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d766b228 JY |
1 | /** @file\r |
2 | Execute 32-bit code in Long Mode\r | |
3 | Provide a thunk function to transition from long mode to compatibility mode to execute 32-bit code and then transit\r | |
4 | back to long mode.\r | |
5 | \r | |
e47459e6 | 6 | Copyright (c) 2010 - 2012, Intel Corporation. All rights reserved.<BR>\r |
d766b228 JY |
7 | This program and the accompanying materials\r |
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 | |
11 | \r | |
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 | |
14 | \r | |
15 | **/\r | |
16 | #include "ScriptSave.h"\r | |
17 | \r | |
18 | #pragma pack(1)\r | |
19 | typedef union {\r | |
20 | struct {\r | |
21 | UINT32 LimitLow : 16;\r | |
22 | UINT32 BaseLow : 16;\r | |
23 | UINT32 BaseMid : 8;\r | |
24 | UINT32 Type : 4;\r | |
25 | UINT32 System : 1;\r | |
26 | UINT32 Dpl : 2;\r | |
27 | UINT32 Present : 1;\r | |
28 | UINT32 LimitHigh : 4;\r | |
29 | UINT32 Software : 1;\r | |
30 | UINT32 Reserved : 1;\r | |
31 | UINT32 DefaultSize : 1;\r | |
32 | UINT32 Granularity : 1;\r | |
33 | UINT32 BaseHigh : 8;\r | |
34 | } Bits;\r | |
35 | UINT64 Uint64;\r | |
36 | } IA32_GDT;\r | |
e47459e6 | 37 | \r |
38 | ///\r | |
39 | /// Byte packed structure for an IA-32 Interrupt Gate Descriptor.\r | |
40 | ///\r | |
41 | typedef union {\r | |
42 | struct {\r | |
43 | UINT32 OffsetLow:16; ///< Offset bits 15..0.\r | |
44 | UINT32 Selector:16; ///< Selector.\r | |
45 | UINT32 Reserved_0:8; ///< Reserved.\r | |
46 | UINT32 GateType:8; ///< Gate Type. See #defines above.\r | |
47 | UINT32 OffsetHigh:16; ///< Offset bits 31..16.\r | |
48 | } Bits;\r | |
49 | UINT64 Uint64;\r | |
50 | } IA32_IDT_ENTRY;\r | |
d766b228 JY |
51 | #pragma pack()\r |
52 | \r | |
e47459e6 | 53 | #define COMPATIBILITY_MODE_SELECTOR 8\r |
54 | \r | |
d766b228 JY |
55 | //\r |
56 | // Global Descriptor Table (GDT)\r | |
57 | //\r | |
58 | GLOBAL_REMOVE_IF_UNREFERENCED IA32_GDT mGdtEntries[] = {\r | |
59 | {{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}}, /* 0x0: reserve */\r | |
60 | {{0xFFFF, 0, 0, 0xB, 1, 0, 1, 0xF, 0, 0, 1, 1, 0}}, /* 0x8: compatibility mode */\r | |
61 | {{0xFFFF, 0, 0, 0xB, 1, 0, 1, 0xF, 0, 1, 0, 1, 0}}, /* 0x10: for long mode */\r | |
62 | {{0xFFFF, 0, 0, 0x3, 1, 0, 1, 0xF, 0, 0, 1, 1, 0}}, /* 0x18: data */\r | |
63 | {{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}}, /* 0x20: reserve */\r | |
64 | };\r | |
65 | \r | |
66 | //\r | |
67 | // IA32 Gdt register\r | |
68 | //\r | |
69 | GLOBAL_REMOVE_IF_UNREFERENCED IA32_DESCRIPTOR mGdt = {\r | |
70 | sizeof (mGdtEntries) - 1,\r | |
71 | (UINTN) mGdtEntries\r | |
72 | };\r | |
73 | /**\r | |
74 | Assembly function to transition from long mode to compatibility mode to execute 32-bit code and then transit back to\r | |
75 | long mode.\r | |
76 | @param Function The 32bit code entry to be executed.\r | |
