estcpu32backend.cpp

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    {
    int status;

    // XXX
    // Do not touch target if an exception occurred.
    // This is a work-around for the EST API's lack of
    // timely knowlege about the emulator's operating mode.

    if (isExcState_m ())
        {
        oldState = EST_MODE_BKM; 
        return (WDB_OK);
        }

    oldState = (EST_OperatingMode) ::EST_GetOperatingMode (emulator_);

    switch (oldState)
        {
        case EST_MODE_BKM:
            status = EST_SUCCESS;
            break;
        case EST_MODE_RUN:                /* Running */
        case EST_MODE_TRC:                /* Non-realtime trace */
            status = ::EST_StopTarget (emulator_);
            if (status != EST_SUCCESS)
                {
                return wdbErrFigure_m ("EST_StopTarget ()", 
                                       status, WDB_ERR_PROC_FAILED);
                }
            break;
        case EST_MODE_ERR:                /* Error */

            //  Re-initialize emulator (and target) to change from ERR mode
            //  to background mode.  Note:  the INN command only reinitializes
            //  background mode and does not reinitialize the target.

            status = ::EST_Initialize (emulator_, EST_INN_COMMAND);
            if (status != EST_SUCCESS)
                {
                return wdbErrFigure_m ("EST_Initialize ()", 
                                       status, WDB_ERR_PROC_FAILED);
                }
            break;
        case EST_MODE_NOCONNECT:        /* Not connected... */
        case EST_MODE_SIM:              /* Simulation mode */
        case EST_MODE_PFA:              /* Performance */
            status = EST_FAILURE;
            WPWR_LOG_ERR ("Est_T::stateBKM_m () : invalid state %s.\n", 
                          ::EST_OperatingModeImage (oldState));
            break;
        default:
            status = EST_FAILURE;
            WPWR_LOG_ERR ("Est_T::stateBKM_m () : invalid mode %d.\n", 
                          oldState);
            break;
        }

    return (wdbErrFigure_m ("Est_T::stateBKM_m ()", status, 
                            WDB_ERR_AGENT_MODE));
    }

/*******************************************************************************
*
* Est_T::stateRestore_m - Restores the old state was called.
*
* This method restores the system to the state it was in before
* background (BKM) mode was entered.
*/

UINT32 Est_T::stateRestore_m (EST_OperatingMode oldState)
    {

    int status = EST_FAILURE;

    // XXX
    // Do not touch target if an exception occurred.
    // This is a work-around for the EST API's lack of
    // timely knowlege about the emulator's operating mode.

    if (isExcState_m ())
        {
        return (WDB_OK);
        }

    switch (oldState)
        {
        case EST_MODE_BKM:
            status = EST_SUCCESS;
            break;
        case EST_MODE_RUN:                /* Running */
            status = ::EST_StartTarget (emulator_, 
                                        1, // Resume from current PC
                                        0);
            break;
        case EST_MODE_NOCONNECT:        /* Not connected... */
        case EST_MODE_SIM:              /* Simulation mode */
        case EST_MODE_PFA:              /* Performance */
        // XXX - should handle TRC mode?
        case EST_MODE_TRC:              /* Non-realtime trace */
            status = EST_FAILURE;
            WPWR_LOG_ERR ("Est_T::stateRestore_m () : invalid state %s.\n", 
                          ::EST_OperatingModeImage (oldState));
            break;
        case EST_MODE_ERR:               /* Error */
            status = EST_SUCCESS;        // Ignore this state and remain in BKM.
            break;
        default:
            status = EST_FAILURE;
            WPWR_LOG_ERR ("Est_T::stateRestore_m () : invalid mode %d.\n", 
                          oldState);
            break;
        }

    return (wdbErrFigure_m ("Est_T::stateRestore_m ()", 
                            status, WDB_ERR_PROC_FAILED));
    }

/*******************************************************************************
*
* Est_T::eventQueuePut_m - put a valid event on the event queue.
*/

void Est_T::eventQueuePut_m (Event_T * pWdbEvent)

    {
    if (pWdbEvent == NULL)
        {
        WPWR_LOG_ERR ("new () failed for event callback.\n");
        }
    else
        {
        // enqueue valid events
        if (pWdbEvent->wdbEvent_.evtType != WDB_EVT_NONE)
            {
            eventQueue_.append (pWdbEvent);
            isEvent_ = TRUE;
            }
        }
    }

/*******************************************************************************
*
* Est_T::eventQueueGet_m - get an event from the event queue.
*/

void Est_T::eventQueueGet_m (WDB_EVT_DATA * pEvtData)

    {
    // Pop event off queue
    Event_T * pWdbEvent = (Event_T *) eventQueue_.get ();

    if (pWdbEvent == rwnil)
        {
        // Queue is empty, but we must synthesize a
        // bogus event for the target server.

        isEvent_ = FALSE;

	// Note:  the target server converts this event type into the
	// event type UNKNOWN for the tools.

        pEvtData->evtType = WDB_EVT_NONE;
        return;
        }
    else
        {
        // The event is valid.

