--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/debugsrv/runmodedebug/rmdriver/src/d_rmd_stepping.cpp Tue Aug 31 16:45:49 2010 +0300
@@ -0,0 +1,1884 @@
+// Copyright (c) 2004-2009 Nokia Corporation and/or its subsidiary(-ies).
+// All rights reserved.
+// This component and the accompanying materials are made available
+// under the terms of the License "Eclipse Public License v1.0"
+// which accompanies this distribution, and is available
+// at the URL "http://www.eclipse.org/legal/epl-v10.html".
+//
+// Initial Contributors:
+// Nokia Corporation - initial contribution.
+//
+// Contributors:
+//
+// Description:
+// This file contains stepping code refactored from rm_debug_kerneldriver.cpp/rm_debug_kerneldriver.h
+//
+
+#include <e32def.h>
+#include <e32def_private.h>
+#include <e32cmn.h>
+#include <e32cmn_private.h>
+#include <kernel/kernel.h>
+#include <kernel/kern_priv.h>
+#include <nk_trace.h>
+#include <arm.h>
+#include <rm_debug_api.h>
+
+#include "d_rmd_stepping.h"
+#include "d_rmd_breakpoints.h"
+#include "rm_debug_kerneldriver.h" // needed to access DRM_DebugChannel
+#include "rm_debug_driver.h"
+#include "debug_logging.h"
+
+using namespace Debug;
+
+//
+// DRMDStepping::DRMDStepping
+//
+DRMDStepping::DRMDStepping(DRM_DebugChannel* aChannel)
+:
+ iChannel(aChannel)
+ {
+ // to do
+ }
+
+//
+// DRMDStepping::~DRM_DebugChannel
+//
+DRMDStepping::~DRMDStepping()
+ {
+ // to do
+ }
+
+//
+// DRMDStepping::IsExecuted
+//
+TBool DRMDStepping::IsExecuted(TUint8 aCondition ,TUint32 aStatusRegister)
+ {
+ LOG_MSG("DRMDStepping::IsExecuted()");
+
+ TBool N = ((aStatusRegister >> 28) & 0x0000000F) & 0x00000008;
+ TBool Z = ((aStatusRegister >> 28) & 0x0000000F) & 0x00000004;
+ TBool C = ((aStatusRegister >> 28) & 0x0000000F) & 0x00000002;
+ TBool V = ((aStatusRegister >> 28) & 0x0000000F) & 0x00000001;
+
+ switch(aCondition)
+ {
+ case 0:
+ return Z;
+ case 1:
+ return !Z;
+ case 2:
+ return C;
+ case 3:
+ return !C;
+ case 4:
+ return N;
+ case 5:
+ return !N;
+ case 6:
+ return V;
+ case 7:
+ return !V;
+ case 8:
+ return (C && !Z);
+ case 9:
+ return (!C || Z);
+ case 10:
+ return (N == V);
+ case 11:
+ return (N != V);
+ case 12:
+ return ((N == V) && !Z);
+ case 13:
+ return (Z || (N != V));
+ case 14:
+ case 15:
+ return ETrue;
+ }
+
+ return EFalse;
+ }
+
+//
+// DRMDStepping::IsPreviousInstructionMovePCToLR
+//
+TBool DRMDStepping::IsPreviousInstructionMovePCToLR(DThread *aThread)
+ {
+ LOG_MSG("DRMDStepping::IsPreviousInstructionMovePCToLR()");
+
+ TInt err = KErrNone;
+
+ // there are several types of instructions that modify the PC that aren't
+ // designated as linked or non linked branches. the way gcc generates the
+ // code can tell us whether or not these instructions are to be treated as
+ // linked branches. the main cases are bx and any type of mov or load or
+ // arithmatic operation that changes the PC. if these are really just
+ // function calls that will return, gcc will generate a mov lr, pc
+ // instruction as the previous instruction. note that this is just for arm
+ // and armi
+
+ // get the address of the previous instruction
+ TUint32 address = 0;
+ err = iChannel->ReadKernelRegisterValue(aThread, PC_REGISTER, address);
+ if(err != KErrNone)
+ {
+ LOG_MSG2("Non-zero error code discarded: %d", err);
+ }
+ address -= 4;
+
+ TBuf8<4> previousInstruction;
+ err = iChannel->DoReadMemory(aThread, address, 4, previousInstruction);
+ if (KErrNone != err)
+ {
+ LOG_MSG2("Error %d reading memory at address %x", address);
+ return EFalse;
+ }
+
+ const TUint32 movePCToLRIgnoringCondition = 0x01A0E00F;
+
+ TUint32 inst = *(TUint32 *)previousInstruction.Ptr();
+
+ if ((inst & 0x0FFFFFFF) == movePCToLRIgnoringCondition)
+ {
+ return ETrue;
+ }
+
+ return EFalse;
+ }
+
+//
+// DRMDStepping::DecodeDataProcessingInstruction
+//
+void DRMDStepping::DecodeDataProcessingInstruction(TUint8 aOpcode, TUint32 aOp1, TUint32 aOp2, TUint32 aStatusRegister, TUint32 &aBreakAddress)
+ {
+ LOG_MSG("DRMDStepping::DecodeDataProcessingInstruction()");
+
+ switch(aOpcode)
+ {
+ case 0:
+ {
+ // AND
+ aBreakAddress = aOp1 & aOp2;
+ break;
+ }
+ case 1:
+ {
+ // EOR
+ aBreakAddress = aOp1 ^ aOp2;
+ break;
+ }
+ case 2:
+ {
+ // SUB
+ aBreakAddress = aOp1 - aOp2;
+ break;
+ }
+ case 3:
+ {
+ // RSB
+ aBreakAddress = aOp2 - aOp1;
+ break;
+ }
+ case 4:
+ {
+ // ADD
+ aBreakAddress = aOp1 + aOp2;
+ break;
+ }
+ case 5:
+ {
+ // ADC
+ aBreakAddress = aOp1 + aOp2 + (aStatusRegister & arm_carry_bit()) ? 1 : 0;
+ break;
+ }
+ case 6:
+ {
+ // SBC
+ aBreakAddress = aOp1 - aOp2 - (aStatusRegister & arm_carry_bit()) ? 0 : 1;
+ break;
+ }
+ case 7:
+ {
+ // RSC
+ aBreakAddress = aOp2 - aOp1 - (aStatusRegister & arm_carry_bit()) ? 0 : 1;
+ break;
+ }
+ case 12:
+ {
+ // ORR
+ aBreakAddress = aOp1 | aOp2;
+ break;
+ }
+ case 13:
+ {
+ // MOV
+ aBreakAddress = aOp2;
+ break;
+ }
+ case 14:
+ {
+ // BIC
+ aBreakAddress = aOp1 & ~aOp2;
+ break;
+ }
+ case 15:
+ {
+ // MVN
+ aBreakAddress = ~aOp2;
+ break;
+ }
+ }
+ }
+
+//
+// DRMDStepping::CurrentInstruction
+//
+// Returns the current instruction bitpattern (either 32-bits or 16-bits) if possible
+TInt DRMDStepping::CurrentInstruction(DThread* aThread, TUint32& aInstruction)
+ {
+ LOG_MSG("DRMDStepping::CurrentInstruction");
+
+ // What is the current PC?
+ TUint32 pc;
+ ReturnIfError(CurrentPC(aThread,pc));
+
+ // Read it one byte at a time to ensure alignment doesn't matter
+ TUint32 inst = 0;
+ for(TInt i=3;i>=0;i--)
+ {
+
+ TBuf8<1> instruction;
+ TInt err = iChannel->DoReadMemory(aThread, (pc+i), 1, instruction);
+ if (KErrNone != err)
+ {
+ LOG_MSG2("DRMDStepping::CurrentInstruction : Failed to read memory at current PC: return 0x%08x",pc);
+ return err;
+ }
+
+ inst = (inst << 8) | (*(TUint8 *)instruction.Ptr());
+ }
+
+ aInstruction = inst;
+
+ LOG_MSG2("DRMDStepping::CurrentInstruction 0x%08x", aInstruction);
+
+ return KErrNone;
+ }
+
+//
+// DRMDStepping::CurrentArchMode
+//
+// Determines architecture mode from the supplied cpsr
+TInt DRMDStepping::CurrentArchMode(const TUint32 aCpsr, Debug::TArchitectureMode& aMode)
+ {
+// Thumb2 work will depend on having a suitable cpu architecture to compile for...
