1.1. Introduction
RISC-V systems which use Advanced Configuration and Power Interface (ACPI) require additional specifications for some ACPI object fields, typically those of type “Resource Descriptor”. A Functional Fixed Hardware (FFH) specification provides those additional specifications. The use cases addressed by this FFH are as follows:
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Lower Power Idle States (LPI), [ACPI 6.5] section 8.4.3
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Collaborative Processor Performance Control (CPPC), [ACPI 6.5] section 8.4.6
1.1.1. Terms and Abbreviations
This specification uses the following terms and abbreviations:
| Term | Meaning |
|---|---|
ACPI |
Advanced Configuration and Power Interface Specification |
ASL |
ACPI Source Language |
CPC |
Continuous Performance Control |
CPPC |
Collaborative Processor Performance Control |
FFH |
Functional Fixed Hardware |
HSM |
Hart State Management |
LPI |
Low Power Idle |
OSPM |
Operating System-directed configuration and Power Management |
SBI |
Supervisor Binary Interface |
1.1.2. References
| Reference | Description |
|---|---|
[ACPI 6.5] |
Advanced Configuration and Power Interface Specification
version 6.5 |
[SBI] |
RISC-V Supervisor Binary Interface Specification version 2.0 |