The steam deck is a custom PC hardware from Valve that is focused on gaming. It can, however, also be used as a regular PC, and comes with a customized Plasma session. Also, it is completely unlocked, so one could install any OS they wish on it, including Arch Linux.
It uses a snapshot of Arch Linux mirrors, plus it has two Valve repositories, called
jupiter. These repositories replaces several core packages of the Arch Linux distribution, including the kernel,
compilers and graphical stack.
The deck uses an A/B update system, with two system partitions that are used for updates. If an update fails or the deck fails to boot it will revert to the previous partition and continue to work normally. This also means that changes made to one of the system partitions are not carried over to the other system partition.
There is a default user called
deck that is used for storing steam profiles and games. Other applications can be installed using Flatpak. The
/home partition is writable by the user.