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bcecde14 | 1 | /** @file\r |
2 | Call into 16-bit BIOS code, Use AsmThunk16 function of BaseLib.\r | |
3 | \r | |
f767f990 | 4 | Copyright (c) 2006 - 2011, Intel Corporation. All rights reserved.<BR>\r |
bcecde14 | 5 | \r |
6 | This program and the accompanying materials\r | |
7 | are licensed and made available under the terms and conditions\r | |
8 | of the BSD License which accompanies this distribution. The\r | |
9 | 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 | \r | |
17 | #include "LegacyBiosInterface.h"\r | |
18 | \r | |
19 | THUNK_CONTEXT mThunkContext;\r | |
20 | \r | |
f767f990 | 21 | /**\r |
22 | Sets the counter value for Timer #0 in a legacy 8254 timer.\r | |
23 | \r | |
24 | @param Count - The 16-bit counter value to program into Timer #0 of the legacy 8254 timer.\r | |
25 | \r | |
26 | **/\r | |
27 | VOID\r | |
28 | SetPitCount (\r | |
29 | IN UINT16 Count\r | |
30 | )\r | |
31 | {\r | |
32 | IoWrite8 (TIMER_CONTROL_PORT, TIMER0_CONTROL_WORD);\r | |
33 | IoWrite8 (TIMER0_COUNT_PORT, (UINT8) (Count & 0xFF));\r | |
34 | IoWrite8 (TIMER0_COUNT_PORT, (UINT8) ((Count>>8) & 0xFF));\r | |
35 | }\r | |
36 | \r | |
bcecde14 | 37 | /**\r |
38 | Thunk to 16-bit real mode and execute a software interrupt with a vector\r | |
39 | of BiosInt. Regs will contain the 16-bit register context on entry and\r | |
40 | exit.\r | |
41 | \r | |
42 | @param This Protocol instance pointer.\r | |
43 | @param BiosInt Processor interrupt vector to invoke\r | |
44 | @param Regs Register contexted passed into (and returned) from thunk to\r | |
45 | 16-bit mode\r | |
46 | \r | |
47 | @retval FALSE Thunk completed, and there were no BIOS errors in the target code.\r | |
48 | See Regs for status.\r | |
49 | @retval TRUE There was a BIOS erro in the target code.\r | |
50 | \r | |
51 | **/\r | |
52 | BOOLEAN\r | |
53 | EFIAPI\r | |
54 | LegacyBiosInt86 (\r | |
55 | IN EFI_LEGACY_BIOS_PROTOCOL *This,\r | |
56 | IN UINT8 BiosInt,\r | |
57 | IN EFI_IA32_REGISTER_SET *Regs\r | |
58 | )\r | |
59 | {\r | |
d057d8c4 JW |
60 | UINT16 Segment;\r |
61 | UINT16 Offset;\r | |
26a74a36 | 62 | \r |
bcecde14 | 63 | Regs->X.Flags.Reserved1 = 1;\r |
64 | Regs->X.Flags.Reserved2 = 0;\r | |
65 | Regs->X.Flags.Reserved3 = 0;\r | |
66 | Regs->X.Flags.Reserved4 = 0;\r | |
67 | Regs->X.Flags.IOPL = 3;\r | |
68 | Regs->X.Flags.NT = 0;\r | |
69 | Regs->X.Flags.IF = 0;\r | |
70 | Regs->X.Flags.TF = 0;\r | |
71 | Regs->X.Flags.CF = 0;\r | |
26a74a36 | 72 | //\r |
73 | // The base address of legacy interrupt vector table is 0.\r | |
74 | // We use this base address to get the legacy interrupt handler.\r | |
75 | //\r | |
2ea3576e JW |
76 | ACCESS_PAGE0_CODE (\r |
77 | Segment = (UINT16)(((UINT32 *)0)[BiosInt] >> 16);\r | |
78 | Offset = (UINT16)((UINT32 *)0)[BiosInt];\r | |
79 | );\r | |
26a74a36 | 80 | \r |
bcecde14 | 81 | return InternalLegacyBiosFarCall (\r |
82 | This,\r | |
d057d8c4 JW |
83 | Segment,\r |
84 | Offset,\r | |
bcecde14 | 85 | Regs,\r |
86 | &Regs->X.Flags,\r | |
87 | sizeof (Regs->X.Flags)\r | |
88 | );\r | |
89 | }\r | |
90 | \r | |
91 | /**\r | |
92 | Thunk to 16-bit real mode and call Segment:Offset. Regs will contain the\r | |
93 | 16-bit register context on entry and exit. Arguments can be passed on\r | |
