TcgPeiplatform

Overview

TcgPeiplatform is a lightweight PEI module that provides TCG platform detection and boot mode management. It detects TPM presence via CMOS/IO ports, verifies the boot mode is BOOT_WITH_FULL_CONFIGURATION, and delegates to a DXE-phase dispatch callback. It is the smallest TCG-related PEIM in the BIOS, primarily serving as a boot-mode guard and TPM presence checker.

Key Functions

• ModuleEntryPoint -- Main entry; checks PCD, verifies boot mode, installs a callback to continue initialization in DXE
• TpmIsPresent -- Detects TPM hardware via CMOS register 0x4A and memory-mapped I/O at FDAF0490h
• GetDebugOutput -- Retrieves the debug output protocol for diagnostic messages
• GetPcdProtocol / GetPcdPpi / PcdSetSku -- PCD service wrappers for platform configuration access

Dependencies

• PiPei, Uefi base libraries
• PCD PPI (PeiPcdLib)
• PEI Services Table Pointer Library (IDT-based)
• CMOS/IO port access (IoLib)

Platform

• Architecture: IA-32 (x86)
• Subsystem: EFI_BOOT_SERVICE_DRIVER (0x0B)
• Linker: MSVS 2015