2 IA32 specific debug support functions
4 Copyright (c) 2006 - 2007, Intel Corporation
5 All rights reserved. This program and the accompanying materials
6 are licensed and made available under the terms and conditions of the BSD License
7 which accompanies this distribution. The full text of the license may be found at
8 http://opensource.org/licenses/bsd-license.php
10 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
11 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
16 // private header files
18 #include "plDebugSupport.h"
21 // This the global main table to keep track of the interrupts
23 IDT_ENTRY
*IdtEntryTable
= NULL
;
24 DESCRIPTOR NullDesc
= 0;
28 IN EFI_EXCEPTION_TYPE ExceptionType
,
33 Routine Description: Allocate pool for a new IDT entry stub. Copy the generic
34 stub into the new buffer and fixup the vector number and jump target address.
37 ExceptionType - This is the exception type that the new stub will be created
39 Stub - On successful exit, *Stub contains the newly allocated entry stub.
42 other possibilities are passed through from AllocatePool
51 // Fixup the stub code for this vector
54 // The stub code looks like this:
56 // 00000000 89 25 00000004 R mov AppEsp, esp ; save stack top
57 // 00000006 BC 00008014 R mov esp, offset DbgStkBot ; switch to debugger stack
58 // 0000000B 6A 00 push 0 ; push vector number - will be modified before installed
59 // 0000000D E9 db 0e9h ; jump rel32
60 // 0000000E 00000000 dd 0 ; fixed up to relative address of CommonIdtEntry
64 // poke in the exception type so the second push pushes the exception type
66 StubCopy
[0x0c] = (UINT8
) ExceptionType
;
69 // fixup the jump target to point to the common entry
71 *(UINT32
*) &StubCopy
[0x0e] = (UINT32
) CommonIdtEntry
- (UINT32
) &StubCopy
[StubSize
];
78 IN EFI_EXCEPTION_TYPE ExceptionType
,
79 IN
VOID (*NewCallback
) ()
84 Creates a nes entry stub. Then saves the current IDT entry and replaces it
85 with an interrupt gate for the new entry point. The IdtEntryTable is updated
86 with the new registered function.
88 This code executes in boot services context. The stub entry executes in interrupt
92 ExceptionType - specifies which vector to hook.
93 NewCallback - a pointer to the new function to be registered.
97 Other possibilities are passed through by CreateEntryStub
101 BOOLEAN OldIntFlagState
;
104 Status
= CreateEntryStub (ExceptionType
, (VOID
**) &IdtEntryTable
[ExceptionType
].StubEntry
);
105 if (Status
== EFI_SUCCESS
) {
106 OldIntFlagState
= WriteInterruptFlag (0);
107 ReadIdt (ExceptionType
, &(IdtEntryTable
[ExceptionType
].OrigDesc
));
109 ((UINT16
*) &IdtEntryTable
[ExceptionType
].OrigVector
)[0] = ((UINT16
*) &IdtEntryTable
[ExceptionType
].OrigDesc
)[0];
110 ((UINT16
*) &IdtEntryTable
[ExceptionType
].OrigVector
)[1] = ((UINT16
*) &IdtEntryTable
[ExceptionType
].OrigDesc
)[3];
112 Vect2Desc (&IdtEntryTable
[ExceptionType
].NewDesc
, IdtEntryTable
[ExceptionType
].StubEntry
);
113 IdtEntryTable
[ExceptionType
].RegisteredCallback
= NewCallback
;
114 WriteIdt (ExceptionType
, &(IdtEntryTable
[ExceptionType
].NewDesc
));
115 WriteInterruptFlag (OldIntFlagState
);
123 IN EFI_EXCEPTION_TYPE ExceptionType
128 Undoes HookEntry. This code executes in boot services context.
131 ExceptionType - specifies which entry to unhook
138 BOOLEAN OldIntFlagState
;
140 OldIntFlagState
= WriteInterruptFlag (0);
141 WriteIdt (ExceptionType
, &(IdtEntryTable
[ExceptionType
].OrigDesc
));
142 WriteInterruptFlag (OldIntFlagState
);
148 ManageIdtEntryTable (
149 VOID (*NewCallback
)(),
150 EFI_EXCEPTION_TYPE ExceptionType
155 This is the main worker function that manages the state of the interrupt
156 handlers. It both installs and uninstalls interrupt handlers based on the
157 value of NewCallback. If NewCallback is NULL, then uninstall is indicated.
