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1 | /** @file\r |
2 | SwitchStack() function for IA-32.\r |
3 | \r |
4 | Copyright (c) 2006, Intel Corporation<BR>\r |
5 | All rights reserved. This program and the accompanying materials\r |
6 | are licensed and made available under the terms and conditions of the BSD License\r |
7 | which accompanies this distribution. The full text of the license may be found at\r |
8 | http://opensource.org/licenses/bsd-license.php\r |
9 | \r |
10 | THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r |
11 | WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r |
12 | \r |
13 | Module Name: InternalSwitchStack.c\r |
14 | \r |
15 | **/\r |
16 | \r |
17 | /**\r |
18 | Transfers control to a function starting with a new stack.\r |
19 | \r |
20 | Transfers control to the function specified by EntryPoint using the new stack\r |
21 | specified by NewStack and passing in the parameters specified by Context1 and\r |
22 | Context2. Context1 and Context2 are optional and may be NULL. The function\r |
23 | EntryPoint must never return.\r |
24 | \r |
25 | @param EntryPoint A pointer to function to call with the new stack.\r |
26 | @param Context1 A pointer to the context to pass into the EntryPoint\r |
27 | function.\r |
28 | @param Context2 A pointer to the context to pass into the EntryPoint\r |
29 | function.\r |
30 | @param NewStack A pointer to the new stack to use for the EntryPoint\r |
31 | function.\r |
32 | \r |
33 | **/\r |
34 | VOID\r |
35 | EFIAPI\r |
36 | InternalSwitchStack (\r |
37 | IN SWITCH_STACK_ENTRY_POINT EntryPoint,\r |
38 | IN VOID *Context1,\r |
39 | IN VOID *Context2,\r |
40 | IN VOID *NewStack\r |
41 | )\r |
42 | {\r |
43 | BASE_LIBRARY_JUMP_BUFFER JumpBuffer;\r |
44 | \r |
45 | JumpBuffer.Eip = (UINTN)EntryPoint;\r |
46 | JumpBuffer.Esp = (UINTN)NewStack - sizeof (VOID*);\r |
47 | JumpBuffer.Esp -= sizeof (Context1) + sizeof (Context2);\r |
48 | ((VOID**)JumpBuffer.Esp)[1] = Context1;\r |
49 | ((VOID**)JumpBuffer.Esp)[2] = Context2;\r |
50 | \r |
51 | LongJump (&JumpBuffer, (UINTN)-1);\r |
52 | }\r |