Memory protection unit
AssigneeHoneywell International Inc.
InventorsRalf Peter Thor, François Germain Vincent, Roland Domke, Ionut Nicorescu
Life of this patent
Estimating the term…
Abstract
One implementation is for a device. The device includes a controller having a memory protection unit, a legally relevant memory portion capable of interacting with the controller, a legally non-relevant memory portion capable of interacting with the controller, an interface in the memory protection unit that allows a privileged application to access the legally relevant memory portion and disallows an unprivileged application to access to the legally relevant portion, and an interrupt system, wherein when the unprivileged application makes an attempt to interact with the legally relevant memory portion, the memory protection unit takes an action associated with the unprivileged application.
Claims14
A device comprising:
- a controller having a memory protection unit;
- a legally relevant memory portion capable of interacting with the controller;
- a legally non-relevant memory portion capable of interacting with the controller;
- an interface in the memory protection unit that allows a privileged application to access the legally relevant memory portion and disallows an unprivileged application to access to the legally relevant memory portion;
- an interrupt system, wherein when the unprivileged application makes an attempt to interact with the legally relevant memory portion, the memory protection unit takes an action associated with the unprivileged application;
- and
- a buffer, created by the memory protection unit in the legally relevant portion, wherein the action includes the controller using the buffer to handle the attempt and return a result to the unprivileged application and disallow the attempt by the unprivileged application to access the legally relevant portion directly.
One or more hardware-based non-transitory memory devices storing computer-readable instructions which, when executed by the one or more processors disposed in a computing device, cause the computing device to:
- enable an interaction between a controller and a legally relevant portion using a memory protection unit;
- enable an interaction between the controller and a legally non-relevant portion using the memory protection unit;
- allow a privileged application to access the legally relevant portion using an interface in the memory protection unit;
- receive an attempt from the unprivileged application to access the legally relevant portion;
- and
- perform at least one action with respect to the unprivileged application,
- creating a buffer in the legally relevant portion;
- and
- using the buffer to handle the attempt and returning a result to the unprivileged application and disallow the attempt by the unprivileged application to handle the legally relevant portion directly.
A method for protecting a device comprising:
- enabling an interaction between a controller and a legally relevant portion using a memory protection unit;
- enabling an interaction between the controller and a legally non-relevant portion using the memory protection unit;
- allowing a privileged application to access the legally relevant portion;
- receiving an interrupt from an unprivileged application configured to interact with the legally relevant portion;
- and
- performing an operating system level response to the interrupt, wherein the step of performing further comprises:
- creating a buffer by the memory protection unit in the legally relevant portion;
- and
- using the buffer to handle the interrupt and returning a result to the unprivileged application and disallow the attempt by the unprivileged application to access the legally relevant portion directly.
Dependencies are inferred from the claim text.