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/** @file
X64 specific debug support functions
Copyright (c) 2006 - 2007, Intel Corporation
All rights reserved. This program and the accompanying materials
are licensed and made available under the terms and conditions of the BSD License
which accompanies this distribution. The full text of the license may be found at
http://opensource.org/licenses/bsd-license.php
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
**/
//
// private header files
//
#include "PlDebugSupport.h"
//
// This the global main table to keep track of the interrupts
//
IDT_ENTRY *IdtEntryTable = NULL;
DESCRIPTOR NullDesc = {0, 0};
/**
Allocate pool for a new IDT entry stub.
Copy the generic stub into the new buffer and fixup the vector number
and jump target address.
@param ExceptionType This is the exception type that the new stub will be created
for.
@param Stub On successful exit, *Stub contains the newly allocated entry stub.
@retval EFI_SUCCESS Always.
**/
EFI_STATUS
CreateEntryStub (
IN EFI_EXCEPTION_TYPE ExceptionType,
OUT VOID **Stub
)
{
UINT8 *StubCopy;
StubCopy = *Stub;
//
// Fixup the stub code for this vector
//
// The stub code looks like this:
//
// 00000000 6A 00 push 0 ; push vector number - will be modified before installed
// 00000002 E9 db 0e9h ; jump rel32
// 00000003 00000000 dd 0 ; fixed up to relative address of CommonIdtEntry
//
//
// poke in the exception type so the second push pushes the exception type
//
StubCopy[0x1] = (UINT8) ExceptionType;
//
// fixup the jump target to point to the common entry
//
*(UINT32 *) &StubCopy[0x3] = (UINT32)((UINTN) CommonIdtEntry - (UINTN) &StubCopy[StubSize]);
return EFI_SUCCESS;
}
/**
Creates a nes entry stub. Then saves the current IDT entry and replaces it
with an interrupt gate for the new entry point. The IdtEntryTable is updated
with the new registered function.
This code executes in boot services context. The stub entry executes in interrupt
context.
@param ExceptionType Specifies which vector to hook.
@param NewCallback A pointer to the new function to be registered.
@retval EFI_SUCCESS Always.
**/
EFI_STATUS
HookEntry (
IN EFI_EXCEPTION_TYPE ExceptionType,
IN VOID (*NewCallback) ()
)
{
BOOLEAN OldIntFlagState;
EFI_STATUS Status;
Status = CreateEntryStub (ExceptionType, (VOID **) &IdtEntryTable[ExceptionType].StubEntry);
if (Status == EFI_SUCCESS) {
OldIntFlagState = WriteInterruptFlag (0);
READ_IDT (ExceptionType, &(IdtEntryTable[ExceptionType].OrigDesc));
((UINT16 *) &IdtEntryTable[ExceptionType].OrigVector)[0] = ((UINT16 *) &IdtEntryTable[ExceptionType].OrigDesc.Low)[0];
((UINT16 *) &IdtEntryTable[ExceptionType].OrigVector)[1] = ((UINT16 *) &IdtEntryTable[ExceptionType].OrigDesc.Low)[3];
((UINT32 *) &IdtEntryTable[ExceptionType].OrigVector)[1] = ((UINT32 *) &IdtEntryTable[ExceptionType].OrigDesc.High)[0];
Vect2Desc (&IdtEntryTable[ExceptionType].NewDesc, IdtEntryTable[ExceptionType].StubEntry);
IdtEntryTable[ExceptionType].RegisteredCallback = NewCallback;
WRITE_IDT (ExceptionType, &(IdtEntryTable[ExceptionType].NewDesc));
WriteInterruptFlag (OldIntFlagState);
}
return Status;
}
/**
Undoes HookEntry. This code executes in boot services context.
@param ExceptionType Specifies which entry to unhook
@retval EFI_SUCCESS Always.
