Flash memory protection scheme for secured shared BIOS implementation in personal computers with an embedded controller

摘要

An apparatus and method are disclosed. The apparatus allows dynamic setting of access permissions to contents of a shared memory in a memory device controlled by an embedded controller and allows updating and recovery of the contents. A computerized system comprising at least one Host linked to the memory device provides access paths to the shared memory, to the Host, and to the embedded controller. The memory device is partitioned into separate blocks, each of which is used to store different types of data. A location is designated in the shared memory for storing protection information that includes data related to access operations allowed by at least one access path to a part of the shared memory. Access, via an arbitration device, to separate parts of the shared memory is permitted by using an access control unit that enables/disables access to predetermined portions of the shared memory.