diff options
Diffstat (limited to 'ArmPkg/Drivers/CpuDxe/ArmV4/ExceptionSupport.S')
| -rw-r--r-- | ArmPkg/Drivers/CpuDxe/ArmV4/ExceptionSupport.S | 191 |
1 files changed, 191 insertions, 0 deletions
diff --git a/ArmPkg/Drivers/CpuDxe/ArmV4/ExceptionSupport.S b/ArmPkg/Drivers/CpuDxe/ArmV4/ExceptionSupport.S new file mode 100644 index 0000000000..96bd68246f --- /dev/null +++ b/ArmPkg/Drivers/CpuDxe/ArmV4/ExceptionSupport.S @@ -0,0 +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 |