RuntimeMemoryHole

Overview

RuntimeMemoryHole is a UEFI DXE module that manages the runtime memory hole configuration, programming memory-mapped I/O (MMIO) and reserved memory ranges required for system stability after boot services are exited. It configures the memory controller to reserve specific address ranges for system management and platform-specific hardware, ensuring these regions remain accessible during OS runtime.

Key Functions

• ModuleEntryPoint: Entry point that initializes and applies the runtime memory hole configuration.
• sub_44C: Memory hole policy initialization and register programming preparation.
• sub_58C: Core memory hole programming, applying reserved address range configuration to hardware.

Dependencies

• UEFI system table and boot services
• Memory controller configuration registers
• Platform memory policy HOBs and data tables
• PCI configuration space access

Platform

HR650X server platform, x64 architecture. Runs during DXE phase and installs runtime services for OS-accessible memory hole configuration.