3 Copyright (c) 2008-2009, Apple Inc. All rights reserved.
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.
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
;
85 This function registers and enables the handler specified by InterruptHandler for a processor
86 interrupt or exception type specified by InterruptType. If InterruptHandler is NULL, then the
87 handler for the processor interrupt or exception type specified by InterruptType is uninstalled.
88 The installed handler is called once for each processor interrupt or exception.
90 @param InterruptType A pointer to the processor's current interrupt state. Set to TRUE if interrupts
91 are enabled and FALSE if interrupts are disabled.
92 @param InterruptHandler A pointer to a function of type EFI_CPU_INTERRUPT_HANDLER that is called
93 when a processor interrupt occurs. If this parameter is NULL, then the handler
96 @retval EFI_SUCCESS The handler for the processor interrupt was successfully installed or uninstalled.
97 @retval EFI_ALREADY_STARTED InterruptHandler is not NULL, and a handler for InterruptType was
99 @retval EFI_INVALID_PARAMETER InterruptHandler is NULL, and a handler for InterruptType was not
100 previously installed.
101 @retval EFI_UNSUPPORTED The interrupt specified by InterruptType is not supported.
105 RegisterDebuggerInterruptHandler (
106 IN EFI_EXCEPTION_TYPE InterruptType
,
107 IN EFI_CPU_INTERRUPT_HANDLER InterruptHandler
110 if (InterruptType
> MAX_ARM_EXCEPTION
) {
111 return EFI_UNSUPPORTED
;
114 if ((InterruptHandler
!= NULL
) && (gDebuggerExceptionHandlers
[InterruptType
] != NULL
)) {
115 return EFI_ALREADY_STARTED
;
118 gDebuggerExceptionHandlers
[InterruptType
] = InterruptHandler
;
127 CommonCExceptionHandler (
128 IN EFI_EXCEPTION_TYPE ExceptionType
,
129 IN OUT EFI_SYSTEM_CONTEXT SystemContext
132 BOOLEAN Dispatched
= FALSE
;
135 if (ExceptionType
<= MAX_ARM_EXCEPTION
) {
136 if (gDebuggerExceptionHandlers
[ExceptionType
]) {
138 // If DebugSupport hooked the interrupt call the handler. This does not disable
139 // the normal handler.
141 gDebuggerExceptionHandlers
[ExceptionType
] (ExceptionType
, SystemContext
);
144 if (gExceptionHandlers
[ExceptionType
]) {
145 gExceptionHandlers
[ExceptionType
] (ExceptionType
, SystemContext
);
149 DEBUG ((EFI_D_ERROR
, "Unknown exception type %d from %08x\n", ExceptionType
, SystemContext
.SystemContextArm
->PC
));
155 // We did work so this was an expected ExceptionType
160 if (ExceptionType
== EXCEPT_ARM_SOFTWARE_INTERRUPT
) {
162 // ARM JTAG debuggers some times use this vector, so it is not an error to get one
167 DefaultExceptionHandler (ExceptionType
, SystemContext
);
173 InitializeExceptions (
174 IN EFI_CPU_ARCH_PROTOCOL
*Cpu
183 EFI_PHYSICAL_ADDRESS Base
;
187 // Disable interrupts
189 Cpu
->GetInterruptState (Cpu
, &IrqEnabled
);
190 Cpu
->DisableInterrupt (Cpu
);
193 // EFI does not use the FIQ, but a debugger might so we must disable
194 // as we take over the exception vectors.
196 FiqEnabled
= ArmGetFiqState ();
200 // Copy an implementation of the ARM exception vectors to PcdCpuVectorBaseAddress.
202 Length
= (UINTN
)ExceptionHandlersEnd
- (UINTN
)ExceptionHandlersStart
;
205 // Reserve space for the exception handlers
207 Base
= (EFI_PHYSICAL_ADDRESS
)PcdGet32 (PcdCpuVectorBaseAddress
);
208 VectorBase
= (UINT32
*)(UINTN
)Base
;
209 Status
= gBS
->AllocatePages (AllocateAddress
, EfiBootServicesCode
, EFI_SIZE_TO_PAGES (Length
), &Base
);
210 // If the request was for memory that's not in the memory map (which is often the case for 0x00000000
211 // on embedded systems, for example, we don't want to hang up. So we'll check here for a status of
212 // EFI_NOT_FOUND, and continue in that case.
213 if (EFI_ERROR(Status
) && (Status
!= EFI_NOT_FOUND
)) {
214 ASSERT_EFI_ERROR (Status
);
217 // Save existing vector table, in case debugger is already hooked in
218 CopyMem ((VOID
*)gDebuggerExceptionHandlers
, (VOID
*)VectorBase
, sizeof (gDebuggerExceptionHandlers
));
221 // Initialize the C entry points for interrupts
223 for (Index
= 0; Index
<= MAX_ARM_EXCEPTION
; Index
++) {
224 Status
= RegisterInterruptHandler (Index
, NULL
);
225 ASSERT_EFI_ERROR (Status
);
227 if (VectorBase
[Index
] == 0xEAFFFFFE) {
228 // Exception handler contains branch to vector location (jmp $) so no handler
229 // NOTE: This code assumes vectors are ARM and not Thumb code
230 gDebuggerExceptionHandlers
[Index
] = NULL
;
234 // Copy our assembly code into the page that contains the exception vectors.
235 CopyMem ((VOID
*)VectorBase
, (VOID
*)ExceptionHandlersStart
, Length
);
238 // Patch in the common Assembly exception handler
240 Offset
= (UINTN
)CommonExceptionEntry
- (UINTN
)ExceptionHandlersStart
;
241 *(UINTN
*) ((UINT8
*)(UINTN
)PcdGet32 (PcdCpuVectorBaseAddress
) + Offset
) = (UINTN
)AsmCommonExceptionEntry
;
243 // Flush Caches since we updated executable stuff
244 InvalidateInstructionCacheRange ((VOID
*)PcdGet32(PcdCpuVectorBaseAddress
), Length
);
252 // Restore interrupt state
254 Status
= Cpu
->EnableInterrupt (Cpu
);