How to add EFI Boot File in BIOS for New Secondary HDD? Acer Aspire E5-575

I have an Acer Aspire E5-575 laptop which is running Ubuntu on the primary HDD (HDD0) which came with the laptop. I've now added a second drive to the laptop and using a USB installation media I installed a second operating system onto the drive. I have two EFI Boot Files in the boot menu for HDD0, one for grubx64.efi and the other for shimx64.efi. I did this 3-4 years ago when I purchased the laptop.

I cannot for the life of me figure out how to modify the entries in this list again. I've used the efibootmgr tool from Linux to update the entries and on reboot I see that they do persist on the system in some form. However they appear to be invisible to the UEFI BIOS menu. When I remove HDD0 I get an error on boot and the BIOS goes to the F12 boot menu which shows the two EFI entries for HDD0, but no entries for HDD1. These entries naturally won't load as the filesystem they refer to is inaccessible.

While I could add Grub entries which point to HDD1 to boot, I'd like to remove HDD0 eventually or possibly switch it back to Windows. I suspect this will likely take me all the way back to this problem so I'd like to get it figured out now so that I can use HDD1 independently.

Is there any more information I could provide or things I could try to make entries persist? I have access to an Ubuntu system on HDD0 and have a USB install media for Windows which I've tested can load so I can execute bcdedit commands from the Windows shell as well.

Thread was edited to add model name to the title

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JackE

>>>I have an Acer Aspire E5-575 laptop which is running Ubuntu on the primary HDD (HDD0) which came with the laptop. >>>

Does this mean no factory operating system was installed? Jack E/NJ

ssnover

Sorry, that statement was ambiguous. "came with the laptop" is referring to the HDD in this case. The laptop did come installed with Windows from the factory.

I managed to figure out the issue myself by a stroke of luck. The Secure Boot settings menu has options for creating these EFI boot file entries (in my opinion this is definitely not the right place for this). Using this, I removed the existing entries and made new ones to point to grubx64.efi and shimx64.efi on HDD1.

As far as I can tell, it is not possible to generate these entries anywhere but in the BIOS menu; they cannot be generated from an operating system which is rather unfortunate. An embrace of standardization, especially with open source tools, could go a long way in making things like this more user friendly.