projects / mirror_edk2.git / blame
| Commit | Line | Data |
|---|---|---|
| 91a03f78 TK |
1 | ;------------------------------------------------------------------------------\r |
| 2 | ;\r | |
| 3 | ; Copyright (c) 2022, Intel Corporation. All rights reserved.<BR>\r | |
| 4 | ; SPDX-License-Identifier: BSD-2-Clause-Patent\r | |
| 5 | ;\r | |
| 6 | ; Abstract:\r | |
| 7 | ;\r | |
| 8 | ; Switch the stack from temporary memory to permanent memory.\r | |
| 9 | ;\r | |
| 10 | ;------------------------------------------------------------------------------\r | |
| 11 | \r | |
| 12 | SECTION .text\r | |
| 13 | \r | |
| 14 | ;------------------------------------------------------------------------------\r | |
| 15 | ; VOID\r | |
| 16 | ; EFIAPI\r | |
| 17 | ; SecSwitchStack (\r | |
| 18 | ; UINT32 TemporaryMemoryBase,\r | |
| 19 | ; UINT32 PermanentMemoryBase\r | |
| 20 | ; );\r | |
| 21 | ;------------------------------------------------------------------------------\r | |
| 22 | global ASM_PFX(SecSwitchStack)\r | |
| 23 | ASM_PFX(SecSwitchStack):\r | |
| 24 | ;\r | |
| 25 | ; Save four register: rax, rbx, rcx, rdx\r | |
| 26 | ;\r | |
| 27 | push rax\r | |
| 28 | push rbx\r | |
| 29 | push rcx\r | |
| 30 | push rdx\r | |
| 31 | \r | |
| 32 | ;\r | |
| 33 | ; !!CAUTION!! this function address's is pushed into stack after\r | |
| 34 | ; migration of whole temporary memory, so need save it to permanent\r | |
| 35 | ; memory at first!\r | |
| 36 | ;\r | |
| 37 | \r | |
| 38 | mov rbx, rcx ; Save the first parameter\r | |
| 39 | mov rcx, rdx ; Save the second parameter\r | |
| 40 | \r | |
| 41 | ;\r | |
| 42 | ; Save this function's return address into permanent memory at first.\r | |
| 43 | ; Then, Fixup the esp point to permanent memory\r | |
| 44 | ;\r | |
| 45 | mov rax, rsp\r | |
| 46 | sub rax, rbx\r | |
| 47 | add rax, rcx\r | |
| 48 | mov rdx, qword [rsp] ; copy pushed register's value to permanent memory\r | |
| 49 | mov qword [rax], rdx\r | |
| 50 | mov rdx, qword [rsp + 8]\r | |
| 51 | mov qword [rax + 8], rdx\r | |
| 52 | mov rdx, qword [rsp + 16]\r | |
| 53 | mov qword [rax + 16], rdx\r | |
| 54 | mov rdx, qword [rsp + 24]\r | |
| 55 | mov qword [rax + 24], rdx\r | |
| 56 | mov rdx, qword [rsp + 32] ; Update this function's return address into permanent memory\r | |
| 57 | mov qword [rax + 32], rdx\r | |
| 58 | mov rsp, rax ; From now, rsp is pointed to permanent memory\r | |
| 59 | \r | |
| 60 | ;\r | |
| 61 | ; Fixup the rbp point to permanent memory\r | |
| 62 | ;\r | |
| 63 | mov rax, rbp\r | |
| 64 | sub rax, rbx\r | |
| 65 | add rax, rcx\r | |
| 66 | mov rbp, rax ; From now, rbp is pointed to permanent memory\r | |
| 67 | \r | |
| 68 | pop rdx\r | |
| 69 | pop rcx\r | |
| 70 | pop rbx\r | |
| 71 | pop rax\r | |
| 72 | ret\r | |
| 73 | \r |