94 | the Stack argument\r | |
95 | \r | |
96 | @param This Protocol instance pointer.\r | |
97 | @param Segment Segemnt of 16-bit mode call\r | |
98 | @param Offset Offset of 16-bit mdoe call\r | |
99 | @param Regs Register contexted passed into (and returned) from\r | |
100 | thunk to 16-bit mode\r | |
101 | @param Stack Caller allocated stack used to pass arguments\r | |
102 | @param StackSize Size of Stack in bytes\r | |
103 | \r | |
104 | @retval FALSE Thunk completed, and there were no BIOS errors in\r | |
105 | the target code. See Regs for status.\r | |
106 | @retval TRUE There was a BIOS erro in the target code.\r | |
107 | \r | |
108 | **/\r | |
109 | BOOLEAN\r | |
110 | EFIAPI\r | |
111 | LegacyBiosFarCall86 (\r | |
112 | IN EFI_LEGACY_BIOS_PROTOCOL *This,\r | |
113 | IN UINT16 Segment,\r | |
114 | IN UINT16 Offset,\r | |
115 | IN EFI_IA32_REGISTER_SET *Regs,\r | |
116 | IN VOID *Stack,\r | |
117 | IN UINTN StackSize\r | |
118 | )\r | |
119 | {\r | |
120 | Regs->X.Flags.Reserved1 = 1;\r | |
121 | Regs->X.Flags.Reserved2 = 0;\r | |
122 | Regs->X.Flags.Reserved3 = 0;\r | |
123 | Regs->X.Flags.Reserved4 = 0;\r | |
124 | Regs->X.Flags.IOPL = 3;\r | |
125 | Regs->X.Flags.NT = 0;\r | |
126 | Regs->X.Flags.IF = 1;\r | |
127 | Regs->X.Flags.TF = 0;\r | |
128 | Regs->X.Flags.CF = 0;\r | |
129 | \r | |
130 | return InternalLegacyBiosFarCall (This, Segment, Offset, Regs, Stack, StackSize);\r | |
131 | }\r | |
132 | \r | |
f767f990 | 133 | /**\r |
134 | Provide NULL interrupt handler which is used to check \r | |
135 | if there is more than one HW interrupt registers with the CPU AP.\r | |
136 | \r | |
137 | @param InterruptType - The type of interrupt that occured\r | |
138 | @param SystemContext - A pointer to the system context when the interrupt occured\r | |
139 | \r | |
140 | **/\r | |
141 | VOID\r | |
142 | EFIAPI\r | |
143 | LegacyBiosNullInterruptHandler (\r | |
144 | IN EFI_EXCEPTION_TYPE InterruptType,\r | |
145 | IN EFI_SYSTEM_CONTEXT SystemContext\r | |
146 | )\r | |
147 | {\r | |
148 | }\r | |
149 | \r | |
bcecde14 | 150 | /**\r |
151 | Thunk to 16-bit real mode and call Segment:Offset. Regs will contain the\r | |
152 | 16-bit register context on entry and exit. Arguments can be passed on\r | |
153 | the Stack argument\r | |
154 | \r | |
155 | @param This Protocol instance pointer.\r | |
156 | @param Segment Segemnt of 16-bit mode call\r | |
157 | @param Offset Offset of 16-bit mdoe call\r | |
158 | @param Regs Register contexted passed into (and returned) from thunk to\r | |
159 | 16-bit mode\r | |
160 | @param Stack Caller allocated stack used to pass arguments\r | |
161 | @param StackSize Size of Stack in bytes\r | |
162 | \r | |
163 | @retval FALSE Thunk completed, and there were no BIOS errors in the target code.\r | |
164 | See Regs for status.\r | |
165 | @retval TRUE There was a BIOS erro in the target code.\r | |
166 | \r | |
167 | **/\r | |
168 | BOOLEAN\r | |
169 | EFIAPI\r | |
170 | InternalLegacyBiosFarCall (\r | |
171 | IN EFI_LEGACY_BIOS_PROTOCOL *This,\r | |
172 | IN UINT16 Segment,\r | |
173 | IN UINT16 Offset,\r | |
174 | IN EFI_IA32_REGISTER_SET *Regs,\r | |
175 | IN VOID *Stack,\r | |
176 | IN UINTN StackSize\r | |
177 | )\r | |
