EndeavourOS suddenly went missing in boot menu

General system Newbie
1

I recently switched from Ubuntu to Endeavour OS.
I had set up a custom partition where my boot and root partition are on my SSD and the home partition was on my hard drive.

[liveuser@eos-2024.06.25 ~]$ sudo fdisk -l
Disk /dev/sda: 931.51 GiB, 1000204886016 bytes, 1953525168 sectors
Disk model: WDC WD10SPZX-24Z
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disklabel type: dos
Disk identifier: 0x0a6cb7b0

Device     Boot     Start        End   Sectors  Size Id Type
/dev/sda1            2048  629147647 629145600  300G  7 HPFS/NTFS/exFAT
/dev/sda2       629147648 1363150847 734003200  350G 83 Linux


Disk /dev/nvme0n1: 238.47 GiB, 256060514304 bytes, 500118192 sectors
Disk model: SAMSUNG MZVLB256HBHQ-000L2              
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: gpt
Disk identifier: 5ABAE845-AF30-4BAF-B8DA-37A0086BC5EC

Device             Start       End   Sectors   Size Type
/dev/nvme0n1p1      2048    206847    204800   100M EFI System
/dev/nvme0n1p2    206848    239615     32768    16M Microsoft reserved
/dev/nvme0n1p3    239616 387946495 387706880 184.9G Microsoft basic data
/dev/nvme0n1p4 388995072 472881151  83886080    40G Linux filesystem
/dev/nvme0n1p5 387946496 388995071   1048576   512M EFI System
/dev/nvme0n1p6 498735104 500115455   1380352   674M Windows recovery environment

Partition table entries are not in disk order.

/dev/sda2 is home partition

/dev/nvme0n1p4 is root partition

/dev/nvme0n1p5 is boot partition



After installation it was working fine and I was able to use it properly. But a few days back, when I booted into Widnows 11, it forced an update and since then, my Endeavour OS is missing from the boot menu.

I also checked in BIOS and I couldn’t find it. However, there were now 2 Windows boot options, and also Ubuntu was present in the BIOS boot menu, even though I had replaced the Ubuntu installation with Endeavour, i.e all the devices/partitions allocated to Ubuntu, were given to Endeavour during installation. But when I select Ubuntu, it just opens a grub page (it was some sort of command line, not the usual boot menu).

I tried to mount my root, boot and home partitions in a live environment and I’m able to see and access all the files there, so the installation is still there, I’m just not able to boot into the OS.

How do I fix this?

2

Mount the root partition and get and post /etc/fstab from EnOS system.
You need to recreate the UEFI boot entry for your system. More info is required in order to provide you some assistance, starting from fstab. You may want to describe how you installed and mainly if you used grub or systemd-boot.

3 
[root@EndeavourOS /]# cat /etc/fstab 
# /etc/fstab: static file system information.
#
# Use 'blkid' to print the universally unique identifier for a device; this may
# be used with UUID= as a more robust way to name devices that works even if
# disks are added and removed. See fstab(5).
#
# <file system>             <mount point>  <type>  <options>  <dump>  <pass>
UUID=5A72-ECAF                            /efi           vfat    fmask=0137,dmask=0027 0 2
UUID=141cb2a6-3f49-4481-81f3-70124b278103 /              ext4    noatime    0 1
UUID=a9f21318-85c1-402b-998d-30eff8d44415 /home          ext4    noatime    0 2
tmpfs                                     /tmp           tmpfs   defaults,noatime,mode=1777 0 0

I don’t remember which one I selected. I left it on default, but…

During installation, initially I left it on default, but later while setting up custom partition, it gave me an error that I am missing a EFI partition, even though I had assigned /boot to /dev/nvme0n1p5. So I went and changed it to /boot/efi and it stopped prompting the error message.

I don’t know if it’s possible for the installer to change the boot option from the default to the other (if it’s not, then mine should be the default option).

But previously when I was using endeavour on my old machine, I used to see a pink-blue-ish background during the boot. But this time, I noticed that the boot menu was similar to the one which is seen when booting into the live iso. Hope this helps determine which one I’m using.

4

Just realised that I may have messed up the installation. Copied my data and did a clean install.

5

Be aware - the problem is likely to reoccur with future Windows updates, it’s very common - Windows assumes it has full control over the bootloader on the system and does as it pleases rather than respecting the fact there may be other OS’s present.

You may have more luck keeping them entirely on separate drives rather than inhabiting the same one and selecting your boot device directly with your system’s relevant hotkey during POST.