X86DisablePaging32.c File Reference

#include "BaseLibInternals.h"

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Functions
VOID EFIAPI	AsmDisablePaging32 (IN SWITCH_STACK_ENTRY_POINT EntryPoint, IN VOID *Context1 OPTIONAL, IN VOID *Context2 OPTIONAL, IN VOID *NewStack)

Detailed Description

IA-32/x64 AsmDisablePaging32()

Copyright (c) 2006 - 2008, Intel Corporation. All rights reserved.
SPDX-License-Identifier: BSD-2-Clause-Patent

Definition in file X86DisablePaging32.c.

Function Documentation

AsmDisablePaging32()

VOID EFIAPI AsmDisablePaging32	(	IN SWITCH_STACK_ENTRY_POINT	EntryPoint,
		IN VOID *Context1	OPTIONAL,
		IN VOID *Context2	OPTIONAL,
		IN VOID *	NewStack
	)

Disables the 32-bit paging mode on the CPU.

Disables the 32-bit paging mode on the CPU and returns to 32-bit protected mode. This function assumes the current execution mode is 32-paged protected mode. This function is only available on IA-32. After the 32-bit paging mode is disabled, control is transferred to the function specified by EntryPoint using the new stack specified by NewStack and passing in the parameters specified by Context1 and Context2. Context1 and Context2 are optional and may be NULL. The function EntryPoint must never return.

If the current execution mode is not 32-bit paged mode, then ASSERT(). If EntryPoint is NULL, then ASSERT(). If NewStack is NULL, then ASSERT().

There are a number of constraints that must be followed before calling this function: 1) Interrupts must be disabled. 2) The caller must be in 32-bit paged mode. 3) CR0, CR3, and CR4 must be compatible with 32-bit paged mode. 4) CR3 must point to valid page tables that guarantee that the pages for this function and the stack are identity mapped.

Parameters

EntryPoint	A pointer to function to call with the new stack after paging is disabled.
Context1	A pointer to the context to pass into the EntryPoint function as the first parameter after paging is disabled.
Context2	A pointer to the context to pass into the EntryPoint function as the second parameter after paging is disabled.
NewStack	A pointer to the new stack to use for the EntryPoint function after paging is disabled.

Definition at line 47 of file X86DisablePaging32.c.