Today’s article is going to tell you how to determine if you’re using UEFI or legacy mode. This is particularly useful if you’ve either forgotten. It’s also useful if you’re using a system you don’t know anything about. It’s handy for troubleshooting things like boot issues.
UEFI (Unified Extensible Firmware Interface) is not really a ‘thing’. It’s a set of specifications that determine how the OS interfaces with the operating system. While it does have its advantages, OEMs have been pretty sporadic with the quality of their implementation. UEFI was predated by EFI, which came from a vendor known as IBM. UEFI was predated by BIOS (legacy) and, for now, vendors seem inclined to more or less support both.
Why should you care? Well, it’ll tell you a lot about how you’re booting your system and it says a lot about how your system interacts with the hardware. While tools like boot-repair are able to work with either, you will need to know what type of system you’re working with if you’re doing it manually.
The good news is that it’s easy to figure this out. Even a beginner can figure it out! So, let’s find out if you’re using UEFI.
Are You Using UEFI:
Yup… You need a terminal open. So, let’s do that. All you need to do is press
Now, the tool we’ll be using is called ‘efibootmgr’. That tool defines itself as:
efibootmgr – manipulate the UEFI Boot Manager
I did some testing and it was installed by default on most of the operating systems I tried it on. If it’s not installed, it’s pretty easy to install. The only time I had to install it manually was with openSUSE Tumbleweed. So, the command for that is:
1 | sudo zypper install efibootmgr |
If it’s not installed on your system, just go ahead and install it. You may need to use apt, dnf, or whatever – but it should be available for your distro. Just install it like you’d install other software from the terminal, suited to your distro’s package manager.
Once it is installed, it’s really, really simple. Just run:
1 | sudo efibootmgr |
Then, check the output. If you’re not using UEFI, it will say:
1 | EFI variables are not supported on this system. |
If it says anything else, you’re using UEFI.
See? I told you that it was easy. That’s all you need to know.
Closure:
Yup. Another article said and done. This one is about determining if you’re using UEFI or if you’re not. It’s so simple that even a rank beginner can figure it out. Don’t forget that you can use the comment section to ask questions that’d be suitable for new articles. Sometimes, even with my notes, it’s harder to decide the subject than it is to write the article.
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ls /sys/firmware/efi/efivars
The above will work in a live session as well.
Thanks for the addition, @feedmebits