Questions about the Unified Extensible Firmware Interface (UEFI), the software interface aiming to replace typical BIOSes. This tag may also be used for questions related to UEFI partitions and systems.

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26
votes
2answers
3k views

When do I need to specify add_efi_memmap as kernel argument in UEFI/EFI boot?

I am reading some tutorials how to EFI stub (efistub) load the Linux kernel. These instructions often use kernel boot parameter add_efi_memmap. The intended hardware is Intel x64 having 8GB of RAM. My ...
21
votes
8answers
62k views

Why is USB not working in Linux when it works in UEFI/BIOS?

For background I have just built a new machine with modern hardware including: AMD FX-8350 Gigabyte GA-990FXA-UD3 motherboard 16GB RAM NVidia GTX 650 Ti Kingston SSD Given that, I tried to install ...
21
votes
7answers
1k views

Why do most distributions chain UEFI and grub?

Most distributions install a additional boot loader on an UEFI system. UEFI itself is a boot loader, it offers a menu to select different operating systems or individual kernels. Furthermore, the UEFI ...
18
votes
2answers
2k views

The UEFI & SecureBoot impact, how severe?

I'm planning to buy a new laptop in the coming days, and I'm quite impressed with new, cool Ultrabooks. As a long-time GNU/Linux user, I'll of course install a distro of my choice on it. Chances are ...
17
votes
2answers
16k views

How to know if I'm booting using UEFI

I was searching, but didn't found an obvious way to know if GRUB is using UEFI in the system boot, or the BIOS compatibility mode or a full fledged BIOS. Only Windows methods. Is there something in ...
13
votes
2answers
619 views

How do I use the TPM to seal away data on an UEFI booted system?

I would like to seal away files on my system using keys stored in the TPM. Since my system uses UEFI to boot, I can no longer use TrustedGrub as a boot loader to maintain my trust chain. Are there any ...
10
votes
1answer
11k views

Dual boot windows on second harddrive, UEFI/GPT system

I'd like to install linux, but I don't want to risk damaging my current windows installation as I have heard a lot of horror stories. Fortunately, I have an extra hard drive. Can I install linux ...
8
votes
1answer
2k views

How do multiple boot loaders work on an EFI system partition

My ESP looks like this Boot Dell fedora Microsoft In the Boot directory, their is a boot-loader named bootx64.efi which I understand is the default boot loader that get started first. But in the ...
8
votes
1answer
2k views

How to write/edit/update the OsIndications efi variable from command line?

In the need to enter the UEFI firmware setup utility while using ultra fast boot (keyboard drivers are not loaded during POST), I wish to write to the "Os Indications" efi variable. My OS is Ubuntu 14....
7
votes
2answers
21k views

Arch Linux GRUB install: “EFI variables are not supported on this system”

I am attempting to install Arch linux to a new (and very crappy) HP Pavillion 15 Notebook. This is a UEFI-based machine. After several swings at it, I have managed to get pretty far. Legacy mode is ...
7
votes
1answer
6k views

UEFI install (14.04) boots to GRUB command prompt, no GUI

I just installed zorin 9 core (14.04) on my Hard-Disk in UEFI mode. But, when I boot, all that comes up is a GRUB2 command line. I've searched for solution and came up with this command configfile (...
6
votes
3answers
24k views

Installing linux on an 32bit UEFI only machine

I have a Intel BayTrial Z3735D tablet which comes with a 32bit UEFI BIOS. After some search I've found that most linux distro don't come with a 32bit efi file. How can I insert one (or build a new ...
6
votes
3answers
4k views

How to make UEFI bootable usb disk from bios bootable iso

Suppose you have an iso image that contains a bios bootable partition. You can write this image to a usb disk In linux you could do this for example with dd if=pmagic_2013_02_28.iso of/dev/sdc1 ...
6
votes
2answers
102 views

Is there a way to enable secure boot in Linux?

Just like Windows has secure boot that prevents any external OS Loader code from running at boot, does Linux have any similar option for itself? I have looked around, but when I search, the only ...
5
votes
1answer
2k views

UEFI and Puppy Linux

I recently installed Puppy Linux on a USB stick using the Universal USB Installer, but I have not being able to boot from it. My notebook came with Windows 8 and had the secure boot activated at UEFI. ...
5
votes
1answer
122 views

Upgrade kernel for linux system without upgrading user apps/libs?

