I successfully installed Qubes OS (UEFI mode) on a storage with GPT following the guide https://www.qubes-os.org/doc/custom-install/#example-custom-luks-configuration with manually configuring boot partition sda1 mount point: /boot/efi file system: EFI System Partition
First boot failed and I recognized in my BIOS boot option was set on Legacy. As I changed it to UEFI I had to choose a file under EFI Boot Selection and I chose xen.cfg. After that booting into Qubes OS worked and I performed the first update. Everything is working.
After the update I wanted to get sure that Qubes OS is setup properly. I checked again my chosen Boot Option under BIOS and it was set then automatically to \EFI\qubes\xen.efi.
Here are the files I can choose under BIOS EFI Boot Selection:
Was it correct to choose xen.cfg under BIOS Boot Selection?
Is it correct that after Qubes OS update the file under BIOS Boot Selection is set to xen.efi and how this was possible?
Why there are also older versions of vmlinuz and initramfs? Should I delete them and if yes what would be the best way to do this?
How can I generally access these files to check them? Is it preferred to access them from dom0 under Qubes OS or via installer Rescue mode on UEFI?
Could your provide a resource about the explanation of these files?