audk/MdePkg/Library/BaseLib/SwitchStack.c

71 lines
2.2 KiB
C

/** @file
Switch Stack functions.
Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#include "BaseLibInternals.h"
/**
Transfers control to a function starting with a new stack.
Transfers control 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. This function
supports a variable number of arguments following the NewStack parameter.
These additional arguments are ignored on IA-32, x64, and EBC.
IPF CPUs expect one additional parameter of type VOID * that specifies
the new backing store pointer.
If EntryPoint is NULL, then ASSERT().
If NewStack is NULL, then ASSERT().
@param EntryPoint A pointer to function to call with the new stack.
@param Context1 A pointer to the context to pass into the EntryPoint
function.
@param Context2 A pointer to the context to pass into the EntryPoint
function.
@param NewStack A pointer to the new stack to use for the EntryPoint
function.
@param ... This variable argument list is ignored for IA32, x64, and EBC.
For IPF, this variable argument list is expected to contain
a single parameter of type VOID * that specifies the new backing
store pointer.
**/
VOID
EFIAPI
SwitchStack (
IN SWITCH_STACK_ENTRY_POINT EntryPoint,
IN VOID *Context1 OPTIONAL,
IN VOID *Context2 OPTIONAL,
IN VOID *NewStack,
...
)
{
VA_LIST Marker;
ASSERT (EntryPoint != NULL);
ASSERT (NewStack != NULL);
//
// New stack must be aligned with CPU_STACK_ALIGNMENT
//
ASSERT (((UINTN)NewStack & (CPU_STACK_ALIGNMENT - 1)) == 0);
VA_START (Marker, NewStack);
InternalSwitchStack (EntryPoint, Context1, Context2, NewStack, Marker);
VA_END (Marker);
//
// InternalSwitchStack () will never return
//
ASSERT (FALSE);
}