ASIL Memory Protection via Dispersed Flag Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing AUTOSAR platforms face challenges in efficiently managing memory access authority between ASIL and QM areas, leading to increased CPU load and potential integrity issues due to frequent system calls and hardware contamination.
Innovation Solution
Implementing an electronic device with multiple dispersed flags to manage memory access authority, where the QM module sets flags to a first value for access and notifies the ASIL module, allowing the MPU to be deactivated, and subsequently resets the flags to a second value to reactivate the MPU, ensuring controlled access to the ASIL area.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the MPU is activated to monitor access to the ASIL area, then memory access integrity is improved, but CPU load increases due to frequent system calls
Solution Approach 1:
The patent segments the memory into distinct ASIL and QM areas with different access rules, and segments the flag management into multiple dispersed flags. This allows the system to monitor only specific areas and conditions, reducing overall monitoring overhead while maintaining integrity where needed.
Solution Approach 2:
The patent uses preliminary flag setting actions to establish access authority before actual memory access occurs. By pre-configuring the flag states and access rules, the system avoids the need for frequent system calls during runtime, thereby reducing CPU load while maintaining security.
2Measurement precision
If multiple flags are used to manage memory access authority, then access control precision is improved, but device complexity increases
Solution Approach 1:
The patent divides the access control mechanism into multiple discrete flags rather than using a single complex permission structure. Each flag represents a specific access condition or authority level, making the system more precise while managing complexity through modular organization.
Solution Approach 2:
Different flags are assigned to different QM functions with specific access requirements. Each flag has localized properties and rules tailored to its specific purpose, allowing precise control for each function while keeping the overall system manageable through localized management strategies.
3Object-affected harmful factors
If flags are dispersed in memory, then hardware contamination resistance is improved, but access overhead increases
Solution Approach 1:
The patent disperses flags across different memory locations rather than concentrating them in one place. This segmentation provides resistance against hardware contamination or corruption affecting a single memory region, while the system manages access overhead through efficient flag checking mechanisms.
Solution Approach 2:
The system performs preliminary checks of dispersed flag states before memory access operations. By preparing and validating flag configurations in advance, the system minimizes the time penalty of accessing multiple dispersed locations during actual memory operations.
Data Source
AI summary
An electronic device for protecting an automotive safety integrity level (ASIL) memory area includes a memory configured to be partitioned into an ASIL area and a quality management (QM) area; at least one flag; and a QM module. The QM module is configured to set the flag to a first value; perform memory access of writing or reading data in certain areas of the ASIL area; and set the flag to a second value after having performed the memory access. The electronic device also includes an ASIL module configured to deactivate a memory protection unit (MPU), which monitors access to the memory, when the flag is set to the first value. The ASIL module is also configured to activate the MPU or maintain a state of the MPU when the flag is set to the second value.