158 If NewCallback is non-NULL, then install is indicated.
161 NewCallback - If non-NULL, NewCallback specifies the new handler to register.
162 If NULL, specifies that the previously registered handler should
164 ExceptionType - Indicates which entry to manage
168 EFI_INVALID_PARAMETER - requested uninstalling a handler from a vector that has
169 no handler registered for it
170 EFI_ALREADY_STARTED - requested install to a vector that already has a handler registered.
172 Other possible return values are passed through from UnHookEntry and HookEntry.
178 Status
= EFI_SUCCESS
;
180 if (!FeaturePcdGet (PcdNtEmulatorEnable
)) {
181 if (CompareDescriptor (&IdtEntryTable
[ExceptionType
].NewDesc
, &NullDesc
)) {
183 // we've already installed to this vector
185 if (NewCallback
!= NULL
) {
187 // if the input handler is non-null, error
189 Status
= EFI_ALREADY_STARTED
;
191 Status
= UnhookEntry (ExceptionType
);
195 // no user handler installed on this vector
197 if (NewCallback
== NULL
) {
199 // if the input handler is null, error
201 Status
= EFI_INVALID_PARAMETER
;
203 Status
= HookEntry (ExceptionType
, NewCallback
);
213 GetMaximumProcessorIndex (
214 IN EFI_DEBUG_SUPPORT_PROTOCOL
*This
,
215 OUT UINTN
*MaxProcessorIndex
219 Routine Description: This is a DebugSupport protocol member function.
222 This - The DebugSupport instance
223 MaxProcessorIndex - The maximuim supported processor index
226 Always returns EFI_SUCCESS with *MaxProcessorIndex set to 0
230 *MaxProcessorIndex
= 0;
231 return (EFI_SUCCESS
);
236 RegisterPeriodicCallback (
237 IN EFI_DEBUG_SUPPORT_PROTOCOL
*This
,
238 IN UINTN ProcessorIndex
,
239 IN EFI_PERIODIC_CALLBACK PeriodicCallback
243 Routine Description: This is a DebugSupport protocol member function.
246 This - The DebugSupport instance
247 ProcessorIndex - Which processor the callback applies to.
248 PeriodicCallback - Callback function
253 EFI_INVALID_PARAMETER - requested uninstalling a handler from a vector that has
254 no handler registered for it
255 EFI_ALREADY_STARTED - requested install to a vector that already has a handler registered.
257 Other possible return values are passed through from UnHookEntry and HookEntry.
261 return ManageIdtEntryTable (PeriodicCallback
, SYSTEM_TIMER_VECTOR
);
