1 files changed, 60 insertions, 0 deletions
diff --git a/Core/MdePkg/Library/BaseLib/Ia32/InternalSwitchStack.c b/Core/MdePkg/Library/BaseLib/Ia32/InternalSwitchStack.c
new file mode 100644
index 0000000000..4b82b339e9
--- /dev/null
+++ b/Core/MdePkg/Library/BaseLib/Ia32/InternalSwitchStack.c
@@ -0,0 +1,60 @@
+/** @file
+  SwitchStack() function for IA-32.
+
+  Copyright (c) 2006 - 2008, Intel Corporation. All rights reserved.<BR>
+  This program and the accompanying materials
+  are licensed and made available under the terms and conditions of the BSD License
+  which accompanies this distribution.  The full text of the license may be found at
+  http://opensource.org/licenses/bsd-license.php.
+
+  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+
+**/
+
+#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);
+}