UEFI boot managers

UEFI firmware technology may have its positive aspects, but it also comes, like everything else, with its not-so positive aspects. It is not-so positive because it was a pain to figure out exactly how it works with OS boot managers and boot devices, especially when attempting to dual-boot multiple OSs on one hard drive, or even on multiple hard drives.

Instead of installing the boot files in the Master Boot Record (MBR), an entry for each OS in created in /boot/efi/EFI directory, which should be in an EFI partition. That results in a corresponding entry for each OS in the boot menu.

For example, take the entries in this screenshot, which was taken from the boot menu of a test PC, a custom-built box with an ASRock motherboard. Each OS entry represents a different installation of the OS, and not necessarily on the same hard drive. You can tell that I’ve installed Fedora a lot more times on the PC than other OSs. The AHCI P2: WDC WD5000… entry is for a 500 GB hard drive, while the ASUS… entries are for an external CD/DVD drive.
UEFI boot managers

Related Post:  How to install Kali Linux 2.0 without a working Internet connection

In this screenshot, the Ut165… entries are for a 4 GB Flash stick used for installing the Linux distributions. The AHCI P3: WDC WD3200… entry is for a 320 GB hard drive.
Windows UEFI boot managers

One thing that I’ve learned about installing an OS on a PC with UEFI firmware is this. The system will not boot if the entry for the hard drive is chosen as the boot device. And that is true whether it is selected as the boot device from the boot menu, or is made the default boot device in the UEFI setup utility. In this screenshot, for example, Ubuntu 14.10 and Windows 7 are installed in dual-boot fashion on a 500 GB hard drive, which is represented by the AHCI P3: WDC WD5000… entry. The system will not boot if the AHCI P3: WDC WD5000… entry is chosen as the boot device. To boot, an entry for any of the installed OSs must be selected from the boot menu or made the default boot device.
UEFI boot managers

Related Post:  Krita Sketch released

Knowing that UEFI is handled differently by each PC vendor, the foregoing might not even be true if your PC is not built using an ASRock motherboard, like a reader indicated in this forum post.

Share:

Share on facebook
Facebook
Share on twitter
Twitter
Share on pinterest
Pinterest
Share on linkedin
LinkedIn

Hola! Did you notice that LinuxBSDos.com no longer runs network ads?  Yep, no more ads from the usual suspects that track you across the Internet.  But since  I still need to pay to keep the site running, feel free to make a small donation by PayPal.

Subscribe for updates. Trust me, no spam!

Mailchimp Signup Form

Sponsored links

1. Attend Algorithm Conference, a top AI and ML event for 2020.
2. Reasons to use control panel for your server.
3. DHgate Computers Electronics, Cell Phones & more.

Leave a Reply

Your email address will not be published. Required fields are marked *

Get the latest

On social media
Via my newsletter
Mailchimp Signup Form

Sponsored links

1. Attend Algorithm Conference, a top AI and ML event for 2020.
2. Reasons to use control panel for your server.
3. DHgate Computers Electronics, Cell Phones & more.
Hacking, pentesting distributions

Linux Distributions for Hacking

Experts use these Linux distributions for hacking, digital forensics, and pentesting.

Categories
Archives

The authors of these books are confirmed to speak during

Algorithm Conference

T-minus AI

Author was the first chairperson of AI for the U.S. Air Force.

The case for killer robots

Author is the Director of the Center for Natural and Artificial Intelligence.

Why greatness cannot be planned

Author works on AI safety as a Senior Research Scientist at Uber AI Labs.

Anastasia Marchenkova

An invitation from Anastasia Marchenkova

Hya, after stints as a quantum researcher at Georgia Tech Quantum Optics & Quantum Telecom Lab, and the University of Maryland Joint Quantum Institute, I’m now working on superconducting qubit quantum processors at Bleximo. I’ll be speaking during Algorithm Conference in Austin, Texas, July 16 – 18, 2020. Meet me there and let’s chat about progress and hype in quantum computing.