projects / mirror_edk2.git / blame
| Commit | Line | Data |
|---|---|---|
| a33a2f62 JY |
1 | #------------------------------------------------------------------------------\r |
| 2 | #\r | |
| 3 | # Copyright (c) 2014, Intel Corporation. All rights reserved.<BR>\r | |
| 19486360 | 4 | # SPDX-License-Identifier: BSD-2-Clause-Patent\r |
| a33a2f62 JY |
5 | #\r |
| 6 | # Abstract:\r | |
| 7 | #\r | |
| 8 | # Switch the stack from temporary memory to permenent memory.\r | |
| 9 | #\r | |
| 10 | #------------------------------------------------------------------------------\r | |
| 11 | \r | |
| 12 | \r | |
| 13 | #------------------------------------------------------------------------------\r | |
| 14 | # VOID\r | |
| 15 | # EFIAPI\r | |
| 16 | # SecSwitchStack (\r | |
| 17 | # UINT32 TemporaryMemoryBase,\r | |
| 18 | # UINT32 PermenentMemoryBase\r | |
| 19 | # )#\r | |
| 20 | #------------------------------------------------------------------------------\r | |
| 21 | ASM_GLOBAL ASM_PFX (SecSwitchStack)\r | |
| 22 | ASM_PFX(SecSwitchStack):\r | |
| 23 | #\r | |
| 24 | # Save standard registers so they can be used to change stack\r | |
| 25 | #\r | |
| 26 | pushl %eax\r | |
| 27 | pushl %ebx\r | |
| 28 | pushl %ecx\r | |
| 29 | pushl %edx\r | |
| 30 | \r | |
| 31 | #\r | |
| 32 | # !!CAUTION!! this function address's is pushed into stack after\r | |
| 33 | # migration of whole temporary memory, so need save it to permenent\r | |
| 34 | # memory at first!\r | |
| 35 | #\r | |
| 36 | movl 20(%esp), %ebx # Save the first parameter\r | |
| 37 | movl 24(%esp), %ecx # Save the second parameter\r | |
| 38 | \r | |
| 39 | #\r | |
| 40 | # Save this function's return address into permenent memory at first.\r | |
| 41 | # Then, Fixup the esp point to permenent memory\r | |
| 42 | #\r | |
| 43 | movl %esp, %eax\r | |
| 44 | subl %ebx, %eax\r | |
| 45 | addl %ecx, %eax\r | |
| 46 | movl 0(%esp), %edx # copy pushed register's value to permenent memory\r | |
| 47 | movl %edx, 0(%eax)\r | |
| 48 | movl 4(%esp), %edx\r | |
| 49 | movl %edx, 4(%eax)\r | |
| 50 | movl 8(%esp), %edx\r | |
| 51 | movl %edx, 8(%eax)\r | |
| 52 | movl 12(%esp), %edx\r | |
| 53 | movl %edx, 12(%eax)\r | |
| 54 | movl 16(%esp), %edx # Update this function's return address into permenent memory\r | |
| 55 | movl %edx, 16(%eax)\r | |
| 56 | movl %eax, %esp # From now, esp is pointed to permenent memory\r | |
| 57 | \r | |
| 58 | #\r | |
| 59 | # Fixup the ebp point to permenent memory\r | |
| 60 | #\r | |
| 61 | movl %ebp, %eax\r | |
| 62 | subl %ebx, %eax\r | |
| 63 | addl %ecx, %eax\r | |
| 64 | movl %eax, %ebp # From now, ebp is pointed to permenent memory\r | |
| 65 | \r | |
| 66 | popl %edx\r | |
| 67 | popl %ecx\r | |
| 68 | popl %ebx\r | |
| 69 | popl %eax\r | |
| 70 | ret\r | |
| 71 | \r |