UnixPkg/Sec/Ia32/SwitchStack.c

   1 /*++
   2
   3 Copyright (c) 2006 - 2010, Intel Corporation. All rights reserved.<BR>
   4 Portions copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
   5 This program and the accompanying materials
   6 are licensed and made available under the terms and conditions of the BSD License
   7 which accompanies this distribution.  The full text of the license may be found at
   8 http://opensource.org/licenses/bsd-license.php
   9
  10 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  11 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  12
  13 Module Name:
  14
  15   SecMain.c
  16
  17 Abstract:
  18   Unix emulator of SEC phase. It's really a Posix application, but this is
  19   Ok since all the other modules for NT32 are NOT Posix applications.
  20
  21   This program processes host environment variables and figures out
  22   what the memory layout will be, how may FD's will be loaded and also
  23   what the boot mode is.
  24
  25   The SEC registers a set of services with the SEC core. gPrivateDispatchTable
  26   is a list of PPI's produced by the SEC that are availble for usage in PEI.
  27
  28   This code produces 128 K of temporary memory for the PEI stack by opening a
  29   host file and mapping it directly to memory addresses.
  30
  31   The system.cmd script is used to set host environment variables that drive
  32   the configuration opitons of the SEC.
  33
  34 --*/
  35
  36 #include "SecMain.h"
  37
  38
  39 /**
  40   Transfers control to a function starting with a new stack.
  41
  42   Transfers control to the function specified by EntryPoint using the new stack
  43   specified by NewStack and passing in the parameters specified by Context1 and
  44   Context2. Context1 and Context2 are optional and may be NULL. The function
  45   EntryPoint must never return.
  46
  47   If EntryPoint is NULL, then ASSERT().
  48   If NewStack is NULL, then ASSERT().
  49
  50   @param  EntryPoint  A pointer to function to call with the new stack.
  51   @param  Context1    A pointer to the context to pass into the EntryPoint
  52                       function.
  53   @param  Context2    A pointer to the context to pass into the EntryPoint
  54                       function.
  55   @param  NewStack    A pointer to the new stack to use for the EntryPoint
  56                       function.
  57   @param  NewBsp      A pointer to the new BSP for the EntryPoint on IPF. It's
  58                       Reserved on other architectures.
  59
  60 **/
  61 VOID
  62 EFIAPI
  63 PeiSwitchStacks (
  64   IN      SWITCH_STACK_ENTRY_POINT  EntryPoint,
  65   IN      VOID                      *Context1,  OPTIONAL
  66   IN      VOID                      *Context2,  OPTIONAL
  67   IN      VOID                      *Context3,  OPTIONAL
  68   IN      VOID                      *NewStack
  69   )
  70 {
  71   BASE_LIBRARY_JUMP_BUFFER  JumpBuffer;
  72
  73   ASSERT (EntryPoint != NULL);
  74   ASSERT (NewStack != NULL);
  75
  76   //
  77   // Stack should be aligned with CPU_STACK_ALIGNMENT
  78   //
  79   ASSERT (((UINTN)NewStack & (CPU_STACK_ALIGNMENT - 1)) == 0);
  80
  81   JumpBuffer.Eip = (UINTN)EntryPoint;
  82   JumpBuffer.Esp = (UINTN)NewStack - sizeof (VOID*);
  83   JumpBuffer.Esp -= sizeof (Context1) + sizeof (Context2) + sizeof(Context3);
  84   ((VOID**)JumpBuffer.Esp)[1] = Context1;
  85   ((VOID**)JumpBuffer.Esp)[2] = Context2;
  86   ((VOID**)JumpBuffer.Esp)[3] = Context3;
  87
  88   LongJump (&JumpBuffer, (UINTN)-1);
  89
  90
  91   //
  92   // InternalSwitchStack () will never return
  93   //
  94   ASSERT (FALSE);
  95 }
  96
  97
  98