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f1294e4a | 1 | /** @file\r |
2 | Provide legacy thunk interface for accessing Bios Video Rom.\r | |
3 | \r | |
4 | Copyright (c) 2006 - 2007, Intel Corporation \r | |
5 | All rights reserved. This program and the accompanying materials \r | |
6 | are licensed and made available under the terms and conditions of the BSD License \r | |
7 | which accompanies this distribution. The full text of the license may be found at \r | |
8 | http://opensource.org/licenses/bsd-license.php \r | |
9 | \r | |
10 | THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, \r | |
11 | WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. \r | |
12 | \r | |
13 | **/\r | |
0d92cdc2 | 14 | \r |
15 | #include "BiosVideo.h"\r | |
16 | \r | |
17 | #define EFI_CPU_EFLAGS_IF 0x200\r | |
18 | \r | |
f1294e4a | 19 | /**\r |
20 | Initialize legacy environment for BIOS INI caller.\r | |
21 | \r | |
22 | @param ThunkContext the instance pointer of THUNK_CONTEXT\r | |
23 | **/\r | |
0d92cdc2 | 24 | VOID\r |
25 | InitializeBiosIntCaller (\r | |
f1294e4a | 26 | THUNK_CONTEXT *ThunkContext\r |
0d92cdc2 | 27 | )\r |
28 | {\r | |
29 | EFI_STATUS Status;\r | |
30 | UINT32 RealModeBufferSize;\r | |
31 | UINT32 ExtraStackSize;\r | |
32 | EFI_PHYSICAL_ADDRESS LegacyRegionBase;\r | |
6c8e40ca | 33 | UINT32 LegacyRegionSize;\r |
0d92cdc2 | 34 | //\r |
35 | // Get LegacyRegion\r | |
36 | //\r | |
37 | AsmGetThunk16Properties (&RealModeBufferSize, &ExtraStackSize);\r | |
6c8e40ca | 38 | LegacyRegionSize = (((RealModeBufferSize + ExtraStackSize) / EFI_PAGE_SIZE) + 1) * EFI_PAGE_SIZE;\r |
0d92cdc2 | 39 | LegacyRegionBase = 0x100000;\r |
40 | Status = gBS->AllocatePages (\r | |
41 | AllocateMaxAddress,\r | |
42 | EfiACPIMemoryNVS,\r | |
6c8e40ca | 43 | EFI_SIZE_TO_PAGES(LegacyRegionSize),\r |
0d92cdc2 | 44 | &LegacyRegionBase\r |
45 | );\r | |
46 | ASSERT_EFI_ERROR (Status);\r | |
47 | \r | |
f1294e4a | 48 | ThunkContext->RealModeBuffer = (VOID*)(UINTN)LegacyRegionBase;\r |
6c8e40ca | 49 | ThunkContext->RealModeBufferSize = LegacyRegionSize;\r |
50 | ThunkContext->ThunkAttributes = THUNK_ATTRIBUTE_BIG_REAL_MODE|THUNK_ATTRIBUTE_DISABLE_A20_MASK_INT_15;\r | |
f1294e4a | 51 | AsmPrepareThunk16(ThunkContext);\r |
0d92cdc2 | 52 | }\r |
53 | \r | |
f1294e4a | 54 | /**\r |
55 | Initialize interrupt redirection code and entries, because\r | |
56 | IDT Vectors 0x68-0x6f must be redirected to IDT Vectors 0x08-0x0f.\r | |
57 | Or the interrupt will lost when we do thunk.\r | |
58 | NOTE: We do not reset 8259 vector base, because it will cause pending\r | |
59 | interrupt lost.\r | |
60 | \r | |
61 | @param Legacy8259 Instance pointer for EFI_LEGACY_8259_PROTOCOL.\r | |
62 | \r | |
63 | **/\r | |
0d92cdc2 | 64 | VOID\r |
65 | InitializeInterruptRedirection (\r | |
f1294e4a | 66 | IN EFI_LEGACY_8259_PROTOCOL *Legacy8259\r |
0d92cdc2 | 67 | )\r |
0d92cdc2 | 68 | {\r |
69 | EFI_STATUS Status;\r | |
70 | EFI_PHYSICAL_ADDRESS LegacyRegionBase;\r | |
71 | UINTN LegacyRegionLength;\r | |
72 | UINT32 *IdtArray;\r | |
