projects / mirror_edk2.git / blame
| Commit | Line | Data |
|---|---|---|
| 365a3aab MM |
1 | ;------------------------------------------------------------------------------\r |
| 2 | ;\r | |
| 3 | ; Copyright (c) 2015 - 2016, Intel Corporation. All rights reserved.<BR>\r | |
| 4 | ; This program and the accompanying materials\r | |
| 5 | ; are licensed and made available under the terms and conditions of the BSD License\r | |
| 6 | ; which accompanies this distribution. The full text of the license may be found at\r | |
| 7 | ; http://opensource.org/licenses/bsd-license.php.\r | |
| 8 | ;\r | |
| 9 | ; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, \r | |
| 10 | ; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r | |
| 11 | ;\r | |
| 12 | ; Abstract:\r | |
| 13 | ;\r | |
| 14 | ; Switch the stack from temporary memory to permanent memory.\r | |
| 15 | ;\r | |
| 16 | ;------------------------------------------------------------------------------\r | |
| 17 | \r | |
| 18 | SECTION .text\r | |
| 19 | \r | |
| 20 | ;------------------------------------------------------------------------------\r | |
| 21 | ; VOID\r | |
| 22 | ; EFIAPI\r | |
| 23 | ; SecSwitchStack (\r | |
| 24 | ; UINT32 TemporaryMemoryBase,\r | |
| 25 | ; UINT32 PermenentMemoryBase\r | |
| 26 | ; );\r | |
| 27 | ;------------------------------------------------------------------------------\r | |
| 28 | global ASM_PFX(SecSwitchStack)\r | |
| 29 | ASM_PFX(SecSwitchStack):\r | |
| 30 | ;\r | |
| 31 | ; Save three register: eax, ebx, ecx\r | |
| 32 | ;\r | |
| 33 | push eax\r | |
| 34 | push ebx\r | |
| 35 | push ecx\r | |
| 36 | push edx\r | |
| 37 | \r | |
| 38 | ;\r | |
| 39 | ; !!CAUTION!! this function address's is pushed into stack after\r | |
| 40 | ; migration of whole temporary memory, so need save it to permanent\r | |
| 41 | ; memory at first!\r | |
| 42 | ;\r | |
| 43 | \r | |
| 44 | mov ebx, [esp + 20] ; Save the first parameter\r | |
| 45 | mov ecx, [esp + 24] ; Save the second parameter\r | |
| 46 | \r | |
| 47 | ;\r | |
| 48 | ; Save this function's return address into permanent memory at first.\r | |
| 49 | ; Then, Fixup the esp point to permanent memory\r | |
| 50 | ;\r | |
| 51 | mov eax, esp\r | |
| 52 | sub eax, ebx\r | |
| 53 | add eax, ecx\r | |
| 54 | mov edx, [esp] ; copy pushed register's value to permanent memory\r | |
| 55 | mov [eax], edx\r | |
| 56 | mov edx, [esp + 4]\r | |
| 57 | mov [eax + 4], edx\r | |
| 58 | mov edx, [esp + 8]\r | |
| 59 | mov [eax + 8], edx\r | |
| 60 | mov edx, [esp + 12]\r | |
| 61 | mov [eax + 12], edx\r | |
| 62 | mov edx, [esp + 16] ; Update return address into permanent memory\r | |
| 63 | mov [eax + 16], edx\r | |
| 64 | mov esp, eax ; From now, esp is pointed to permanent memory\r | |
| 65 | \r | |
| 66 | ;\r | |
| 67 | ; Fixup the ebp point to permenent memory\r | |
| 68 | ;\r | |
| 69 | mov eax, ebp\r | |
| 70 | sub eax, ebx\r | |
| 71 | add eax, ecx\r | |
| 72 | mov ebp, eax ; From now, ebp is pointed to permanent memory\r | |
| 73 | \r | |
| 74 | pop edx\r | |
| 75 | pop ecx\r | |
| 76 | pop ebx\r | |
| 77 | pop eax\r | |
| 78 | ret\r |