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ARM Packages: Fixed line endings

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This large code change only modifies the line endings to be CRLF to be
compliant with the EDK2 coding convention document.



git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@14088 6f19259b-4bc3-4df7-8a09-765794883524
This commit is contained in:
oliviermartin
2013-01-25 11:28:06 +00:00
parent 5767f22fca
commit 1e57a46299
280 changed files with 48862 additions and 48862 deletions
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382
ArmPkg/Drivers/CpuDxe/ArmV4/ExceptionSupport.S
View File

@@ -1,191 +1,191 @@
#------------------------------------------------------------------------------
#
# Copyright (c) 2008 - 2010, Apple Inc. All rights reserved.<BR>
#
# 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.
#
#------------------------------------------------------------------------------
.text
.align 3
GCC_ASM_EXPORT(ExceptionHandlersStart)
GCC_ASM_EXPORT(ExceptionHandlersEnd)
GCC_ASM_EXPORT(CommonExceptionEntry)
GCC_ASM_EXPORT(AsmCommonExceptionEntry)
GCC_ASM_EXPORT(CommonCExceptionHandler)
ASM_PFX(ExceptionHandlersStart):
ASM_PFX(Reset):
b ASM_PFX(ResetEntry)
ASM_PFX(UndefinedInstruction):
b ASM_PFX(UndefinedInstructionEntry)
ASM_PFX(SoftwareInterrupt):
b ASM_PFX(SoftwareInterruptEntry)
ASM_PFX(PrefetchAbort):
b ASM_PFX(PrefetchAbortEntry)
ASM_PFX(DataAbort):
b ASM_PFX(DataAbortEntry)
ASM_PFX(ReservedException):
b ASM_PFX(ReservedExceptionEntry)
ASM_PFX(Irq):
b ASM_PFX(IrqEntry)
ASM_PFX(Fiq):
b ASM_PFX(FiqEntry)
ASM_PFX(ResetEntry):
srsdb #0x13! @ Store return state on SVC 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,ASM_PFX(CommonExceptionEntry)
bx R1
ASM_PFX(UndefinedInstructionEntry):
srsdb #0x13! @ Store return state on SVC stack
cps #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,ASM_PFX(CommonExceptionEntry)
bx r1
ASM_PFX(SoftwareInterruptEntry):
srsdb #0x13! @ Store return state on SVC 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,ASM_PFX(CommonExceptionEntry)
bx r1
ASM_PFX(PrefetchAbortEntry):
sub LR,LR,#4
srsdb #0x13! @ Store return state on SVC stack
cps #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,ASM_PFX(CommonExceptionEntry)
bx r1
ASM_PFX(DataAbortEntry):
sub LR,LR,#8
srsdb #0x13! @ Store return state on SVC stack
cps #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,ASM_PFX(CommonExceptionEntry)
bx r1
ASM_PFX(ReservedExceptionEntry):
srsdb #0x13! @ Store return state on SVC stack
cps #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,ASM_PFX(CommonExceptionEntry)
bx r1
ASM_PFX(IrqEntry):
sub LR,LR,#4
srsdb #0x13! @ Store return state on SVC stack
cps #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,ASM_PFX(CommonExceptionEntry)
bx r1
ASM_PFX(FiqEntry):
sub LR,LR,#4
srsdb #0x13! @ Store return state on SVC stack
cps #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,ASM_PFX(CommonExceptionEntry)
bx r1
ASM_PFX(CommonExceptionEntry):
.byte 0x12
.byte 0x34
.byte 0x56
.byte 0x78
ASM_PFX(ExceptionHandlersEnd):
ASM_PFX(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] @ srsdb saved pre-exception CPSR on the stack
str R1, [SP, #0x40] @ Store it in EFI_SYSTEM_CONTEXT_ARM.CPSR
and r1, r1, #0x1f @ Check to see if User or System Mode
cmp r1, #0x1f
cmpne r1, #0x10
add R2, SP, #0x38 @ Store it in EFI_SYSTEM_CONTEXT_ARM.LR
ldmneed r2, {lr}^ @ User or System mode, use unbanked register
ldmneed r2, {lr} @ All other modes used banked register
ldr R1, [SP, #0x58] @ PC is the LR pushed by srsdb
str R1, [SP, #0x3c] @ Store it in EFI_SYSTEM_CONTEXT_ARM.PC
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 ASM_PFX(CommonCExceptionHandler) @ Call exception handler
ldr R2,[SP,#0x40] @ EFI_SYSTEM_CONTEXT_ARM.CPSR
str R2,[SP,#0x5c] @ Store it back to srsdb stack slot so it can be restored
ldr R2,[SP,#0x3c] @ EFI_SYSTEM_CONTEXT_ARM.PC
str R2,[SP,#0x58] @ Store it back to srsdb 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 srsdb stack slot
