I had the same problem, that is the Dell Bios not preserving the "PCIROOT(...." File system path on boot options between reboots.  It would constantly revert to "VenHW(...." and fail to see boot from that UEFI drive.

It didn't matter what I did.  BIOS updates (latest firmware), remove CMOS battery, recheck drive partition/layout (GPT, no MBR hangovers, ESP partition flags on an EFI VFAT partition)... nothing worked.

What fixed it was copying my bootloader (grubx64.efi) to the universal default location and allow the BIOS to "autodetect" it and add it to the bootloader list.

Let's assume on your EFI partition you have:

/EFI/MY-HOST/grubx64.efi

copy and rename to this location:

/EFI/BOOT/BOOTX64.EFI

Reboot your PC and F2 to get back into BIOS.

You should see your drive autodetected (drive manufacturer name) and if you view the details, you'll see the

/EFI/BOOT/BOOTX64.EFI path.

This does some voodoo in the bios, resetting it as such.

You should be able to reboot again, then add any PCIROOT paths you like (even to the same drive) and they should stick.

I tested this on an Optiplex 3040 Micro with 1.20.1 bios version and working CMOS battery.

I forgot to add....

I also removed all boot loader entries, setting the bios to UEFI mode only (no legacy).  So there was nothing defined to boot from, with the file in the above location, I then rebooted and the BIOS added a default entry to that location.

New entries can then be added cleanly, and the PCIROOT(... .will stick

Hi

I think youarereferring to using the mountvol command,and setting the EFI area as A: drive, for instance.

Which can have a lot of directories and sub-directories to work thru....

C:\>dir a:\ /s
 Volume in drive A is SYSTEM_DRV
 

 Directory of a:\

13/09/2021  12:46    <DIR>          EFI
25/07/2021  21:17    <DIR>          BOOT
18/09/2021  11:39    <DIR>          opensuse
             

 Directory of a:\EFI

25/07/2021  21:17    <DIR>          .
25/07/2021  21:17    <DIR>          ..
25/07/2021  21:17    <DIR>          Microsoft
20/08/2021  13:26    <DIR>          Boot
06/08/2021  11:52    <DIR>          UpdateCapsule
16/08/2021  15:07    <DIR>          Insyde
13/09/2021  12:46    <DIR>          pclinuxos
18/09/2021  13:13    <DIR>          opensuse
              

 Directory of a:\EFI\Microsoft

25/07/2021  21:17    <DIR>          .
25/07/2021  21:17    <DIR>          ..
25/07/2021  21:17    <DIR>          Boot
25/07/2021  21:17    <DIR>          Recovery
               

 Directory of a:\EFI\Microsoft\Boot

25/07/2021  21:17    <DIR>          .
25/07/2021  21:17    <DIR>          ..
07/12/2019  10:09            18,960 kd_07_1415.dll
07/12/2019  10:09            48,952 kd_0C_8086.dll
07/12/2019  10:08             9,796 winsipolicy.p7b
17/09/2021  09:36         1,558,856 bootmgfw.efi
17/09/2021  09:36         1,542,472 bootmgr.efi
07/12/2019  10:09            17,720 kdnet_uart16550.dll
05/08/2021  12:19            27,464 kdstub.dll
07/12/2019  10:09            31,544 kd_02_10df.dll
07/12/2019  10:09           379,192 kd_02_10ec.dll
07/12/2019  10:09            26,424 kd_02_1137.dll
07/12/2019  10:09           239,928 kd_02_14e4.dll
07/12/2019  10:09            44,344 kd_02_15b3.dll
07/12/2019  10:09            44,344 kd_02_1969.dll
07/12/2019  10:09            31,544 kd_02_19a2.dll
07/12/2019  10:09            20,280 kd_02_1af4.dll
17/09/2021  09:36         1,348,920 memtest.efi
05/08/2021  12:19             5,145 boot.stl
07/12/2019  10:09           298,296 kd_02_8086.dll
25/07/2021  21:17    <DIR>          Fonts
25/07/2021  21:17    <DIR>          Resources
03/10/2021  17:38            40,960 BCD
              19 File(s)      5,735,141 bytes

 
          Directory of a:\EFI\Microsoft\Boot\en-GB

25/07/2021  21:17    <DIR>          .
25/07/2021  21:17    <DIR>          ..
07/12/2019  10:09            77,320 bootmgfw.efi.mui
07/12/2019  10:09            77,320 bootmgr.efi.mui
               2 File(s)        154,640 bytes

 Directory of a:\EFI\Microsoft\Boot\Resources

25/07/2021  21:17    <DIR>          .
25/07/2021  21:17    <DIR>          ..
07/12/2019  01:08            92,472 bootres.dll
25/07/2021  21:17    <DIR>          en-US
               1 File(s)         92,472 bytes

