24
votes
Unmount /boot after booting
In theory neither /boot/ nor /boot/efi are commonly used after boot. The two form a bridge between the BIOS (or similar) and the operating system. They are not generally used at runtime.
They are ...
- 16.1k
16
votes
Unmount /boot after booting
Side effects : None that I have ever noticed myself. Apart of course from the burden brought by the necessity to be certain to have it mounted prior to installing a new kernel. (be certain because in ...
- 5,835
8
votes
Unmount /boot after booting
Now that I think about it, you are asking this from the specific point of view of a bastion virtual machine. These typically are stateless with very little installed.
If you are remotely concerned ...
- 16.1k
6
votes
Accepted
Unmount /boot after booting
Testing this, no problems seem to appear; can it have any side effects I'm missing?
No, not really, except that some tools may actually need it mounted that you may have not thought of (for example, ...
- 10.1k
5
votes
Unmount /boot after booting
/boot is typically used by the bootloader, usually by GRUB. In typical usage, /boot will contain any bootloader configuration files that might need updating on kernel updates, and the kernel and ...
- 79.9k
4
votes
How check EFI revision?
Preface
I see (and appreciate!) that you were attempting to be as precise as possible about the language you used in your question, especially since the UEFI¹ Specifications and those which preceded ...
- 429
3
votes
Unmount /boot after booting
Unmounting /boot after the OS is up is certainly possible. In fact it's standard practice on many Linux distros. The Gentoo guide certainly assumes it and I've done it on every Gentoo install I've ...
- 31
2
votes
Is there a free (libre) open source alternative to memtest86+ that works with UEFI?
Memtest 6 should work with uefi.
A beta is available at memtest.org
code is available at https://github.com/memtest86plus/memtest86plus
Memtest86+ v6.00 Beta 2
Released: 2022-06-03
v6 is NOT READY for ...
- 361
2
votes
Determine what program is in my MBR code
The ms-sys utility can not only identify many variants of MBR and PBR boot codes, but also write them if needed.
Usage:
ms-sys [options] [device]
Options:
-1, --fat12 Write a FAT12 ...
- 79.9k
2
votes
Determine what program is in my MBR code
Another way to find out the MBR-technology is the bootinfoscript that was originally published on Source Forge.
As it seems bytes 0x80 and 0x81 can be used to identify the MBR-Code:
case ${...
- 187
2
votes
Cannot access BIOS after installing Linux
After 4/5 years of having the issue, I finally fixed it. Thanks to David Kariuki for informing me of the Ubuntu bug report.
I was going to swap out the hard drive temporarily and install Ubuntu 17.10 ...
- 33
2
votes
UEFI boot never runs from /dev/sda but works from rescue DVD
You need to understand that with UEFI, there is no such thing as "boot block" any more: the UEFI firmware can understand filesystems and load files.
The *.efi boot file needs to be in a ...
- 79.9k
2
votes
How to run custom kernel and initrd in UEFI?
For anyone running into a blank screen as well, the problem was that I needed to enable FRAMEBUFFER:
CONFIG_FB_EFI=y
CONFIG_FRAMEBUFFER_CONSOLE=y
Turns out you can also disable CONFIG_EFI_STUB if you'...
- 309
2
votes
Accepted
Two SSD, Two Linux Distro - Which grub is showing the grub menu during boot?
It looks like only Mint's GRUB is currently being used.
If you go to the firmware boot settings menu ("BIOS settings"), you may find that the current primary boot target is named just ubuntu ...
- 79.9k
2
votes
Who creates EFI partition on a UEFI system?
That's the job of any OS installer: If there's no EFI partition there already, you'll have to make one, or else your system can't boot anything in UEFI mode.
So, if the first OS that gets installed on ...
- 15.5k
2
votes
Accepted
What does it mean when UEFI boot option returns immediately without doing anything?
When you try to boot a EFI removable drive, the firmware looks for the executable at /EFI/BOOT/BOOTX64.EFI (or at /EFI/BOOT/BOOTIA32.EFI if the system is 32-bit). This is the usual location where the ...
