BIOS-EC Power Management via Physical Memory Flags
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current power management methods, such as ACPI, lack flexibility in reducing power consumption of high-power components like CPUs and displays, leading to limited power saving performance and performance degradation when downgrading CPU frequency.
Innovation Solution
A power management method involving a BIOS and embedded controller that determines if a mobile device is in DC mode and adjusts power settings by adding a flag in physical memory to notify the embedded controller to perform power-saving actions, such as reducing display brightness and processor speed, to decrease power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If ACPI power management is used to control hardware power states, then power consumption is reduced, but flexibility in power management is limited
Solution Approach 1:
The patent segments power management into two layers: ACPI handles basic power states (S0-S5) while the new mechanism divides power management into EC-driven actions (discrete, granular control) and OS-driven actions (softer, less aggressive control), allowing flexible combination of different power saving strategies based on system state and user needs
Solution Approach 2:
The patent introduces dynamic power management where the EC can execute immediate power-saving actions (like reducing display brightness or CPU frequency) based on real-time conditions, while the OS provides softer, less aggressive control when needed, creating a dynamic, adaptive power management system that adjusts to varying system states
2Use of energy by moving object
If CPU frequency is downgraded to decrease power consumption, then power saving is achieved, but laptop performance degrades seriously
Solution Approach 1:
The patent changes power management from fixed ACPI states to dynamic parameter adjustment, where the EC can modify CPU frequency, display brightness, and other hardware parameters in real-time based on system state, allowing fine-grained power saving without permanently degrading performance
Solution Approach 2:
The embedded controller operates autonomously to execute power-saving actions based on EC flags set by the OS, automatically adjusting hardware parameters like CPU frequency and display brightness without requiring manual intervention or permanent performance degradation
3Duration of action of moving object
If ACPI controls hardware to enter power saving states, then battery life is extended, but power saving performance is limited
Solution Approach 1:
The patent introduces EC flags as an intermediary mechanism between the OS and hardware power management. The OS sets EC flags in memory to indicate desired power-saving actions, and the EC reads these flags to execute specific power-saving measures, creating a flexible bridge that enhances ACPI's limited power-saving capabilities
Solution Approach 2:
The OS proactively sets EC flags in memory before power-saving actions are needed, allowing the EC to execute predetermined power-saving measures (like reducing display brightness or CPU frequency) immediately when conditions warrant, thereby extending battery life more effectively than reactive ACPI states
Data Source
AI summary
A power management method for a mobile device including a basic input output system (BIOS) and an embedded controller (EC) includes determining whether the mobile device is operated in a direct current (DC) mode, determining whether a loading of an operating system of the mobile device exceeds a predetermined value, adding a flag associated with the embedded controller in a physical memory of the mobile device when the mobile device is operated in the DC mode and the loading of the operating system exceeds the predetermined value, and reading the flag in the physical memory via the basic input output system, to notify the embedded controller to perform a power management process corresponding to the flag.