Patent ID: 9116845
Filing Date: 2015-08-25
Classification: G06F

Abstract:
1. A method comprising: receiving a first access request to write to a first memory, the first access request including a first address; determining a first region descriptor at a local memory protection unit includes a first accessibility indicator specifying that writing to locations within a first region including the first address is not permitted; determining a second region descriptor at the local memory protection unit includes a second accessibility indicator specifying that writing to locations within a second region including the first address is permitted; determining a first access permission allowing the first access request based on the second accessibility indicator in response to determining the second accessibility indicator is less restrictive than the first accessibility indicator; determining a third region descriptor at a global memory protection unit includes a third accessibility indicator specifying that writing to locations within a third region including the first address is not permitted; and determining a second access permission denying the first access request based on the third accessibility indicator; and denying the first access request at the local memory protection unit based on the second access permission in response to determining the second access permission denying the first access request is more restrictive than the first access permission allowing the request, wherein the first region descriptor and the second region descriptor are provided at the local memory protection unit included at a first processor core, and the third region descriptor is provided at the global memory protection unit included in a processor system, the global memory protection unit outside the first processor core.