2 X64 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.
15 #include "DebugSupport.h"
17 IA32_IDT_GATE_DESCRIPTOR NullDesc
= {{0,0}};
20 Get Interrupt Handle from IDT Gate Descriptor.
22 @param IdtGateDecriptor IDT Gate Descriptor.
24 @return Interrupt Handle stored in IDT Gate Descriptor.
28 GetInterruptHandleFromIdt (
29 IN IA32_IDT_GATE_DESCRIPTOR
*IdtGateDecriptor
32 UINTN InterruptHandle
;
34 ((UINT16
*) &InterruptHandle
)[0] = (UINT16
) IdtGateDecriptor
->Bits
.OffsetLow
;
35 ((UINT16
*) &InterruptHandle
)[1] = (UINT16
) IdtGateDecriptor
->Bits
.OffsetHigh
;
36 ((UINT32
*) &InterruptHandle
)[1] = (UINT32
) IdtGateDecriptor
->Bits
.OffsetUpper
;
38 return InterruptHandle
;
42 Allocate pool for a new IDT entry stub.
44 Copy the generic stub into the new buffer and fixup the vector number
45 and jump target address.
47 @param ExceptionType This is the exception type that the new stub will be created
49 @param Stub On successful exit, *Stub contains the newly allocated entry stub.
54 IN EFI_EXCEPTION_TYPE ExceptionType
,
63 // Fixup the stub code for this vector
66 // The stub code looks like this:
68 // 00000000 6A 00 push 0 ; push vector number - will be modified before installed
69 // 00000002 E9 db 0e9h ; jump rel32
70 // 00000003 00000000 dd 0 ; fixed up to relative address of CommonIdtEntry
74 // poke in the exception type so the second push pushes the exception type
76 StubCopy
[0x1] = (UINT8
) ExceptionType
;
79 // fixup the jump target to point to the common entry
81 *(UINT32
*) &StubCopy
[0x3] = (UINT32
)((UINTN
) CommonIdtEntry
- (UINTN
) &StubCopy
[StubSize
]);
87 This is the main worker function that manages the state of the interrupt
88 handlers. It both installs and uninstalls interrupt handlers based on the
89 value of NewCallback. If NewCallback is NULL, then uninstall is indicated.
90 If NewCallback is non-NULL, then install is indicated.
92 @param NewCallback If non-NULL, NewCallback specifies the new handler to register.
93 If NULL, specifies that the previously registered handler should
95 @param ExceptionType Indicates which entry to manage.
97 @retval EFI_SUCCESS Process is ok.
98 @retval EFI_INVALID_PARAMETER Requested uninstalling a handler from a vector that has
99 no handler registered for it
100 @retval EFI_ALREADY_STARTED Requested install to a vector that already has a handler registered.
101 @retval others Possible return values are passed through from UnHookEntry and HookEntry.
105 ManageIdtEntryTable (
106 VOID (*NewCallback
)(),
107 EFI_EXCEPTION_TYPE ExceptionType
112 Status
= EFI_SUCCESS
;
114 if (CompareMem (&IdtEntryTable
[ExceptionType
].NewDesc
, &NullDesc
, sizeof (IA32_IDT_GATE_DESCRIPTOR
)) != 0) {
116 // we've already installed to this vector
118 if (NewCallback
!= NULL
) {
120 // if the input handler is non-null, error
122 Status
= EFI_ALREADY_STARTED
;
124 UnhookEntry (ExceptionType
);
128 // no user handler installed on this vector
130 if (NewCallback
== NULL
) {
132 // if the input handler is null, error
134 Status
= EFI_INVALID_PARAMETER
;
136 HookEntry (ExceptionType
, NewCallback
);