MdePkg: Replace BSD License with BSD+Patent License

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

/** @file\r
  Switch Stack functions.\r
\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
\r
/**\r
  Transfers control to a function starting with a new stack.\r
\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
\r
  @param  EntryPoint  A pointer to function to call with the new stack.\r
  @param  Context1    A pointer to the context to pass into the EntryPoint\r
                      function.\r
  @param  Context2    A pointer to the context to pass into the EntryPoint\r
                      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,  OPTIONAL\r
  IN      VOID                      *Context2,  OPTIONAL\r
  IN      VOID                      *NewStack,\r
  ...\r
  )\r
{\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
  //\r
  // InternalSwitchStack () will never return\r
  //\r
  ASSERT (FALSE);\r
}\r