#------------------------------------------------------------------------------
#
# Copyright (c) 2008 - 2010, Apple Inc. All rights reserved.<BR>
#
# 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.
#
#------------------------------------------------------------------------------
.text
.align 3
GCC_ASM_EXPORT(ExceptionHandlersStart)
GCC_ASM_EXPORT(ExceptionHandlersEnd)
GCC_ASM_EXPORT(CommonExceptionEntry)
GCC_ASM_EXPORT(AsmCommonExceptionEntry)
GCC_ASM_EXPORT(CommonCExceptionHandler)
ASM_PFX(ExceptionHandlersStart):
ASM_PFX(Reset):
b ASM_PFX(ResetEntry)
ASM_PFX(UndefinedInstruction):
b ASM_PFX(UndefinedInstructionEntry)
ASM_PFX(SoftwareInterrupt):
b ASM_PFX(SoftwareInterruptEntry)
ASM_PFX(PrefetchAbort):
b ASM_PFX(PrefetchAbortEntry)
ASM_PFX(DataAbort):
b ASM_PFX(DataAbortEntry)
ASM_PFX(ReservedException):
b ASM_PFX(ReservedExceptionEntry)
ASM_PFX(Irq):
b ASM_PFX(IrqEntry)
ASM_PFX(Fiq):
b ASM_PFX(FiqEntry)
ASM_PFX(ResetEntry):
srsdb #0x13! @ Store return state on SVC 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,ASM_PFX(CommonExceptionEntry)
bx R1
ASM_PFX(UndefinedInstructionEntry):
srsdb #0x13! @ Store return state on SVC stack
cps #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,ASM_PFX(CommonExceptionEntry)
bx r1
ASM_PFX(SoftwareInterruptEntry):
srsdb #0x13! @ Store return state on SVC 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,ASM_PFX(CommonExceptionEntry)
bx r1
ASM_PFX(PrefetchAbortEntry):
sub LR,LR,#4
srsdb #0x13! @ Store return state on SVC stack
cps #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,ASM_PFX(CommonExceptionEntry)
bx r1
ASM_PFX(DataAbortEntry):
sub LR,LR,#8
srsdb #0x13! @ Store return state on SVC stack
cps #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,ASM_PFX(CommonExceptionEntry)
bx r1
ASM_PFX(ReservedExceptionEntry):
srsdb #0x13! @ Store return state on SVC stack
cps #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,ASM_PFX(CommonExceptionEntry)
bx r1
ASM_PFX(IrqEntry):
sub LR,LR,#4
srsdb #0x13! @ Store return state on SVC stack
cps #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,ASM_PFX(CommonExceptionEntry)
bx r1
ASM_PFX(FiqEntry):
sub LR,LR,#4
srsdb #0x13! @ Store return state on SVC stack
cps #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,ASM_PFX(CommonExceptionEntry)
bx r1
ASM_PFX(CommonExceptionEntry):
.byte 0x12
.byte 0x34
.byte 0x56
.byte 0x78
ASM_PFX(ExceptionHandlersEnd):
ASM_PFX(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] @ srsdb saved pre-exception CPSR on the stack
str R1, [SP, #0x40] @ Store it in EFI_SYSTEM_CONTEXT_ARM.CPSR
and r1, r1, #0x1f @ Check to see if User or System Mode
cmp r1, #0x1f
cmpne r1, #0x10
add R2, SP, #0x38 @ Store it in EFI_SYSTEM_CONTEXT_ARM.LR
ldmneed r2, {lr}^ @ User or System mode, use unbanked register
ldmneed r2, {lr} @ All other modes used banked register
ldr R1, [SP, #0x58] @ PC is the LR pushed by srsdb
str R1, [SP, #0x3c] @ Store it in EFI_SYSTEM_CONTEXT_ARM.PC
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 ASM_PFX(CommonCExceptionHandler) @ Call exception handler
ldr R2,[SP,#0x40] @ EFI_SYSTEM_CONTEXT_ARM.CPSR
str R2,[SP,#0x5c] @ Store it back to srsdb stack slot so it can be restored