178 | {\r | |
179 | UINTN Status;\r | |
180 | LEGACY_BIOS_INSTANCE *Private;\r | |
181 | UINT16 *Stack16;\r | |
182 | EFI_TPL OriginalTpl;\r | |
183 | IA32_REGISTER_SET ThunkRegSet;\r | |
184 | BOOLEAN InterruptState;\r | |
f767f990 | 185 | UINT64 TimerPeriod;\r |
bcecde14 | 186 | \r |
187 | Private = LEGACY_BIOS_INSTANCE_FROM_THIS (This);\r | |
188 | \r | |
189 | ZeroMem (&ThunkRegSet, sizeof (ThunkRegSet));\r | |
190 | ThunkRegSet.X.DI = Regs->X.DI;\r | |
191 | ThunkRegSet.X.SI = Regs->X.SI;\r | |
192 | ThunkRegSet.X.BP = Regs->X.BP;\r | |
193 | ThunkRegSet.X.BX = Regs->X.BX;\r | |
194 | ThunkRegSet.X.DX = Regs->X.DX;\r | |
195 | //\r | |
196 | // Sometimes, ECX is used to pass in 32 bit data. For example, INT 1Ah, AX = B10Dh is\r | |
197 | // "PCI BIOS v2.0c + Write Configuration DWORD" and ECX has the dword to write.\r | |
198 | //\r | |
199 | ThunkRegSet.E.ECX = Regs->E.ECX;\r | |
200 | ThunkRegSet.X.AX = Regs->X.AX;\r | |
201 | ThunkRegSet.E.DS = Regs->X.DS;\r | |
202 | ThunkRegSet.E.ES = Regs->X.ES;\r | |
203 | \r | |
204 | CopyMem (&(ThunkRegSet.E.EFLAGS.UintN), &(Regs->X.Flags), sizeof (Regs->X.Flags));\r | |
205 | \r | |
206 | //\r | |
207 | // Clear the error flag; thunk code may set it. Stack16 should be the high address\r | |
208 | // Make Statk16 address the low 16 bit must be not zero.\r | |
209 | //\r | |
210 | Stack16 = (UINT16 *)((UINT8 *) mThunkContext.RealModeBuffer + mThunkContext.RealModeBufferSize - sizeof (UINT16));\r | |
211 | \r | |
212 | //\r | |
f767f990 | 213 | // Save current rate of DXE Timer\r |
214 | //\r | |
215 | Private->Timer->GetTimerPeriod (Private->Timer, &TimerPeriod);\r | |
216 | \r | |
217 | //\r | |
218 | // Disable DXE Timer while executing in real mode\r | |
219 | //\r | |
220 | Private->Timer->SetTimerPeriod (Private->Timer, 0);\r | |
221 | \r | |
222 | //\r | |
223 | // Save and disable interrupt of debug timer\r | |
bcecde14 | 224 | //\r |
225 | InterruptState = SaveAndSetDebugTimerInterrupt (FALSE);\r | |
226 | \r | |
227 | //\r | |
228 | // The call to Legacy16 is a critical section to EFI\r | |
229 | //\r | |
230 | OriginalTpl = gBS->RaiseTPL (TPL_HIGH_LEVEL);\r | |
231 | \r | |
f767f990 | 232 | //\r |
233 | // Check to see if there is more than one HW interrupt registers with the CPU AP.\r | |
234 | // If there is, then ASSERT() since that is not compatible with the CSM because \r | |
235 | // interupts other than the Timer interrupt that was disabled above can not be \r | |
236 | // handled properly from real mode.\r | |
237 | //\r | |
238 | DEBUG_CODE (\r | |
239 | UINTN Vector;\r | |
240 | UINTN Count;\r | |
241 | \r | |
242 | for (Vector = 0x20, Count = 0; Vector < 0x100; Vector++) {\r | |
243 | Status = Private->Cpu->RegisterInterruptHandler (Private->Cpu, Vector, LegacyBiosNullInterruptHandler);\r | |
244 | if (Status == EFI_ALREADY_STARTED) {\r | |
245 | Count++;\r | |
246 | }\r | |
247 | if (Status == EFI_SUCCESS) {\r | |
248 | Private->Cpu->RegisterInterruptHandler (Private->Cpu, Vector, NULL);\r | |
249 | }\r | |
250 | }\r | |
251 | if (Count >= 2) {\r | |
252 | DEBUG ((EFI_D_ERROR, "ERROR: More than one HW interrupt active with CSM enabled\n"));\r | |
253 | }\r | |
254 | ASSERT (Count < 2);\r | |
255 | );\r | |
256 | \r | |
257 | //\r | |