+#ifdef ECpuJf
+ // State table as per ARM ARM DDI0406A, section A.2.5.1
+ if(aCpsr & ECpuJf)
+ {
+ if (aCpsr & ECpuThumb)
+ {
+ // ThumbEE (Thumb2)
+ aMode = Debug::EThumb2EEMode;
+ }
+ else
+ {
+ // Jazelle mode - not supported
+ return KErrNotSupported;
+ }
+ }
+ else
+#endif
+ {
+ if (aCpsr & ECpuThumb)
+ {
+ // Thumb mode
+ aMode = Debug::EThumbMode;
+ }
+ else
+ {
+ // ARM mode
+ aMode = Debug::EArmMode;
+ }
+ }
+
+ return KErrNone;
+ }
+
+//
+// DRMDStepping::PCAfterInstructionExecutes
+//
+// Note, this function pretty much ignores all the arguments except for aThread.
+// The arguments continue to exist so that the function has the same prototype as
+// the original from Nokia. In the long term this function will be re-factored
+// to remove obsolete parameters.
+//
+TUint32 DRMDStepping::PCAfterInstructionExecutes(DThread *aThread, TUint32 aCurrentPC, TUint32 aStatusRegister, TInt aInstSize, /*TBool aStepInto,*/ TUint32 &aNewRangeEnd, TBool &aChangingModes)
+ {
+ LOG_MSG("DRMDStepping::PCAfterInstructionExecutes()");
+
+ // by default we will set the breakpoint at the next instruction
+ TUint32 breakAddress = aCurrentPC + aInstSize;
+
+ TInt err = KErrNone;
+
+ // determine the architecture
+ TUint32 cpuid;
+ asm("mrc p15, 0, cpuid, c0, c0, 0 ");
+ LOG_MSG2("DRMDStepping::PCAfterInstructionExecutes() - cpuid = 0x%08x\n",cpuid);
+
+ cpuid >>= 8;
+ cpuid &= 0xFF;
+
+ // determine the architecture mode for the current instruction
+ TArchitectureMode mode = EArmMode; // Default assumption is ARM
+
+ // Now we must examine the CPSR to read the T and J bits. See ARM ARM DDI0406A, section B1.3.3
+ TUint32 cpsr;
+
+ ReturnIfError(CurrentCPSR(aThread,cpsr));
+ LOG_MSG2("DRMDStepping::PCAfterInstructionExecutes() - cpsr = 0x%08x\n",cpsr);
+
+ // Determine the mode
+ ReturnIfError(CurrentArchMode(cpsr,mode));
+
+ // Decode instruction based on current CPU mode
+ switch(mode)
+ {
+ case Debug::EArmMode:
+ {
+ // Obtain the current instruction bit pattern
+ TUint32 inst;
+ ReturnIfError(CurrentInstruction(aThread,inst));
+
+ LOG_MSG2("Current instruction: %x", inst);
+
+ // check the conditions to see if this will actually get executed
+ if (IsExecuted(((inst>>28) & 0x0000000F), aStatusRegister))
+ {
+ switch(arm_opcode(inst)) // bits 27-25
+ {
+ case 0:
+ {
+ switch((inst & 0x00000010) >> 4) // bit 4
+ {
+ case 0:
+ {
+ switch((inst & 0x01800000) >> 23) // bits 24-23
+ {
+ case 2:
+ {
+ // move to/from status register. pc updates not allowed
+ // or TST, TEQ, CMP, CMN which don't modify the PC
+ break;
+ }
+ default:
+ {
+ // Data processing immediate shift
+ if (arm_rd(inst) == PC_REGISTER)
+ {
+ TUint32 rn = aCurrentPC + 8;
+ if (arm_rn(inst) != PC_REGISTER) // bits 19-16
+ {
+ err = iChannel->ReadKernelRegisterValue(aThread, arm_rn(inst), rn);
+ if(err != KErrNone)
+ {
+ LOG_MSG2("Non-zero error code discarded: %d", err);
+ }
+ }
+
+ TUint32 shifter = ShiftedRegValue(aThread, inst, aCurrentPC, aStatusRegister);
+
+ DecodeDataProcessingInstruction(((inst & 0x01E00000) >> 21), rn, shifter, aStatusRegister, breakAddress);
+ }
+ break;
+ }
+ }
+ break;
+ }
+ case 1:
+ {
+ switch((inst & 0x00000080) >> 7) // bit 7
+ {
+ case 0:
+ {
+ switch((inst & 0x01900000) >> 20) // bits 24-23 and bit 20
+ {
+ case 0x10:
+ {
+ // from figure 3-3
+ switch((inst & 0x000000F0) >> 4) // bits 7-4
+ {
+ case 1:
+ {
+ if (((inst & 0x00400000) >> 22) == 0) // bit 22
+ {
+ // BX
+ // this is a strange case. normally this is used in the epilogue to branch the the link
+ // register. sometimes it is used to call a function, and the LR is stored in the previous
+ // instruction. since what we want to do is different for the two cases when stepping over,
+ // we need to read the previous instruction to see what we should do
+ err = iChannel->ReadKernelRegisterValue(aThread, (inst & 0x0000000F), breakAddress);
+ if(err != KErrNone)
+ {
+ LOG_MSG2("Non-zero error code discarded: %d", err);
+ }
+
+ if ((breakAddress & 0x00000001) == 1)
+ {
+ aChangingModes = ETrue;
+ }
+
+ breakAddress &= 0xFFFFFFFE;
+ }
+ break;
+ }
+ case 3:
+ {
+ // BLX
+ {
+ err = iChannel->ReadKernelRegisterValue(aThread, (inst & 0x0000000F), breakAddress);
+ if(err != KErrNone)
+ {
+ LOG_MSG2("Non-zero error code discarded: %d", err);
+ }
+
+ if ((breakAddress & 0x00000001) == 1)
+ {
+ aChangingModes = ETrue;
+ }
+
+ breakAddress &= 0xFFFFFFFE;
+ }
+ break;
+ }
+ default:
+ {
+ // either doesn't modify the PC or it is illegal to
+ break;
+ }
+ }
+ break;
+ }
+ default:
+ {
+ // Data processing register shift
+ if (((inst & 0x01800000) >> 23) == 2) // bits 24-23
+ {
+ // TST, TEQ, CMP, CMN don't modify the PC
+ }
+ else if (arm_rd(inst) == PC_REGISTER)
+ {
+ // destination register is the PC
+ TUint32 rn = aCurrentPC + 8;
+ if (arm_rn(inst) != PC_REGISTER) // bits 19-16
+ {
+ err = iChannel->ReadKernelRegisterValue(aThread, arm_rn(inst), rn);
+ if(err != KErrNone)
+ {
+ LOG_MSG2("Non-zero error code discarded: %d", err);
+ }
+ }
+
+ TUint32 shifter = ShiftedRegValue(aThread, inst, aCurrentPC, aStatusRegister);
+
+ DecodeDataProcessingInstruction(((inst & 0x01E00000) >> 21), rn, shifter, aStatusRegister, breakAddress);
+ }
+ break;
+ }
+ }
+ break;
+ }
+ default:
+ {
+ // from figure 3-2, updates to the PC illegal
+ break;
+ }
+ }
+ break;
+ }
+ }
+ break;
+ }
+ case 1:
+ {
+ if (((inst & 0x01800000) >> 23) == 2) // bits 24-23
+ {
+ // cannot modify the PC
+ break;
+ }
+ else if (arm_rd(inst) == PC_REGISTER)
+ {
+ // destination register is the PC
