Unprivileged Mode System Task Execution via Verification Key
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Solution Overview
Problem
Existing methods for switching between privileged and unprivileged modes in electronic devices cause latency and limit design flexibility, especially when multiple user programs need to be executed.
Innovation Solution
A method where a processor uses an instruction set architecture (ISA) to transmit a request with a verification key to a hardware component, allowing the hardware component to determine access to a target hardware address in unprivileged mode, thereby reducing mode switching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the processor switches to privileged mode to execute system tasks after each user program, then system task execution is ensured, but execution latency increases due to repeated mode switching
Solution Approach 1:
The patent applies preliminary action by pre-configuring verification keys in the hardware component before user programs execute. This allows the system to verify and execute system tasks in unprivileged mode without requiring mode switching, as the verification mechanism is already in place. The verification key is stored in a protected memory region and used by the hardware component to authorize system task execution, eliminating the need to switch to privileged mode after each user program completes.
2Loss of time
If user programs are combined into a single combined user program, then mode switching frequency is reduced, but design flexibility is limited and not all user programs can be combined
Solution Approach 1:
The patent introduces an intermediary verification key mechanism that mediates between user programs and system task execution. Instead of combining user programs or requiring privileged mode switching, the verification key acts as an intermediary that enables system tasks to execute in unprivileged mode. The hardware component uses the verification key to authorize system task execution, allowing individual user programs to run independently while still enabling system task execution without mode switching.
3Reliability
If user programs run in unprivileged mode to ensure security, then system security is improved, but system task execution becomes difficult without frequent mode switching
Solution Approach 1:
The verification key serves as an intermediary that bridges the security requirements of unprivileged mode with the execution needs of system tasks. The hardware component stores the verification key in a protected memory region and uses it to authorize system task execution. This allows system tasks to execute in unprivileged mode without compromising security, as the verification key mechanism ensures that only authorized system tasks can access protected resources.
Solution Approach 2:
The patent changes the operational parameter from requiring privileged mode to using verification key-based authorization in unprivileged mode. By introducing the verification key as a new parameter for authorization, the system can execute system tasks in unprivileged mode while maintaining security. The verification key acts as a credential that enables system task execution without requiring elevated privileges, fundamentally changing how system tasks are authorized and executed.
Data Source
AI summary
An electronic device includes a processor and a hardware component. The processor is arranged to utilize an instruction set architecture (ISA) to transmit a first request with a first verification key to a hardware component, for requesting the hardware component to execute a system task in an unprivileged mode, wherein the ISA corresponds to the hardware component, and the system task requests to access a target hardware address. The hardware component is arranged to determine whether to access the target hardware address according to the first verification key.