Why do UEFI bootup entries show up back again after removing them?

**goahead97** · April 2nd, 2021

I tried to remove some UEFI entries, shimx64_centos.efi and shimx64.efi , by booting with a live Ubuntu 18.04.5 USB stick. It seems it works but when I reboot, the deleted UEFI entries show up back again. Can you provide any insight to solve this? I also tried to remove them in Windows 10 with bcdedit /delete {UUID} and it also seemed they got removed successfully but they showed up again after rebooting. At least they show up again in the "Boot priority order" menu of the BIOS.

Code:

root@qwerty:~# fdisk -l
Disk /dev/loop0: 1.2 GiB, 1257197568 bytes, 2455464 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes




Disk /dev/nvme0n1: 477 GiB, 512110190592 bytes, 1000215216 sectors
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: 6D6F8511-B8C7-4B5D-A2FF-B42C6C2F38D6


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  998117375 997877760 475.8G Microsoft basic data
/dev/nvme0n1p4 998117376 1000214527   2097152     1G Windows recovery environmen




Disk /dev/sda: 953.9 GiB, 1024209543168 bytes, 2000409264 sectors
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: gpt
Disk identifier: 9EE6F1C8-1D82-43CA-9D9D-C29761888DBA


Device          Start        End    Sectors   Size Type
/dev/sda1          34      32767      32734    16M Microsoft reserved
/dev/sda2       32768  209747967  209715200   100G Microsoft basic data
/dev/sda3   209747968  210259967     512000   250M EFI System
/dev/sda4   210259968 1983631359 1773371392 845.6G Linux filesystem
/dev/sda5  1983631360 2000408575   16777216     8G Linux swap


Partition 1 does not start on physical sector boundary.




Disk /dev/sdb: 28.9 GiB, 31029460992 bytes, 60604416 sectors
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: dos
Disk identifier: 0x0002c450


Device     Boot Start      End  Sectors  Size Id Type
/dev/sdb1  *     2048 60604415 60602368 28.9G  c W95 FAT32 (LBA)




Disk /dev/zram0: 484.6 MiB, 508129280 bytes, 124055 sectors
Units: sectors of 1 * 4096 = 4096 bytes
Sector size (logical/physical): 4096 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes




Disk /dev/zram1: 484.6 MiB, 508129280 bytes, 124055 sectors
Units: sectors of 1 * 4096 = 4096 bytes
Sector size (logical/physical): 4096 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes




Disk /dev/zram2: 484.6 MiB, 508129280 bytes, 124055 sectors
Units: sectors of 1 * 4096 = 4096 bytes
Sector size (logical/physical): 4096 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes




Disk /dev/zram3: 484.6 MiB, 508129280 bytes, 124055 sectors
Units: sectors of 1 * 4096 = 4096 bytes
Sector size (logical/physical): 4096 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes




Disk /dev/zram4: 484.6 MiB, 508129280 bytes, 124055 sectors
Units: sectors of 1 * 4096 = 4096 bytes
Sector size (logical/physical): 4096 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes




Disk /dev/zram5: 484.6 MiB, 508129280 bytes, 124055 sectors
Units: sectors of 1 * 4096 = 4096 bytes
Sector size (logical/physical): 4096 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes




Disk /dev/zram6: 484.6 MiB, 508129280 bytes, 124055 sectors
Units: sectors of 1 * 4096 = 4096 bytes
Sector size (logical/physical): 4096 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes




Disk /dev/zram7: 484.6 MiB, 508129280 bytes, 124055 sectors
Units: sectors of 1 * 4096 = 4096 bytes
Sector size (logical/physical): 4096 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes

Code:

root@qwerty:~# sudo mount /dev/sda3 /mnt
root@qwerty:~# cd mnt
bash: cd: mnt: No such file or directory
root@qwerty:~# cd /mnt
root@qwerty:/mnt# ls
EFI
root@qwerty:/mnt# cd EFI
root@qwerty:/mnt/EFI# ls
BOOT
root@qwerty:/mnt/EFI# cd BOOT/
root@qwerty:/mnt/EFI/BOOT# ls
BOOTX64.EFI  fbx64.efi
root@qwerty:/mnt/EFI/BOOT# cd ..

Code:

root@qwerty:/mnt/EFI# sudo efibootmgr
BootCurrent: 0003
Timeout: 0 seconds
BootOrder: 0003,0002,2002,2003,2001
Boot0000* USB HDD: Intenso
Boot0001* shimx64_centos.efi
Boot0002* Windows Boot Manager
Boot0003* Linpus lite
Boot0004* shimx64.efi
Boot2001* EFI USB Device
Boot2002* EFI DVD/CDROM
Boot2003* EFI Network

Code:

root@qwerty:/mnt/EFI# sudo efibootmgr -b 4 -B
BootCurrent: 0003
Timeout: 0 seconds
BootOrder: 0003,0002,2002,2003,2001
Boot0000* USB HDD: Intenso
Boot0001* shimx64_centos.efi
Boot0002* Windows Boot Manager
Boot0003* Linpus lite
Boot2001* EFI USB Device
Boot2002* EFI DVD/CDROM
Boot2003* EFI Network

Code:

root@qwerty:/mnt/EFI# sudo efibootmgr -b 1 -B
BootCurrent: 0003
Timeout: 0 seconds
BootOrder: 0003,0002,2002,2003,2001
Boot0000* USB HDD: Intenso
Boot0002* Windows Boot Manager
Boot0003* Linpus lite
Boot2001* EFI USB Device
Boot2002* EFI DVD/CDROM
Boot2003* EFI Network