        *pEvtData = pWdbEvent->wdbEvent_; 
        delete pWdbEvent;

        if (eventQueue_.isEmpty ())
            isEvent_ = FALSE;        // Clear event flag
        return;
        }
    }

/*******************************************************************************
*
* Est_T::regGetOne_m - read only one register.
*
* Caveat - the emulator is assumed to be in background (BKM) state!
*/

UINT32 Est_T::regGetOne_m
    (
    uint16    estRegNum,
    void *    pRegValue
    )

    {
    int        status;

    //    the emulator is assumed to be in background (BKM) state!

    status = ::EST_ReadTargetRegister (emulator_, (uint16) estRegNum, 
                                       pRegValue );
    return (wdbErrFigure_m ("EST_ReadTargetRegister ()", status, 
            WDB_ERR_PROC_FAILED));
    }

/*******************************************************************************
*
* Est_T::regSetOne_m - write only one register.
*
* Caveat - the emulator is assumed to be in background (BKM) state!
*/

UINT32 Est_T::regSetOne_m
    (
    uint16    estRegNum,
    void *    pRegValue
    )

    {
    int        status;

    //    the emulator is assumed to be in background (BKM) state!

    status = ::EST_WriteTargetRegister (emulator_, (uint16) estRegNum, 
                                        pRegValue );
    return (wdbErrFigure_m ("EST_WriteTargetRegister ()", status, 
            WDB_ERR_PROC_FAILED));
    }

/*******************************************************************************
*
* Est_T::whichEstRegGet_m - converts a Wind River offset to EST's information.
*
* This functions converts the byte offset into a WRS REG_SET structure,
* for the 68k, into the corresponding EST register information.
*
* Warning: this function is highly architecture-dependent.
*/

UINT32 Est_T::whichEstRegGet_m 
    (
    UINT32          regSetOffset,
    EST_Register *  pWhichEstReg, 
    uint32 *        pEstRegSize
    )

    {

    // Determine which EST register is specified
    // by the register set offset.
    //
    // Warning:  this is highly architecture dependent!

    switch (regSetOffset)

        {

        // Data Registers:
        case         0:
            *pWhichEstReg = EST_REG_D0;
            break;
        case         4:
            *pWhichEstReg = EST_REG_D1;
            break;
        case         8:
            *pWhichEstReg = EST_REG_D2;
            break;
        case        12:
            *pWhichEstReg = EST_REG_D3;
            break;
        case        16:
            *pWhichEstReg = EST_REG_D4;
            break;
        case        20:
            *pWhichEstReg = EST_REG_D5;
            break;
        case        24:
            *pWhichEstReg = EST_REG_D6;
            break;
        case        28:
            *pWhichEstReg = EST_REG_D7;
            break;

        // Address Registers
        case (32 +  0):
            *pWhichEstReg = EST_REG_A0;
            break;
        case (32 +  4):
            *pWhichEstReg = EST_REG_A1;
            break;
        case (32 +  8):
            *pWhichEstReg = EST_REG_A2;
            break;
        case (32 + 12):
            *pWhichEstReg = EST_REG_A3;
            break;
        case (32 + 16):
            *pWhichEstReg = EST_REG_A4;
            break;
        case (32 + 20):
            *pWhichEstReg = EST_REG_A5;
            break;
        case (32 + 24):
            *pWhichEstReg = EST_REG_A6;
            break;
        case (32 + 28):
            *pWhichEstReg = EST_REG_A7;
            break;

        // Status Register
        case       64:        // GDB is thinks the status register is 32-bits.
        case       66:
            *pWhichEstReg = EST_REG_SR;
            break;

        // Program counter
        case       68:
            *pWhichEstReg = EST_REG_PC;
            break;
        
        default:
            return (WDB_ERR_INVALID_PARAMS);
            break;
        }

    *pEstRegSize = EST_RegisterSize (*pWhichEstReg);
    return (WDB_OK);

    }

/*******************************************************************************
*
* Est_T::memChecksum_m - perform checksum on a chunk of target memory.
*
* Caveat - because of performance limitations of the API, the checksum
* is only performed on small chunks of memory.  Large requests are failed.
*/

UINT32 Est_T::memChecksum_m 
    (
    WDB_MEM_REGION * pMemRegion,
    UINT32 *         pChecksumValue
    )
    {

    // Only perform checksum on small regions
    if (pMemRegion->numBytes < 128 )
        {
        return (Backend_T::memChecksum_m (pMemRegion, pChecksumValue));
        }

    *pChecksumValue = 0x0;
    return (WDB_OK);
    };


////////////////////////////////////////////////////////////////////////////////
// Backend_T's mandatory helper methods.