I built a custom Linux "recovery-cd" image that consists of a compressed initrd and boots via bcdedit (like Ubuntu Wubi) instead of a physical CD. It has various recovery tools for partition editing, ...
5
votes
1answer
453 views

UEFI boot Fedora from USB 2.0 on 3.0 port (l75d-a7280)

I'm trying to make a bootable usb in ubuntu for fedora, but my settings are not working. I formatted the USB with FAT & Ext4, MBR, and Legacy BIOS bootable. My BIOS allows the USB 3.0 controller ...
4
votes
5answers
8k views

Restore EFI boot partition

I am triple booting Ubuntu, Debian, and Fedora. When I installed Fedora from a liveCD I got excited and kept hitting next, not realizing I was not installing GPT, but rather LVM. After doing this I ...
4
votes
1answer
18k views

How much speed difference for a tweaked bios versus uefi boot? [closed]

EFI can be faster, but that's not certain. The biggest speed difference is in hardware initialization early in the process. On my systems, this is a fraction of the total boot time, so a reduction ...
4
votes
1answer
609 views

Does UEFI increase battery life?

I've heard about a better power management when using UEFI instead of BIOS. Is that true? It was about energy consumption being more efficient or something like that. If it is true, has the ...
4
votes
2answers
5k views

Dual boot Fedora and Windows 8 gives error: you need to load the kernel first

While there seem to be a lot of questions regarding dual booting Windows and Linux, I did not see one that seemed to cover this problem. That said, I believe a lot of the problems may be fixed in a ...
4
votes
2answers
3k views

arch linux boots into grub command line

I'm trying to install arch linux over virtual box guest machine in a UEFI mode. I've followed beginners guide to install base system, generate fstab and etc and my system now boots into grub command ...
4
votes
1answer
2k views

Installed CentOS, Now There is No Windows 8 Options on Restart

I bought a new PC with Windows 8 and wanted to dual-boot linux. I shrank the partition by 50GB in windows, then installed CentOS from a live CD. CentOS is working fine, but I can't boot into ...
4
votes
2answers
923 views

Can't boot, task btrfs-transacti blocked for more than 120 seconds, how to fix this?

My computer was set up to boot Ubuntu 15.04 via UEFI. I have two disks. My first disk /dev/sda is a 128 GB ssd formatted as GPT, containing an EFI partition and a btrfs partiton with subvolume @ ...
4
votes
0answers
813 views

Parititioning for a UEFI boot loader, can LVM be used?

I just bought a gently used laptop and I am trying to figure out why this is. It has a single SSD that when running fdisk -l shows as Disk: /dev/sda. Under it though are 5 "devices" under that disk, ...
4
votes
1answer
1k views

How do I dual-boot 2 (or more) Linux distributions with gummiboot and UEFI?

I have Arch installed as my main OS with gummiboot for booting. I'm planning to dual boot with Fedora 20 soon but I am currently held back by some doubts. Do I need to install Grub2 for Fedora even ...
3
votes
2answers
1k views

What is the purpose of UEFI partition?

On old computers (using BIOS) we had to create 2 partitions, one to mount / and second for swap. But on new systems with UEFI we need to create third partition EFI System in addition to those two ...
3
votes
4answers
31k views

USB booting to installing Linux on a new Lenovo laptop

I recently got a Thinkpad T440s with Windows 8.1 for my job, and since most of my work is done under Linux I am going to install Ubuntu on it, so that I can dual boot. The problem is that it won't ...
3
votes
2answers
711 views

How to query EFI signature

It appears that Grub-EFI will only boot a "signed" Linux kernel. Is there some command that will allow me to query a given kernel image to find out what signatures (if any) are present on it?
3
votes
1answer
2k views

Arch Linux not showing bootloader on UEFI system

I recently installed Arch on my laptop (Dell Precision M4500). I had just changed the hard disk so I had to partition from scratch during the installation. I chose to go for a GPT partition and also ...
3
votes
1answer
2k views

Can I add Windows to my systemd-boot bootloader if I have separate EFI partitions?

I've just installed Arch Linux on to a new set of partitions on my Windows 8 machine. In doing so, I created a new 512MB EFI partition for Linux to load from, leaving the existing Windows EFI ...
3
votes
1answer
4k views

Boot SystemRescueCd using UEFI?

How would you boot SystemRescueCd if you don't have the option to use the legacy-bios? I have the new UEFI and I have no luck booting SystemRescueCd(with a USB stick). I am planning to back up my ...
3
votes
1answer
49 views

How to boot via grub2 rescue promt on UEFI system?

I installed Ubuntu 16.04 by booting from a USB, choosing "Try Ubuntu without installing", and then inserting another USB and directing the installer to install there. I told the installer to instal ...
3
votes
1answer
77 views

What is the proper way to use ISOLINUX with UEFI?

I've been trying to add UEFI support in the 64-bit version of Minimal Linux Live for quite some time, unfortunately without much success. As you can see from the below image, I get critical error each ...
3
votes
1answer
63 views

Is it possible to use Grub to run an EFI binary?

