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//------------------------------------------------------------------------------
//
// 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.
//
//------------------------------------------------------------------------------
/*
This is the stack constructed by the exception handler
R0 0x00 # stmfd SP!,{R0-R12}
R1 0x04
R2 0x08
R3 0x0c
R4 0x10
R5 0x14
R6 0x18
R7 0x1c
R8 0x20
R9 0x24
R10 0x28
R11 0x2c
R12 0x30
SP 0x34 # reserved via adding 0x20 (32) to the SP
LR 0x38
PC 0x3c
CPSR 0x40
DFSR 0x44
DFAR 0x48
IFSR 0x4c
IFAR 0x50
LR 0x54 # SVC Link register (we need to restore it)
LR 0x58 # pushed by srsfd
CPSR 0x5c # pushed by srsfd
*/
EXPORT ExceptionHandlersStart
EXPORT ExceptionHandlersEnd
EXPORT CommonExceptionEntry
EXPORT AsmCommonExceptionEntry
IMPORT CommonCExceptionHandler
PRESERVE8
AREA DxeExceptionHandlers, CODE, READONLY
ExceptionHandlersStart
Reset
b ResetEntry
UndefinedInstruction
b UndefinedInstructionEntry
SoftwareInterrupt
b SoftwareInterruptEntry
PrefetchAbort
b PrefetchAbortEntry
DataAbort
b DataAbortEntry
ReservedException
b ReservedExceptionEntry
Irq
b IrqEntry
Fiq
b FiqEntry
ResetEntry
srsfd #0x13! ; Store return state on SVC stack
cpsid if,#0x13 ; Switch to SVC for common stack
stmfd SP!,{LR} ; Store the link register for the current mode
sub SP,SP,#0x20 ; Save space for SP, LR, PC, IFAR - CPSR
stmfd SP!,{R0-R12} ; Store the register state
mov R0,#0
ldr R1,CommonExceptionEntry
bx R1
UndefinedInstructionEntry
srsfd #0x13! ; Store return state on SVC stack
cpsid i,#0x13 ; Switch to SVC for common stack
stmfd SP!,{LR} ; Store the link register for the current mode
sub SP,SP,#0x20 ; Save space for SP, LR, PC, IFAR - CPSR
stmfd SP!,{R0-R12} ; Store the register state
mov R0,#1
ldr R1,CommonExceptionEntry
bx R1
SoftwareInterruptEntry
srsfd #0x13! ; Store return state on SVC stack
cpsid i,#0x13 ; Switch to SVC for common stack
stmfd SP!,{LR} ; Store the link register for the current mode
sub SP,SP,#0x20 ; Save space for SP, LR, PC, IFAR - CPSR
stmfd SP!,{R0-R12} ; Store the register state
mov R0,#2
ldr R1,CommonExceptionEntry
bx R1
PrefetchAbortEntry
sub LR,LR,#4
srsfd #0x13! ; Store return state on SVC stack
cpsid i,#0x13 ; Switch to SVC for common stack
stmfd SP!,{LR} ; Store the link register for the current mode
sub SP,SP,#0x20 ; Save space for SP, LR, PC, IFAR - CPSR
stmfd SP!,{R0-R12} ; Store the register state
mov R0,#3
ldr R1,CommonExceptionEntry
bx R1
DataAbortEntry
sub LR,LR,#8
srsfd #0x13! ; Store return state on SVC stack
cpsid i,#0x13 ; Switch to SVC for common stack
stmfd SP!,{LR} ; Store the link register for the current mode
sub SP,SP,#0x20 ; Save space for SP, LR, PC, IFAR - CPSR
stmfd SP!,{R0-R12} ; Store the register state
mov R0,#4
ldr R1,CommonExceptionEntry
bx R1
ReservedExceptionEntry
srsfd #0x13! ; Store return state on SVC stack
cpsid if,#0x13 ; Switch to SVC for common stack
stmfd SP!,{LR} ; Store the link register for the current mode
sub SP,SP,#0x20 ; Save space for SP, LR, PC, IFAR - CPSR
stmfd SP!,{R0-R12} ; Store the register state
mov R0,#5
ldr R1,CommonExceptionEntry
bx R1
IrqEntry
sub LR,LR,#4
srsfd #0x13! ; Store return state on SVC stack
cpsid i,#0x13 ; Switch to SVC for common stack
stmfd SP!,{LR} ; Store the link register for the current mode
sub SP,SP,#0x20 ; Save space for SP, LR, PC, IFAR - CPSR
stmfd SP!,{R0-R12} ; Store the register state
mov R0,#6
ldr R1,CommonExceptionEntry
bx R1
FiqEntry
sub LR,LR,#4
srsfd #0x13! ; Store return state on SVC stack
cpsid if,#0x13 ; Switch to SVC for common stack
stmfd SP!,{LR} ; Store the link register for the current mode
sub SP,SP,#0x20 ; Save space for SP, LR, PC, IFAR - CPSR
stmfd SP!,{R0-R12} ; Store the register state
mov R0,#7
ldr R1,CommonExceptionEntry
bx R1
CommonExceptionEntry
dcd 0x12345678
ExceptionHandlersEnd
AsmCommonExceptionEntry
mrc p15, 0, R1, c6, c0, 2 ; Read IFAR
str R1, [SP, #0x50] ; Store it in EFI_SYSTEM_CONTEXT_ARM.IFAR
mrc p15, 0, R1, c5, c0, 1 ; Read IFSR
str R1, [SP, #0x4c] ; Store it in EFI_SYSTEM_CONTEXT_ARM.IFSR
mrc p15, 0, R1, c6, c0, 0 ; Read DFAR
str R1, [SP, #0x48] ; Store it in EFI_SYSTEM_CONTEXT_ARM.DFAR
mrc p15, 0, R1, c5, c0, 0 ; Read DFSR
str R1, [SP, #0x44] ; Store it in EFI_SYSTEM_CONTEXT_ARM.DFSR
ldr R1, [SP, #0x5c] ; srsfd saved pre-exception CPSR on the stack
str R1, [SP, #0x40] ; Store it in EFI_SYSTEM_CONTEXT_ARM.CPSR
ldr R1, [SP, #0x58] ; PC is the LR pushed by srsfd
str R1, [SP, #0x3c] ; Store it in EFI_SYSTEM_CONTEXT_ARM.PC
str R1, [SP, #0x38] ; Store it in EFI_SYSTEM_CONTEXT_ARM.LR
sub R1, SP, #0x60 ; We pused 0x60 bytes on the stack
str R1, [SP, #0x34] ; Store it in EFI_SYSTEM_CONTEXT_ARM.SP
; R0 is exception type
mov R1,SP ; Prepare System Context pointer as an argument for the exception handler
blx CommonCExceptionHandler ; Call exception handler
ldr R2,[SP,#0x40] ; EFI_SYSTEM_CONTEXT_ARM.CPSR
str R2,[SP,#0x5c] ; Store it back to srsfd stack slot so it can be restored
ldr R2,[SP,#0x3c] ; EFI_SYSTEM_CONTEXT_ARM.PC
str R2,[SP,#0x58] ; Store it back to srsfd stack slot so it can be restored
ldmfd SP!,{R0-R12} ; Restore general purpose registers
; Exception handler can not change SP or LR as we would blow chunks
add SP,SP,#0x20 ; Clear out the remaining stack space
ldmfd SP!,{LR} ; restore the link register for this context
rfefd SP! ; return from exception via srsfd stack slot
END
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