ldr R2,[SP,#0x3c] @ EFI_SYSTEM_CONTEXT_ARM.PC
str R2,[SP,#0x58] @ Store it back to srsdb 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 srsdb stack slot

304
ArmPkg/Drivers/CpuDxe/ArmV4/ExceptionSupport.asm
View File

@@ -1,152 +1,152 @@
//------------------------------------------------------------------------------
//
// Copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
//
// 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.
//
//------------------------------------------------------------------------------
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
stmfd SP!,{R0-R1}
mov R0,#0
ldr R1,CommonExceptionEntry
bx R1
UndefinedInstructionEntry
stmfd SP!,{R0-R1}
mov R0,#1
ldr R1,CommonExceptionEntry
bx R1
SoftwareInterruptEntry
stmfd SP!,{R0-R1}
mov R0,#2
ldr R1,CommonExceptionEntry
bx R1
PrefetchAbortEntry
stmfd SP!,{R0-R1}
mov R0,#3
SUB LR,LR,#4
ldr R1,CommonExceptionEntry
bx R1
DataAbortEntry
stmfd SP!,{R0-R1}
mov R0,#4
SUB LR,LR,#8
ldr R1,CommonExceptionEntry
bx R1
ReservedExceptionEntry
stmfd SP!,{R0-R1}
mov R0,#5
ldr R1,CommonExceptionEntry
bx R1
IrqEntry
stmfd SP!,{R0-R1}
mov R0,#6
SUB LR,LR,#4
ldr R1,CommonExceptionEntry
bx R1
FiqEntry
stmfd SP!,{R0-R1}
mov R0,#7
SUB LR,LR,#4
ldr R1,CommonExceptionEntry
bx R1
CommonExceptionEntry
dcd 0x12345678
ExceptionHandlersEnd
AsmCommonExceptionEntry
mrc p15, 0, r1, c6, c0, 2 ; Read IFAR
stmfd SP!,{R1} ; Store the IFAR
mrc p15, 0, r1, c5, c0, 1 ; Read IFSR
stmfd SP!,{R1} ; Store the IFSR
mrc p15, 0, r1, c6, c0, 0 ; Read DFAR
stmfd SP!,{R1} ; Store the DFAR
mrc p15, 0, r1, c5, c0, 0 ; Read DFSR
stmfd SP!,{R1} ; Store the DFSR
mrs R1,SPSR ; Read SPSR (which is the pre-exception CPSR)
stmfd SP!,{R1} ; Store the SPSR
stmfd SP!,{LR} ; Store the link register (which is the pre-exception PC)
stmfd SP,{SP,LR}^ ; Store user/system mode stack pointer and link register
nop ; Required by ARM architecture
SUB SP,SP,#0x08 ; Adjust stack pointer
stmfd SP!,{R2-R12} ; Store general purpose registers
ldr R3,[SP,#0x50] ; Read saved R1 from the stack (it was saved by the exception entry routine)
ldr R2,[SP,#0x4C] ; Read saved R0 from the stack (it was saved by the exception entry routine)
stmfd SP!,{R2-R3} ; Store general purpose registers R0 and R1
mov R1,SP ; Prepare System Context pointer as an argument for the exception handler
sub SP,SP,#4 ; Adjust SP to preserve 8-byte alignment
blx CommonCExceptionHandler ; Call exception handler
add SP,SP,#4 ; Adjust SP back to where we were
ldr R2,[SP,#0x40] ; Load CPSR from context, in case it has changed
MSR SPSR_cxsf,R2 ; Store it back to the SPSR to be restored when exiting this handler
ldmfd SP!,{R0-R12} ; Restore general purpose registers
ldm SP,{SP,LR}^ ; Restore user/system mode stack pointer and link register
nop ; Required by ARM architecture
add SP,SP,#0x08 ; Adjust stack pointer
ldmfd SP!,{LR} ; Restore the link register (which is the pre-exception PC)
add SP,SP,#0x1C ; Clear out the remaining stack space
movs PC,LR ; Return from exception
END
//------------------------------------------------------------------------------
//
// Copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
//
// 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.
