7.4 Required Functions

The following functions are required to exist and to execute in the given order. The component that provides the function is not specified because it is not required by the architecture.
* In the common EDK II open source code.
The required functions for Stage IV are presented organized by phase and subsystem (e.g. ACPI, SMM, etc). See Appendix: Full Functions Map for a complete ordering for all stages.

7.4.1 Required PEI functions

Name
Purpose
PeimEntryMA (*)
Entry point for the TPM2 PEIM
IntelVTdPmrInitialize (*)
Entry point for the VT-d PEIM

Table 59 Stage V PEI Functions

* In the common EDK II open source code.

7.4.2 Required DXE functions

Name
Purpose
DriverEntry (*)
Entry point for the TPM2 DXE module
IntelVTdInitialize(*)
Entry point for the VT-d DXE module
UserPhysicalPresent (*)
Indicates whether a physical user is present for UEFI secure boot
ProcessTcgPp
Process the TPM physical presence (PP) request
ProcessTcgMor
Process the TPM memory overwrite request (MOR)

Table 60 Stage V DXE Functions

* In the common EDK II open source code.

7.4.3 Required SMM functions

Name
Purpose
InitializeTcgSmm (*)
Entry point for the TPM2 SMM module
MemoryClearCallback (*)
Callback function for setting the MOR variable

Table 61 Stage V SMM Functions

* In the common EDK II open source code.