73 | UINTN Index;\r | |
74 | UINT8 ProtectedModeBaseVector;\r | |
75 | UINT32 InterruptRedirectionCode[] = {\r | |
76 | 0x90CF08CD, // INT8; IRET; NOP\r | |
77 | 0x90CF09CD, // INT9; IRET; NOP\r | |
78 | 0x90CF0ACD, // INTA; IRET; NOP\r | |
79 | 0x90CF0BCD, // INTB; IRET; NOP\r | |
80 | 0x90CF0CCD, // INTC; IRET; NOP\r | |
81 | 0x90CF0DCD, // INTD; IRET; NOP\r | |
82 | 0x90CF0ECD, // INTE; IRET; NOP\r | |
83 | 0x90CF0FCD // INTF; IRET; NOP\r | |
84 | };\r | |
85 | \r | |
86 | //\r | |
87 | // Get LegacyRegion\r | |
88 | //\r | |
89 | LegacyRegionLength = sizeof(InterruptRedirectionCode);\r | |
90 | LegacyRegionBase = 0x100000;\r | |
91 | Status = gBS->AllocatePages (\r | |
92 | AllocateMaxAddress,\r | |
93 | EfiACPIMemoryNVS,\r | |
94 | EFI_SIZE_TO_PAGES(LegacyRegionLength),\r | |
95 | &LegacyRegionBase\r | |
96 | );\r | |
97 | ASSERT_EFI_ERROR (Status);\r | |
98 | \r | |
99 | //\r | |
100 | // Copy code to legacy region\r | |
101 | //\r | |
102 | CopyMem ((VOID *)(UINTN)LegacyRegionBase, InterruptRedirectionCode, sizeof (InterruptRedirectionCode));\r | |
103 | \r | |
104 | //\r | |
105 | // Get VectorBase, it should be 0x68\r | |
106 | //\r | |
f1294e4a | 107 | Status = Legacy8259->GetVector (Legacy8259, Efi8259Irq0, &ProtectedModeBaseVector);\r |
0d92cdc2 | 108 | ASSERT_EFI_ERROR (Status);\r |
109 | \r | |
110 | //\r | |
111 | // Patch IVT 0x68 ~ 0x6f\r | |
112 | //\r | |
113 | IdtArray = (UINT32 *) 0;\r | |
114 | for (Index = 0; Index < 8; Index++) {\r | |
115 | IdtArray[ProtectedModeBaseVector + Index] = ((EFI_SEGMENT (LegacyRegionBase + Index * 4)) << 16) | (EFI_OFFSET (LegacyRegionBase + Index * 4));\r | |
116 | }\r | |
117 | \r | |
118 | return ;\r | |
119 | }\r | |
120 | \r | |
f1294e4a | 121 | /**\r |
122 | Thunk to 16-bit real mode and execute a software interrupt with a vector \r | |
123 | of BiosInt. Regs will contain the 16-bit register context on entry and \r | |
124 | exit.\r | |
125 | \r | |
126 | @param This Protocol instance pointer.\r | |
127 | @param BiosInt Processor interrupt vector to invoke\r | |
128 | @param Reg Register contexted passed into (and returned) from thunk to 16-bit mode\r | |
129 | \r | |
130 | @retval TRUE Thunk completed, and there were no BIOS errors in the target code.\r | |
131 | See Regs for status.\r | |
132 | @retval FALSE There was a BIOS erro in the target code. \r | |
133 | **/\r | |
0d92cdc2 | 134 | BOOLEAN\r |
135 | EFIAPI\r | |
136 | LegacyBiosInt86 (\r | |
137 | IN BIOS_VIDEO_DEV *BiosDev,\r | |
138 | IN UINT8 BiosInt,\r | |
d0c94e59 | 139 | IN IA32_REGISTER_SET *Regs\r |
0d92cdc2 | 140 | )\r |
0d92cdc2 | 141 | {\r |
142 | UINTN Status;\r | |
143 | UINTN Eflags;\r | |
144 | IA32_REGISTER_SET ThunkRegSet;\r | |
145 | BOOLEAN Ret;\r | |
146 | UINT16 *Stack16;\r | |
147 | \r | |
0d92cdc2 | 148 | ZeroMem (&ThunkRegSet, sizeof (ThunkRegSet));\r |
237bb9d0 | 149 | ThunkRegSet.E.EFLAGS.Bits.Reserved_0 = 1;\r |
150 | ThunkRegSet.E.EFLAGS.Bits.Reserved_1 = 0;\r | |
151 | ThunkRegSet.E.EFLAGS.Bits.Reserved_2 = 0;\r | |
