Context-Sensitive Debug Access for Real-Time Virtualized Processors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional debugging techniques in processor-based systems are intrusive, requiring the processor to halt and suspend operations, which is undesirable for time-critical applications, and do not effectively handle complex systems with virtualized environments.
Innovation Solution
Implementing context-sensitive debug requests that allow processors to service memory and register accesses only when specific conditional criteria are met, enabling non-intrusive debugging in real-time mode by using debug context registers and logic to evaluate these criteria.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the processor enters a suspended state to service debug requests, then memory and register access can be performed, but processor operations are halted and time-critical deadlines cannot be met
Solution Approach 1:
The system pre-conditions debug requests with contextual criteria (process ID, memory region, register type) before execution. This preliminary action allows the debug mechanism to be ready and configured in advance, enabling it to service requests without halting the processor by already having the filtering logic in place.
Solution Approach 2:
A debug management unit acts as an intermediary between the processor and debug requests. This intermediary component evaluates contextual criteria and routes requests appropriately, allowing debug operations to proceed without requiring the processor itself to enter a suspended state, thus maintaining continuous execution while enabling precise debug access.
2Measurement precision
If the processor halts to service debug requests, then accurate memory and register access is achieved, but real-time operations and interrupts cannot be serviced
Solution Approach 1:
The debug mechanism applies local quality by selectively servicing debug requests based on contextual criteria (specific process IDs, memory regions, register types). Instead of globally halting the processor, only specific debug access points are activated when their conditions are met, allowing real-time operations to continue uninterrupted while maintaining accurate debug access where needed.
Solution Approach 2:
The system dynamically evaluates contextual criteria for each debug request rather than using a static halt approach. The debug management unit adaptively determines whether to service a request based on current processor state, active processes, and request specificity, enabling the system to maintain reliability by continuing real-time operations while providing accurate debug access when conditions permit.
3Ease of operation
If conventional debug requests are used without contextual criteria, then simple memory access is possible, but complex virtualized environments cannot be properly debugged
Solution Approach 1:
The debug request format is designed with universal applicability through included contextual fields (process ID, memory region, register type) that can accommodate both simple and complex debugging scenarios. This multi-functional design allows the same debug mechanism to handle basic memory access in single-process systems while also supporting sophisticated virtualized environments with multiple processes and memory spaces, maintaining ease of operation across different complexity levels.
Data Source
AI summary
Embodiments include a system having processing circuitry to execute instructions to perform a variety of activities, operate in any of multiple operating modes, as well as run any of multiple virtual machines. A register stores operating state information of the processing circuitry. The processing circuitry is further able to selectively service requests issued by a controller coupled to the processing circuitry. Each service request includes one or more fields, each of which includes data to specify a respective qualifier for servicing. Each qualifier can be enabled to make the qualifier a condition of servicing the debug request. When all enabled qualifiers are satisfied, the processing circuitry services the service request. Servicing of the request may be performed in real-time without suspending the processing circuitry.