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6e8a984e | 1 | /** @file\r |
509bc208 | 2 | IA32 specific functions to support Debug Support protocol.\r |
6e8a984e | 3 | \r |
509bc208 | 4 | Copyright (c) 2008, Intel Corporation\r |
6e8a984e | 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 | |
14 | \r | |
15 | #include "DebugSupport.h"\r | |
16 | \r | |
43a99f08 | 17 | IA32_IDT_GATE_DESCRIPTOR NullDesc = {{0}};\r |
18 | \r | |
6e8a984e | 19 | /**\r |
c84507ab | 20 | Get Interrupt Handle from IDT Gate Descriptor.\r |
6e8a984e | 21 | \r |
c84507ab | 22 | @param IdtGateDescriptor IDT Gate Descriptor.\r |
6e8a984e | 23 | \r |
c84507ab | 24 | @return Interrupt Handle stored in IDT Gate Descriptor.\r |
6e8a984e | 25 | \r |
26 | **/\r | |
c84507ab | 27 | UINTN\r |
28 | GetInterruptHandleFromIdt (\r | |
29 | IN IA32_IDT_GATE_DESCRIPTOR *IdtGateDescriptor\r | |
6e8a984e | 30 | )\r |
31 | {\r | |
c84507ab | 32 | UINTN InterruptHandle;\r |
6e8a984e | 33 | \r |
c84507ab | 34 | ((UINT16 *) &InterruptHandle)[0] = (UINT16) IdtGateDescriptor->Bits.OffsetLow;\r |
35 | ((UINT16 *) &InterruptHandle)[1] = (UINT16) IdtGateDescriptor->Bits.OffsetHigh;\r | |
6e8a984e | 36 | \r |
c84507ab | 37 | return InterruptHandle;\r |
6e8a984e | 38 | }\r |
39 | \r | |
40 | /**\r | |
41 | Allocate pool for a new IDT entry stub.\r | |
42 | \r | |
43 | Copy the generic stub into the new buffer and fixup the vector number\r | |
44 | and jump target address.\r | |
45 | \r | |
46 | @param ExceptionType This is the exception type that the new stub will be created\r | |
47 | for.\r | |
48 | @param Stub On successful exit, *Stub contains the newly allocated entry stub.\r | |
49 | \r | |
6e8a984e | 50 | **/\r |
c84507ab | 51 | VOID\r |
6e8a984e | 52 | CreateEntryStub (\r |
53 | IN EFI_EXCEPTION_TYPE ExceptionType,\r | |
54 | OUT VOID **Stub\r | |
55 | )\r | |
56 | {\r | |
57 | UINT8 *StubCopy;\r | |
58 | \r | |
59 | StubCopy = *Stub;\r | |
60 | \r | |
61 | //\r | |
62 | // Fixup the stub code for this vector\r | |
63 | //\r | |
64 | \r | |
65 | // The stub code looks like this:\r | |
66 | //\r | |
67 | // 00000000 89 25 00000004 R mov AppEsp, esp ; save stack top\r | |
68 | // 00000006 BC 00008014 R mov esp, offset DbgStkBot ; switch to debugger stack\r | |
69 | // 0000000B 6A 00 push 0 ; push vector number - will be modified before installed\r | |
70 | // 0000000D E9 db 0e9h ; jump rel32\r | |
71 | // 0000000E 00000000 dd 0 ; fixed up to relative address of CommonIdtEntry\r | |
72 | //\r | |
73 | \r | |
74 | //\r | |
75 | // poke in the exception type so the second push pushes the exception type\r | |
76 | //\r | |
77 | StubCopy[0x0c] = (UINT8) ExceptionType;\r | |
78 | \r | |
79 | //\r | |
80 | // fixup the jump target to point to the common entry\r | |
81 | //\r | |
82 | *(UINT32 *) &StubCopy[0x0e] = (UINT32) CommonIdtEntry - (UINT32) &StubCopy[StubSize];\r | |
83 | \r | |
c84507ab | 84 | return ;\r |
6e8a984e | 85 | }\r |
86 | \r | |
87 | /**\r | |
88 | This is the main worker function that manages the state of the interrupt\r | |
89 | handlers. It both installs and uninstalls interrupt handlers based on the\r | |
90 | value of NewCallback. If NewCallback is NULL, then uninstall is indicated.\r | |
91 | If NewCallback is non-NULL, then install is indicated.\r | |
92 | \r | |
93 | @param NewCallback If non-NULL, NewCallback specifies the new handler to register.\r | |
94 | If NULL, specifies that the previously registered handler should\r | |
95 | be uninstalled.\r | |
96 | @param ExceptionType Indicates which entry to manage.\r | |
97 | \r | |
c84507ab | 98 | @retval EFI_SUCCESS Installing or Uninstalling operation is ok.\r |
6e8a984e | 99 | @retval EFI_INVALID_PARAMETER Requested uninstalling a handler from a vector that has\r |
100 | no handler registered for it\r | |
101 | @retval EFI_ALREADY_STARTED Requested install to a vector that already has a handler registered.\r | |
6e8a984e | 102 | \r |
103 | **/\r | |
104 | EFI_STATUS\r | |
105 | ManageIdtEntryTable (\r | |
c84507ab | 106 | VOID (*NewCallback)(),\r |
6e8a984e | 107 | EFI_EXCEPTION_TYPE ExceptionType\r |
108 | )\r | |
109 | {\r | |
110 | EFI_STATUS Status;\r | |
111 | \r | |
112 | Status = EFI_SUCCESS;\r | |
113 | \r | |
114 | if (!FeaturePcdGet (PcdNtEmulatorEnable)) {\r | |
115 | if (CompareMem (&IdtEntryTable[ExceptionType].NewDesc, &NullDesc, sizeof (IA32_IDT_GATE_DESCRIPTOR)) != 0) {\r | |
116 | //\r | |
117 | // we've already installed to this vector\r | |
118 | //\r | |
119 | if (NewCallback != NULL) {\r | |
120 | //\r | |
121 | // if the input handler is non-null, error\r | |
122 | //\r | |
123 | Status = EFI_ALREADY_STARTED;\r | |
124 | } else {\r | |
c84507ab | 125 | UnhookEntry (ExceptionType);\r |
6e8a984e | 126 | }\r |
127 | } else {\r | |
128 | //\r | |
129 | // no user handler installed on this vector\r | |
130 | //\r | |
131 | if (NewCallback == NULL) {\r | |
132 | //\r | |
133 | // if the input handler is null, error\r | |
134 | //\r | |
135 | Status = EFI_INVALID_PARAMETER;\r | |
136 | } else {\r | |
c84507ab | 137 | HookEntry (ExceptionType, NewCallback);\r |
6e8a984e | 138 | }\r |
139 | }\r | |
140 | }\r | |
141 | \r | |
142 | return Status;\r | |
143 | }\r |