A quick daydream, the Grub boot menu rushes by, and the wrong operating system starts. Users of dual-boot systems with Linux and Windows that are installed side by side on the same computer are familiar with this annoyance. There are many reasons for dual-boot installations, for example, both systems can access the hardware without any speed disadvantages. Mom can train neural networks with the thick graphics card under Linux during the day, while the offspring demand the 3D performance for gaming under Windows in the evening. And if you want, you can also experiment with a different operating system out of pure curiosity.
The most common solution for multiboot is the open-source boot loader Grub 2. After the system starts, the UEFI bios gives it control and it can start Windows as well as all Linuxes. The choice is made via a text-based selection menu. However, since most users start the first option very often and do not want the computer to remain stuck in this menu forever, a timer expires, after which Grub either boots a default operating system or the last used one. While you’re angry because you weren’t careful and started the wrong system again, you ask yourself during the reboot: Why can’t it be as easy as with an old dishwasher with mechanical program selection?
The project “The GRUB Switch” fulfills exactly this wish. With a small extension of the grub.cfg boot script, Grub looks on a USB storage medium to see which menu entry it should boot. In the simplest usage variant, you select the desired operating system by inserting a normal USB stick with the appropriate file. You can also build yourself a real switch for the same purpose using a microcontroller and a bit of soldering.
