1 files changed, 64 insertions, 0 deletions
diff --git a/IntelFspPkg/Library/BaseFspSwitchStackLib/Ia32/Stack.s b/IntelFspPkg/Library/BaseFspSwitchStackLib/Ia32/Stack.s
new file mode 100644
index 0000000000..6932cd8448
--- /dev/null
+++ b/IntelFspPkg/Library/BaseFspSwitchStackLib/Ia32/Stack.s
@@ -0,0 +1,64 @@
+#------------------------------------------------------------------------------
+#
+# Copyright (c) 2014, 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.
+#
+# Abstract:
+#
+#   Switch the stack from temporary memory to permenent memory.
+#
+#------------------------------------------------------------------------------
+
+ASM_GLOBAL ASM_PFX(Pei2LoaderSwitchStack)
+ASM_GLOBAL ASM_PFX(Loader2PeiSwitchStack)
+
+#------------------------------------------------------------------------------
+# UINT32
+# EFIAPI
+# Pei2LoaderSwitchStack (
+#   VOID
+#   )
+#------------------------------------------------------------------------------
+ASM_GLOBAL ASM_PFX(Pei2LoaderSwitchStack)
+ASM_PFX(Pei2LoaderSwitchStack):
+    jmp     ASM_PFX(Loader2PeiSwitchStack)
+
+#------------------------------------------------------------------------------
+# UINT32
+# EFIAPI
+# Loader2PeiSwitchStack (
+#   )
+#------------------------------------------------------------------------------
+ASM_GLOBAL ASM_PFX(Loader2PeiSwitchStack)
+ASM_PFX(Loader2PeiSwitchStack):
+#Save current contexts
+    push    $exit
+    pushf
+    pushf
+    cli
+    pusha
+    push    $0x0
+    push    $0x0
+    sidt    (%esp)
+
+    # Load new stack
+    push   %esp
+    call   ASM_PFX(SwapStack)
+    mov    %eax,%esp
+
+    # Restore previous contexts
+    lidt    (%esp)
+    add     $8,%esp
+    popa
+    popf
+    popf
+exit:
+    ret
+
+