+ TUint32 rn;
+ err = iChannel->ReadKernelRegisterValue(aThread, arm_rn(inst), rn); // bits 19-16
+ if(err != KErrNone)
+ {
+ LOG_MSG2("Non-zero error code discarded: %d", err);
+ }
+ TUint32 shifter = ((arm_data_imm(inst) >> arm_data_rot(inst)) | (arm_data_imm(inst) << (32 - arm_data_rot(inst)))) & 0xffffffff;
+
+ DecodeDataProcessingInstruction(((inst & 0x01E00000) >> 21), rn, shifter, aStatusRegister, breakAddress);
+ }
+ break;
+ }
+ case 2:
+ {
+ // load/store immediate offset
+ if (arm_load(inst)) // bit 20
+ {
+ // loading a register from memory
+ if (arm_rd(inst) == PC_REGISTER)
+ {
+ // loading the PC register
+ TUint32 base;
+ err = iChannel->ReadKernelRegisterValue(aThread, arm_rn(inst), base);
+ if(err != KErrNone)
+ {
+ LOG_MSG2("Non-zero error code discarded: %d", err);
+ }
+
+ /* Note: At runtime the PC would be 8 further on
+ */
+ if (arm_rn(inst) == PC_REGISTER)
+ {
+ base = aCurrentPC + 8;
+ }
+
+ TUint32 offset = 0;
+
+ if (arm_single_pre(inst))
+ {
+ // Pre-indexing
+ offset = arm_single_imm(inst);
+
+ if (arm_single_u(inst))
+ {
+ base += offset;
+ }
+ else
+ {
+ base -= offset;
+ }
+ }
+
+ TBuf8<4> destination;
+ err = iChannel->DoReadMemory(aThread, base, 4, destination);
+
+ if (KErrNone == err)
+ {
+ breakAddress = *(TUint32 *)destination.Ptr();
+
+ if ((breakAddress & 0x00000001) == 1)
+ {
+ aChangingModes = ETrue;
+ }
+ breakAddress &= 0xFFFFFFFE;
+ }
+ else
+ {
+ LOG_MSG("Error reading memory in decoding step instruction");
+ }
+ }
+ }
+ break;
+ }
+ case 3:
+ {
+ if (((inst & 0xF0000000) != 0xF0000000) && ((inst & 0x00000010) == 0))
+ {
+ // load/store register offset
+ if (arm_load(inst)) // bit 20
+ {
+ // loading a register from memory
+ if (arm_rd(inst) == PC_REGISTER)
+ {
+ // loading the PC register
+ TUint32 base = 0;
+ if(arm_rn(inst) == PC_REGISTER)
+ {
+ base = aCurrentPC + 8;
+ }
+ else
+ {
+ err = iChannel->ReadKernelRegisterValue(aThread, arm_rn(inst), base);
+ if(err != KErrNone)
+ {
+ LOG_MSG2("Non-zero error code discarded: %d", err);
+ }
+ }
+
+ TUint32 offset = 0;
+
+ if (arm_single_pre(inst))
+ {
+ offset = ShiftedRegValue(aThread, inst, aCurrentPC, aStatusRegister);
+
+ if (arm_single_u(inst))
+ {
+ base += offset;
+ }
+ else
+ {
+ base -= offset;
+ }
+ }
+
+ TBuf8<4> destination;
+ err = iChannel->DoReadMemory(aThread, base, 4, destination);
+
+ if (KErrNone == err)
+ {
+ breakAddress = *(TUint32 *)destination.Ptr();
+
+ if ((breakAddress & 0x00000001) == 1)
+ {
+ aChangingModes = ETrue;
+ }
+ breakAddress &= 0xFFFFFFFE;
+ }
+ else
+ {
+ LOG_MSG("Error reading memory in decoding step instruction");
+ }
+ }
+ }
+ }
+ break;
+ }
+ case 4:
+ {
+ if ((inst & 0xF0000000) != 0xF0000000)
+ {
+ // load/store multiple
+ if (arm_load(inst)) // bit 20
+ {
+ // loading a register from memory
+ if (((inst & 0x00008000) >> 15))
+ {
+ // loading the PC register
+ TInt offset = 0;
+ if (arm_block_u(inst))
+ {
+ TUint32 reglist = arm_block_reglist(inst);
+ offset = iChannel->Bitcount(reglist) * 4 - 4;
+ if (arm_block_pre(inst))
+ offset += 4;
+ }
+ else if (arm_block_pre(inst))
+ {
+ offset = -4;
+ }
+
+ TUint32 temp = 0;
+ err = iChannel->ReadKernelRegisterValue(aThread, arm_rn(inst), temp);
+ if(err != KErrNone)
+ {
+ LOG_MSG2("Non-zero error code discarded: %d", err);
+ }
+
+ temp += offset;
+
+ TBuf8<4> destination;
+ err = iChannel->DoReadMemory(aThread, temp, 4, destination);
+
+ if (KErrNone == err)
+ {
+ breakAddress = *(TUint32 *)destination.Ptr();
+ if ((breakAddress & 0x00000001) == 1)
+ {
+ aChangingModes = ETrue;
+ }
+ breakAddress &= 0xFFFFFFFE;
+ }
+ else
+ {
+ LOG_MSG("Error reading memory in decoding step instruction");
+ }
+ }
+ }
+ }
+ break;
+ }
+ case 5:
+ {
+ if ((inst & 0xF0000000) == 0xF0000000)
+ {
+ // BLX
+ breakAddress = (TUint32)arm_instr_b_dest(inst, aCurrentPC);
+
+ // Unconditionally change into Thumb mode
+ aChangingModes = ETrue;
+ breakAddress &= 0xFFFFFFFE;
+ }
+ else
+ {
+ if ((inst & 0x01000000)) // bit 24
+ {
+ // BL
+ breakAddress = (TUint32)arm_instr_b_dest(inst, aCurrentPC);
+ }
+ else
+ {
+ // B
+ breakAddress = (TUint32)arm_instr_b_dest(inst, aCurrentPC);
+ }
+ }
+ break;
+ } // case 5
+ } //switch(arm_opcode(inst)) // bits 27-25
+ } // if (IsExecuted(((inst>>28) & 0x0000000F), aStatusRegister))
+ } // case Debug::EArmMode:
+ break;
+
+ case Debug::EThumbMode:
+ {
+ // Thumb Mode
+ //
+ // Notes: This now includes the extra code
+ // required to decode V6T2 instructions
+
+ LOG_MSG("DRMDStepping::PCAfterInstructionExecutes: Thumb Instruction");
+
+ TUint16 inst;
+
+ // Obtain the current instruction bit pattern
+ TUint32 inst32;
+ ReturnIfError(CurrentInstruction(aThread,inst32));
+
+ inst = static_cast<TUint16>(inst32 & 0xFFFF);
+
+ LOG_MSG2("Current Thumb instruction: 0x%x", inst);
+
+ // v6T2 instructions
+
+ // Note: v6T2 decoding is only enabled for DEBUG builds or if using an
+ // an ARM_V6T2 supporting build system. At the time of writing, no
+ // ARM_V6T2 supporting build system exists, so the stepping code cannot
+ // be said to be known to work. Hence it is not run for release builds
+
+ TBool use_v6t2_decodings = EFalse;
+
+#if defined(DEBUG) || defined(__ARMV6T2__)
+ use_v6t2_decodings = ETrue;
+#endif
+ // coverity[dead_error_line]
+ if (use_v6t2_decodings)
+ {
+ // 16-bit encodings
+
+ // A6.2.5 Misc 16-bit instructions
+ // DONE Compare and branch on zero (page A8-66)
+ // If then hints
+
+ // ARM ARM DDI0406A - section A8.6.27 CBNZ, CBZ
+ //
+ // Compare and branch on Nonzero and Compare and Branch on Zero.