//
//------------------------------------------------------------------------------
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
stmfd SP!,{R0-R1}
mov R0,#0
ldr R1,CommonExceptionEntry
bx R1
UndefinedInstructionEntry
stmfd SP!,{R0-R1}
mov R0,#1
ldr R1,CommonExceptionEntry
bx R1
SoftwareInterruptEntry
stmfd SP!,{R0-R1}
mov R0,#2
ldr R1,CommonExceptionEntry
bx R1
PrefetchAbortEntry
stmfd SP!,{R0-R1}
mov R0,#3
SUB LR,LR,#4
ldr R1,CommonExceptionEntry
bx R1
DataAbortEntry
stmfd SP!,{R0-R1}
mov R0,#4
SUB LR,LR,#8
ldr R1,CommonExceptionEntry
bx R1
ReservedExceptionEntry
stmfd SP!,{R0-R1}
mov R0,#5
ldr R1,CommonExceptionEntry
bx R1
IrqEntry
stmfd SP!,{R0-R1}
mov R0,#6
SUB LR,LR,#4
ldr R1,CommonExceptionEntry
bx R1
FiqEntry
stmfd SP!,{R0-R1}
mov R0,#7
SUB LR,LR,#4
ldr R1,CommonExceptionEntry
bx R1
CommonExceptionEntry
dcd 0x12345678
ExceptionHandlersEnd
AsmCommonExceptionEntry
mrc p15, 0, r1, c6, c0, 2 ; Read IFAR
stmfd SP!,{R1} ; Store the IFAR
mrc p15, 0, r1, c5, c0, 1 ; Read IFSR
stmfd SP!,{R1} ; Store the IFSR
mrc p15, 0, r1, c6, c0, 0 ; Read DFAR
stmfd SP!,{R1} ; Store the DFAR
mrc p15, 0, r1, c5, c0, 0 ; Read DFSR
stmfd SP!,{R1} ; Store the DFSR
mrs R1,SPSR ; Read SPSR (which is the pre-exception CPSR)
stmfd SP!,{R1} ; Store the SPSR
stmfd SP!,{LR} ; Store the link register (which is the pre-exception PC)
stmfd SP,{SP,LR}^ ; Store user/system mode stack pointer and link register
nop ; Required by ARM architecture
SUB SP,SP,#0x08 ; Adjust stack pointer
stmfd SP!,{R2-R12} ; Store general purpose registers
ldr R3,[SP,#0x50] ; Read saved R1 from the stack (it was saved by the exception entry routine)
ldr R2,[SP,#0x4C] ; Read saved R0 from the stack (it was saved by the exception entry routine)
stmfd SP!,{R2-R3} ; Store general purpose registers R0 and R1
mov R1,SP ; Prepare System Context pointer as an argument for the exception handler
sub SP,SP,#4 ; Adjust SP to preserve 8-byte alignment
blx CommonCExceptionHandler ; Call exception handler
add SP,SP,#4 ; Adjust SP back to where we were
ldr R2,[SP,#0x40] ; Load CPSR from context, in case it has changed
MSR SPSR_cxsf,R2 ; Store it back to the SPSR to be restored when exiting this handler
ldmfd SP!,{R0-R12} ; Restore general purpose registers
ldm SP,{SP,LR}^ ; Restore user/system mode stack pointer and link register
nop ; Required by ARM architecture
add SP,SP,#0x08 ; Adjust stack pointer
ldmfd SP!,{LR} ; Restore the link register (which is the pre-exception PC)
add SP,SP,#0x1C ; Clear out the remaining stack space
movs PC,LR ; Return from exception
END

594
ArmPkg/Drivers/CpuDxe/ArmV6/ExceptionSupport.S
View File

@@ -1,297 +1,297 @@
#------------------------------------------------------------------------------
#
# Use ARMv6 instruction to operate on a single stack
#
# Copyright (c) 2008 - 2010, Apple Inc. All rights reserved.<BR>
#
# 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 <Library/PcdLib.h>
/*
This is the stack constructed by the exception handler (low address to high address)