266 RegisterExceptionCallback (
267 IN EFI_DEBUG_SUPPORT_PROTOCOL
*This
,
268 IN UINTN ProcessorIndex
,
269 IN EFI_EXCEPTION_CALLBACK NewCallback
,
270 IN EFI_EXCEPTION_TYPE ExceptionType
275 This is a DebugSupport protocol member function.
277 This code executes in boot services context.
280 This - The DebugSupport instance
281 ProcessorIndex - Which processor the callback applies to.
282 NewCallback - Callback function
283 ExceptionType - Which exception to hook
288 EFI_INVALID_PARAMETER - requested uninstalling a handler from a vector that has
289 no handler registered for it
290 EFI_ALREADY_STARTED - requested install to a vector that already has a handler registered.
292 Other possible return values are passed through from UnHookEntry and HookEntry.
296 return ManageIdtEntryTable (NewCallback
, ExceptionType
);
301 InvalidateInstructionCache (
302 IN EFI_DEBUG_SUPPORT_PROTOCOL
*This
,
303 IN UINTN ProcessorIndex
,
310 This is a DebugSupport protocol member function.
311 Calls assembly routine to flush cache.
314 This - The DebugSupport instance
315 ProcessorIndex - Which processor the callback applies to.
316 Start - Physical base of the memory range to be invalidated
317 Length - mininum number of bytes in instruction cache to invalidate
321 EFI_SUCCESS - always return success
330 plInitializeDebugSupportDriver (
336 Initializes driver's handler registration database.
338 This code executes in boot services context.
345 EFI_UNSUPPORTED - if IA32 processor does not support FXSTOR/FXRSTOR instructions,
346 the context save will fail, so these processor's are not supported.
347 EFI_OUT_OF_RESOURCES - not resource to finish initialization
351 EFI_EXCEPTION_TYPE ExceptionType
;
353 if (!FxStorSupport ()) {
354 return EFI_UNSUPPORTED
;
357 IdtEntryTable
= AllocateZeroPool (sizeof (IDT_ENTRY
) * NUM_IDT_ENTRIES
);
358 if (IdtEntryTable
== NULL
) {
359 return EFI_OUT_OF_RESOURCES
;
362 for (ExceptionType
= 0; ExceptionType
< NUM_IDT_ENTRIES
; ExceptionType
++) {
363 IdtEntryTable
[ExceptionType
].StubEntry
= (DEBUG_PROC
) (UINTN
) AllocatePool (StubSize
);
364 if (IdtEntryTable
[ExceptionType
].StubEntry
== NULL
) {
368 CopyMem ((VOID
*)(UINTN
)IdtEntryTable
[ExceptionType
].StubEntry
, InterruptEntryStub
, StubSize
);
374 for (ExceptionType
= 0; ExceptionType
< NUM_IDT_ENTRIES
; ExceptionType
++) {
375 if (IdtEntryTable
[ExceptionType
].StubEntry
!= NULL
) {
376 FreePool ((VOID
*)(UINTN
)IdtEntryTable
[ExceptionType
].StubEntry
);
379 FreePool (IdtEntryTable
);
381 return EFI_OUT_OF_RESOURCES
;
386 plUnloadDebugSupportDriver (
387 IN EFI_HANDLE ImageHandle
392 This is the callback that is written to the LoadedImage protocol instance
393 on the image handle. It uninstalls all registered handlers and frees all entry
396 This code executes in boot services context.
399 ImageHandle - The image handle of the unload handler
403 EFI_SUCCESS - always return success
407 EFI_EXCEPTION_TYPE ExceptionType
;
409 for (ExceptionType
= 0; ExceptionType
< NUM_IDT_ENTRIES
; ExceptionType
++) {
410 ManageIdtEntryTable (NULL
, ExceptionType
);
413 FreePool (IdtEntryTable
);
418 InterruptDistrubutionHub (
419 EFI_EXCEPTION_TYPE ExceptionType
,
420 EFI_SYSTEM_CONTEXT_IA32
*ContextRecord
424 Routine Description: Common piece of code that invokes the registered handlers.
426 This code executes in exception context so no efi calls are allowed.
429 ExceptionType - exception type
430 ContextRecord - system context
438 if (IdtEntryTable
[ExceptionType
].RegisteredCallback
!= NULL
) {
439 if (ExceptionType
!= SYSTEM_TIMER_VECTOR
) {
440 IdtEntryTable
[ExceptionType
].RegisteredCallback (ExceptionType
, ContextRecord
);
442 OrigVector
= IdtEntryTable
[ExceptionType
].OrigVector
;
443 IdtEntryTable
[ExceptionType
].RegisteredCallback (ContextRecord
);