PpmInitialize

Index: 0078 (78)
Size: 30592 bytes (PE32+ body)
Phase: DXE (Driver eXecution Environment)
Subsystem: EFI_BOOT_SERVICE_DRIVER (0x0B)

Overview

Processor Power Management (PPM) DXE driver for the Purley platform. Initializes processor power management features including ConfigTDP, PBF (Power Balance Feature), C-states, Turbo mode, and energy-efficient features. Consumes the PPM Info HOB produced by earlier PEIMs, locates the MP Services Protocol, and programs MSRs per socket. Registers SmmReadyToLock and ReadyToBoot callbacks for late-stage configuration and boot script save/restore for S3 resume.

Key Functions

• PpmInitializeEntryPoint -- Module entry point; initializes PPM context, locates MP services, programs per-socket MSRs
• PpmConfigTdpInit -- Configures ConfigTDP (Thermal Design Power) ratios and power limits
• PpmPbfInit -- Programs Power Balance Feature (PBF) MSRs
• PpmCStateInit -- Configures C-state entry/exit parameters
• PpmTurboInit -- Enables and configures Turbo mode parameters
• PpmEnergyEfficientInit -- Sets energy-efficient performance bias and HWP (Hardware P-State) parameters
• PpmS3BootScriptSave -- Saves PPM MSR programming to boot script for S3 resume
• SmmReadyToLockCallback -- Locks SMM configuration at SmmReadyToLock event
• ReadyToBootCallback -- Finalizes PPM configuration before boot

Protocols / Dependencies

• EFI_MP_SERVICES_PROTOCOL -- Multi-processor service for per-socket MSR programming
• EFI_SMM_COMMUNICATION_PROTOCOL -- Communication with SMM for PPM coordination
• PPM Info HOB (produced by PEIM) -- PPM configuration data from pre-memory phase
• UEFI Boot Services -- Event registration (SmmReadyToLock, ReadyToBoot)
• S3 Boot Script -- Save/Restore PPM registers for S3 resume

Platform

Purley platform (Intel Xeon Scalable), HR650X BIOS. Built from PurleySktPkg/Dxe/PowerManagement/PpmInitialize.c with DEBUG_VS2015, X64 target.