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
14 --*/
15
16 #include "Host.h"
17
18
19 /**
20 Transfers control to a function starting with a new stack.
21
22 Transfers control to the function specified by EntryPoint using the new stack
23 specified by NewStack and passing in the parameters specified by Context1 and
24 Context2. Context1 and Context2 are optional and may be NULL. The function
25 EntryPoint must never return.
26
27 If EntryPoint is NULL, then ASSERT().
28 If NewStack is NULL, then ASSERT().
29
30 @param EntryPoint A pointer to function to call with the new stack.
31 @param Context1 A pointer to the context to pass into the EntryPoint
32 function.
33 @param Context2 A pointer to the context to pass into the EntryPoint
34 function.
35 @param NewStack A pointer to the new stack to use for the EntryPoint
36 function.
37
38 **/
39 VOID
40 EFIAPI
PeiSwitchStacks(IN SWITCH_STACK_ENTRY_POINT EntryPoint,IN VOID * Context1,OPTIONAL IN VOID * Context2,OPTIONAL IN VOID * NewStack)41 PeiSwitchStacks (
42 IN SWITCH_STACK_ENTRY_POINT EntryPoint,
43 IN VOID *Context1, OPTIONAL
44 IN VOID *Context2, OPTIONAL
45 IN VOID *NewStack
46 )
47 {
48 BASE_LIBRARY_JUMP_BUFFER JumpBuffer;
49
50 ASSERT (EntryPoint != NULL);
51 ASSERT (NewStack != NULL);
52
53 //
54 // Stack should be aligned with CPU_STACK_ALIGNMENT
55 //
56 ASSERT (((UINTN)NewStack & (CPU_STACK_ALIGNMENT - 1)) == 0);
57
58 JumpBuffer.Eip = (UINTN)EntryPoint;
59 JumpBuffer.Esp = (UINTN)NewStack - sizeof (VOID*);
60 JumpBuffer.Esp -= sizeof (Context1) + sizeof (Context2);
61 ((VOID**)JumpBuffer.Esp)[1] = Context1;
62 ((VOID**)JumpBuffer.Esp)[2] = Context2;
63
64 LongJump (&JumpBuffer, (UINTN)-1);
65
66
67 //
68 // PeiSwitchStacks () will never return
69 //
70 ASSERT (FALSE);
71 }
72
73
74
75