nick_gentoo · Tux's lil' helper Joined: 07 Jan 2019 Posts: 140

OK, maybe I hurried a bit in answering. I went through an install recently and I needed that line for mounting the efivars, for me it worked.

You mention using an USB stick for the install - what installer image did you write on the stick?

huttuded · n00b Joined: 27 Jan 2019 Posts: 15

I used the Minimal Installation CD image from the official site.

nick_gentoo · Tux's lil' helper Joined: 07 Jan 2019 Posts: 140

Just to check: at https://wiki.gentoo.org/wiki/Handbook:AMD64/Installation/Media#Minimal_installation_CD, it says that

huttuded · n00b Joined: 27 Jan 2019 Posts: 15

Yep, I even tried the newest one, which is dated 27/1/19. Meanwhile I've been trying more various options and combinations of my UEFI/BIOS settings to boot the media in UEFI mode, but still with no success. I think could the firmware itself be bugged, because I updated my BIOS a while ago. I think I'll try to burn the installation media to DVD and see if that works.

fedeliallalinea · Posted: Mon Jan 28, 2019 1:25 pm Post subject:

You can also use SystemRescueCd (gentoo based)
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nick_gentoo · Tux's lil' helper Joined: 07 Jan 2019 Posts: 140

I also used SystemRescueCD and could create an UEFI bootable USB stick with it.
That motherboard is pretty recent, so I would assume it uses UEFI anyway. As far as I understand it, then it's a matter of choosing between booting from an GPT- or MBR-formatted disk; the MBR way needs the CSM setting activated.

You clearly could initially boot the stick for the install - what did you later change that did not boot anymore?

huttuded · n00b Joined: 27 Jan 2019 Posts: 15

I can still boot it but it doesn't boot in UEFI mode. In my understanding that is the reason I can't mount the /sys/firmware/efi -partition. When I boot the minimal CD, grepping dmesg for 'EFI' or "efi" returns nothing related, and the sys/firmware is missing the "efi" part, which I presume is to be mounted in /sys before chrooting. In my BIOS boot menu I see two entries for the USB stick, one labeled "UEFI data traveler 3.0" or something and other is just plain "data traveler 3.0", which I can boot and used to install the base system in the first place. I think the UEFI -labeled version of that stick is the one I'm supposed to boot to get the /sys/firmware/efi partition included, but selecting that just flashes the screen rapidly and returns to the boot menu. I'd love it if there would be some debug-option in the BIOS to see what happens or isn't happening...

EDIT: typo

Jaglover · Posted: Mon Jan 28, 2019 2:00 pm Post subject:

You may need to run 'isohybrid -u' on that ISO image before putting it on USB stick. Just guessing, never used Gentoo ISO myself.
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nick_gentoo · Tux's lil' helper Joined: 07 Jan 2019 Posts: 140

So there could be two possible reasons for this:

the motherboard might have an issue with booting from that stick - make sure that the latest "BIOS" (firmware) is installed or try to burn the install image on a CD/DVD, like you suggested
the install image itself - maybe somebody else who tried it could confirm that it works, or you could try the SystemRescueCD that fedeliallalinea mentioned (btw, I wrote the image on the USB stick with unetbootin in my case)

huttuded · n00b Joined: 27 Jan 2019 Posts: 15

I'm extremely confused. I got my new install to boot with EFI stub kernel, without efibootmgr, which I thought was a necessity. I just placed the kernel image in /boot/EFI/BOOT/ and gave a desperate reboot and it booted!

Thank you everyone for your help. I'm surprised from so quick responses. The rumors I've heard about the Gentoo's community aren't lies.

nick_gentoo · Tux's lil' helper Joined: 07 Jan 2019 Posts: 140

Nice! And now you can certainly install grub, if you still want it

(to enable the efivars, a certain option has to be enabled in the kernel config: https://wiki.gentoo.org/wiki/Efibootmgr)

Never tried it, but I have to keep in mind this method. I think it works without a boot manager as long as the kernel image is placed at that specific location and an eventual initramfs is embedded in the kernel. What is the filename of your kernel image?

huttuded · n00b Joined: 27 Jan 2019 Posts: 15

It's located exactly as:
/boot/EFI/BOOT/BOOTX64.efi

I once had trouble with my other computer for UEFI to find the image, so I've find this to work.

Edit: and I'm more than happy with the stub-kernel boot, since I'm not going to dual-boot or anything. Plus it feels so fast.

The Doctor · Moderator Joined: 27 Jul 2010 Posts: 2678

efivars are only used to add or remove entries. Now that you have a working system you should be able to edit to your heart's content. I would at least add a backup kernel so when (not if) you botch a kernel update you have a known working kernel to fall back on.
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dmpogo · Advocate Joined: 02 Sep 2004 Posts: 3472 Location: Canada

nick_gentoo · Tux's lil' helper Joined: 07 Jan 2019 Posts: 140