1 files changed, 48 insertions, 0 deletions
diff --git a/Core/UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/Semaphore.c b/Core/UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/Semaphore.c
new file mode 100644
index 0000000000..02a866b430
--- /dev/null
+++ b/Core/UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/Semaphore.c
@@ -0,0 +1,48 @@
+/** @file
+Semaphore mechanism to indicate to the BSP that an AP has exited SMM
+after SMBASE relocation.
+
+Copyright (c) 2009 - 2015, 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 "PiSmmCpuDxeSmm.h"
+
+UINTN             mSmmRelocationOriginalAddress;
+volatile BOOLEAN  *mRebasedFlag;
+
+/**
+  Hook return address of SMM Save State so that semaphore code
+  can be executed immediately after AP exits SMM to indicate to
+  the BSP that an AP has exited SMM after SMBASE relocation.
+
+  @param[in] CpuIndex     The processor index.
+  @param[in] RebasedFlag  A pointer to a flag that is set to TRUE
+                          immediately after AP exits SMM.
+
+**/
+VOID
+SemaphoreHook (
+  IN UINTN             CpuIndex,
+  IN volatile BOOLEAN  *RebasedFlag
+  )
+{
+  SMRAM_SAVE_STATE_MAP  *CpuState;
+
+  mRebasedFlag = RebasedFlag;
+
+  CpuState = (SMRAM_SAVE_STATE_MAP *)(UINTN)(SMM_DEFAULT_SMBASE + SMRAM_SAVE_STATE_MAP_OFFSET);
+  mSmmRelocationOriginalAddress = (UINTN)HookReturnFromSmm (
+                                           CpuIndex,
+                                           CpuState,
+                                           (UINT64)(UINTN)&SmmRelocationSemaphoreComplete,
+                                           (UINT64)(UINTN)&SmmRelocationSemaphoreComplete
+                                           );
+}