+ if ((inst & 0xF500) == 0xB100)
+ {
+ LOG_MSG("ARM ARM DDI0406A - section A8.6.27 CBNZ, CBZ");
+
+ // Decoding as per ARM ARM description
+ TUint32 op = (inst & 0x0800) >> 11;
+ TUint32 i = (inst & 0x0200) >> 9;
+ TUint32 imm5 = (inst & 0x00F8) >> 3;
+ TUint32 Rn = inst & 0x0007;
+
+ TUint32 imm32 = (i << 6) | (imm5 << 1);
+
+ // Obtain value for register Rn
+ TUint32 RnVal = 0;
+ ReturnIfError(RegisterValue(aThread,Rn,RnVal));
+
+ if (op)
+ {
+ // nonzero
+ if (RnVal != 0x0)
+ {
+ // Branch
+ breakAddress = aCurrentPC + imm32;
+ }
+ }
+ else
+ {
+ // zero
+ if (RnVal == 0x0)
+ {
+ // Branch
+ breakAddress = aCurrentPC + imm32;
+ }
+ }
+ }
+
+ // ARM ARM DDI0406A - section A8.6.50 IT
+ //
+ // If Then instruction
+ if ((inst & 0xFF00) == 0xBF00)
+ {
+ LOG_MSG("ARM ARM DDI0406A - section A8.6.50 IT");
+
+ // Decoding as per ARM ARM description
+ TUint32 firstcond = inst & 0x00F0 >> 4;
+ TUint32 mask = inst & 0x000F;
+
+ if (firstcond == 0xF)
+ {
+ // unpredictable
+ LOG_MSG("ARM ARM DDI0406A - section A8.6.50 IT - Unpredictable");
+ break;
+ }
+
+ if ((firstcond == 0xE) && (BitCount(mask) != 1))
+ {
+ // unpredictable
+ LOG_MSG("ARM ARM DDI0406A - section A8.6.50 IT - Unpredictable");
+ break;
+ }
+
+ // should check if 'in-it-block'
+ LOG_MSG("Cannot step IT instructions.");
+
+ // all the conds are as per Table A8-1 (i.e. the usual 16 cases)
+ // no idea how to decode the it block 'after-the-fact'
+ // so probably need to treat instructions in the it block
+ // as 'may' be executed. So breakpoints at both possible locations
+ // depending on whether the instruction is executed or not.
+
+ // also, how do we know if we have hit a breakpoint whilst 'in' an it block?
+ // can we check the status registers to find out?
+ //
+ // see arm arm page 390.
+ //
+ // seems to depend on the itstate field. this also says what the condition code
+ // actually is, and how many instructions are left in the itblock.
+ // perhaps we can just totally ignore this state, and always do the two-instruction
+ // breakpoint thing? Not if there is any possibility that the address target
+ // would be invalid for the non-taken branch address...
+ }
+
+
+ // 32-bit encodings.
+ //
+
+ // Load word A6-23
+ // Data processing instructions a6-28
+ //
+
+ // ARM ARM DDI0406A - section A8.6.26
+ if (inst32 & 0xFFF0FFFF == 0xE3C08F00)
+ {
+ LOG_MSG("ARM ARM DDI0406A - section A8.6.26 - BXJ is not supported");
+
+ // Decoding as per ARM ARM description
+ // TUint32 Rm = inst32 & 0x000F0000; // not needed yet
+ }
+
+ // return from exception... SUBS PC,LR. page b6-25
+ //
+ // ARM ARM DDi046A - section B6.1.13 - SUBS PC,LR
+ //
+ // Encoding T1
+ if (inst32 & 0xFFFFFF00 == 0xF3DE8F00)
+ {
+ LOG_MSG("ARM ARM DDI0406A - section B6.1.13 - SUBS PC,LR Encoding T1");
+
+ // Decoding as per ARM ARM description
+ TUint32 imm8 = inst32 & 0x000000FF;
+ TUint32 imm32 = imm8;
+
+ // TUint32 register_form = EFalse; // not needed for this decoding
+ // TUint32 opcode = 0x2; // SUB // not needed for this decoding
+ TUint32 n = 14;
+
+ // Obtain LR
+ TUint32 lrVal;
+ ReturnIfError(RegisterValue(aThread,n,lrVal));
+
+ TUint32 operand2 = imm32; // always for Encoding T1
+
+ TUint32 result = lrVal - operand2;
+
+ breakAddress = result;
+ }
+
+ // ARM ARM DDI0406A - section A8.6.16 - B
+ //
+ // Branch Encoding T3
+ if (inst32 & 0xF800D000 == 0xF0008000)
+ {
+ LOG_MSG("ARM ARM DDI0406A - section A8.6.16 - B Encoding T3");
+
+ // Decoding as per ARM ARM description
+ TUint32 S = inst32 & 0x04000000 >> 26;
+ // TUint32 cond = inst32 & 0x03C00000 >> 22; // not needed for this decoding
+ TUint32 imm6 = inst32 & 0x003F0000 >> 16;
+ TUint32 J1 = inst32 & 0x00002000 >> 13;
+ TUint32 J2 = inst32 & 0x00000800 >> 11;
+ TUint32 imm11 = inst32 & 0x000007FF;
+
+ TUint32 imm32 = S ? 0xFFFFFFFF : 0 ;
+ imm32 = (imm32 << 1) | J2;
+ imm32 = (imm32 << 1) | J1;
+ imm32 = (imm32 << 6) | imm6;
+ imm32 = (imm32 << 11) | imm11;
+ imm32 = (imm32 << 1) | 0;
+
+ breakAddress = aCurrentPC + imm32;
+ }
+
+ // ARM ARM DDI0406A - section A8.6.16 - B
+ //
+ // Branch Encoding T4
+ if (inst32 & 0xF800D000 == 0xF0009000)
+ {
+ LOG_MSG("ARM ARM DDI0406A - section A8.6.16 - B");
+
+ // Decoding as per ARM ARM description
+ TUint32 S = inst32 & 0x04000000 >> 26;
+ TUint32 imm10 = inst32 & 0x03FF0000 >> 16;
+ TUint32 J1 = inst32 & 0x00002000 >> 12;
+ TUint32 J2 = inst32 & 0x00000800 >> 11;
+ TUint32 imm11 = inst32 & 0x000003FF;
+
+ TUint32 I1 = !(J1 ^ S);
+ TUint32 I2 = !(J2 ^ S);
+
+ TUint32 imm32 = S ? 0xFFFFFFFF : 0;
+ imm32 = (imm32 << 1) | S;
+ imm32 = (imm32 << 1) | I1;
+ imm32 = (imm32 << 1) | I2;
+ imm32 = (imm32 << 10) | imm10;
+ imm32 = (imm32 << 11) | imm11;
+ imm32 = (imm32 << 1) | 0;
+
+ breakAddress = aCurrentPC + imm32;
+ }
+
+
+ // ARM ARM DDI0406A - section A8.6.225 - TBB, TBH
+ //
+ // Table Branch Byte, Table Branch Halfword
+ if (inst32 & 0xFFF0FFE0 == 0xE8D0F000)
+ {
+ LOG_MSG("ARM ARM DDI0406A - section A8.6.225 TBB,TBH Encoding T1");
+
+ // Decoding as per ARM ARM description
+ TUint32 Rn = inst32 & 0x000F0000 >> 16;
+ TUint32 H = inst32 & 0x00000010 >> 4;
+ TUint32 Rm = inst32 & 0x0000000F;
+
+ // Unpredictable?
