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1 | #------------------------------------------------------------------------------ |
2 | # | |
3 | # Copyright (c) 2013, 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 | # Abstract: | |
13 | # | |
14 | # Switch the stack from temporary memory to permenent memory. | |
15 | # | |
16 | #------------------------------------------------------------------------------ | |
17 | ||
18 | ||
19 | #------------------------------------------------------------------------------ | |
20 | # VOID | |
21 | # EFIAPI | |
22 | # SecSwitchStack ( | |
23 | # UINT32 TemporaryMemoryBase, | |
24 | # UINT32 PermenentMemoryBase | |
25 | # )# | |
26 | #------------------------------------------------------------------------------ | |
27 | ASM_GLOBAL ASM_PFX (SecSwitchStack) | |
28 | ASM_PFX(SecSwitchStack): | |
29 | # | |
30 | # Save standard registers so they can be used to change stack | |
31 | # | |
32 | pushl %eax | |
33 | pushl %ebx | |
34 | pushl %ecx | |
35 | pushl %edx | |
36 | ||
37 | # | |
38 | # !!CAUTION!! this function address's is pushed into stack after | |
39 | # migration of whole temporary memory, so need save it to permenent | |
40 | # memory at first! | |
41 | # | |
42 | movl 20(%esp), %ebx # Save the first parameter | |
43 | movl 24(%esp), %ecx # Save the second parameter | |
44 | ||
45 | # | |
46 | # Save this function's return address into permenent memory at first. | |
47 | # Then, Fixup the esp point to permenent memory | |
48 | # | |
49 | movl %esp, %eax | |
50 | subl %ebx, %eax | |
51 | addl %ecx, %eax | |
52 | movl 0(%esp), %edx # copy pushed register's value to permenent memory | |
53 | movl %edx, 0(%eax) | |
54 | movl 4(%esp), %edx | |
55 | movl %edx, 4(%eax) | |
56 | movl 8(%esp), %edx | |
57 | movl %edx, 8(%eax) | |
58 | movl 12(%esp), %edx | |
59 | movl %edx, 12(%eax) | |
60 | movl 16(%esp), %edx # Update this function's return address into permenent memory | |
61 | movl %edx, 16(%eax) | |
62 | movl %eax, %esp # From now, esp is pointed to permenent memory | |
63 | ||
64 | # | |
65 | # Fixup the ebp point to permenent memory | |
66 | # | |
67 | movl %ebp, %eax | |
68 | subl %ebx, %eax | |
69 | addl %ecx, %eax | |
70 | movl %eax, %ebp # From now, ebp is pointed to permenent memory | |
71 | ||
72 | popl %edx | |
73 | popl %ecx | |
74 | popl %ebx | |
75 | popl %eax | |
76 | ret | |
77 | ||
78 |