# R0 - IFAR is EFI_SYSTEM_CONTEXT for ARM
Reg Offset
=== ======
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
*/
GCC_ASM_EXPORT(ExceptionHandlersStart)
GCC_ASM_EXPORT(ExceptionHandlersEnd)
GCC_ASM_EXPORT(CommonExceptionEntry)
GCC_ASM_EXPORT(AsmCommonExceptionEntry)
GCC_ASM_EXPORT(CommonCExceptionHandler)
.text
#if !defined(__APPLE__)
.fpu neon @ makes vpush/vpop assemble
#endif
.align 5
//
// This code gets copied to the ARM vector table
// ExceptionHandlersStart - ExceptionHandlersEnd gets copied
//
ASM_PFX(ExceptionHandlersStart):
ASM_PFX(Reset):
b ASM_PFX(ResetEntry)
ASM_PFX(UndefinedInstruction):
b ASM_PFX(UndefinedInstructionEntry)
ASM_PFX(SoftwareInterrupt):
b ASM_PFX(SoftwareInterruptEntry)
ASM_PFX(PrefetchAbort):
b ASM_PFX(PrefetchAbortEntry)
ASM_PFX(DataAbort):
b ASM_PFX(DataAbortEntry)
ASM_PFX(ReservedException):
b ASM_PFX(ReservedExceptionEntry)
ASM_PFX(Irq):
b ASM_PFX(IrqEntry)
ASM_PFX(Fiq):
b ASM_PFX(FiqEntry)
ASM_PFX(ResetEntry):
srsdb #0x13! @ Store return state on SVC stack
@ We are already in SVC mode
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 @ ExceptionType
ldr R1,ASM_PFX(CommonExceptionEntry)
bx R1
ASM_PFX(UndefinedInstructionEntry):
sub LR, LR, #4 @ Only -2 for Thumb, adjust in CommonExceptionEntry
srsdb #0x13! @ Store return state on SVC stack
cps #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 @ ExceptionType
ldr R1,ASM_PFX(CommonExceptionEntry)
bx R1
ASM_PFX(SoftwareInterruptEntry):
sub LR, LR, #4 @ Only -2 for Thumb, adjust in CommonExceptionEntry
srsdb #0x13! @ Store return state on SVC stack
@ We are already in SVC mode
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 @ ExceptionType
ldr R1,ASM_PFX(CommonExceptionEntry)
bx R1
ASM_PFX(PrefetchAbortEntry):
sub LR,LR,#4
srsdb #0x13! @ Store return state on SVC stack
cps #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 @ ExceptionType
ldr R1,ASM_PFX(CommonExceptionEntry)
bx R1
ASM_PFX(DataAbortEntry):
sub LR,LR,#8
srsdb #0x13! @ Store return state on SVC stack
cps #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,ASM_PFX(CommonExceptionEntry)
bx R1
ASM_PFX(ReservedExceptionEntry):
srsdb #0x13! @ Store return state on SVC stack
cps #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,ASM_PFX(CommonExceptionEntry)
bx R1
ASM_PFX(IrqEntry):
sub LR,LR,#4
srsdb #0x13! @ Store return state on SVC stack
cps #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 @ ExceptionType
ldr R1,ASM_PFX(CommonExceptionEntry)
bx R1
ASM_PFX(FiqEntry):
sub LR,LR,#4
srsdb #0x13! @ Store return state on SVC stack
cps #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
@ Since we have already switch to SVC R8_fiq - R12_fiq
@ never get used or saved
mov R0,#7 @ ExceptionType
ldr R1,ASM_PFX(CommonExceptionEntry)
bx R1
//
// This gets patched by the C code that patches in the vector table
//
ASM_PFX(CommonExceptionEntry):
.word ASM_PFX(AsmCommonExceptionEntry)
ASM_PFX(ExceptionHandlersEnd):
//
// This code runs from CpuDxe driver loaded address. It is patched into
// CommonExceptionEntry.