+ if (Rm == 13 || Rm == 15)
+ {
+ LOG_MSG("ARM ARM DDI0406A - section A8.6.225 TBB,TBH Encoding T1 - Unpredictable");
+ break;
+ }
+
+ TUint32 halfwords;
+ TUint32 address;
+ ReturnIfError(RegisterValue(aThread,Rn,address));
+
+ TUint32 offset;
+ ReturnIfError(RegisterValue(aThread,Rm,offset));
+
+ if (H)
+ {
+ address += offset << 1;
+ }
+ else
+ {
+ address += offset;
+ }
+
+ ReturnIfError(ReadMem32(aThread,address,halfwords));
+
+ breakAddress = aCurrentPC + 2*halfwords;
+ break;
+ }
+
+ // ARM ARM DDI0406A - section A8.6.55 - LDMDB, LDMEA
+ //
+ // LDMDB Encoding T1
+ if (inst32 & 0xFFD02000 == 0xE9100000)
+ {
+ LOG_MSG("ARM ARM DDI0406 - section A8.6.55 LDMDB Encoding T1");
+
+ // Decoding as per ARM ARM description
+ // TUint32 W = inst32 & 0x00200000 >> 21; // Not needed for this encoding
+ TUint32 Rn = inst32 & 0x000F0000 >> 16;
+ TUint32 P = inst32 & 0x00008000 >> 15;
+ TUint32 M = inst32 & 0x00004000 >> 14;
+ TUint32 registers = inst32 & 0x00001FFF;
+
+ //TBool wback = (W == 1); // not needed for this encoding
+
+ // Unpredictable?
+ if (Rn == 15 || BitCount(registers) < 2 || ((P == 1) && (M==1)))
+ {
+ LOG_MSG("ARM ARM DDI0406 - section A8.6.55 LDMDB Encoding T1 - Unpredictable");
+ break;
+ }
+
+ TUint32 address;
+ ReturnIfError(RegisterValue(aThread,Rn,address));
+
+ address -= 4*BitCount(registers);
+
+ for(TInt i=0; i<15; i++)
+ {
+ if (IsBitSet(registers,i))
+ {
+ address +=4;
+ }
+ }
+
+ if (IsBitSet(registers,15))
+ {
+ TUint32 RnVal = 0;
+ ReturnIfError(ReadMem32(aThread,address,RnVal));
+
+ breakAddress = RnVal;
+ }
+ break;
+ }
+
+ // ARM ARM DDI0406A - section A8.6.121 POP
+ //
+ // POP.W Encoding T2
+ if (inst32 & 0xFFFF2000 == 0xE8BD0000)
+ {
+ LOG_MSG("ARM ARM DDI0406A - section A8.6.121 POP Encoding T2");
+
+ // Decoding as per ARM ARM description
+ TUint32 registers = inst32 & 0x00001FFF;
+ TUint32 P = inst32 & 0x00008000;
+ TUint32 M = inst32 & 0x00004000;
+
+ // Unpredictable?
+ if ( (BitCount(registers)<2) || ((P == 1)&&(M == 1)) )
+ {
+ LOG_MSG("ARM ARM DDI0406A - section A8.6.121 POP Encoding T2 - Unpredictable");
+ break;
+ }
+
+ TUint32 address;
+ ReturnIfError(RegisterValue(aThread,13,address));
+
+ for(TInt i=0; i< 15; i++)
+ {
+ if (IsBitSet(registers,i))
+ {
+ address += 4;
+ }
+ }
+
+ // Is the PC written?
+ if (IsBitSet(registers,15))
+ {
+ // Yes
+ ReturnIfError(ReadMem32(aThread,address,breakAddress));
+ }
+ }
+
+ // POP Encoding T3
+ if (inst32 & 0xFFFF0FFFF == 0xF85D0B04)
+ {
+ LOG_MSG("ARM ARM DDI0406A - section A8.6.121 POP Encoding T3");
+
+ // Decoding as per ARM ARM description
+ TUint32 Rt = inst32 & 0x0000F000 >> 12;
+ TUint32 registers = 1 << Rt;
+
+ // Unpredictable?
+ if (Rt == 13 || Rt == 15)
+ {
+ LOG_MSG("ARM ARM DDI0406A - section A8.6.121 POP Encoding T3 - Unpredictable");
+ break;
+ }
+
+ TUint32 address;
+ ReturnIfError(RegisterValue(aThread,13,address));
+
+ for(TInt i=0; i< 15; i++)
+ {
+ if (IsBitSet(registers,i))
+ {
+ address += 4;
+ }
+ }
+
+ // Is the PC written?
+ if (IsBitSet(registers,15))
+ {
+ // Yes
+ ReturnIfError(ReadMem32(aThread,address,breakAddress));
+ }
+
+ break;
+ }
+
+ // ARM ARM DDI0406A - section A8.6.53 LDM
+ //
+ // Load Multiple Encoding T2
+ if ((inst32 & 0xFFD02000) == 0xE8900000)
+ {
+ LOG_MSG("ARM ARM DDI0406A - section A8.6.53 LDM Encoding T2");
+
+ // Decoding as per ARM ARM description
+ TUint32 W = inst32 & 0x0020000 >> 21;
+ TUint32 Rn = inst32 & 0x000F0000 >> 16;
+ TUint32 P = inst32 & 0x00008000 >> 15;
+ TUint32 M = inst32 & 0x00004000 >> 14;
+ TUint32 registers = inst32 & 0x0000FFFF;
+ TUint32 register_list = inst32 & 0x00001FFF;
+
+ // POP?
+ if ( (W == 1) && (Rn == 13) )
+ {
+ // POP instruction
+ LOG_MSG("ARM ARM DDI0406A - section A8.6.53 LDM Encoding T2 - POP");
+ }
+
+ // Unpredictable?
+ if (Rn == 15 || BitCount(register_list) < 2 || ((P == 1) && (M == 1)) )
+ {
+ LOG_MSG("ARM ARM DDI0406A - section A8.6.53 LDM Encoding T2 - Unpredictable");
+ break;
+ }
+
+ TUint32 RnVal;
+ ReturnIfError(RegisterValue(aThread,Rn,RnVal));
+
+ TUint32 address = RnVal;
+
+ // Calculate offset of address
+ for(TInt i = 0; i < 15; i++)
+ {
+ if (IsBitSet(registers,i))
+ {
+ address += 4;
+ }
+ }
+
+ // Does it load the PC?