On an efi system it it possible to run arbitrary efi binaries. Especially I can use the efi shell (one efi binary) to run grub (another efi binary). Is it also possible to use grub to run for ...
3
votes
3answers
205 views

How do I create a utility USB?

I do a lot of work with many different bootable images all on different flash drives. However, it gets annoying to search for a specific drive, plug it in, and use it. Is there a way I can consolidate ...
3
votes
1answer
358 views

Can't format HDDs and install linux to Dell hybrid ultrabook

I've tried installing OpenSUSE 13.2, Debian 8/8.1 and Ubuntu 15.04 (all them amd64). Debian/Ubuntu won't show disks and OpenSUSE can't format the partitions created on them. During the install, ...
3
votes
1answer
12k views

Creating EFI bootable GPT partition with gdisk on previous MBR, GPT Damaged

So this is a sister question to my previous one about partitioning for a UEFI boot loader. Parititioning for a UEFI boot loader, can LVM be used? Disclaimer: I don't give a flip about the data on it....
3
votes
2answers
1k views

How can I install Linux on a UEFI system with Secure boot?

My motherboard is a Gigabyte 990XA-UD3 (CPU 1), it's a UEFI -Dual boot, and when I try installing Linux Mint 16 Cinnamon or Ubuntu 13.10 it always bring this error (initramfs) Unable to find a medium ...
3
votes
1answer
951 views

How can I get a new Fedora 19 install to boot on Intel NUC

I have a newly installed Fedora 19 on an Intel NUC computer. During installation, I selected the "reclaim all space" option and took the default partitioning. The install created an EFI boot ...
3
votes
1answer
2k views

USB keyboard only works intermittently in GRUB 2 on reboots - how to make it work consistently?

Something weird is going on with my keyboard. The keyboard is a USB-connected Unicomp, which works absolutely flawlessly once the computer is up and running. However, GRUB 2 (specifically, 1.99-27+...
3
votes
2answers
613 views

Any chance to fix dual boot not having to turn UEFI on and off to switch OS?

I had a single Linux hard drive with LUKS partitions. Linux was installed in legacy mode, but it worked with UEFI option turned on later. I decided to install a Windows 8 on a second hard drive. So I ...
3
votes
1answer
838 views

Can't get past EFI to install RHEL on HP Itanium Server

When I am trying to install RHEL (6.3, 5.8, 4.8) on an HP Integrity Server rx2660 Itanium with 4GB RAM, I keep getting to the same point which is Loading file efi\boot\initrd.img...done After that ...
3
votes
2answers
300 views

Linux boot loader is not detected after BIOS update

I use Lenovo y500 and after buying a 250 gb Samsung SSD, I decided to use dual OS consisting of Arch Linux and Windows 8.1. In order to prevent boot problems, I installed Arch later. I used UEFI and ...
3
votes
2answers
282 views

Preseeding debian install - EFI

The EFI partition is formatted in ext4 during the setup of debian whereas it should be vfat. I am trying to preseed the install of debian jessie and I can't get it working since the UEFI partition is ...
3
votes
0answers
340 views

Preinstalled windows 8.1 not booting after installing Linux mint 17.1

I have pre-installed windows 8.1 on my machine and its a uefi enabled machine. I installed linux mint 17.1 on this by the side of windows 8.1. As I was unaware about the approach to install linux ...
3
votes
1answer
132 views

UEFI and LVM causing BIOS to hang under various conditions

Using Fedora 23 with LVM on a Toshiba C50-B-021 laptop with UEFI, the BIOS will hang on boot every time: the computer runs out of battery, it is turned off for more than a few seconds, a new ...
3
votes
0answers
191 views

Questions Regarding UEFI Shell - Version 2.0 Wanted

I bought a cheap laptop for myself last Christmas, just because I wanted a laptop. A Toshiba Satellite C55-A5310 on special. I'm also a big believer in OEM software for laptops, so I left Windows 8.1 ...
3
votes
1answer
673 views

Startup problem: invalid partition table or use UEFI BOOT

I'm working on a Dell Latitude E5430. Recently I booted pcbsd from USB using this file: PCBSD10.1.1-RELEASE-01-31-2015-x64-DVD-USB_0.iso But I guess I did something wrong. I was trying to install ...
3
votes
0answers
622 views

How to clean up bootloaders & UEFI entries from other installs?

I got a new Windows laptop, and I wanted to dual boot with Linux. I installed Fedora, before changing my mind and going back to Mint. I'd like to keep Win 8.1 and Mint. However, now my UEFI boot menu ...