//
ASM_PFX(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] @ srsdb saved pre-exception CPSR on the stack
str R1, [SP, #0x40] @ Store it in EFI_SYSTEM_CONTEXT_ARM.CPSR
add R2, SP, #0x38 @ Make R2 point to EFI_SYSTEM_CONTEXT_ARM.LR
and R3, R1, #0x1f @ Check CPSR to see if User or System Mode
cmp R3, #0x1f @ if ((CPSR == 0x10) || (CPSR == 0x1df))
cmpne R3, #0x10 @
stmeqed R2, {lr}^ @ save unbanked lr
@ else
stmneed R2, {lr} @ save SVC lr
ldr R5, [SP, #0x58] @ PC is the LR pushed by srsfd
@ Check to see if we have to adjust for Thumb entry
sub r4, r0, #1 @ if (ExceptionType == 1 || ExceptionType ==2)) {
cmp r4, #1 @ // UND & SVC have differnt LR adjust for Thumb
bhi NoAdjustNeeded
tst r1, #0x20 @ if ((CPSR & T)) == T) { // Thumb Mode on entry
addne R5, R5, #2 @ PC += 2@
str R5,[SP,#0x58] @ Update LR value pused by srsfd
NoAdjustNeeded:
str R5, [SP, #0x3c] @ Store it in EFI_SYSTEM_CONTEXT_ARM.PC
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 ExceptionType
mov R1,SP @ R1 is SystemContext
#if (FixedPcdGet32(PcdVFPEnabled))
vpush {d0-d15} @ save vstm registers in case they are used in optimizations
#endif
/*
VOID
EFIAPI
CommonCExceptionHandler (
IN EFI_EXCEPTION_TYPE ExceptionType, R0
IN OUT EFI_SYSTEM_CONTEXT SystemContext R1
)
*/
blx ASM_PFX(CommonCExceptionHandler) @ Call exception handler
#if (FixedPcdGet32(PcdVFPEnabled))
vpop {d0-d15}
#endif
ldr R1, [SP, #0x4c] @ Restore EFI_SYSTEM_CONTEXT_ARM.IFSR
mcr p15, 0, R1, c5, c0, 1 @ Write IFSR
ldr R1, [SP, #0x44] @ sRestore EFI_SYSTEM_CONTEXT_ARM.DFSR
mcr p15, 0, R1, c5, c0, 0 @ Write DFSR
ldr R1,[SP,#0x3c] @ EFI_SYSTEM_CONTEXT_ARM.PC
str R1,[SP,#0x58] @ Store it back to srsfd stack slot so it can be restored
ldr R1,[SP,#0x40] @ EFI_SYSTEM_CONTEXT_ARM.CPSR
str R1,[SP,#0x5c] @ Store it back to srsfd stack slot so it can be restored
add R3, SP, #0x54 @ Make R3 point to SVC LR saved on entry
add R2, SP, #0x38 @ Make R2 point to EFI_SYSTEM_CONTEXT_ARM.LR
and R1, R1, #0x1f @ Check to see if User or System Mode
cmp R1, #0x1f @ if ((CPSR == 0x10) || (CPSR == 0x1f))
cmpne R1, #0x10 @
ldmeqed R2, {lr}^ @ restore unbanked lr
@ else
ldmneed R3, {lr} @ restore SVC lr, via ldmfd SP!, {LR}
ldmfd SP!,{R0-R12} @ Restore general purpose registers
@ Exception handler can not change SP
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
#------------------------------------------------------------------------------
#
# Use ARMv6 instruction to operate on a single stack
#
# Copyright (c) 2008 - 2010, Apple Inc. All rights reserved.<BR>
#
# 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 <Library/PcdLib.h>
/*
This is the stack constructed by the exception handler (low address to high address)
# R0 - IFAR is EFI_SYSTEM_CONTEXT for ARM
Reg Offset
=== ======
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
*/
GCC_ASM_EXPORT(ExceptionHandlersStart)
