AmiTcgPlatformPeiAfterMem

Overview

AmiTcgPlatformPeiAfterMem is a PEI module from AmiModulePkg/TCG2 that provides TCG (Trusted Computing Group) platform initialization after system memory is available. It measures DXE firmware volumes into PCRs, manages TPM startup (TPM12/TPM20), and publishes TPM-related HOBs for later boot phases. This module executes after memory initialization and handles the post-memory TCG boot sequence.

Key Functions

• TcgPlatformPeiEntry -- Main entry dispatch; checks boot mode, installs TCG PPI, performs TPM startup
• TcgPlatformAfterMemInit -- Core initialization; enumerates firmware volumes, creates TPM FV HOB structures
• MeasureLogDxeFwVol -- Iterates DXE firmware volumes, hashes each, and extends the measurement into a PCR
• TpmMeasureDigestIntoPCR -- Sends TPM extend command to record a digest into a specified PCR
• TpmStartupCommand -- Sends TPM_Startup command (ST_CLEAR or ST_STATE) to the TPM
• PeiServicesInstallPpi -- Installs TCG-related PPI notifiers for downstream PEIMs
• LocateTcgOrTpmPpi -- Locates both gTcgPpiGuid and gTpmDevicePpiGuid PPIs
• BootGuardTcg2MeasureCRTMVersion -- Measures CRTM version from Boot Guard policy
• InitHashContext / AllocateAndMeasureFwVol / HashFirmwareVolume -- SHA-1 hashing utilities

Dependencies

• PiPei, Uefi base libraries
• TPM device PPI (gTpmDevicePpiGuid)
• TCG PPI (gTcgPpiGuid)
• PCD services (PeiPcdSetSku, PeiGetPcdPtr)
• Debug services (DebugPrintWrapper, AssertReport)
• Boot Guard policy HOB for CRTM measurement
• HOB services for FV ROM area enumeration

Platform

• Architecture: IA-32 (x86)
• Subsystem: EFI_BOOT_SERVICE_DRIVER (0x0B)
• Source: AmiModulePkg/TCG2/Common/AmiTcgPlatformPei/AmiTcgPlatformPeiAfterMem.c
• Linker: MSVS 2015