Code:

root@qwerty:/mnt/EFI# sudo efibootmgr -b 0 -B
BootCurrent: 0003
Timeout: 0 seconds
BootOrder: 0003,0002,2002,2003,2001
Boot0002* Windows Boot Manager
Boot0003* Linpus lite
Boot2001* EFI USB Device
Boot2002* EFI DVD/CDROM
Boot2003* EFI Network
root@qwerty:/mnt/EFI# ls
BOOT
root@qwerty:/mnt/EFI# cd BOOT

root@qwerty:/mnt/EFI/BOOT# ls
BOOTX64.EFI  fbx64.efi

**oldfred** · April 3rd, 2021

You show two ESP partitions.
Are you deleting Linux folders in those partitions at same time.
And some systems sync Windows BCD & UEFI, so on reboot the BCD may be adding them back in.
For those systems, you may have to delete from UEFI menu and the boot settings tab, not UEFI one time boot key.

**goahead97** · April 3rd, 2021

Originally Posted by oldfred

You show two ESP partitions.
Are you deleting Linux folders in those partitions at same time.
And some systems sync Windows BCD & UEFI, so on reboot the BCD may be adding them back in.
For those systems, you may have to delete from UEFI menu and the boot settings tab, not UEFI one time boot key.

You said "You show two ESP partitions".
Well, I guess you mean the two UEFI entries: shimx64_centos.efi and shimx64.efi
Well, I think these two UEFI entries were created when I could not boot up in CentOS. Both of them correspond to trusted UEFI files I had to add in the BIOS settings to be able to boot up the CentOS I had in an external USB drive. Both of them were created while I was fiddling with the BIOS settings to make CentOS able to boot up from an external USB drive. Actually I should probably have added just one of them because both of them were targeting the same partition USB drive that had only one operating system installed: CentOS.

Anyway, with reference to "Are you deleting Linux folders in those partitions at same time.", when I tried to remove the two mentioned UEFI entries and rebooted, this external USB drive was not plugged into the computer. Therefore I do not think I need to delete Linux folders of this external USB drive.

My computer internal's drive is indeed Windows 10.

With reference to "you may have to delete from UEFI men", I guess that means doing what I already did, either with efibootmgr in Ubuntu or bcdedit /delete in Windows .

With reference to what I might still need to do:

What did you mean with "delete ...the boot settings tab, not UEFI one time boot key". Can you explain what you meant and how I could do this? I do not know how to do this.
If you meant deleting the entry on the boot tab of msconfig of Windows10, I just have one single entry in that tab and it corresponds to Windows 10.

Thanks

**tea for one** · April 3rd, 2021

Originally Posted by goahead97

You said "You show two ESP partitions".
Well, I guess you mean the two UEFI entries: [COLOR=#242729][FONT=Arial]shimx64_centos.efi and shimx64.efi

You have two ESP (partitions) as follows:-

Code:

/dev/nvme0n1p1      2048     206847    204800   100M EFI System

Code:

/dev/sda3   209747968  210259967     512000   250M EFI System

**oldfred** · April 3rd, 2021

You have a UEFI boot key, often f2 to get into UEFI settings.
The UEFI boot menu for one time boot is often f12.
But many brands use different keys.

In UEFI settings is typically a boot tab where you can change boot items.

**goahead97** · April 3rd, 2021

Originally Posted by tea for one

You have two ESP (partitions) as follows:-

Code:

/dev/nvme0n1p1      2048     206847    204800   100M EFI System

Code:

/dev/sda3   209747968  210259967     512000   250M EFI System

/dev/nvme0n1p1 is a partition of the internal SSD drive that has Windows 10.
/dev/sda3 is the EFI partition of the external SSD where I installed CentOS.

**goahead97** · April 3rd, 2021

Originally Posted by oldfred

You have a UEFI boot key, often f2 to get into UEFI settings.
The UEFI boot menu for one time boot is often f12.
But many brands use different keys.

In UEFI settings is typically a boot tab where you can change boot items.

I confirm F12 displays the menu to choose operating system at start up.
I also confirm F2 lets me go in the UEFI setting.

I only see three boot entries in the UEFI settings for Boot priority order:
1. Windows Boot Manager
2. EFI File Boot 0: shimx64_centos.efi
3. EFI File Boot 1: shimx64.efi

I know the entries EFI File Boot 0: shimx64_centos.efi and EFI File Boot 1: shimx64.efi got added when I explicitly added two UEFI files as trusted to be able to boot up with CentOS.

Does this information let us close to find any solution?

**tea for one** · April 3rd, 2021

Originally Posted by goahead97

/dev/nvme0n1p1 is a partition of the internal SSD drive that has Windows 10.
/dev/sda3 is the EFI partition of the external SSD where I installed CentOS.

You have not installed Ubuntu on either drive?

**goahead97** · April 4th, 2021

Originally Posted by tea for one

You have not installed Ubuntu on either drive?

No, I do not currently have any drive with Ubuntu operating system.

I am just trying to solve the mentioned problem booting Ubuntu live from a USB stick.

**oldfred** · April 4th, 2021

Since not Ubuntu moved to Other operating systems.

Lets see details, use ppa version with your live installer (2nd option) or any working install, not Boot-Repair ISO:
Please copy & paste the pastebin link to the Boot-info summary report ( do not post report), do not run the auto fix till reviewed.
https://help.ubuntu.com/community/Boot-Repair