/*******************************************************************************
*
* Est_T::halt_m - halt target processor.
*/

UINT32 Est_T::halt_m ()
    {
    UINT32              status;

    status     = stateBKM_m (oldTgtState_);

    return (status);
    }

/*******************************************************************************
*
* Est_T::unhalt_m - unhalt target processor.
*
* If previous state was running, resume target,
* otherwise remain halted.
*/

UINT32 Est_T::unhalt_m ()
    {
    UINT32              status;

    status = stateRestore_m (oldTgtState_);

    return (status);
    }

/*******************************************************************************
*
* Est_T::fdGet_m - returns event file descriptor.
*/

int Est_T::fdGet_m () 
    { 
    return eventFd_;
    }


////////////////////////////////////////////////////////////////////////////////
// Exception Management Methods
//
// When a target exception occurs, the back end is notified
// of the exception by a target-resident exception hook
// which gathers information about the exception, and executes
// the 'bgnd' instruction.  The back end must then switch
// from "normal" to "exception" state.  In "exception" state,
// attempts to read IU registers will return the value of the
// IU registers for the task which generated the execption.  Also,
// the contextCont, contextStep, and contextResume operations
// cause the back end to step over the 'bgnd' instruction, and
// return to "normal" state.

/*******************************************************************************
*
* Est_T::excStateEnter_m - put EST back end in "exception" state.
*/

UINT32 Est_T::excStateEnter_m (BDM_EXC_INFO * pExcInfo)

    {

    STATUS status;

    // increment exception flag.
    excCount_++;

    // get IU registers for the context which generated the exception.
    TGT_ADDR_T tgtRegAddr = (TGT_ADDR_T) pExcInfo->pIuRegs;

    status = tgtRead_s (tgtRegAddr, pExcRegSet_, sizeof (*pExcRegSet_));

    if (status != OK)
        {
        WPWR_LOG_ERR ("Backend_T::tgtRead_s() failed!\n");
        return (WDB_ERR_MEM_ACCES);
        }

    return (WDB_OK);
    }

/*******************************************************************************
*
* Est_T::excStateExit_m - return EST back end to "normal" state.
*
* Only call this function if the emulator is in BKM mode,
* which should be true whenever the back end is in "exception" state.
*/

UINT32 Est_T::excStateExit_m (BOOL doStep)
    {

    if (excCount_ == 0)
        {
        WPWR_LOG_ERR ("Est_T::excStateExit_m () - unmatched exit attempt.\n");
        return (WDB_ERR_PROC_FAILED);
        }

    // decrement exception count.
    excCount_--;


    // step past 'bgnd' instruction.
    //
    // Intuitively, you would want to use Est_StepTarget() to
    // step one instruction to bypass the 'bgnd' instruction, or
    // to use Est_StartTarget() to continue.  Unfortunately, the 
    // former causes a breakpoint event, and the later can not
    // continue past a 'bgnd' instruction.  The work around is to
    // use EST_StepTargetOutOf() to step one instruction, because
    // this function does not generate a breakpoint event.

    if (doStep)
        {
        EST_TargetAddress startAddr;
        EST_TargetAddress endAddr;
        int               status;

        startAddr = (EST_TargetAddress) pExcRegSet_->pc;
        endAddr   = startAddr + 1;

        status = ::EST_StepTargetOutOf (emulator_, startAddr, endAddr);

        if (status != EST_SUCCESS)
            {
            return (wdbErrFigure_m ("EST_StepTargetOutOf ()", status, 
                                    WDB_ERR_PROC_FAILED));
            }
        }

    return (WDB_OK);
    }

/*******************************************************************************
*
* Est_T::excRegsGet_m - read REG_SET from task which generated exception.
*/

UINT32 Est_T::excRegsGet_m
    (
    WDB_REG_READ_DESC * pRegRead, 
    WDB_MEM_XFER *      pMemXfer
    )

    {
    char * pWrsRegSet;

    pMemXfer->numBytes    = pRegRead->memRegion.numBytes;
    pMemXfer->destination = 0;

    pWrsRegSet            = (char *) pExcRegSet_;
    pMemXfer->source      = &pWrsRegSet [(int)pRegRead->memRegion.baseAddr];

    return (WDB_OK);
    }