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7b414b4e | 1 | ;/** @file\r |
f45af90b | 2 | ; \r |
3 | ; This code provides low level routines that support the Virtual Machine.\r | |
4 | ; for option ROMs.\r | |
5 | ; \r | |
e5eed7d3 HT |
6 | ; Copyright (c) 2006 - 2008, Intel Corporation. All rights reserved.<BR>\r |
7 | ; This program and the accompanying materials\r | |
7b414b4e | 8 | ; are licensed and made available under the terms and conditions of the BSD License\r |
9 | ; which accompanies this distribution. The full text of the license may be found at\r | |
10 | ; http://opensource.org/licenses/bsd-license.php\r | |
f45af90b | 11 | ; \r |
7b414b4e | 12 | ; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r |
13 | ; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r | |
f45af90b | 14 | ; \r |
7b414b4e | 15 | ;**/\r |
16 | \r | |
7b414b4e | 17 | page ,132\r |
18 | title VM ASSEMBLY LANGUAGE ROUTINES\r | |
53c71d09 | 19 | \r |
20 | ;---------------------------------------------------------------------------\r | |
21 | ; Equate files needed.\r | |
22 | ;---------------------------------------------------------------------------\r | |
23 | \r | |
24 | text SEGMENT\r | |
25 | \r | |
26 | ;---------------------------------------------------------------------------\r | |
27 | ;;GenericPostSegment SEGMENT USE16\r | |
28 | ;---------------------------------------------------------------------------\r | |
29 | \r | |
30 | ;****************************************************************************\r | |
31 | ; EbcLLCALLEX\r | |
32 | ;\r | |
7b414b4e | 33 | ; This function is called to execute an EBC CALLEX instruction.\r |
53c71d09 | 34 | ; This instruction requires that we thunk out to external native\r |
35 | ; code. For x64, we switch stacks, copy the arguments to the stack\r | |
7b414b4e | 36 | ; and jump to the specified function.\r |
53c71d09 | 37 | ; On return, we restore the stack pointer to its original location.\r |
38 | ;\r | |
39 | ; Destroys no working registers.\r | |
40 | ;****************************************************************************\r | |
41 | ; VOID EbcLLCALLEXNative(UINTN FuncAddr, UINTN NewStackPointer, VOID *FramePtr)\r | |
42 | \r | |
43 | CopyMem PROTO Destination:PTR DWORD, Source:PTR DWORD, Count:DWORD\r | |
44 | \r | |
45 | \r | |
db01f13e | 46 | EbcLLCALLEXNative PROC PUBLIC\r |
53c71d09 | 47 | push rbp\r |
48 | push rbx\r | |
49 | mov rbp, rsp\r | |
50 | ; Function prolog\r | |
7b414b4e | 51 | \r |
53c71d09 | 52 | ; Copy FuncAddr to a preserved register.\r |
53 | mov rbx, rcx\r | |
54 | \r | |
55 | ; Set stack pointer to new value\r | |
56 | sub r8, rdx\r | |
57 | sub rsp, r8\r | |
58 | mov rcx, rsp\r | |
59 | sub rsp, 20h\r | |
7b414b4e | 60 | call CopyMem\r |
53c71d09 | 61 | add rsp, 20h\r |
7b414b4e | 62 | \r |
53c71d09 | 63 | ; Considering the worst case, load 4 potiential arguments\r |
64 | ; into registers.\r | |
65 | mov rcx, qword ptr [rsp]\r | |
66 | mov rdx, qword ptr [rsp+8h]\r | |
67 | mov r8, qword ptr [rsp+10h]\r | |
68 | mov r9, qword ptr [rsp+18h]\r | |
69 | \r | |
70 | ; Now call the external routine\r | |
71 | call rbx\r | |
7b414b4e | 72 | \r |
53c71d09 | 73 | ; Function epilog\r |
74 | mov rsp, rbp\r | |
75 | pop rbx\r | |
76 | pop rbp\r | |
77 | ret\r | |
78 | EbcLLCALLEXNative ENDP\r | |
79 | \r | |
80 | \r | |
81 | ; UINTN EbcLLGetEbcEntryPoint(VOID);\r | |
82 | ; Routine Description:\r | |
83 | ; The VM thunk code stuffs an EBC entry point into a processor\r | |
84 | ; register. Since we can't use inline assembly to get it from\r | |
7b414b4e | 85 | ; the interpreter C code, stuff it into the return value\r |
53c71d09 | 86 | ; register and return.\r |
87 | ;\r | |
88 | ; Arguments:\r | |
89 | ; None.\r | |
90 | ;\r | |
91 | ; Returns:\r | |
92 | ; The contents of the register in which the entry point is passed.\r | |
93 | ;\r | |
db01f13e | 94 | EbcLLGetEbcEntryPoint PROC PUBLIC\r |
045e90ac | 95 | mov rax, r10\r |
53c71d09 | 96 | ret\r |
97 | EbcLLGetEbcEntryPoint ENDP\r | |
98 | \r | |
99 | ;/*++\r | |
100 | ;\r | |
101 | ;Routine Description:\r | |
7b414b4e | 102 | ;\r |
53c71d09 | 103 | ; Return the caller's value of the stack pointer.\r |
104 | ;\r | |
105 | ;Arguments:\r | |
106 | ;\r | |
107 | ; None.\r | |
108 | ;\r | |
109 | ;Returns:\r | |
110 | ;\r | |
111 | ; The current value of the stack pointer for the caller. We\r | |
112 | ; adjust it by 4 here because when they called us, the return address\r | |
113 | ; is put on the stack, thereby lowering it by 4 bytes.\r | |
114 | ;\r | |
115 | ;--*/\r | |
116 | \r | |
7b414b4e | 117 | ; UINTN EbcLLGetStackPointer()\r |
db01f13e | 118 | EbcLLGetStackPointer PROC PUBLIC\r |
53c71d09 | 119 | mov rax, rsp ; get current stack pointer\r |
120 | ; Stack adjusted by this much when we were called,\r | |
121 | ; For this function, it's 4.\r | |
122 | add rax, 4\r | |
123 | ret\r | |
124 | EbcLLGetStackPointer ENDP\r | |
125 | \r | |
126 | ; UINT64 EbcLLGetReturnValue(VOID);\r | |
127 | ; Routine Description:\r | |
128 | ; When EBC calls native, on return the VM has to stuff the return\r | |
129 | ; value into a VM register. It's assumed here that the value is still\r | |
130 | ; in the register, so simply return and the caller should get the\r | |
131 | ; return result properly.\r | |
132 | ;\r | |
133 | ; Arguments:\r | |
134 | ; None.\r | |
135 | ;\r | |
136 | ; Returns:\r | |
137 | ; The unmodified value returned by the native code.\r | |
138 | ;\r | |
db01f13e | 139 | EbcLLGetReturnValue PROC PUBLIC\r |
53c71d09 | 140 | ret\r |
141 | EbcLLGetReturnValue ENDP\r | |
142 | \r | |
143 | text ENDS\r | |
144 | END\r | |
145 | \r |