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.
17 //FIXME: Will not compile on non-ARMv7 builds
18 #include <Chipset/ArmV7.h>
21 ExceptionHandlersStart (
26 ExceptionHandlersEnd (
31 CommonExceptionEntry (
36 AsmCommonExceptionEntry (
41 EFI_EXCEPTION_CALLBACK gExceptionHandlers
[MAX_ARM_EXCEPTION
+ 1];
42 EFI_EXCEPTION_CALLBACK gDebuggerExceptionHandlers
[MAX_ARM_EXCEPTION
+ 1];
47 This function registers and enables the handler specified by InterruptHandler for a processor
48 interrupt or exception type specified by InterruptType. If InterruptHandler is NULL, then the
49 handler for the processor interrupt or exception type specified by InterruptType is uninstalled.
50 The installed handler is called once for each processor interrupt or exception.
52 @param InterruptType A pointer to the processor's current interrupt state. Set to TRUE if interrupts
53 are enabled and FALSE if interrupts are disabled.
54 @param InterruptHandler A pointer to a function of type EFI_CPU_INTERRUPT_HANDLER that is called
55 when a processor interrupt occurs. If this parameter is NULL, then the handler
58 @retval EFI_SUCCESS The handler for the processor interrupt was successfully installed or uninstalled.
59 @retval EFI_ALREADY_STARTED InterruptHandler is not NULL, and a handler for InterruptType was
61 @retval EFI_INVALID_PARAMETER InterruptHandler is NULL, and a handler for InterruptType was not
63 @retval EFI_UNSUPPORTED The interrupt specified by InterruptType is not supported.
67 RegisterInterruptHandler (
68 IN EFI_EXCEPTION_TYPE InterruptType
,
69 IN EFI_CPU_INTERRUPT_HANDLER InterruptHandler
72 if (InterruptType
> MAX_ARM_EXCEPTION
) {
73 return EFI_UNSUPPORTED
;
76 if ((InterruptHandler
!= NULL
) && (gExceptionHandlers
[InterruptType
] != NULL
)) {
77 return EFI_ALREADY_STARTED
;
80 gExceptionHandlers
[InterruptType
] = InterruptHandler
;
90 CommonCExceptionHandler (
91 IN EFI_EXCEPTION_TYPE ExceptionType
,
92 IN OUT EFI_SYSTEM_CONTEXT SystemContext
95 if (ExceptionType
<= MAX_ARM_EXCEPTION
) {
96 if (gExceptionHandlers
[ExceptionType
]) {
97 gExceptionHandlers
[ExceptionType
] (ExceptionType
, SystemContext
);
101 DEBUG ((EFI_D_ERROR
, "Unknown exception type %d from %08x\n", ExceptionType
, SystemContext
.SystemContextArm
->PC
));
105 if (ExceptionType
== EXCEPT_ARM_SOFTWARE_INTERRUPT
) {
107 // ARM JTAG debuggers some times use this vector, so it is not an error to get one
112 DefaultExceptionHandler (ExceptionType
, SystemContext
);
118 InitializeExceptions (
119 IN EFI_CPU_ARCH_PROTOCOL
*Cpu
128 EFI_PHYSICAL_ADDRESS Base
;
131 Status
= EFI_SUCCESS
;
132 ZeroMem (gExceptionHandlers
,sizeof(*gExceptionHandlers
));
135 // Disable interrupts
137 Cpu
->GetInterruptState (Cpu
, &IrqEnabled
);
138 Cpu
->DisableInterrupt (Cpu
);
141 // EFI does not use the FIQ, but a debugger might so we must disable
142 // as we take over the exception vectors.
144 FiqEnabled
= ArmGetFiqState ();
147 if (FeaturePcdGet(PcdRelocateVectorTable
) == TRUE
) {
149 // Copy an implementation of the ARM exception vectors to PcdCpuVectorBaseAddress.
151 Length
= (UINTN
)ExceptionHandlersEnd
- (UINTN
)ExceptionHandlersStart
;
153 // Check if the exception vector is in the low address
154 if (PcdGet32 (PcdCpuVectorBaseAddress
) == 0x0) {
155 // Set SCTLR.V to 0 to enable VBAR to be used
158 ArmSetHighVectors ();
162 // Reserve space for the exception handlers
164 Base
= (EFI_PHYSICAL_ADDRESS
)PcdGet32 (PcdCpuVectorBaseAddress
);
165 VectorBase
= (UINT32
*)(UINTN
)Base
;
166 Status
= gBS
->AllocatePages (AllocateAddress
, EfiBootServicesCode
, EFI_SIZE_TO_PAGES (Length
), &Base
);
167 // If the request was for memory that's not in the memory map (which is often the case for 0x00000000
168 // on embedded systems, for example, we don't want to hang up. So we'll check here for a status of
169 // EFI_NOT_FOUND, and continue in that case.
170 if (EFI_ERROR(Status
) && (Status
!= EFI_NOT_FOUND
)) {
171 ASSERT_EFI_ERROR (Status
);
174 if (FeaturePcdGet(PcdDebuggerExceptionSupport
) == TRUE
) {
175 // Save existing vector table, in case debugger is already hooked in
176 CopyMem ((VOID
*)gDebuggerExceptionHandlers
, (VOID
*)VectorBase
, sizeof (gDebuggerExceptionHandlers
));
179 // Copy our assembly code into the page that contains the exception vectors.
180 CopyMem ((VOID
*)VectorBase
, (VOID
*)ExceptionHandlersStart
, Length
);
183 // Patch in the common Assembly exception handler
185 Offset
= (UINTN
)CommonExceptionEntry
- (UINTN
)ExceptionHandlersStart
;
186 *(UINTN
*) ((UINT8
*)(UINTN
)PcdGet32 (PcdCpuVectorBaseAddress
) + Offset
) = (UINTN
)AsmCommonExceptionEntry
;
189 // Initialize the C entry points for interrupts
191 for (Index
= 0; Index
<= MAX_ARM_EXCEPTION
; Index
++) {
192 if (!FeaturePcdGet(PcdDebuggerExceptionSupport
) ||
193 (gDebuggerExceptionHandlers
[Index
] == 0) || (gDebuggerExceptionHandlers
[Index
] == (VOID
*)(UINTN
)0xEAFFFFFE)) {
194 // Exception handler contains branch to vector location (jmp $) so no handler
195 // NOTE: This code assumes vectors are ARM and not Thumb code
196 Status
= RegisterInterruptHandler (Index
, NULL
);
197 ASSERT_EFI_ERROR (Status
);
199 // If the debugger has already hooked put its vector back
200 VectorBase
[Index
] = (UINT32
)(UINTN
)gDebuggerExceptionHandlers
[Index
];
204 // Flush Caches since we updated executable stuff
205 InvalidateInstructionCacheRange ((VOID
*)PcdGet32(PcdCpuVectorBaseAddress
), Length
);
207 //Note: On ARM processor with the Security Extension, the Vector Table can be located anywhere in the memory.
208 // The Vector Base Address Register defines the location
209 ArmWriteVBar(PcdGet32(PcdCpuVectorBaseAddress
));
211 // We do not copy the Exception Table at PcdGet32(PcdCpuVectorBaseAddress). We just set Vector Base Address to point into CpuDxe code.
212 ArmWriteVBar((UINT32
)ExceptionHandlersStart
);
221 // Restore interrupt state
223 Status
= Cpu
->EnableInterrupt (Cpu
);