GCC_ASM_EXPORT(ExceptionHandlersEnd)
GCC_ASM_EXPORT(CommonExceptionEntry)
GCC_ASM_EXPORT(AsmCommonExceptionEntry)
GCC_ASM_EXPORT(CommonCExceptionHandler)
.text
#if !defined(__APPLE__)
.fpu neon @ makes vpush/vpop assemble
#endif
.align 5
//
// This code gets copied to the ARM vector table
// ExceptionHandlersStart - ExceptionHandlersEnd gets copied
//
ASM_PFX(ExceptionHandlersStart):
ASM_PFX(Reset):
b ASM_PFX(ResetEntry)
ASM_PFX(UndefinedInstruction):
b ASM_PFX(UndefinedInstructionEntry)
ASM_PFX(SoftwareInterrupt):
b ASM_PFX(SoftwareInterruptEntry)
ASM_PFX(PrefetchAbort):
b ASM_PFX(PrefetchAbortEntry)
ASM_PFX(DataAbort):
b ASM_PFX(DataAbortEntry)
ASM_PFX(ReservedException):
b ASM_PFX(ReservedExceptionEntry)
ASM_PFX(Irq):
b ASM_PFX(IrqEntry)
ASM_PFX(Fiq):
b ASM_PFX(FiqEntry)
ASM_PFX(ResetEntry):
srsdb #0x13! @ Store return state on SVC stack
@ We are already in SVC mode
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 @ ExceptionType
ldr R1,ASM_PFX(CommonExceptionEntry)
bx R1
ASM_PFX(UndefinedInstructionEntry):
sub LR, LR, #4 @ Only -2 for Thumb, adjust in CommonExceptionEntry
srsdb #0x13! @ Store return state on SVC stack
cps #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 @ ExceptionType
ldr R1,ASM_PFX(CommonExceptionEntry)
bx R1
ASM_PFX(SoftwareInterruptEntry):
sub LR, LR, #4 @ Only -2 for Thumb, adjust in CommonExceptionEntry
srsdb #0x13! @ Store return state on SVC stack
@ We are already in SVC mode
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 @ ExceptionType
ldr R1,ASM_PFX(CommonExceptionEntry)
bx R1
ASM_PFX(PrefetchAbortEntry):
sub LR,LR,#4
srsdb #0x13! @ Store return state on SVC stack
cps #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 @ ExceptionType
ldr R1,ASM_PFX(CommonExceptionEntry)
bx R1
ASM_PFX(DataAbortEntry):
sub LR,LR,#8
srsdb #0x13! @ Store return state on SVC stack
cps #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,ASM_PFX(CommonExceptionEntry)
bx R1
ASM_PFX(ReservedExceptionEntry):
srsdb #0x13! @ Store return state on SVC stack
cps #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,ASM_PFX(CommonExceptionEntry)
bx R1
ASM_PFX(IrqEntry):
sub LR,LR,#4
srsdb #0x13! @ Store return state on SVC stack
cps #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 @ ExceptionType
ldr R1,ASM_PFX(CommonExceptionEntry)
bx R1
ASM_PFX(FiqEntry):
sub LR,LR,#4
srsdb #0x13! @ Store return state on SVC stack
cps #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
@ Since we have already switch to SVC R8_fiq - R12_fiq
@ never get used or saved
mov R0,#7 @ ExceptionType
ldr R1,ASM_PFX(CommonExceptionEntry)
bx R1
//
// This gets patched by the C code that patches in the vector table
//
ASM_PFX(CommonExceptionEntry):
.word ASM_PFX(AsmCommonExceptionEntry)
ASM_PFX(ExceptionHandlersEnd):
//
// This code runs from CpuDxe driver loaded address. It is patched into
// CommonExceptionEntry.