77 | @param Param1 The first parameter to pass to 32bit code\r | |
78 | @param Param2 The second parameter to pass to 32bit code\r | |
79 | @param InternalGdtr The GDT and GDT descriptor used by this library\r | |
80 | \r | |
81 | @retval EFI_SUCCESS Execute 32bit code successfully.\r | |
82 | @retval other Something wrong when execute the 32bit code \r | |
83 | **/\r | |
84 | EFI_STATUS\r | |
85 | AsmExecute32BitCode (\r | |
86 | IN UINT64 Function,\r | |
87 | IN UINT64 Param1,\r | |
88 | IN UINT64 Param2,\r | |
89 | IN IA32_DESCRIPTOR *InternalGdtr\r | |
90 | );\r | |
91 | \r | |
92 | /**\r | |
93 | Wrapper for a thunk to transition from long mode to compatibility mode to execute 32-bit code and then transit back to\r | |
94 | long mode.\r | |
95 | \r | |
96 | @param Function The 32bit code entry to be executed.\r | |
97 | @param Param1 The first parameter to pass to 32bit code\r | |
98 | @param Param2 The second parameter to pass to 32bit code\r | |
99 | @retval EFI_SUCCESS Execute 32bit code successfully.\r | |
100 | @retval other Something wrong when execute the 32bit code \r | |
101 | \r | |
102 | **/ \r | |
103 | EFI_STATUS\r | |
104 | Execute32BitCode (\r | |
105 | IN UINT64 Function,\r | |
106 | IN UINT64 Param1,\r | |
107 | IN UINT64 Param2\r | |
108 | )\r | |
109 | {\r | |
110 | EFI_STATUS Status;\r | |
e47459e6 | 111 | IA32_DESCRIPTOR *Ia32Idtr;\r |
112 | IA32_DESCRIPTOR X64Idtr;\r | |
113 | UINTN Ia32IdtEntryCount;\r | |
114 | UINTN Index;\r | |
115 | IA32_IDT_ENTRY *Ia32IdtEntry;\r | |
116 | \r | |
117 | //\r | |
118 | // Save x64 IDT Descriptor\r | |
119 | //\r | |
120 | AsmReadIdtr ((IA32_DESCRIPTOR *) &X64Idtr);\r | |
121 | \r | |
122 | //\r | |
123 | // Get the IA32 IDT Descriptor saved in 16 bytes in front of X64 IDT table.\r | |
124 | //\r | |
125 | Ia32Idtr = (IA32_DESCRIPTOR *) (UINTN) (X64Idtr.Base - 16);\r | |
126 | Ia32IdtEntryCount = (Ia32Idtr->Limit + 1) / sizeof (IA32_IDT_ENTRY);\r | |
127 | \r | |
128 | Ia32IdtEntry = (IA32_IDT_ENTRY *)(Ia32Idtr->Base);\r | |
129 | for (Index = 0; Index < Ia32IdtEntryCount; Index ++ ) {\r | |
130 | //\r | |
131 | // Use the new Code Selector value\r | |
132 | //\r | |
133 | Ia32IdtEntry[Index].Bits.Selector = COMPATIBILITY_MODE_SELECTOR;\r | |
134 | }\r | |
135 | \r | |
136 | //\r | |
137 | // Setup IA32 IDT table for 32-bit framework Boot Script code\r | |
138 | //\r | |
139 | AsmWriteIdtr (Ia32Idtr);\r | |
140 | \r | |
d766b228 JY |
141 | ASSERT (Function != 0);\r |
142 | \r | |
143 | Status = AsmExecute32BitCode (\r | |
144 | Function,\r | |
145 | Param1,\r | |
146 | Param2,\r | |
147 | &mGdt\r | |
148 | );\r | |
e47459e6 | 149 | \r |
150 | //\r | |
151 | // Restore X64 IDT table\r | |
152 | //\r | |
153 | AsmWriteIdtr ((IA32_DESCRIPTOR *) &X64Idtr);\r | |
154 | \r | |
d766b228 JY |
155 | return Status;\r |
156 | }\r | |
157 | \r |