+ if (IsBitSet(registers,15))
+ {
+ // Obtain the value loaded into the PC
+ ReturnIfError(ReadMem32(aThread,address,breakAddress));
+ }
+ break;
+
+ }
+
+ // ARM ARM DDI0406A - section B6.1.8 RFE
+ //
+ // Return From Exception Encoding T1 RFEDB
+ if ((inst32 & 0xFFD0FFFF) == 0xE810C000)
+ {
+ LOG_MSG("ARM ARM DDI0406A - section B6.1.8 RFE Encoding T1");
+
+ // Decoding as per ARM ARM description
+ // TUint32 W = (inst32 & 0x00200000) >> 21; // not needed for this encoding
+ TUint32 Rn = (inst32 & 0x000F0000) >> 16;
+
+ // TBool wback = (W == 1); // not needed for this encoding
+ TBool increment = EFalse;
+ TBool wordhigher = EFalse;
+
+ // Do calculation
+ if (Rn == 15)
+ {
+ // Unpredictable
+ LOG_MSG("ARM ARM DDI0406A - section B6.1.8 RFE Encoding T1 - Unpredictable");
+ break;
+ }
+
+ TUint32 RnVal = 0;
+ ReturnIfError(RegisterValue(aThread,Rn,RnVal));
+
+ TUint32 address = 0;
+ ReturnIfError(ReadMem32(aThread,RnVal,address));
+
+ if (increment)
+ {
+ address -= 8;
+ }
+
+ if (wordhigher)
+ {
+ address += 4;
+ }
+
+ breakAddress = address;
+ break;
+ }
+
+ // Return From Exception Encoding T2 RFEIA
+ if ((inst32 & 0xFFD0FFFF) == 0xE990C000)
+ {
+ LOG_MSG("ARM ARM DDI0406A - section B6.1.8 RFE Encoding T2");
+
+ // Decoding as per ARM ARM description
+ // TUint32 W = (inst32 & 0x00200000) >> 21; // not needed for this encoding
+ TUint32 Rn = (inst32 & 0x000F0000) >> 16;
+
+ // TBool wback = (W == 1); // not needed for this encoding
+ TBool increment = ETrue;
+ TBool wordhigher = EFalse;
+
+ // Do calculation
+ if (Rn == 15)
+ {
+ // Unpredictable
+ LOG_MSG("ARM ARM DDI0406A - section B6.1.8 RFE Encoding T2 - Unpredictable");
+ break;
+ }
+
+ TUint32 RnVal = 0;
+ ReturnIfError(RegisterValue(aThread,Rn,RnVal));
+
+ TUint32 address = 0;
+ ReturnIfError(ReadMem32(aThread,RnVal,address));
+
+ if (increment)
+ {
+ address -= 8;
+ }
+
+ if (wordhigher)
+ {
+ address += 4;
+ }
+
+ breakAddress = RnVal;
+ break;
+ }
+
+ // Return From Exception Encoding A1 RFE<amode>
+ if ((inst32 & 0xFE50FFFF) == 0xF8100A00)
+ {
+ LOG_MSG("ARM ARM DDI0406A - section B6.1.8 RFE Encoding A1");
+
+ // Decoding as per ARM ARM description
+ TUint32 P = (inst32 & 0x01000000) >> 24;
+ TUint32 U = (inst32 & 0x00800000) >> 23;
+ // TUint32 W = (inst32 & 0x00200000) >> 21; // not needed for this encoding
+ TUint32 Rn = (inst32 & 0x000F0000) >> 16;
+
+ // TBool wback = (W == 1); // not needed for this encoding
+ TBool increment = (U == 1);
+ TBool wordhigher = (P == U);
+
+ // Do calculation
+ if (Rn == 15)
+ {
+ // Unpredictable
+ LOG_MSG("ARM ARM DDI0406A - section B6.1.8 RFE Encoding A1 - Unpredictable");
+ break;
+ }
+
+ TUint32 RnVal = 0;
+ ReturnIfError(RegisterValue(aThread,Rn,RnVal));
+
+ TUint32 address = 0;
+ ReturnIfError(ReadMem32(aThread,RnVal,address));
+
+ if (increment)
+ {
+ address -= 8;
+ }
+
+ if (wordhigher)
+ {
+ address += 4;
+ }
+
+ breakAddress = address;
+ break;
+ }
+ }
+
+ // v4T/v5T/v6T instructions
+ switch(thumb_opcode(inst))
+ {
+ case 0x08:
+ {
+ // Data-processing. See ARM ARM DDI0406A, section A6-8, A6.2.2.
+
+ if ((thumb_inst_7_15(inst) == 0x08F))
+ {
+ // BLX(2)
+ err = iChannel->ReadKernelRegisterValue(aThread, ((inst & 0x0078) >> 3), breakAddress);
+ if(err != KErrNone)
+ {
+ LOG_MSG2("Non-zero error code discarded: %d", err);
+ }
+
+ if ((breakAddress & 0x00000001) == 0)
+ {
+ aChangingModes = ETrue;
+ }
+
+ breakAddress &= 0xFFFFFFFE;
+
+ // Report how we decoded this instruction
+ LOG_MSG("DRMDStepping::PCAfterInstructionExecutes: Decoded as BLX (2)");
+ }
+ else if (thumb_inst_7_15(inst) == 0x08E)
+ {
+ // BX
+ err = iChannel->ReadKernelRegisterValue(aThread, ((inst & 0x0078) >> 3), breakAddress);
+ if(err != KErrNone)
+ {
+ LOG_MSG2("Non-zero error code discarded: %d", err);
+ }
+
+ if ((breakAddress & 0x00000001) == 0)
+ {
+ aChangingModes = ETrue;
+ }
+
+ breakAddress &= 0xFFFFFFFE;
+
+ // Report how we decoded this instruction
+ LOG_MSG("DRMDStepping::PCAfterInstructionExecutes: Decoded as BX");
+ }
+ else if ((thumb_inst_8_15(inst) == 0x46) && ((inst & 0x87) == 0x87))
+ {
+ // MOV with PC as the destination
+ err = iChannel->ReadKernelRegisterValue(aThread, ((inst & 0x0078) >> 3), breakAddress);
+ if(err != KErrNone)
+ {
+ LOG_MSG2("Non-zero error code discarded: %d", err);
+ }
+
+ // Report how we decoded this instruction
+ LOG_MSG("DRMDStepping::PCAfterInstructionExecutes: Decoded as MOV with PC as the destination");
+ }
+ else if ((thumb_inst_8_15(inst) == 0x44) && ((inst & 0x87) == 0x87))
+ {
+ // ADD with PC as the destination
+ err = iChannel->ReadKernelRegisterValue(aThread, ((inst & 0x0078) >> 3), breakAddress);
+ if(err != KErrNone)
+ {
+ LOG_MSG2("Non-zero error code discarded: %d", err);
+ }
+ breakAddress += aCurrentPC + 4; // +4 because we need to use the PC+4 according to ARM ARM DDI0406A, section A6.1.2.
+
+ // Report how we decoded this instruction
+ LOG_MSG("DRMDStepping::PCAfterInstructionExecutes: Decoded as ADD with PC as the destination");
+ }
+ break;
+ }
+ case 0x13:
+ {
+ // Load/Store single data item. See ARM ARM DDI0406A, section A6-10
+
+ //This instruction doesn't modify the PC.
+
+ //if (thumb_inst_8_15(inst) == 0x9F)
+ //{
+ // LDR(4) with the PC as the destination
+ // breakAddress = ReadRegister(aThread, SP_REGISTER) + (4 * (inst & 0x00FF));
+ //}
+
+ // Report how we decoded this instruction
+ LOG_MSG("DRMDStepping::PCAfterInstructionExecutes: Decoded as This instruction doesn't modify the PC.");
+ break;
+ }
+ case 0x17:
+ {
+ // Misc 16-bit instruction. See ARM ARM DDI0406A, section A6-11
+
+ if (thumb_inst_8_15(inst) == 0xBD)
+ {
+ // POP with the PC in the list
+ TUint32 regList = (inst & 0x00FF);
+ TInt offset = 0;
+ err = iChannel->ReadKernelRegisterValue(aThread, SP_REGISTER, (T4ByteRegisterValue&)offset);
+ if(err != KErrNone)
+ {
+ LOG_MSG2("Non-zero error code discarded: %d", err);
+ }
+ offset += (iChannel->Bitcount(regList) * 4);
+
+ TBuf8<4> destination;
+ err = iChannel->DoReadMemory(aThread, offset, 4, destination);
+
+ if (KErrNone == err)
+ {
+ breakAddress = *(TUint32 *)destination.Ptr();
+
+ if ((breakAddress & 0x00000001) == 0)
+ {
+ aChangingModes = ETrue;
+ }
+
+ breakAddress &= 0xFFFFFFFE;
+ }
+ else
+ {
+ LOG_MSG("Error reading memory in decoding step instruction");
+ }
+
+ // Report how we decoded this instruction
+ LOG_MSG("DRMDStepping::PCAfterInstructionExecutes: Decoded as POP with the PC in the list");
+ }
+ break;
+ }
+ case 0x1A:
+ case 0x1B:
+ {
+ // Conditional branch, and supervisor call. See ARM ARM DDI0406A, section A6-13
+
+ if (thumb_inst_8_15(inst) < 0xDE)
+ {
+ // B(1) conditional branch
+ if (IsExecuted(((inst & 0x0F00) >> 8), aStatusRegister))
+ {
+ TUint32 offset = ((inst & 0x000000FF) << 1);
+ if (offset & 0x00000100)
+ {
+ offset |= 0xFFFFFF00;
+ }
+
+ breakAddress = aCurrentPC + 4 + offset;
+
+ // Report how we decoded this instruction
+ LOG_MSG("DRMDStepping::PCAfterInstructionExecutes: Decoded as B(1) conditional branch");
+ }
+ }
+ break;
+ }
+ case 0x1C:
+ {
+ // Unconditional branch, See ARM ARM DDI0406A, section A8-44.
