My stupid Lenovo "Thinkpad" UEFI doesnt have a real F12 devices menu.
It just shows registered UEFI targets that can be booted.
This is pretty catastrophic, somehow I got Fedora and Windows installed, but thats it. If something breaks, I am in trouble. I cant do a memtest86 even though I think my RAM is faulty.
So in Linux, is there a way to add an UEFI entry to boot just any USB stick? Or to boot a specific one, like with Ventoy on it?
rEFInd can auto-detect bootable devices, and you can select them during startup. You need to install it to the efi partition as your boot manager.
With a simple config edit and file copy operation, I put a memtest86 efi image on my boot partition, and it shows up as an option for every boot. It's nice to know I won't have to fumble around with USB drives if I need to test my RAM in the future.
I use Fedora Sericea, another Silverblue spin, on my laptop. It wasn't hard to install rEFInd, and it coexists just fine with GRUB in my experience. rEFInd detects that grub is there and shows it as an option, like any other bootable media.
Try F1 instead of F12. It should be under Setup -> Boot, and then just make your USB the first entry, save, and exit. And just so we're covering all bases, the usb should be plugged in before you reboot into the bios settings and it may be under a name that doesn't say "usb" anywhere (for example, the name of my usb in the bios settings contains the manufacturer and size in GB in addition to some other nonsense that i think is a model number).
I had to enable "USB hard drives" in the regular bios setup to get access to them in the F12 menu (Thinkpad L480). Not in front of me at the moment but on the "boot" or startup page there was a sort of unintuitive to find "boot" menu that looked like a page header that lets you enable or disable boot devices. USB was disabled by default.
But what I meant is that I am pretty sure there is no secret setting, but that I simply need to fix it otherwise, like with rEFInd or something like that
Huh? Every ThinkPad I've had let's me boot to a USB drive. Check your bios settings something is off, unless it's through a company and they have it specifically disabled.
If you have UEFI enabled, probably you also have secure boot.
I did a script to create a usb pendrive that works with UEFI and Secure Boot, you can boot a liveusb Debian, Ubuntu or clonezilla at the moment
One thing you might be running into is having hiberboot (AKA fast startup)enabled in windows. Instead of shutting down it hibernates when you choose "shutdown".
If it is in the hibernated state instead of actually shutdown. You won't be able to choose a different boot option.
I'm a bit late here but when installing grub to a USB drive with a GPT/EFI compatible partitioning, you need to run the following command: "grub-install --target=x86_64-efi --efi-directory=/boot/efi --removable" (without the quotes).