Abstract: An example non-transitory machine-readable medium includes instructions that cause a processor of a computing device to create a first virtual machine using a hypervisor, execute a trusted basic input/output system (BIOS) in the first virtual machine, create a second virtual machine using the hypervisor, and execute an untrusted BIOS component in the second virtual machine. The first virtual machine is executed with a greater privilege to access a resource of the computing device than the second virtual machine.

Abstract: In an embodiment, an operating system is defined in terms of a set of actors, each of which implements one or more capabilities built into the system. The actors may establish channels between them for communication of messages between the actors. Some actors may interpose between other actors. These other actors may, in some cases, interpose on channels used by the base actor. In some embodiments, some channels may be interposed while others may be monitored by the interposing actor but may still communicate directly with the underlying actor. Some channels may not be affected by the interposition (e.g. the channels may not be interposed or monitored), in an embodiment. Other examples of interposition may include debugging, simulation, and sandboxing.

Abstract: In an embodiment, an operating system is defined in terms of a set of actors, each of which implements one or more capabilities built into the system. The actors may establish channels between them for communication of messages between the actors. Some actors may interpose between other actors. These other actors may, in some cases, interpose on channels used by the base actor. In some embodiments, some channels may be interposed while others may be monitored by the interposing actor but may still communicate directly with the underlying actor. Some channels may not be affected by the interposition (e.g. the channels may not be interposed or monitored), in an embodiment. Other examples of interposition may include debugging, simulation, and sandboxing.