+
+ // B(2) unconditional branch
+ TUint32 offset = (inst & 0x000007FF) << 1;
+ if (offset & 0x00000800)
+ {
+ offset |= 0xFFFFF800;
+ }
+
+ breakAddress = aCurrentPC + 4 + offset;
+
+ // Report how we decoded this instruction
+ LOG_MSG("DRMDStepping::PCAfterInstructionExecutes: Decoded as B(2) unconditional branch");
+
+ break;
+ }
+ case 0x1D:
+ {
+ if (!(inst & 0x0001))
+ {
+ // BLX(1)
+ err = iChannel->ReadKernelRegisterValue(aThread, LINK_REGISTER, breakAddress);
+ if(err != KErrNone)
+ {
+ LOG_MSG2("Non-zero error code discarded: %d", err);
+ }
+ breakAddress += ((inst & 0x07FF) << 1);
+ if ((breakAddress & 0x00000001) == 0)
+ {
+ aChangingModes = ETrue;
+ }
+
+ breakAddress &= 0xFFFFFFFC;
+
+ // Report how we decoded this instruction
+ LOG_MSG("DRMDStepping::PCAfterInstructionExecutes: Decoded as BLX(1)");
+
+ }
+ break;
+ }
+ case 0x1E:
+ {
+ // Check for ARMv7 CPU
+ if(cpuid == 0xC0)
+ {
+ // BL/BLX 32-bit instruction
+ aNewRangeEnd += 4;
+
+ breakAddress = (TUint32)thumb_instr_b_dest(inst32, aCurrentPC);
+
+ if((inst32 >> 27) == 0x1D)
+ {
+ // BLX(1)
+ if ((breakAddress & 0x00000001) == 0)
+ {
+ aChangingModes = ETrue;
+ }
+
+ breakAddress &= 0xFFFFFFFC;
+
+ // Report how we decoded this instruction
+ LOG_MSG("DRMDStepping::PCAfterInstructionExecutes: Decoded as 32-bit BLX(1)");
+ }
+ else
+ {
+ // Report how we decoded this instruction
+ LOG_MSG("DRMDStepping::PCAfterInstructionExecutes: 32-bit BL instruction");
+ }
+ LOG_MSG2(" 32-bit BL/BLX instruction: breakAddress = 0x%X", breakAddress);
+ } // if(cpuid == 0xC0)
+ else
+ {
+ // BL/BLX prefix - destination is encoded in this and the next instruction
+ aNewRangeEnd += 2;
+
+ // Report how we decoded this instruction
+ LOG_MSG("DRMDStepping::PCAfterInstructionExecutes: BL/BLX prefix - destination is encoded in this and the next instruction");
+ }
+
+ break;
+ }
+ case 0x1F:
+ {
+ // BL
+ err = iChannel->ReadKernelRegisterValue(aThread, LINK_REGISTER, breakAddress);
+ if(err != KErrNone)
+ {
+ LOG_MSG2("Non-zero error code discarded: %d", err);
+ }
+ breakAddress += ((inst & 0x07FF) << 1);
+
+ // Report how we decoded this instruction
+ LOG_MSG("DRMDStepping::PCAfterInstructionExecutes: Decoded as BL");
+ break;
+ }
+ default:
+ {
+ // Don't know any better at this point!
+ LOG_MSG("DRMDStepping::PCAfterInstructionExecutes:- default to next instruction");
+ }
+ break;
+ } // switch(thumb_opcode(inst))
+ } // case Debug::EThumbMode:
+ break;
+
+ case Debug::EThumb2EEMode:
+ {
+ // Not yet supported
+ LOG_MSG("DRMDStepping::PCAfterInstructionExecutes - Debug::EThumb2Mode is not supported");
+
+ }
+ break;
+
+ default:
+ LOG_MSG("DRMDStepping::PCAfterInstructionExecutes - Cannot determine CPU mode architecture");
+ } // switch(mode)
+
+ LOG_MSG2("DRMDStepping::PCAfterInstructionExecutes : return 0x%08x",breakAddress);
+ return breakAddress;
+ }
+
+// Obtain a 32-bit memory value with minimum fuss
+TInt DRMDStepping::ReadMem32(DThread* aThread, const TUint32 aAddress, TUint32& aValue)
+ {
+ TBuf8<4> valBuf;
+ TInt err = iChannel->DoReadMemory(aThread, aAddress, 4, valBuf);
+ if (err != KErrNone)
+ {
+ LOG_MSG2("DRMDStepping::ReadMem32 failed to read memory at 0x%08x", aAddress);
+ return err;
+ }
+
+ aValue = *(TUint32 *)valBuf.Ptr();
+
+ return KErrNone;
+ }
+
+// Obtain a 16-bit memory value with minimum fuss
+TInt DRMDStepping::ReadMem16(DThread* aThread, const TUint32 aAddress, TUint16& aValue)
+ {
+ TBuf8<2> valBuf;
+ TInt err = iChannel->DoReadMemory(aThread, aAddress, 2, valBuf);
+ if (err != KErrNone)
+ {
+ LOG_MSG2("DRMDStepping::ReadMem16 failed to read memory at 0x%08x", aAddress);
+ return err;
+ }
+
+ aValue = *(TUint16 *)valBuf.Ptr();
+
+ return KErrNone;
+ }
+
+// Obtain a 16-bit memory value with minimum fuss
+TInt DRMDStepping::ReadMem8(DThread* aThread, const TUint32 aAddress, TUint8& aValue)
+ {
+ TBuf8<1> valBuf;
+ TInt err = iChannel->DoReadMemory(aThread, aAddress, 1, valBuf);
+ if (err != KErrNone)
+ {
+ LOG_MSG2("DRMDStepping::ReadMem8 failed to read memory at 0x%08x", aAddress);
+ return err;
+ }
+
+ aValue = *(TUint8 *)valBuf.Ptr();
+
+ return KErrNone;
+ }
+
+// Obtain a core register value with minimum fuss
+TInt DRMDStepping::RegisterValue(DThread *aThread, const TUint32 aKernelRegisterId, TUint32 &aValue)
+ {
+ TInt err = iChannel->ReadKernelRegisterValue(aThread, aKernelRegisterId, aValue);
+ if(err != KErrNone)
+ {
+ LOG_MSG3("DRMDStepping::RegisterValue failed to read register %d err = %d", aKernelRegisterId, err);
+ }
+ return err;
+ }
+
+
+// Encodings from ARM ARM DDI0406A, section 9.2.1
+enum TThumb2EEOpcode
+ {
+ EThumb2HDP, // Handler Branch with Parameter
+ EThumb2UNDEF, // UNDEFINED
+ EThumb2HB, // Handler Branch, Handler Branch with Link
+ EThumb2HBLP, // Handle Branch with Link and Parameter
+ EThumb2LDRF, // Load Register from a frame
+ EThumb2CHKA, // Check Array
+ EThumb2LDRL, // Load Register from a literal pool
+ EThumb2LDRA, // Load Register (array operations)
+ EThumb2STR // Store Register to a frame
+ };
+
+//
+// DRMDStepping::ShiftedRegValue
+//
+TUint32 DRMDStepping::ShiftedRegValue(DThread *aThread, TUint32 aInstruction, TUint32 aCurrentPC, TUint32 aStatusRegister)
+ {
+ LOG_MSG("DRMDStepping::ShiftedRegValue()");
+
+ TUint32 shift = 0;
+ if (aInstruction & 0x10) // bit 4
+ {
+ shift = (arm_rs(aInstruction) == PC_REGISTER ? aCurrentPC + 8 : aStatusRegister) & 0xFF;
+ }
+ else
+ {
+ shift = arm_data_c(aInstruction);
+ }
+
+ TInt rm = arm_rm(aInstruction);
+
+ TUint32 res = 0;
+ if(rm == PC_REGISTER)
+ {
+ res = aCurrentPC + ((aInstruction & 0x10) ? 12 : 8);
+ }
+ else
+ {
+ TInt err = iChannel->ReadKernelRegisterValue(aThread, rm, res);
+ if(err != KErrNone)
+ {
+ LOG_MSG2("DRMDStepping::ShiftedRegValue - Non-zero error code discarded: %d", err);
+ }
+ }
+
+ switch(arm_data_shift(aInstruction))
+ {
+ case 0: // LSL
+ {
+ res = shift >= 32 ? 0 : res << shift;
+ break;
+ }
+ case 1: // LSR
+ {
+ res = shift >= 32 ? 0 : res >> shift;
+ break;
+ }
+ case 2: // ASR
+ {
+ if (shift >= 32)
+ shift = 31;
+ res = ((res & 0x80000000L) ? ~((~res) >> shift) : res >> shift);
+ break;
+ }
+ case 3: // ROR/RRX
+ {
+ shift &= 31;
+ if (shift == 0)
+ {
+ res = (res >> 1) | ((aStatusRegister & arm_carry_bit()) ? 0x80000000L : 0);
+ }
+ else
+ {
+ res = (res >> shift) | (res << (32 - shift));
+ }
+ break;
+ }
+ }
+
+ return res & 0xFFFFFFFF;
+}
+
+//
+// DRMDStepping::CurrentPC
+//
+//
+//
+TInt DRMDStepping::CurrentPC(DThread* aThread, TUint32& aPC)
+ {
+ LOG_MSG("DRMDStepping::CurrentPC");
+
+ TInt err = iChannel->ReadKernelRegisterValue(aThread, PC_REGISTER, aPC);
+ if(err != KErrNone)
+ {
+ // We don't know the current PC for this thread!
