3 Copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
5 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.
19 ExceptionHandlersStart (
24 ExceptionHandlersEnd (
29 CommonExceptionEntry (
34 AsmCommonExceptionEntry (
39 EFI_EXCEPTION_CALLBACK gExceptionHandlers
[MAX_ARM_EXCEPTION
+ 1];
40 EFI_EXCEPTION_CALLBACK gDebuggerExceptionHandlers
[MAX_ARM_EXCEPTION
+ 1];
45 This function registers and enables the handler specified by InterruptHandler for a processor
46 interrupt or exception type specified by InterruptType. If InterruptHandler is NULL, then the
47 handler for the processor interrupt or exception type specified by InterruptType is uninstalled.
48 The installed handler is called once for each processor interrupt or exception.
50 @param InterruptType A pointer to the processor's current interrupt state. Set to TRUE if interrupts
51 are enabled and FALSE if interrupts are disabled.
52 @param InterruptHandler A pointer to a function of type EFI_CPU_INTERRUPT_HANDLER that is called
53 when a processor interrupt occurs. If this parameter is NULL, then the handler
56 @retval EFI_SUCCESS The handler for the processor interrupt was successfully installed or uninstalled.
57 @retval EFI_ALREADY_STARTED InterruptHandler is not NULL, and a handler for InterruptType was
59 @retval EFI_INVALID_PARAMETER InterruptHandler is NULL, and a handler for InterruptType was not
61 @retval EFI_UNSUPPORTED The interrupt specified by InterruptType is not supported.
65 RegisterInterruptHandler (
66 IN EFI_EXCEPTION_TYPE InterruptType
,
67 IN EFI_CPU_INTERRUPT_HANDLER InterruptHandler
70 if (InterruptType
> MAX_ARM_EXCEPTION
) {
71 return EFI_UNSUPPORTED
;
74 if ((InterruptHandler
!= NULL
) && (gExceptionHandlers
[InterruptType
] != NULL
)) {
75 return EFI_ALREADY_STARTED
;
78 gExceptionHandlers
[InterruptType
] = InterruptHandler
;
88 CommonCExceptionHandler (
89 IN EFI_EXCEPTION_TYPE ExceptionType
,
90 IN OUT EFI_SYSTEM_CONTEXT SystemContext
94 if (ExceptionType
<= MAX_ARM_EXCEPTION
) {
95 if (gExceptionHandlers
[ExceptionType
]) {
96 gExceptionHandlers
[ExceptionType
] (ExceptionType
, SystemContext
);
100 DEBUG ((EFI_D_ERROR
, "Unknown exception type %d from %08x\n", ExceptionType
, SystemContext
.SystemContextArm
->PC
));
104 if (ExceptionType
== EXCEPT_ARM_SOFTWARE_INTERRUPT
) {
106 // ARM JTAG debuggers some times use this vector, so it is not an error to get one
111 DefaultExceptionHandler (ExceptionType
, SystemContext
);
117 InitializeExceptions (
118 IN EFI_CPU_ARCH_PROTOCOL
*Cpu
127 EFI_PHYSICAL_ADDRESS Base
;
131 // Disable interrupts
133 Cpu
->GetInterruptState (Cpu
, &IrqEnabled
);
134 Cpu
->DisableInterrupt (Cpu
);
137 // EFI does not use the FIQ, but a debugger might so we must disable
138 // as we take over the exception vectors.
140 FiqEnabled
= ArmGetFiqState ();
144 // Copy an implementation of the ARM exception vectors to PcdCpuVectorBaseAddress.
146 Length
= (UINTN
)ExceptionHandlersEnd
- (UINTN
)ExceptionHandlersStart
;
149 // Reserve space for the exception handlers
151 Base
= (EFI_PHYSICAL_ADDRESS
)PcdGet32 (PcdCpuVectorBaseAddress
);
152 VectorBase
= (UINT32
*)(UINTN
)Base
;
153 Status
= gBS
->AllocatePages (AllocateAddress
, EfiBootServicesCode
, EFI_SIZE_TO_PAGES (Length
), &Base
);
154 // If the request was for memory that's not in the memory map (which is often the case for 0x00000000
155 // on embedded systems, for example, we don't want to hang up. So we'll check here for a status of
156 // EFI_NOT_FOUND, and continue in that case.
157 if (EFI_ERROR(Status
) && (Status
!= EFI_NOT_FOUND
)) {
158 ASSERT_EFI_ERROR (Status
);
161 // Save existing vector table, in case debugger is already hooked in
162 CopyMem ((VOID
*)gDebuggerExceptionHandlers
, (VOID
*)VectorBase
, sizeof (gDebuggerExceptionHandlers
));
164 // Copy our assembly code into the page that contains the exception vectors.
165 CopyMem ((VOID
*)VectorBase
, (VOID
*)ExceptionHandlersStart
, Length
);
168 // Patch in the common Assembly exception handler
170 Offset
= (UINTN
)CommonExceptionEntry
- (UINTN
)ExceptionHandlersStart
;
171 *(UINTN
*) ((UINT8
*)(UINTN
)PcdGet32 (PcdCpuVectorBaseAddress
) + Offset
) = (UINTN
)AsmCommonExceptionEntry
;
174 // Initialize the C entry points for interrupts
176 for (Index
= 0; Index
<= MAX_ARM_EXCEPTION
; Index
++) {
177 if ((gDebuggerExceptionHandlers
[Index
] == 0) || (gDebuggerExceptionHandlers
[Index
] == (VOID
*)(UINTN
)0xEAFFFFFE)) {
178 // Exception handler contains branch to vector location (jmp $) so no handler
179 // NOTE: This code assumes vectors are ARM and not Thumb code
180 Status
= RegisterInterruptHandler (Index
, NULL
);
181 ASSERT_EFI_ERROR (Status
);
183 // If the debugger has alread hooked put its vector back
184 VectorBase
[Index
] = (UINT32
)(UINTN
)gDebuggerExceptionHandlers
[Index
];
188 // Flush Caches since we updated executable stuff
189 InvalidateInstructionCacheRange ((VOID
*)PcdGet32(PcdCpuVectorBaseAddress
), Length
);
197 // Restore interrupt state
199 Status
= Cpu
->EnableInterrupt (Cpu
);