zlacker

>As of January 2021 deleting SecureBoot keys and installing your own keys (for example by using KeyTool) will brick the device. This is a problem that is similar to one which has been reported on some other Lenovo laptops [0] and is likely due to a faulty firmware. If the device is stuck in a boot loop after replacing the SecureBoot keys, the only way to repair it is by replacing the mainboard of the device.

[0] https://forums.lenovo.com/t5/ThinkPad-X-Series-Laptops/BIOS-...

From https://wiki.archlinux.org/title/Lenovo_ThinkPad_T14/T14s_(I...

>>SSLy+(OP)
Does reflashing the BIOS EEPROM (via hardware clip) work? Or have they "secured" that out of the question too?

>>userbi+Aj
I'd be surprised if that's not one of the bits of firmware that's checked on boot. So yeah, probably not possible, and not possible to downgrade.

>>userbi+Aj
The goal is that it's secured as well; the bios image itself is measured into the TPM and pluton as part of secure boot.