**/
EFI_STATUS
UnhookEntry (
IN EFI_EXCEPTION_TYPE ExceptionType
)
{
BOOLEAN OldIntFlagState;
OldIntFlagState = WriteInterruptFlag (0);
WRITE_IDT (ExceptionType, &(IdtEntryTable[ExceptionType].OrigDesc));
WriteInterruptFlag (OldIntFlagState);
return EFI_SUCCESS;
}
/**
This is the main worker function that manages the state of the interrupt
handlers. It both installs and uninstalls interrupt handlers based on the
value of NewCallback. If NewCallback is NULL, then uninstall is indicated.
If NewCallback is non-NULL, then install is indicated.
@param NewCallback If non-NULL, NewCallback specifies the new handler to register.
If NULL, specifies that the previously registered handler should
be uninstalled.
@param ExceptionType Indicates which entry to manage.
@retval EFI_SUCCESS Process is ok.
@retval EFI_INVALID_PARAMETER Requested uninstalling a handler from a vector that has
no handler registered for it
@retval EFI_ALREADY_STARTED Requested install to a vector that already has a handler registered.
@retval others Possible return values are passed through from UnHookEntry and HookEntry.
**/
EFI_STATUS
ManageIdtEntryTable (
VOID (*NewCallback)(),
EFI_EXCEPTION_TYPE ExceptionType
)
{
EFI_STATUS Status;
Status = EFI_SUCCESS;
if (COMPARE_DESCRIPTOR (&IdtEntryTable[ExceptionType].NewDesc, &NullDesc)) {
//
// we've already installed to this vector
//
if (NewCallback != NULL) {
//
// if the input handler is non-null, error
//
Status = EFI_ALREADY_STARTED;
} else {
Status = UnhookEntry (ExceptionType);
}
} else {
//
// no user handler installed on this vector
//
if (NewCallback == NULL) {
//
// if the input handler is null, error
//
Status = EFI_INVALID_PARAMETER;
} else {
Status = HookEntry (ExceptionType, NewCallback);
}
}
return Status;
}
/**
This is a DebugSupport protocol member function, hard
coded to support only 1 processor for now.
@param This The DebugSupport instance
@param MaxProcessorIndex The maximuim supported processor index
@retval EFI_SUCCESS Always returned with **MaxProcessorIndex set to 0.
**/
EFI_STATUS
EFIAPI
GetMaximumProcessorIndex (
IN EFI_DEBUG_SUPPORT_PROTOCOL *This,
OUT UINTN *MaxProcessorIndex
)
{
*MaxProcessorIndex = 0;
return (EFI_SUCCESS);
}
/**
DebugSupport protocol member function.
@param This The DebugSupport instance
@param ProcessorIndex Which processor the callback applies to.
@param PeriodicCallback Callback function
@retval EFI_SUCCESS Indicates the callback was registered.
@retval others Callback was not registered.
**/
EFI_STATUS
EFIAPI
RegisterPeriodicCallback (
IN EFI_DEBUG_SUPPORT_PROTOCOL *This,
IN UINTN ProcessorIndex,
IN EFI_PERIODIC_CALLBACK PeriodicCallback
)
{
return ManageIdtEntryTable (PeriodicCallback, SYSTEM_TIMER_VECTOR);
}
/**
DebugSupport protocol member function.
This code executes in boot services context.
@param This The DebugSupport instance
@param ProcessorIndex Which processor the callback applies to.
@param NewCallback Callback function
@param ExceptionType Which exception to hook
@retval EFI_SUCCESS Indicates the callback was registered.
@retval others Callback was not registered.
**/
EFI_STATUS
EFIAPI
RegisterExceptionCallback (
IN EFI_DEBUG_SUPPORT_PROTOCOL *This,
IN UINTN ProcessorIndex,
IN EFI_EXCEPTION_CALLBACK NewCallback,
IN EFI_EXCEPTION_TYPE ExceptionType
)
{
return ManageIdtEntryTable (NewCallback, ExceptionType);
}
/**
DebugSupport protocol member function. Calls assembly routine to flush cache.