+ LOG_MSG("DRMDStepping::CurrentPC - Failed to read the current PC");
+
+ return KErrGeneral;
+ }
+
+ LOG_MSG2("DRMDStepping::CurrentPC 0x%08x", aPC);
+
+ return KErrNone;
+ }
+
+//
+// DRMDStepping::CurrentCPSR
+//
+//
+//
+TInt DRMDStepping::CurrentCPSR(DThread* aThread, TUint32& aCPSR)
+ {
+ LOG_MSG("DRMDStepping::CurrentCPSR");
+
+ TInt err = iChannel->ReadKernelRegisterValue(aThread, STATUS_REGISTER, aCPSR);
+ if(err != KErrNone)
+ {
+ // We don't know the current PC for this thread!
+ LOG_MSG("DRMDStepping::CurrentPC - Failed to read the current CPSR");
+
+ return KErrGeneral;
+ }
+
+ LOG_MSG2("DRMDStepping::CurrentCPSR 0x%08x", aCPSR);
+
+ return KErrNone;
+ }
+
+//
+// DRMDStepping::ModifyBreaksForStep
+//
+// Set a temporary breakpoint at the next instruction to be executed after the one at the current PC
+// Disable the breakpoint at the current PC if one exists
+//
+TInt DRMDStepping::ModifyBreaksForStep(DThread *aThread, TUint32 aRangeStart, TUint32 aRangeEnd, /*TBool aStepInto,*/ TBool aResumeOnceOutOfRange, TBool aCheckForStubs, const TUint32 aNumSteps)
+ {
+ LOG_MSG2("DRMDStepping::ModifyBreaksForStep() Numsteps 0x%d",aNumSteps);
+
+ // Validate arguments
+ if (!aThread)
+ {
+ LOG_MSG("DRMDStepping::ModifyBreaksForStep() - No aThread specified to step");
+ return KErrArgument;
+ }
+
+ // Current PC
+ TUint32 currentPC;
+
+ ReturnIfError(CurrentPC(aThread,currentPC));
+ LOG_MSG2("Current PC: 0x%x", currentPC);
+
+ // disable breakpoint at the current PC if necessary
+ ReturnIfError(iChannel->iBreakManager->DisableBreakAtAddress(currentPC));
+
+ // Current CPSR
+ TUint32 statusRegister;
+
+ ReturnIfError(CurrentCPSR(aThread,statusRegister));
+ LOG_MSG2("Current CPSR: %x", statusRegister);
+
+ TBool thumbMode = (statusRegister & ECpuThumb);
+ if (thumbMode)
+ LOG_MSG("Thumb Mode");
+
+ TInt instSize = thumbMode ? 2 : 4;
+
+ TBool changingModes = EFalse;
+
+ TUint32 breakAddress = 0;
+
+ TUint32 newRangeEnd = aRangeEnd;
+
+ breakAddress = PCAfterInstructionExecutes(aThread, currentPC, statusRegister, instSize, /* aStepInto, */ newRangeEnd, changingModes);
+
+ /*
+ If there is already a user breakpoint at this address, we do not need to set a temp breakpoint. The program
+ should simply stop at that address.
+ */
+ TBreakEntry* breakEntry = NULL;
+ do
+ {
+ breakEntry = iChannel->iBreakManager->GetNextBreak(breakEntry);
+ if(breakEntry && !iChannel->iBreakManager->IsTemporaryBreak(*breakEntry))
+ {
+ if ((breakEntry->iAddress == breakAddress) && ((breakEntry->iThreadSpecific && breakEntry->iId == aThread->iId) || (!breakEntry->iThreadSpecific && breakEntry->iId == aThread->iOwningProcess->iId)))
+ {
+ LOG_MSG("DRMDStepping::ModifyBreaksForStep - Breakpoint already exists at the step target address\n");
+
+ // note also that if this is the case, we will not keep stepping if we hit a real breakpoint, so may as well set
+ // the step count = 0.
+ breakEntry->iNumSteps = 0;
+
+ return KErrNone;
+ }
+ }
+ } while(breakEntry);
+
+ breakEntry = NULL;
+ do
+ {
+ breakEntry = iChannel->iBreakManager->GetNextBreak(breakEntry);
+ if(breakEntry && iChannel->iBreakManager->IsTemporaryBreak(*breakEntry))
+ {
+ if (breakEntry->iAddress == 0)
+ {
+ breakEntry->iId = aThread->iId;
+ breakEntry->iAddress = breakAddress;
+ breakEntry->iThreadSpecific = ETrue;
+
+ TBool realThumbMode = (thumbMode && !changingModes) || (!thumbMode && changingModes);
+
+ // Need to set the correct type of breakpoint for the mode we are in
+ // and the the one we are changing into
+ if(realThumbMode)
+ {
+ // We are remaining in Thumb mode
+ breakEntry->iMode = EThumbMode;
+ }
+ else
+ {
+ // We are switching to ARM mode
+ breakEntry->iMode = EArmMode;
+ }
+
+ breakEntry->iResumeOnceOutOfRange = aResumeOnceOutOfRange;
+ breakEntry->iSteppingInto = ETrue /* aStepInto */;
+ breakEntry->iRangeStart = 0; // no longer used
+ breakEntry->iRangeEnd = 0; // no longer used
+
+ LOG_MSG2("Adding temp breakpoint with id: %d", breakEntry->iBreakId);
+ LOG_MSG2("Adding temp breakpoint with thread id: %d", aThread->iId);
+
+ // Record how many more steps to go after we hit this one
+ breakEntry->iNumSteps = aNumSteps;
+
+ LOG_MSG3("Setting temp breakpoint id %d with %d steps to go\n", breakEntry->iBreakId, aNumSteps);
+
+ return iChannel->iBreakManager->DoEnableBreak(*breakEntry, ETrue);
+ }
+ }
+ } while(breakEntry);
+ LOG_MSG("ModifyBreaksForStep : Failed to set suitable breakpoint for stepping");
+ return KErrNoMemory; // should never get here
+}
+
+// End of file - d-rmd-stepping.cpp