1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
|
/** @file
Copyright (c) 2008-2009, Apple Inc. All rights reserved.
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.
**/
#include "CpuDxe.h"
VOID
ExceptionHandlersStart (
VOID
);
VOID
ExceptionHandlersEnd (
VOID
);
VOID
CommonExceptionEntry (
VOID
);
VOID
AsmCommonExceptionEntry (
VOID
);
EFI_EXCEPTION_CALLBACK gExceptionHandlers[MAX_ARM_EXCEPTION + 1];
EFI_EXCEPTION_CALLBACK gDebuggerExceptionHandlers[MAX_ARM_EXCEPTION + 1];
/**
This function registers and enables the handler specified by InterruptHandler for a processor
interrupt or exception type specified by InterruptType. If InterruptHandler is NULL, then the
handler for the processor interrupt or exception type specified by InterruptType is uninstalled.
The installed handler is called once for each processor interrupt or exception.
@param InterruptType A pointer to the processor's current interrupt state. Set to TRUE if interrupts
are enabled and FALSE if interrupts are disabled.
@param InterruptHandler A pointer to a function of type EFI_CPU_INTERRUPT_HANDLER that is called
when a processor interrupt occurs. If this parameter is NULL, then the handler
will be uninstalled.
@retval EFI_SUCCESS The handler for the processor interrupt was successfully installed or uninstalled.
@retval EFI_ALREADY_STARTED InterruptHandler is not NULL, and a handler for InterruptType was
previously installed.
@retval EFI_INVALID_PARAMETER InterruptHandler is NULL, and a handler for InterruptType was not
previously installed.
@retval EFI_UNSUPPORTED The interrupt specified by InterruptType is not supported.
**/
EFI_STATUS
RegisterInterruptHandler (
IN EFI_EXCEPTION_TYPE InterruptType,
IN EFI_CPU_INTERRUPT_HANDLER InterruptHandler
)
{
if (InterruptType > MAX_ARM_EXCEPTION) {
return EFI_UNSUPPORTED;
}
if ((InterruptHandler != NULL) && (gExceptionHandlers[InterruptType] != NULL)) {
return EFI_ALREADY_STARTED;
}
gExceptionHandlers[InterruptType] = InterruptHandler;
return EFI_SUCCESS;
}
VOID
EFIAPI
CommonCExceptionHandler (
IN EFI_EXCEPTION_TYPE ExceptionType,
IN OUT EFI_SYSTEM_CONTEXT SystemContext
)
{
if (ExceptionType <= MAX_ARM_EXCEPTION) {
if (gExceptionHandlers[ExceptionType]) {
gExceptionHandlers[ExceptionType] (ExceptionType, SystemContext);
return;
}
} else {
DEBUG ((EFI_D_ERROR, "Unknown exception type %d from %08x\n", ExceptionType, SystemContext.SystemContextArm->PC));
ASSERT (FALSE);
}
if (ExceptionType == EXCEPT_ARM_SOFTWARE_INTERRUPT) {
//
// ARM JTAG debuggers some times use this vector, so it is not an error to get one
//
return;
}
DefaultExceptionHandler (ExceptionType, SystemContext);
}
EFI_STATUS
InitializeExceptions (
IN EFI_CPU_ARCH_PROTOCOL *Cpu
)
{
EFI_STATUS Status;
UINTN Offset;
UINTN Length;
UINTN Index;
BOOLEAN IrqEnabled;
BOOLEAN FiqEnabled;
EFI_PHYSICAL_ADDRESS Base;
UINT32 *VectorBase;
//
// Disable interrupts
//
Cpu->GetInterruptState (Cpu, &IrqEnabled);
Cpu->DisableInterrupt (Cpu);
//
// EFI does not use the FIQ, but a debugger might so we must disable
// as we take over the exception vectors.
//
FiqEnabled = ArmGetFiqState ();
ArmDisableFiq ();
//
// Copy an implementation of the ARM exception vectors to PcdCpuVectorBaseAddress.
//
Length = (UINTN)ExceptionHandlersEnd - (UINTN)ExceptionHandlersStart;
//
// Reserve space for the exception handlers
//
Base = (EFI_PHYSICAL_ADDRESS)PcdGet32 (PcdCpuVectorBaseAddress);
VectorBase = (UINT32 *)(UINTN)Base;
Status = gBS->AllocatePages (AllocateAddress, EfiBootServicesCode, EFI_SIZE_TO_PAGES (Length), &Base);
// If the request was for memory that's not in the memory map (which is often the case for 0x00000000
// on embedded systems, for example, we don't want to hang up. So we'll check here for a status of
// EFI_NOT_FOUND, and continue in that case.
if (EFI_ERROR(Status) && (Status != EFI_NOT_FOUND)) {
ASSERT_EFI_ERROR (Status);
}
// Save existing vector table, in case debugger is already hooked in
CopyMem ((VOID *)gDebuggerExceptionHandlers, (VOID *)VectorBase, sizeof (gDebuggerExceptionHandlers));
// Copy our assembly code into the page that contains the exception vectors.
CopyMem ((VOID *)VectorBase, (VOID *)ExceptionHandlersStart, Length);
//
// Patch in the common Assembly exception handler
//
Offset = (UINTN)CommonExceptionEntry - (UINTN)ExceptionHandlersStart;
*(UINTN *) ((UINT8 *)(UINTN)PcdGet32 (PcdCpuVectorBaseAddress) + Offset) = (UINTN)AsmCommonExceptionEntry;
//
// Initialize the C entry points for interrupts
//
for (Index = 0; Index <= MAX_ARM_EXCEPTION; Index++) {
if ((gDebuggerExceptionHandlers[Index] == 0) || (gDebuggerExceptionHandlers[Index] == (VOID *)(UINTN)0xEAFFFFFE)) {
// Exception handler contains branch to vector location (jmp $) so no handler
// NOTE: This code assumes vectors are ARM and not Thumb code
Status = RegisterInterruptHandler (Index, NULL);
ASSERT_EFI_ERROR (Status);
} else {
// If the debugger has alread hooked put its vector back
VectorBase[Index] = (UINT32)(UINTN)gDebuggerExceptionHandlers[Index];
}
}
// Flush Caches since we updated executable stuff
InvalidateInstructionCacheRange ((VOID *)PcdGet32(PcdCpuVectorBaseAddress), Length);
if (FiqEnabled) {
ArmEnableFiq ();
}
if (IrqEnabled) {
//
// Restore interrupt state
//
Status = Cpu->EnableInterrupt (Cpu);
}
return Status;
}
|
