audk/MdePkg/Library/BaseLib/Ia32/InternalSwitchStack.c
Michael D Kinney 9344f09215 MdePkg: Replace BSD License with BSD+Patent License
https://bugzilla.tianocore.org/show_bug.cgi?id=1373

Replace BSD 2-Clause License with BSD+Patent License.  This change is
based on the following emails:

  https://lists.01.org/pipermail/edk2-devel/2019-February/036260.html
  https://lists.01.org/pipermail/edk2-devel/2018-October/030385.html

RFCs with detailed process for the license change:

  V3: https://lists.01.org/pipermail/edk2-devel/2019-March/038116.html
  V2: https://lists.01.org/pipermail/edk2-devel/2019-March/037669.html
  V1: https://lists.01.org/pipermail/edk2-devel/2019-March/037500.html

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Michael D Kinney <michael.d.kinney@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>
2019-04-09 10:58:13 -07:00

55 lines
1.9 KiB
C

/** @file
SwitchStack() function for IA-32.
Copyright (c) 2006 - 2008, 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.
Marker will be 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 Marker VA_LIST marker for the variable argument list.
**/
VOID
EFIAPI
InternalSwitchStack (
IN SWITCH_STACK_ENTRY_POINT EntryPoint,
IN VOID *Context1, OPTIONAL
IN VOID *Context2, OPTIONAL
IN VOID *NewStack,
IN VA_LIST Marker
)
{
BASE_LIBRARY_JUMP_BUFFER JumpBuffer;
JumpBuffer.Eip = (UINTN)EntryPoint;
JumpBuffer.Esp = (UINTN)NewStack - sizeof (VOID*);
JumpBuffer.Esp -= sizeof (Context1) + sizeof (Context2);
((VOID**)JumpBuffer.Esp)[1] = Context1;
((VOID**)JumpBuffer.Esp)[2] = Context2;
LongJump (&JumpBuffer, (UINTN)-1);
}