HeciSmm

Index

0186

Size

39E4h (14,820 bytes)

Phase

DXE SMM (System Management Mode driver)

Source Package

PurleySktPkg/Me/Heci/Smm

Overview

HeciSmm is an SMM driver that manages the HECI (Host Embedded Controller Interface) communication channel within System Management Mode. HECI is the primary messaging interface between the host CPU and the Intel Management Engine (ME). This driver enables SMM-level code to send and receive HECI messages for platform management functions such as power capping, thermal management, and ME firmware updates during runtime.

Key Functions

• ModuleEntryPoint (0x4B4): Entry point; initializes HECI hardware interface for SMM operation.
• sub_560: HECI SMM initialization; configures HECI1 device registers for SMM-mode access and sets up message buffers.
• sub_D1C: Core HECI message transfer function; handles host-to-ME and ME-to-host communication within SMM context.
• sub_1E60 (12 callees): HECI protocol dispatch; routes HECI messages to appropriate handler routines based on message type.
• sub_14A0: HECI device initialization and reset sequence for the HECI1 controller.

Strings

• "HeciDev == HECI1_DEVICE" (device validation)
• Build path: PurleySktPkg\Me\Heci\Smm\HeciSmm
• References to HeciCoreLib\HeciCore.c for core HECI protocol library
• References to PchCycleDecodingLib for PCH MMIO configuration

Libraries Referenced

• HeciCoreLib (PurleySktPkg)
• SmmMmPciBaseLib (CpRcPkg)
• PchCycleDecodingLib

Platform

Intel Purley (HR650X server platform)