#------------------------------------------------------------------------------ # # Copyright (c) 2008-2010 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. # #------------------------------------------------------------------------------ .text .align 3 .globl ASM_PFX(ExceptionHandlersStart) .globl ASM_PFX(ExceptionHandlersEnd) .globl ASM_PFX(CommonExceptionEntry) .globl ASM_PFX(AsmCommonExceptionEntry) .globl ASM_PFX(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