- 36
2
votes
Which file does UEFI execute?
sudo efibootmgr -v shows exactly what you're looking for.
In case it says EFI variables are not supported on this system. you need to sudo mount -t efivarfs none /sys/firmware/efi/efivars first.
- 24.1k
2
votes
Accepted
Does Debian 11.5 really need 500MB+ partition for EFI?
There is no size limitation of the EFI system partition in the standard. The only restriction is it must be FAT32. However some system firmware can read FAT16 partitions.
Microsoft recommends 100 MB. ...
- 1,067
2
votes
Accepted
What is this update exactly designed for? (new BIOS?)
These are UEFI revocation list updates; they revoke signatures used for Secure Boot.
Since you don’t use Secure Boot they are irrelevant for you. Since UEFI capsule updates are disabled you probably ...
- 393k
1
vote
Accepted
Unable to boot Linux kernel directly through EFISTUB
I had to enable framebuffer on kernel .config in order to prevent running into a blank screen:
CONFIG_FB_EFI=y
CONFIG_FRAMEBUFFER_CONSOLE=y
Thanks to d9ngle for his answer
- 748
1
vote
UEFI boot never runs from /dev/sda but works from rescue DVD
Documenting exactly what I had to do, for future visitors. Without the details provided in the other answers, this would have been far more difficult.
I was converting my Hyper-V machine from "...
- 433
1
vote
Accepted
UEFI boot never runs from /dev/sda but works from rescue DVD
Answer currently above is pretty good, but does not stress adequately root cause of your issue.
From reading of your information dump, you probably only have linux formatted /boot partition, but that ...
- 814
1
vote
grub not working with lvm
as @psusi pointed out, the issue was that my lvm binaries were corrupt. I ran
apt-cache depends lvm2 | grep Depends | awk '{print $2}' | xargs apt install --reinstall -y
apt install --reinstall -y ...
- 677
1
vote
Accepted
Is my server using Legacy BIOS or UEFI?
root@debian:/~$ efibootmgr
EFI variables are not supported on this system.
root@debian:/~$ ls -l /sys/firmware/efi
ls: cannot access '/sys/firmware/efi': No such file or directory
So, legacy BIOS, ...
- 30.7k
1
vote
Accepted
Can you use MBR with UEFI - a question about the UEFI specification
So is this basically saying if you put the firmware in legacy boot mode, this is how to define an MBR which will play nicely with that legacy boot mode?
Yes, it's possible to have a disk that's boot ...
- 1,927
1
vote
Accepted
How to reboot on a specific device from command-line?
First, run sudo efibootmgr -v to display your current UEFI boot variables. The boot entries will be named BootXXXX where XXXX=four-digit number (might be hexadecimal).
If there is a boot entry whose ...
- 79.9k
1
vote
Debian 11 Setup fails with a shim_init() error
I know this is an old post, but i had the same issue. I fixed it for me by swapping the EFI-Boot file (/EFI/boot/bootx64.efi) inside the bootable stick with one from a working iso (for me it was a ...
- 11
1
vote
How to restore grub after cloning hard disk for a dual boot laptop
I also had issues booting to GRUB on my dual-boot laptop after resetting the UEFI values to their defaults. I was able to recreate the missing UEFI boot option using efibootmgr like this. Please note ...
- 156
1
vote
how i can install arch-linux-x64 on UEFI-32bit
hey so i might be late but there is actually this
https://wiki.archlinux.org/title/GRUB#Installation
and there it basically says to switch out x86_64-efi with i386-efi to install a 32 bit EFI but this ...
- 11
1
vote
Arch ─ 'grub-install: error: efibootmgr failed to register the boot entry: No such file or directory'
I got the above error when trying to install Arch Linux. In my case I had to boot with the UEFI option from the boot menu, which I entered by pressing F11 (F7 for some UEFIs) during boot.
- 111
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