 Directory of a:\EFI\Microsoft\Recovery

25/07/2021  21:17    <DIR>          .
25/07/2021  21:17    <DIR>          ..
25/07/2021  21:35            20,480 BCD
               1 File(s)         20,480 bytes

 Directory of a:\EFI\Boot

25/07/2021  21:17    <DIR>          .
25/07/2021  21:17    <DIR>          ..
20/08/2021  13:26            85,672 fbx64.efi
20/08/2021  13:26           856,232 mmx64.efi
20/08/2021  13:26           955,656 bootx64.efi
18/09/2021  11:40             2,593 grub.cfg
24/05/2021  00:06         1,222,656 grub.efi
24/05/2021  00:06           846,240 MokManager.efi
               6 File(s)      3,969,049 bytes

 Directory of a:\EFI\UpdateCapsule

06/08/2021  11:51    <DIR>          .
06/08/2021  11:51    <DIR>          ..
               0 File(s)              0 bytes

 Directory of a:\EFI\Insyde

16/08/2021  15:07    <DIR>          .
16/08/2021  15:07    <DIR>          ..
16/08/2021  15:07        26,783,984 isflash.bin
               1 File(s)     26,783,984 bytes

 Directory of a:\EFI\pclinuxos

13/09/2021  12:46    <DIR>          .
13/09/2021  12:46    <DIR>          ..
14/09/2021  11:48           143,360 grubx64.efi
               1 File(s)        143,360 bytes

 Directory of a:\EFI\opensuse

18/09/2021  11:44    <DIR>          .
18/09/2021  11:44    <DIR>          ..
19/09/2021  14:24           846,240 MokManager.efi
19/09/2021  14:24         1,222,656 grub.efi
19/09/2021  14:24           934,680 shim.efi
19/09/2021  14:24                58 boot.csv
19/09/2021  14:24               125 grub.cfg
19/09/2021  14:24           143,360 grubx64.efi
               6 File(s)      3,147,119 bytes

 Directory of a:\BOOT

25/07/2021  21:17    <DIR>          .
25/07/2021  21:17    <DIR>          ..
07/12/2019  01:10         3,170,304 BOOT.SDI
               1 File(s)      3,170,304 bytes

      Total Files Listed:

             148 File(s)     63,135,880 bytes
             160 Dir(s)     204,308,480 bytes free

I trimmed down the list considerably.  

AND because the BIOS flasher and MEMTEST etc etc reside there alongside the boot files, so can harmful viruses and backdoors, so that needs to be considered when re-installing an OS because of problems, that you are not necessarily purging the whole storage device.

Hello,

can you check using the live boot disk, how is formatted and partitioned the disk that you are not managing to get efi persist ?

lsblk -f
sudo fdisk -l

Please check if is GPT (mbr would not be ok and cause this issue), and you should be able to see a small Fat32 EFI partition ( max 500mb I think ) with the esp  flag (this too is required to have persistent efi entries)

Also if the cmos battery is too low, it could lose the custom efi path and revert to the default at reboot.

Another trick that could work ( to abuse of the default efi\boot\bootx64.efi ) would be to mount the esp partition of the disk you installed onto and 

sudo mkdir -p /boot/efi/EFI/BOOT
sudo cp /boot/efi/EFI/<yourdistro>/grubx64.efi \ /boot/efi/EFI/BOOT/BOOTX64.EFI

then set the disk as first in boot order, and it should boot

@mazzinia_​ 

Thank you for your reply,

It is GPT fat32 ESP enabled. My boot path is /efi/EFI/Linux/vmlinuz.efi and I tried moving to match the default boot path and name BOOTX64.EFI

I can try replacing the CMOS battery. I also formatted it to 1000mb, I can try reformatting. 

It is able to find the disk and my linux efi binary in the BIOS menu. Could there be any other settings preventing it from persisting? I disabled admin pass for uefi. Boot from USB works fine and it detects the efi on that.

possibly related!

https://www.dell.com/community/en/conversations/precision-fixed-workstations/t7910-sas3008-updated-firmware/647f8e1df4ccf8a8deee3b5d

I forgot to mention that I am totally unable to boot even from the live usb by selecting the efi. It loads the initramfs, but it hangs on mpt3x64 and totally fails to detect drives. I thought it was an issue with my gentoo installation and kernel, and I have been banging my head against a wall trying to get it to boot, but I did not consider that the issues might be related.

Do you know anything about this? @mazzinia_ ?

no, sorry, I don't. But have you tried disabling secure boot like they mentioned in that thread ?

Supported operating systems (if it helps):

BIOS

Red Hat® Linux 7.0

Red Hat® Workstation 7.3

Ubuntu® 12.04

Ubuntu® 14.04

Windows 10, 32-bit

Windows 10, 64-bit

Windows 7, 32-bit

Windows 7, 64-bit

Windows 8.1, 64-bit

Hi

Daft Idea .......

https://www.rodsbooks.com/refind/

I followed the instructions in the post I linked for flashing the storage controller, but no luck.