SecVariableControl

Overview

Secure Variable Control Driver that locates the DRAM fail data HOB produced during PEI memory training, parses up to 210 DRAM failure entries across up to 5 DIMMs, and saves the parsed data to UEFI runtime variables (STEP_RESULT, STEP_RESULT_NUM00-04). Each entry encodes the full DDR address map of a failed bit with Post-Package Repair (PPR) status and temperature at failure time.

Key Functions

• SecVariableControlDriverEntry -- Main entry point
• SaveDramFailDataToVariable -- HOB parsing and UEFI variable storage
• DebugProtocolInit -- Initialize debug output (DXE or SMM path)
• EntryDriverInit -- Save globals, initialize HOB list and DXE Services Table
• GetDebugLevel -- Read debug level from CMOS 0x4B
• DebugBspPrint / DebugPrint / DebugAssert -- Debug output functions

Dependencies

• gEfiVariableGuid -- UEFI variable services
• gEfiHobListGuid -- HOB list for DRAM fail data
• gEfiSmmCommunicationProtocolGuid -- SMM communication (SMM path)
• gEfiDxeServicesTableGuid -- DXE services table
• gEfiDebugPortProtocolGuid -- Debug port protocol

Platform

Intel Purley (Xeon Scalable). x86-64 UEFI Driver (Boot Services Driver, Subsystem 000Bh).