EdkCompatibilityPkg/Foundation/Library/EdkIIGlueLib/Library/BaseLib/Ia32/InternalSwitchStack.c

   1 /*++
   2
   3 Copyright (c) 2004 - 2006, Intel Corporation. All rights reserved.<BR>
   4 This program and the accompanying materials
   5 are licensed and made available under the terms and conditions of the BSD License
   6 which accompanies this distribution.  The full text of the license may be found at
   7 http://opensource.org/licenses/bsd-license.php
   8
   9 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  10 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  11
  12
  13 Module Name:
  14
  15   InternalSwitchStack.c
  16
  17 Abstract:
  18
  19   SwitchStack() function for IA-32.
  20
  21 --*/
  22
  23 #include "BaseLibInternals.h"
  24
  25 /**
  26   Transfers control to a function starting with a new stack.
  27
  28   Transfers control to the function specified by EntryPoint using the new stack
  29   specified by NewStack and passing in the parameters specified by Context1 and
  30   by Context1 and Context2.  Context1 and Context2 are optional and may
  31   be NULL.  The function EntryPoint must never return.
  32   Marker will be ignored on IA-32, x64, and EBC.
  33   IPF CPUs expect one additional parameter of type VOID * that specifies
  34   the new backing store pointer.
  35
  36   If EntryPoint is NULL, then ASSERT().
  37   If NewStack is NULL, then ASSERT().
  38
  39   @param  EntryPoint  A pointer to function to call with the new stack.
  40   @param  Context1    A pointer to the context to pass into the EntryPoint
  41                       function.
  42   @param  Context2    A pointer to the context to pass into the EntryPoint
  43                       function.
  44   @param  NewStack    A pointer to the new stack to use for the EntryPoint
  45                       function.
  46   @param  Marker      VA_LIST marker for the variable argument list.
  47
  48 **/
  49 VOID
  50 EFIAPI
  51 InternalSwitchStack (
  52   IN      SWITCH_STACK_ENTRY_POINT  EntryPoint,
  53   IN      VOID                      *Context1,   OPTIONAL
  54   IN      VOID                      *Context2,   OPTIONAL
  55   IN      VOID                      *NewStack,
  56   IN      VA_LIST                   Marker
  57   )
  58 {
  59   BASE_LIBRARY_JUMP_BUFFER  JumpBuffer;
  60
  61   //
  62   // Stack should be aligned with CPU_STACK_ALIGNMENT
  63   //
  64   ASSERT (((UINTN)NewStack & (CPU_STACK_ALIGNMENT - 1)) == 0);
  65
  66   JumpBuffer.Eip = (UINTN)EntryPoint;
  67   JumpBuffer.Esp = (UINTN)NewStack - sizeof (VOID*);
  68   JumpBuffer.Esp -= sizeof (Context1) + sizeof (Context2);
  69   ((VOID**)JumpBuffer.Esp)[1] = Context1;
  70   ((VOID**)JumpBuffer.Esp)[2] = Context2;
  71
  72   LongJump (&JumpBuffer, (UINTN)-1);
  73 }