Mediatek Corporation

Chih-Pin Su

Chih-Hsiang Hsiao

Yu-Tien Chang

Jing-Kuang Huang

Hungwen Li

A power management system includes at least one device, at least one memory management unit (MMU), a processor, and at least one device controller, wherein the at least one MMU corresponds to the at least one device, respectively. The processor is arranged to execute at least one access control power manager, an operating system (OS), and a hypervisor, wherein the OS is arranged to generate a trigger signal, and the hypervisor is arranged to generate a first hint according to the trigger signal. The at least one device controller is arranged to control the at least one access control power manager according to the first hint, to manage at least one power of the at least one MMU.

Power management system of input-output memory management unit and associated method

A system includes a memory addressable by addresses within a physical address (PA) space, and one or more processors that perform operations of virtual machines (VMs). The VMs are allocated with extended PA regions outside the PA space. The system further includes a memory interface controller coupled to the memory and the one or more processors. The memory interface controller receives a request for accessing an address in the extended PA regions from a requesting VM, and uses a remap circuit to map the address in the extended PA regions to a remapped address in the PA space. A memory protection unit (MPU) in the memory interface controller grants or denies the request based on stored information indicating whether the remapped address is accessible to the requesting VM.

Memory protection for virtual machines

A system is provided to perform secure operations. The system includes an I/O subsystem, a memory subsystem and processors. The processors are operative to execute processes in trusted execution environments (TEEs) and rich execution environments (REEs). Each of the TEEs and the REEs is identified by a corresponding access identifier (AID) and protected by a corresponding system resource protection unit (SRPU). The corresponding SRPU of a TEE includes instructions, when executed by a corresponding processor, cause the corresponding processor to control access to the TEE using a data structure including allowed AIDs and pointers to memory locations accessible by the allowed AIDs.

Security schemes for multiple trusted-execution-environments (TEEs) and multiple rich-execution-environments (REEs)

A computing system and method providing normal security services and high security services are disclosed. The computing system includes hardware resources, a processor core and an access right checker. The hardware resources are grouped into resource security levels. The processor, switching between a normal security and a high security state, assigns a user access right to a request. In comparison with the normal security state, user access right assigned in the high security state further allows the request to use the hardware resources of a higher resource security level. According to the assigned user access right and the resource security levels of required hardware resources of the request, the access right checker determines whether the request has the authority to use the hardware resources, and thereby, the access right checker executes the request or responds the issued request with an exception.

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Hsinchu, Taiwan

Chih-Pin Su