MdePkg: Replace BSD License with BSD+Patent License

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

diff --git a/MdePkg/Library/BaseLib/SwitchStack.c b/MdePkg/Library/BaseLib/SwitchStack.c
index 353efa8f6e56a31bf426495bbe0dceb36d1129c1..cb9f69f1eaceba690b48e9ca6b8a9af2e348bddd 100644 (file)
--- a/MdePkg/Library/BaseLib/SwitchStack.c
+++ b/MdePkg/Library/BaseLib/SwitchStack.c
@@ -1,28 +1,24 @@
 /** @file\r
   Switch Stack functions.\r
 \r
-  Copyright (c) 2006, Intel Corporation<BR>\r
-  All rights reserved. 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
-\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
+  Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>\r
+  SPDX-License-Identifier: BSD-2-Clause-Patent\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
@@ -34,22 +30,41 @@
                       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
-#ifdef MDE_CPU_IPF\r
-  ASSERT (((UINTN)NewStack & 0xf) == 0);\r
-#endif\r
+  VA_END (Marker);\r
 \r
-  InternalSwitchStack (EntryPoint, Context1, Context2, NewStack);\r
+  //\r
+  // InternalSwitchStack () will never return\r
+  //\r
+  ASSERT (FALSE);\r
 }\r