Questions tagged [uefi]

For questions about the Unified Extensible Firmware Interface, commonly used in later x86 computers as a replacement of BIOS, as well as in ARM servers and more. UEFI supports booting with and without Secure Boot enabled and legacy booting via CSM.

For questions about the Secure Boot feature read and use:

About UEFI

UEFI firmware provides several technical advantages over a traditional BIOS system:

  • Ability to boot from large disks (over 2 TiB) with a GUID Partition Table, GPT.
  • CPU-independent architecture
  • CPU-independent drivers
  • Flexible pre-OS environment, including network capability
  • Modular design

Excerpt from Wikipedia article about UEFI

AdamW on UEFI boot: how does that actually work, then?

Known issues

  • Some computers support legacy booting, but this feature is not available on all devices and planned to be phased out.
  • Some UEFI firmware implementations from computer manufacturers only support booting through \EFI\BOOT\BOOTX64.EFI from the EFI System Partition, not honoring commands to boot a certain UEFI NVRAM boot entry.

Noteable questions

  • http://askubuntu.com/q/233687/40581

    • Troubleshooting the following error GRUB messages when trying to boot Windows:

      error: can't find command drivemap.
      error: invalid EFI file path
      

BIOS vs. UEFI           BIOS vs. UEFI

5539 questions
585
votes
12 answers

How do I install Ubuntu alongside a pre-installed Windows with UEFI?

I'm absolutely new to Linux. I would like to know how to install Ubuntu alongside the pre-installed Windows 8+ OS. Should I do it with Wubi, or through the Live USB/DVD? What steps do I need to take to correctly install Ubuntu?
193
votes
4 answers

How can I tell if my system was booted as EFI/UEFI or BIOS?

How do I determine whether a particular running Ubuntu system was booted using EFI/UEFI, or BIOS?
131
votes
3 answers

How to create UEFI-only bootable USB live media?

Having live media that can boot both ways can be a problem when installing Ubuntu onto currently available Windows 8 computers. In other words the key advantage to creating UEFI-only bootable USB live media is: You know that it definitely booted and…
LiveWireBT
  • 29,785
120
votes
5 answers

How to get GRUB to be the default bootloader instead of Windows Boot Manager on a UEFI laptop?

I've got an HP Pavilion Touchsmart notebook that came with Windows 8. I've upgraded to 8.1, and now I want to dual-boot an Ubuntu distribution with Windows 10. When dual-booting with Windows 8.1, the Windows Boot Manager always took priority, even…
105
votes
5 answers

Why do I get "Required key not available" when install 3rd party kernel modules or after a kernel upgrade?

This issue happens only on UEFI systems with enabled Secure Boot. When I try to install DKMS modules like VirtualBox, Nvidia, or Broadcom drivers, they do not install and I get Required key not available when I try to modprobe them. VirtualBox…
Pilot6
  • 92,697
99
votes
13 answers

How can I reinstall GRUB to the EFI partition?

I want to reinstall GRUB 2 and I found these instructions: How to Repair, Restore, or Reinstall Grub 2 with a Ubuntu Live CD or USB . In my case, the boot loader is installed in the EFI partition. If I use the commands provided in this guide, will…
Generoso
  • 1,389
99
votes
11 answers

Can't install Ubuntu 18.10 on XPS 15 - EFI\BOOT\mmx64.efi not found

I tried to install Ubuntu 18.10 on my XPS 15 9570 earlier. Everything was working fine until I got to the partition selection part of the installation. That's when the installer crashed and I had to shut down my machine. I think it's because I had…
rykeeboy
  • 1,013
85
votes
12 answers

16.04 new installation gives grub-efi-amd64-signed failed installation /target/ ubuntu 16.04 at the end

I am installing Ubuntu 16.04 in an Intel NUC computer with UEFI enabled. I am using an SSD from another computer. During the installation I chose Erase the disk and make a new full install At the end of the process I see: grub-efi-amd64-signed…
Kaf
  • 1,255
84
votes
4 answers

How can I change/convert a Ubuntu MBR drive to a GPT, and make Ubuntu boot from EFI?

I recently have upgraded my PC, my new Motherboard (ASUS M5A99X EVO) uses UEFi instead of the regular MBR option. I have a Ubuntu 11.10 installation that I did when I had my previous hardware (MSI MS 7267) , Ubuntu alone boots fine, and so does…
Uri Herrera
  • 15,468
60
votes
14 answers

VirtualBox boots only in UEFI Interactive shell

I installed Ubuntu 14.10 in VirtualBox with UEFI. But now I have rebooted this OS and now it boots into a UEFI Interactive Shell v2.0. How can I boot normally into Grub again?
59
votes
3 answers

How do I remove "Ubuntu" in the bios boot menu? (UEFI)

See this ubuntu appears in BIOS menu (UEFI) I have this on my Lenovo s205 too. Is there some way to remove "ubuntu" from the menu? I don't even have it installed anymore.
nvr
  • 591
49
votes
5 answers

Is it possible to boot Ubuntu using the Windows bootloader?

As noted by many people, Windows 8's UEFI requirements might will won't get in the way of installing Linux (or whatever), as the replacement bootloader will also need to be signed somehow. Some systems All systems will let you disable the signature…
badp
  • 12,832
49
votes
4 answers

Verification failed: (0x1A) Security Violation while installing Ubuntu

I'm trying to install Ubuntu 22.04.1 via a USB drive, but when I want to boot the USB drive when the secure boot is enabled, I get the error Verification failed:(0x1A) Security Violation . I need the secure boot to be enabled. Back then, I had no…
48
votes
6 answers

Can I boot memtest86+ if I'm using UEFI?

Downloaded the Ubuntu 16.04.2 .iso install disk and flashed it onto a USB stick. Booting on the USB stick, there is no memtest86+ option (along with "Try Ubuntu"). Is there a way to add it to the install options? (it's for a UEFI boot PC running…
Déjà vu
  • 1,229
48
votes
4 answers

Why disabling "Secure Boot" is enforced policy when installing 3rd party modules

When installing 16.04 , I was asked to turn off " Secure Boot " if I wanted to install 3rd party modules/drivers . I did not comply. And when I installed manually the only 3rd party drivers I use ( bcmwl-kernel-source ), I was asked again (during…
solsTiCe
  • 9,605
1
2 3
…
99 100