152 | ThunkRegSet.E.EFLAGS.Bits.Reserved_3 = 0;\r | |
153 | ThunkRegSet.E.EFLAGS.Bits.IOPL = 3;\r | |
154 | ThunkRegSet.E.EFLAGS.Bits.NT = 0;\r | |
155 | ThunkRegSet.E.EFLAGS.Bits.IF = 1;\r | |
156 | ThunkRegSet.E.EFLAGS.Bits.TF = 0;\r | |
157 | ThunkRegSet.E.EFLAGS.Bits.CF = 0;\r | |
158 | \r | |
0d92cdc2 | 159 | ThunkRegSet.E.EDI = Regs->E.EDI;\r |
160 | ThunkRegSet.E.ESI = Regs->E.ESI;\r | |
161 | ThunkRegSet.E.EBP = Regs->E.EBP;\r | |
162 | ThunkRegSet.E.EBX = Regs->E.EBX;\r | |
163 | ThunkRegSet.E.EDX = Regs->E.EDX;\r | |
164 | ThunkRegSet.E.ECX = Regs->E.ECX;\r | |
165 | ThunkRegSet.E.EAX = Regs->E.EAX;\r | |
166 | ThunkRegSet.E.DS = Regs->E.DS;\r | |
167 | ThunkRegSet.E.ES = Regs->E.ES;\r | |
168 | \r | |
0d92cdc2 | 169 | //\r |
170 | // The call to Legacy16 is a critical section to EFI\r | |
171 | //\r | |
172 | Eflags = AsmReadEflags ();\r | |
173 | if ((Eflags | EFI_CPU_EFLAGS_IF) != 0) {\r | |
174 | DisableInterrupts ();\r | |
175 | }\r | |
176 | \r | |
177 | //\r | |
178 | // Set Legacy16 state. 0x08, 0x70 is legacy 8259 vector bases.\r | |
179 | //\r | |
180 | Status = BiosDev->Legacy8259->SetMode (BiosDev->Legacy8259, Efi8259LegacyMode, NULL, NULL);\r | |
181 | ASSERT_EFI_ERROR (Status);\r | |
182 | \r | |
f1294e4a | 183 | Stack16 = (UINT16 *)((UINT8 *) BiosDev->ThunkContext->RealModeBuffer + BiosDev->ThunkContext->RealModeBufferSize - sizeof (UINT16));\r |
0d92cdc2 | 184 | \r |
185 | ThunkRegSet.E.SS = (UINT16) (((UINTN) Stack16 >> 16) << 12);\r | |
186 | ThunkRegSet.E.ESP = (UINT16) (UINTN) Stack16;\r | |
237bb9d0 | 187 | \r |
0d92cdc2 | 188 | ThunkRegSet.E.Eip = (UINT16)((UINT32 *)NULL)[BiosInt];\r |
189 | ThunkRegSet.E.CS = (UINT16)(((UINT32 *)NULL)[BiosInt] >> 16);\r | |
f1294e4a | 190 | BiosDev->ThunkContext->RealModeState = &ThunkRegSet;\r |
191 | AsmThunk16 (BiosDev->ThunkContext);\r | |
237bb9d0 | 192 | \r |
0d92cdc2 | 193 | //\r |
194 | // Restore protected mode interrupt state\r | |
195 | //\r | |
196 | Status = BiosDev->Legacy8259->SetMode (BiosDev->Legacy8259, Efi8259ProtectedMode, NULL, NULL);\r | |
197 | ASSERT_EFI_ERROR (Status);\r | |
198 | \r | |
199 | //\r | |
200 | // End critical section\r | |
201 | //\r | |
202 | if ((Eflags | EFI_CPU_EFLAGS_IF) != 0) {\r | |
203 | EnableInterrupts ();\r | |
204 | }\r | |
205 | \r | |
206 | Regs->E.EDI = ThunkRegSet.E.EDI; \r | |
207 | Regs->E.ESI = ThunkRegSet.E.ESI; \r | |
208 | Regs->E.EBP = ThunkRegSet.E.EBP; \r | |
209 | Regs->E.EBX = ThunkRegSet.E.EBX; \r | |
210 | Regs->E.EDX = ThunkRegSet.E.EDX; \r | |
211 | Regs->E.ECX = ThunkRegSet.E.ECX; \r | |
212 | Regs->E.EAX = ThunkRegSet.E.EAX;\r | |
213 | Regs->E.SS = ThunkRegSet.E.SS;\r | |
214 | Regs->E.CS = ThunkRegSet.E.CS; \r | |
215 | Regs->E.DS = ThunkRegSet.E.DS; \r | |
216 | Regs->E.ES = ThunkRegSet.E.ES;\r | |
217 | \r | |
d0c94e59 | 218 | CopyMem (&(Regs->E.EFLAGS), &(ThunkRegSet.E.EFLAGS), sizeof (UINT32));\r |
0d92cdc2 | 219 | \r |
d0c94e59 | 220 | Ret = (BOOLEAN) (Regs->E.EFLAGS.Bits.CF == 1);\r |
0d92cdc2 | 221 | \r |
222 | return Ret;\r | |
223 | }\r | |
224 | \r | |
225 | \r |