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Bootloader Recovery After BIOS Update for CachyOS

·3 mins

If you’re reading this, you might be in the same panic I was in after updating my motherboard’s BIOS: staring at a screen that refuses to boot into your Linux installation. Here’s what happened and how I fixed it.

The Problem #

I recently updated the BIOS on my B550 AORUS ELITE V2 motherboard from version F16C to F18. After the update completed and I rebooted, my CachyOS bootloader had completely disappeared. The system couldn’t find anything to boot from, leaving me with a very expensive paperweight.

BIOS updates can sometimes reset boot priorities or, in worse cases, clear UEFI boot entries entirely. This is exactly what happened to me.

The Solution: Booting from Live USB #

Step 1: Boot into CachyOS Live USB #

I used my laptop to create a CachyOS live USB and booted into the live environment. If you do not have another machine handy, you might need a friend’s desktop, or use your phone to rent a cloud-based virtual machine :).

Step 2: Identify Your Partitions #

With multiple partitions on my system, I needed to figure out which was which. The parted command came to the rescue:

sudo parted -l

I first used lsblk but I got my partitions without labels. Therefore I just used parted because I was familiar with it.

This command lists all your disks and partitions with their sizes and types, making it easy to identify your root partition, EFI partition, and any other partitions you have.

Step 3: Follow the CachyOS Bootloader Recovery Guide #

The CachyOS wiki has an excellent guide for recovering your bootloader. I followed the steps at:

https://wiki.cachyos.org/cachyos_basic/faq/#steps-to-recover-your-bootloader

The process involves:

  1. Mounting your partitions - Mount your root partition and EFI partition to appropriate locations
  2. Chrooting into your system - Use arch-chroot to access your installed system from the live environment. When you run the command, it will prompt you to answer questions about how to want to mount your partitions. Make sure you look at the example given in the guide
  3. Reinstalling the bootloader - Reinstall refind (or whichever bootloader you use)

I first did not know what ‘chroot’ is. It’s a command that allows you to run a command or shell in a different directory tree than the one you’re currently in. It’s useful for accessing your installed (not working) system from the live environment (the one you’re booting from your usb).

Step 4: Reinstall your bootloader #

Using the chroot environment, I reinstalled rEFInd:

refind-install

This recreated the necessary UEFI boot entries and restored my bootloader.

Why did this happen? #

I eluded to it before but BIOS updates c an:

  • Clear or reset UEFI boot entries
  • Change order
  • Reset secure boot settings
  • Modify CSM/UEFI mode settings

Apparently manufeacturers often reset these settings as a precaution during BIOS flashing to prevent boos issues with incompatible configurations.

Prevention (or more, recovery) tips #

Next time I will:

  1. Keep a live USB handy - Always have a bootable USB stick available
  2. Label your partitions - Would have made it easier to identify them during recovery.
  3. Check boot settings post-update - After any BIOS update, check your BIOS after an update.

Wrapping up #

The CachyOS community has excellent documentation that made this recovery process much smoother than it could have been. I now know I should not update my BIOS on a random Tuesday evening without a live USB and labels on my partitions :)