default.ipxe loading but freezes

[fierke]

These two lines made the screen freeze while booting (UEFI, Secure Boot Off, DELL Latitude E7240):
param secureboot ${efi/SecureBoot}
param setupmode ${efi/SetupMode}

I solved it commenting these out, but thats only a temporarily solution.

[Tom Elliott]

@fierke Are you running secure boot?

I think this is a firmware bug. I’ll take a look but just asking.

[fierke]

This post is deleted!

[fierke]

@Tom-Elliott No, so thats fine for me, but maybe the problem occurs somewhere else too

[Tom Elliott]

(Yes I’m using AI to help out in troubleshooting and fixing as well trying to get more details in an AI model so the posting below is a reply requested for information.)

@fierke Thanks, that narrows it down a lot.

Those two lines read EFI variables. To find one, iPXE walks the firmware’s whole variable list. Some older UEFI firmware never ends that list, so iPXE loops forever. That fits what you see.

Can you help me confirm it? On the E7240:

1. Leave the two lines commented out for now.
2. PXE boot, and press Ctrl+B when iPXE starts to get the iPXE shell.
3. Run dhcp, then show efi/SecureBoot.
4. Tell me whether it prints a value, prints an error, or hangs.

Also, which BIOS version is on the machine? It shows on the F2 setup screen.

Either way, I am removing those two lines from default.ipxe so this cannot stop a boot. I am also fixing iPXE so it reads the Secure Boot state directly, without the walk. Your workaround is safe until then. Note that re-running the installer writes the lines back, so comment them out again after an install.

[Tom Elliott]

@fierke A correction to my last post. The fix is now merged into working-1.6 and rc-1.6.0. Update your checkout and re-run the installer. The installer now writes default.ipxe without those two lines, so you do not need to comment them out again.

You are right that this can happen on other machines too. Any UEFI firmware that never ends its variable list hangs the same way. The update fixes it for all of them.

I would still like the show efi/SecureBoot result and your BIOS version when you have time. That confirms the cause before the iPXE side ships.