@param This The DebugSupport instance
@param ProcessorIndex Which processor the callback applies to.
@param Start Physical base of the memory range to be invalidated
@param Length mininum number of bytes in instruction cache to invalidate
@retval EFI_SUCCESS Always returned.
**/
EFI_STATUS
EFIAPI
InvalidateInstructionCache (
IN EFI_DEBUG_SUPPORT_PROTOCOL *This,
IN UINTN ProcessorIndex,
IN VOID *Start,
IN UINT64 Length
)
{
AsmWbinvd ();
return EFI_SUCCESS;
}
/**
Initializes driver's handler registration databas.
This code executes in boot services context
Must be public because it's referenced from DebugSupport.c
@retval EFI_UNSUPPORTED If x64 processor does not support FXSTOR/FXRSTOR instructions,
the context save will fail, so these processor's are not supported.
@retval EFI_OUT_OF_RESOURCES Fails to allocate memory.
@retval EFI_SUCCESS Initializes successfully.
**/
EFI_STATUS
PlInitializeDebugSupportDriver (
VOID
)
{
EFI_EXCEPTION_TYPE ExceptionType;
if (!FxStorSupport ()) {
return EFI_UNSUPPORTED;
}
IdtEntryTable = AllocateZeroPool (sizeof (IDT_ENTRY) * NUM_IDT_ENTRIES);
if (IdtEntryTable == NULL) {
return EFI_OUT_OF_RESOURCES;
}
for (ExceptionType = 0; ExceptionType < NUM_IDT_ENTRIES; ExceptionType++) {
IdtEntryTable[ExceptionType].StubEntry = (DEBUG_PROC) (UINTN) AllocatePool (StubSize);
if (IdtEntryTable[ExceptionType].StubEntry == NULL) {
goto ErrorCleanup;
}
CopyMem ((VOID *)(UINTN)IdtEntryTable[ExceptionType].StubEntry, InterruptEntryStub, StubSize);
}
return EFI_SUCCESS;
ErrorCleanup:
for (ExceptionType = 0; ExceptionType < NUM_IDT_ENTRIES; ExceptionType++) {
if (IdtEntryTable[ExceptionType].StubEntry != NULL) {
FreePool ((VOID *)(UINTN)IdtEntryTable[ExceptionType].StubEntry);
}
}
FreePool (IdtEntryTable);
return EFI_OUT_OF_RESOURCES;
}
/**
This is the callback that is written to the LoadedImage protocol instance
on the image handle. It uninstalls all registered handlers and frees all entry
stub memory.
@param ImageHandle The firmware allocated handle for the EFI image.
@retval EFI_SUCCESS Always.
**/
EFI_STATUS
EFIAPI
PlUnloadDebugSupportDriver (
IN EFI_HANDLE ImageHandle
)
{
EFI_EXCEPTION_TYPE ExceptionType;
for (ExceptionType = 0; ExceptionType < NUM_IDT_ENTRIES; ExceptionType++) {
ManageIdtEntryTable (NULL, ExceptionType);
}
FreePool (IdtEntryTable);
return EFI_SUCCESS;
}
/**
Common piece of code that invokes the registered handlers.
This code executes in exception context so no efi calls are allowed.
@param ExceptionType Exception type
@param ContextRecord System context
**/
VOID
InterruptDistrubutionHub (
EFI_EXCEPTION_TYPE ExceptionType,
EFI_SYSTEM_CONTEXT_IA32 *ContextRecord
)
{
if (IdtEntryTable[ExceptionType].RegisteredCallback != NULL) {
if (ExceptionType != SYSTEM_TIMER_VECTOR) {
IdtEntryTable[ExceptionType].RegisteredCallback (ExceptionType, ContextRecord);
} else {
OrigVector = IdtEntryTable[ExceptionType].OrigVector;
IdtEntryTable[ExceptionType].RegisteredCallback (ContextRecord);
}
}
}
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