258 | // If the Timer AP has enabled the 8254 timer IRQ and the current 8254 timer \r | |
259 | // period is less than the CSM required rate of 54.9254, then force the 8254 \r | |
260 | // PIT counter to 0, which is the CSM required rate of 54.9254 ms\r | |
261 | //\r | |
262 | if (Private->TimerUses8254 && TimerPeriod < 549254) {\r | |
263 | SetPitCount (0);\r | |
264 | }\r | |
265 | \r | |
bcecde14 | 266 | if (Stack != NULL && StackSize != 0) {\r |
267 | //\r | |
268 | // Copy Stack to low memory stack\r | |
269 | //\r | |
270 | Stack16 -= StackSize / sizeof (UINT16);\r | |
271 | CopyMem (Stack16, Stack, StackSize);\r | |
272 | }\r | |
273 | \r | |
274 | ThunkRegSet.E.SS = (UINT16) (((UINTN) Stack16 >> 16) << 12);\r | |
275 | ThunkRegSet.E.ESP = (UINT16) (UINTN) Stack16;\r | |
276 | ThunkRegSet.E.CS = Segment;\r | |
277 | ThunkRegSet.E.Eip = Offset;\r | |
278 | \r | |
279 | mThunkContext.RealModeState = &ThunkRegSet;\r | |
280 | \r | |
281 | //\r | |
282 | // Set Legacy16 state. 0x08, 0x70 is legacy 8259 vector bases.\r | |
283 | //\r | |
284 | Status = Private->Legacy8259->SetMode (Private->Legacy8259, Efi8259LegacyMode, NULL, NULL);\r | |
285 | ASSERT_EFI_ERROR (Status);\r | |
286 | \r | |
287 | AsmThunk16 (&mThunkContext);\r | |
288 | \r | |
bcecde14 | 289 | if (Stack != NULL && StackSize != 0) {\r |
290 | //\r | |
291 | // Copy low memory stack to Stack\r | |
292 | //\r | |
293 | CopyMem (Stack, Stack16, StackSize);\r | |
294 | }\r | |
295 | \r | |
296 | //\r | |
297 | // Restore protected mode interrupt state\r | |
298 | //\r | |
299 | Status = Private->Legacy8259->SetMode (Private->Legacy8259, Efi8259ProtectedMode, NULL, NULL);\r | |
300 | ASSERT_EFI_ERROR (Status);\r | |
301 | \r | |
302 | mThunkContext.RealModeState = NULL;\r | |
303 | \r | |
304 | //\r | |
b17f22f5 | 305 | // Enable and restore rate of DXE Timer\r |
bcecde14 | 306 | //\r |
b17f22f5 | 307 | Private->Timer->SetTimerPeriod (Private->Timer, TimerPeriod);\r |
bcecde14 | 308 | \r |
309 | //\r | |
b17f22f5 | 310 | // End critical section\r |
f767f990 | 311 | //\r |
b17f22f5 | 312 | gBS->RestoreTPL (OriginalTpl);\r |
f767f990 | 313 | \r |
2ea3576e JW |
314 | //\r |
315 | // OPROM may allocate EBDA range by itself and change EBDA base and EBDA size.\r | |
316 | // Get the current EBDA base address, and compared with pre-allocate minimum\r | |
317 | // EBDA base address, if the current EBDA base address is smaller, it indicates\r | |
318 | // PcdEbdaReservedMemorySize should be adjusted to larger for more OPROMs.\r | |
319 | //\r | |
320 | DEBUG_CODE (\r | |
321 | {\r | |
322 | UINTN EbdaBaseAddress;\r | |
323 | UINTN ReservedEbdaBaseAddress;\r | |
324 | \r | |
325 | ACCESS_PAGE0_CODE (\r | |
326 | EbdaBaseAddress = (*(UINT16 *) (UINTN) 0x40E) << 4;\r | |
327 | ReservedEbdaBaseAddress = CONVENTIONAL_MEMORY_TOP\r | |
328 | - PcdGet32 (PcdEbdaReservedMemorySize);\r | |
329 | ASSERT (ReservedEbdaBaseAddress <= EbdaBaseAddress);\r | |
330 | );\r | |
331 | }\r | |
332 | );\r | |
333 | \r | |
f767f990 | 334 | //\r |
335 | // Restore interrupt of debug timer\r | |
bcecde14 | 336 | //\r |
337 | SaveAndSetDebugTimerInterrupt (InterruptState);\r | |
338 | \r | |
339 | Regs->E.EDI = ThunkRegSet.E.EDI;\r | |
340 | Regs->E.ESI = ThunkRegSet.E.ESI;\r | |
