[storage][bootloaders] Portable drives can only have one UEFI boot entry

[LukeShortCloud]

Removable media devices cannot have more than one boot entry added to the UEFI boot menu.

The boot manager finds the first EFI partition that contains \EFI\BOOT\BOOT{machine type short name}.EFI before moving to the next device, so any additional partitions, however properly formatted, are ignored.

Haven't got a clue why it's designed that way.

For removable media devices there must be only one UEFI-compliant system partition, and that partition must contain an UEFI-defined directory in the root directory. The directory will be named EFI. All OS loaders and applications will be stored in a subdirectory below EFI called BOOT. There must only be one executable EFI image for each supported processor architecture in the BOOT directory. For removable media to be bootable under EFI, it must be built in accordance with the rules laid out in Section3.5.1.1. This guarantees that there is only one image that can be automatically loaded from a removable media device by the EFI Boot Manager. Any additional EFI executables must be in directories other than BOOT.

https://superuser.com/questions/1572963/how-to-add-uefi-boot-entry-for-a-removable-drive-that-persists-between-devices https://uefi.org/sites/default/files/resources/UEFI%20Spec%202.8B%20May%202020.pdf#page=573

[LukeShortCloud]

Creating a UEFI entry with efibootmgr requires rebuilding the GRUB configuration with grub-mkconfig.

https://unix.stackexchange.com/questions/624544/rename-efi-boot-entry

[LukeShortCloud]

It is optional for UEFI firmware to show the device information in the format of <UEFI_BOOT_NAME> (<DEVICE_INFORMATION>).

https://forums.linuxmint.com/viewtopic.php?t=349733