Techniques are disclosed relating to a method that includes executing, by a processor of a computer system, a particular operating system (OS) from a system memory coupled to the processor. A sideband processor of the computer system may receive, via a network, instructions for an updated version of the OS. While the processor executes the particular OS, the sideband processor may send, to a controller hub, a series of commands that cause the controller hub to store the received instructions into one or more regions of the system memory. The sideband processor may then cause the processor to switch, without rebooting, from executing the particular OS to executing the updated version of the OS.