341 | Regs->E.EBP = ThunkRegSet.E.EBP;\r | |
342 | Regs->E.EBX = ThunkRegSet.E.EBX;\r | |
343 | Regs->E.EDX = ThunkRegSet.E.EDX;\r | |
344 | Regs->E.ECX = ThunkRegSet.E.ECX;\r | |
345 | Regs->E.EAX = ThunkRegSet.E.EAX;\r | |
346 | Regs->X.SS = ThunkRegSet.E.SS;\r | |
347 | Regs->X.CS = ThunkRegSet.E.CS;\r | |
348 | Regs->X.DS = ThunkRegSet.E.DS;\r | |
349 | Regs->X.ES = ThunkRegSet.E.ES;\r | |
350 | \r | |
351 | CopyMem (&(Regs->X.Flags), &(ThunkRegSet.E.EFLAGS.UintN), sizeof (Regs->X.Flags));\r | |
352 | \r | |
353 | return (BOOLEAN) (Regs->X.Flags.CF == 1);\r | |
354 | }\r | |
355 | \r | |
356 | /**\r | |
357 | Allocate memory < 1 MB and copy the thunker code into low memory. Se up\r | |
358 | all the descriptors.\r | |
359 | \r | |
360 | @param Private Private context for Legacy BIOS\r | |
361 | \r | |
362 | @retval EFI_SUCCESS Should only pass.\r | |
363 | \r | |
364 | **/\r | |
365 | EFI_STATUS\r | |
366 | LegacyBiosInitializeThunk (\r | |
367 | IN LEGACY_BIOS_INSTANCE *Private\r | |
368 | )\r | |
369 | {\r | |
f767f990 | 370 | EFI_STATUS Status;\r |
bcecde14 | 371 | EFI_PHYSICAL_ADDRESS MemoryAddress;\r |
f767f990 | 372 | UINT8 TimerVector;\r |
bcecde14 | 373 | \r |
374 | MemoryAddress = (EFI_PHYSICAL_ADDRESS) (UINTN) Private->IntThunk;\r | |
375 | \r | |
376 | mThunkContext.RealModeBuffer = (VOID *) (UINTN) (MemoryAddress + ((sizeof (LOW_MEMORY_THUNK) / EFI_PAGE_SIZE) + 1) * EFI_PAGE_SIZE);\r | |
377 | mThunkContext.RealModeBufferSize = EFI_PAGE_SIZE;\r | |
378 | mThunkContext.ThunkAttributes = THUNK_ATTRIBUTE_BIG_REAL_MODE | THUNK_ATTRIBUTE_DISABLE_A20_MASK_INT_15;\r | |
379 | \r | |
380 | AsmPrepareThunk16 (&mThunkContext);\r | |
381 | \r | |
f767f990 | 382 | //\r |
383 | // Get the interrupt vector number corresponding to IRQ0 from the 8259 driver\r | |
384 | //\r | |
385 | TimerVector = 0;\r | |
386 | Status = Private->Legacy8259->GetVector (Private->Legacy8259, Efi8259Irq0, &TimerVector);\r | |
387 | ASSERT_EFI_ERROR (Status);\r | |
388 | \r | |
389 | //\r | |
390 | // Check to see if the Timer AP has hooked the IRQ0 from the 8254 PIT\r | |
391 | // \r | |
392 | Status = Private->Cpu->RegisterInterruptHandler (\r | |
393 | Private->Cpu, \r | |
394 | TimerVector, \r | |
395 | LegacyBiosNullInterruptHandler\r | |
396 | );\r | |
397 | if (Status == EFI_SUCCESS) {\r | |
398 | //\r | |
399 | // If the Timer AP has not enabled the 8254 timer IRQ, then force the 8254 PIT \r | |
400 | // counter to 0, which is the CSM required rate of 54.9254 ms\r | |
401 | //\r | |
402 | Private->Cpu->RegisterInterruptHandler (\r | |
403 | Private->Cpu, \r | |
404 | TimerVector, \r | |
405 | NULL\r | |
406 | );\r | |
407 | SetPitCount (0);\r | |
408 | \r | |
409 | //\r | |
410 | // Save status that the Timer AP is not using the 8254 PIT\r | |
411 | //\r | |
412 | Private->TimerUses8254 = FALSE;\r | |
413 | } else if (Status == EFI_ALREADY_STARTED) {\r | |
414 | //\r | |
415 | // Save status that the Timer AP is using the 8254 PIT\r | |
416 | //\r | |
417 | Private->TimerUses8254 = TRUE;\r | |
418 | } else {\r | |
419 | //\r | |
420 | // Unexpected status from CPU AP RegisterInterruptHandler()\r | |
421 | //\r | |
422 | ASSERT (FALSE);\r | |
423 | }\r | |
424 | \r | |
bcecde14 | 425 | return EFI_SUCCESS;\r |
426 | }\r |