//
ASM_PFX(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] @ srsdb saved pre-exception CPSR on the stack
str R1, [SP, #0x40] @ Store it in EFI_SYSTEM_CONTEXT_ARM.CPSR
add R2, SP, #0x38 @ Make R2 point to EFI_SYSTEM_CONTEXT_ARM.LR
and R3, R1, #0x1f @ Check CPSR to see if User or System Mode
cmp R3, #0x1f @ if ((CPSR == 0x10) || (CPSR == 0x1df))
cmpne R3, #0x10 @
stmeqed R2, {lr}^ @ save unbanked lr
@ else
stmneed R2, {lr} @ save SVC lr
ldr R5, [SP, #0x58] @ PC is the LR pushed by srsfd
@ Check to see if we have to adjust for Thumb entry
sub r4, r0, #1 @ if (ExceptionType == 1 || ExceptionType ==2)) {
cmp r4, #1 @ // UND & SVC have differnt LR adjust for Thumb
bhi NoAdjustNeeded
tst r1, #0x20 @ if ((CPSR & T)) == T) { // Thumb Mode on entry
addne R5, R5, #2 @ PC += 2@
str R5,[SP,#0x58] @ Update LR value pused by srsfd
NoAdjustNeeded:
str R5, [SP, #0x3c] @ Store it in EFI_SYSTEM_CONTEXT_ARM.PC
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 ExceptionType
mov R1,SP @ R1 is SystemContext
#if (FixedPcdGet32(PcdVFPEnabled))
vpush {d0-d15} @ save vstm registers in case they are used in optimizations
#endif
/*
VOID
EFIAPI
CommonCExceptionHandler (
IN EFI_EXCEPTION_TYPE ExceptionType, R0
IN OUT EFI_SYSTEM_CONTEXT SystemContext R1
)
*/
blx ASM_PFX(CommonCExceptionHandler) @ Call exception handler
#if (FixedPcdGet32(PcdVFPEnabled))
vpop {d0-d15}
#endif
ldr R1, [SP, #0x4c] @ Restore EFI_SYSTEM_CONTEXT_ARM.IFSR
mcr p15, 0, R1, c5, c0, 1 @ Write IFSR
ldr R1, [SP, #0x44] @ sRestore EFI_SYSTEM_CONTEXT_ARM.DFSR
mcr p15, 0, R1, c5, c0, 0 @ Write DFSR
ldr R1,[SP,#0x3c] @ EFI_SYSTEM_CONTEXT_ARM.PC
str R1,[SP,#0x58] @ Store it back to srsfd stack slot so it can be restored
ldr R1,[SP,#0x40] @ EFI_SYSTEM_CONTEXT_ARM.CPSR
str R1,[SP,#0x5c] @ Store it back to srsfd stack slot so it can be restored
add R3, SP, #0x54 @ Make R3 point to SVC LR saved on entry
add R2, SP, #0x38 @ Make R2 point to EFI_SYSTEM_CONTEXT_ARM.LR
and R1, R1, #0x1f @ Check to see if User or System Mode
cmp R1, #0x1f @ if ((CPSR == 0x10) || (CPSR == 0x1f))
cmpne R1, #0x10 @
ldmeqed R2, {lr}^ @ restore unbanked lr
@ else
ldmneed R3, {lr} @ restore SVC lr, via ldmfd SP!, {LR}
ldmfd SP!,{R0-R12} @ Restore general purpose registers
@ Exception handler can not change SP
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