#include "PeiMain.h"
#include "Dependency.h"

Functions
BOOLEAN	IsPpiInstalled (IN EFI_PEI_SERVICES *PeiServices, IN EVAL_STACK_ENTRY Stack)

BOOLEAN	PeimDispatchReadiness (IN EFI_PEI_SERVICES *PeiServices, IN VOID DependencyExpression)

Detailed Description

PEI Dispatcher Dependency Evaluator

This routine evaluates a dependency expression (DEPENDENCY_EXPRESSION) to determine if a driver can be scheduled for execution. The criteria to be scheduled is that the dependency expression is satisfied.

Copyright (c) 2006 - 2019, Intel Corporation. All rights reserved.
SPDX-License-Identifier: BSD-2-Clause-Patent

Definition in file Dependency.c.

Function Documentation

◆ IsPpiInstalled()

BOOLEAN IsPpiInstalled	(	IN EFI_PEI_SERVICES **	PeiServices,
		IN EVAL_STACK_ENTRY *	Stack
	)

This routine determines if a PPI has been installed. The truth value of a GUID is determined by if the PPI has been published and can be queried from the PPI database.

Parameters

PeiServices	An indirect pointer to the EFI_PEI_SERVICES table published by the PEI Foundation
Stack	Reference to EVAL_STACK_ENTRY that contains PPI GUID to check

Return values

TRUE	if the PPI is already installed.
FALSE	if the PPI has yet to be installed.

Definition at line 31 of file Dependency.c.

◆ PeimDispatchReadiness()

BOOLEAN PeimDispatchReadiness	(	IN EFI_PEI_SERVICES **	PeiServices,
		IN VOID *	DependencyExpression
	)

This is the POSTFIX version of the dependency evaluator. When a PUSH [PPI GUID] is encountered, a pointer to the GUID is stored on the evaluation stack. When that entry is popped from the evaluation stack, the PPI is checked if it is installed. This method allows some time savings as not all PPIs must be checked for certain operation types (AND, OR).