MdePkg/BaseLib: Support IA32 processors without CLFLUSH

[mirror_edk2.git] / MdePkg / Library / BaseLib / SwitchStack.c

diff --git a/MdePkg/Library/BaseLib/SwitchStack.c b/MdePkg/Library/BaseLib/SwitchStack.c
index fec3cfaa60bb4cb55192557924e36eaa3aededcc..36811175af74f0b5213c402dc94597d6081d9017 100644 (file)
--- a/MdePkg/Library/BaseLib/SwitchStack.c
+++ b/MdePkg/Library/BaseLib/SwitchStack.c
@@ -1,28 +1,30 @@
 /** @file\r
   Switch Stack functions.\r
 \r
-  Copyright (c) 2006, Intel Corporation<BR>\r
-  All rights reserved. This program and the accompanying materials\r
+  Copyright (c) 2006 - 2008, Intel Corporation. All rights reserved.<BR>\r
+  This program and the accompanying materials\r
   are licensed and made available under the terms and conditions of the BSD License\r
   which accompanies this distribution.  The full text of the license may be found at\r
-  http://opensource.org/licenses/bsd-license.php\r
+  http://opensource.org/licenses/bsd-license.php.\r
 \r
   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
 \r
-  Module Name:  SwitchStack.c\r
-\r
 **/\r
 \r
-#include <BaseLibInternals.h>\r
+#include "BaseLibInternals.h"\r
 \r
 /**\r
   Transfers control to a function starting with a new stack.\r
 \r
-  Transfers control to the function specified by EntryPoint using the new stack\r
-  specified by NewStack and passing in the parameters specified by Context1 and\r
-  Context2. Context1 and Context2 are optional and may be NULL. The function\r
-  EntryPoint must never return.\r
+  Transfers control to the function specified by EntryPoint using the\r
+  new stack specified by NewStack and passing in the parameters specified\r
+  by Context1 and Context2.  Context1 and Context2 are optional and may\r
+  be NULL.  The function EntryPoint must never return.  This function\r
+  supports a variable number of arguments following the NewStack parameter.\r
+  These additional arguments are ignored on IA-32, x64, and EBC.\r
+  IPF CPUs expect one additional parameter of type VOID * that specifies\r
+  the new backing store pointer.\r
 \r
   If EntryPoint is NULL, then ASSERT().\r
   If NewStack is NULL, then ASSERT().\r
@@ -34,18 +36,41 @@
                       function.\r
   @param  NewStack    A pointer to the new stack to use for the EntryPoint\r
                       function.\r
+  @param  ...         This variable argument list is ignored for IA32, x64, and EBC.  \r
+                      For IPF, this variable argument list is expected to contain \r
+                      a single parameter of type VOID * that specifies the new backing \r
+                      store pointer.\r
+\r
 \r
 **/\r
 VOID\r
 EFIAPI\r
 SwitchStack (\r
   IN      SWITCH_STACK_ENTRY_POINT  EntryPoint,\r
-  IN      VOID                      *Context1,\r
-  IN      VOID                      *Context2,\r
-  IN      VOID                      *NewStack\r
+  IN      VOID                      *Context1,  OPTIONAL\r
+  IN      VOID                      *Context2,  OPTIONAL\r
+  IN      VOID                      *NewStack,\r
+  ...\r
   )\r
 {\r
-  ASSERT (EntryPoint != NULL && NewStack != NULL);\r
+  VA_LIST    Marker;\r
+\r
+  ASSERT (EntryPoint != NULL);\r
+  ASSERT (NewStack != NULL);\r
+\r
+  //\r
+  // New stack must be aligned with CPU_STACK_ALIGNMENT\r
+  //\r
+  ASSERT (((UINTN)NewStack & (CPU_STACK_ALIGNMENT - 1)) == 0);\r
+\r
+  VA_START (Marker, NewStack);\r
+\r
+  InternalSwitchStack (EntryPoint, Context1, Context2, NewStack, Marker);\r
+\r
+  VA_END (Marker);\r
 \r
-  InternalSwitchStack (EntryPoint, Context1, Context2, NewStack);\r
+  //\r
+  // InternalSwitchStack () will never return\r
+  //\r
+  ASSERT (FALSE);\r
 }\r