1 files changed, 74 insertions, 0 deletions
diff --git a/EmulatorPkg/Unix/Host/Ia32/SwitchStack.c b/EmulatorPkg/Unix/Host/Ia32/SwitchStack.c
new file mode 100644
index 0000000000..c75073ac2e
--- /dev/null
+++ b/EmulatorPkg/Unix/Host/Ia32/SwitchStack.c
@@ -0,0 +1,74 @@
+/*++
+
+Copyright (c) 2006 - 2010, Intel Corporation. All rights reserved.<BR>
+Portions copyright (c) 2008 - 2009, Apple Inc. 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 "SecMain.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.
+
+  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.
+
+**/
+VOID
+EFIAPI
+PeiSwitchStacks (
+  IN      SWITCH_STACK_ENTRY_POINT  EntryPoint,
+  IN      VOID                      *Context1,  OPTIONAL
+  IN      VOID                      *Context2,  OPTIONAL
+  IN      VOID                      *NewStack
+  )
+{
+  BASE_LIBRARY_JUMP_BUFFER  JumpBuffer;
+  
+  ASSERT (EntryPoint != NULL);
+  ASSERT (NewStack != NULL);
+
+  //
+  // Stack should be aligned with CPU_STACK_ALIGNMENT
+  //
+  ASSERT (((UINTN)NewStack & (CPU_STACK_ALIGNMENT - 1)) == 0);
+
+  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);
+  
+
+  //
+  // PeiSwitchStacks () will never return
+  //
+  ASSERT (FALSE);  
+}
+
+
+