diff options
Diffstat (limited to 'ArmPkg/Drivers/CpuDxe/ArmV4/ExceptionSupport.asm')
-rw-r--r-- | ArmPkg/Drivers/CpuDxe/ArmV4/ExceptionSupport.asm | 152 |
1 files changed, 152 insertions, 0 deletions
diff --git a/ArmPkg/Drivers/CpuDxe/ArmV4/ExceptionSupport.asm b/ArmPkg/Drivers/CpuDxe/ArmV4/ExceptionSupport.asm new file mode 100644 index 0000000000..4af58339b7 --- /dev/null +++ b/ArmPkg/Drivers/CpuDxe/ArmV4/ExceptionSupport.asm @@ -0,0 +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 + + |