Posts on Spezialks Blog

Developing bootsecure

Sun, 19 Apr 2026 00:00:00 +0000

Introduction to bootsecure

Bootsecure is a small rust application that runs on every system login for the user and detects if the computer has been used without logging in. And notifies the User if that has been the case. This uses a feature of the UEFI Spec so it is relatively portable. I found this feature while working on my next blog post about UEFI variables. And I thought that this could make an interesting security application for people worried that their hardware is interacted with while they are away from it. Hence, I build this application. Currently, It’s still quite new, so bugs can happen since it was build in a single weekend, so I am happy if people report bugs with it or contribute to improve this.

Disabling FN+4 under Lenovo

Mon, 16 Mar 2026 00:00:00 +0000

My Problem

Lenovo has this feature that allows you to press FN+4 to put your laptop to sleep. Though this clashes with the switching of the FN and the Ctrl key. Because it seems that there is a bug in the Lenovo Bios of my E14 G6, that when I switched the keys now both keys are recognized as FN only for the sleep shortcut. All Other FN behaviour works as expected.

Understanding Uefi Vars

Sat, 07 Mar 2026 00:00:00 +0000

What are UEFI Vars

UEFI vars are variables that are stored on your motherboard. They store things like boot options, SHIM settings, and other information that have to be independent of your hard drive.

Under the Linux system they are mapped under /sys/firmware/efi/efivars/ using the EFI vars file system ¹.

Under Windows there are some special permissions needed for an app to read them out². Though system calls exist to ask for specific variables ³.