yuzu/src/core/arm/interpreter/armsupp.cpp

/*  armsupp.c -- ARMulator support code:  ARM6 Instruction Emulator.
    Copyright (C) 1994 Advanced RISC Machines Ltd.

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */

#include "core/arm/skyeye_common/armdefs.h"
#include "core/arm/skyeye_common/armemu.h"
#include "core/arm/disassembler/arm_disasm.h"
#include "core/mem_map.h"


static ARMword ModeToBank (ARMword);
static void EnvokeList (ARMul_State *, unsigned int, unsigned int);

struct EventNode {
    /* An event list node.  */
    unsigned (*func) (ARMul_State *);	/* The function to call.  */
    struct EventNode *next;
};

/* This routine returns the value of a register from a mode.  */

ARMword
ARMul_GetReg (ARMul_State * state, unsigned mode, unsigned reg)
{
    mode &= MODEBITS;
    if (mode != state->Mode)
        return (state->RegBank[ModeToBank ((ARMword) mode)][reg]);
    else
        return (state->Reg[reg]);
}

/* This routine sets the value of a register for a mode.  */

void
ARMul_SetReg (ARMul_State * state, unsigned mode, unsigned reg, ARMword value)
{
    mode &= MODEBITS;
    if (mode != state->Mode)
        state->RegBank[ModeToBank ((ARMword) mode)][reg] = value;
    else
        state->Reg[reg] = value;
}

/* This routine returns the value of the PC, mode independently.  */

ARMword
ARMul_GetPC (ARMul_State * state)
{
    if (state->Mode > SVC26MODE)
        return state->Reg[15];
    else
        return R15PC;
}

/* This routine returns the value of the PC, mode independently.  */

ARMword
ARMul_GetNextPC (ARMul_State * state)
{
    if (state->Mode > SVC26MODE)
        return state->Reg[15] + INSN_SIZE;
    else
        return (state->Reg[15] + INSN_SIZE) & R15PCBITS;
}

/* This routine sets the value of the PC.  */

void
ARMul_SetPC (ARMul_State * state, ARMword value)
{
    if (ARMul_MODE32BIT)
        state->Reg[15] = value & PCBITS;
    else
        state->Reg[15] = R15CCINTMODE | (value & R15PCBITS);
    FLUSHPIPE;
}

/* This routine returns the value of register 15, mode independently.  */

ARMword
ARMul_GetR15 (ARMul_State * state)
{
    if (state->Mode > SVC26MODE)
        return (state->Reg[15]);
    else
        return (R15PC | ECC | ER15INT | EMODE);
}

/* This routine sets the value of Register 15.  */

void
ARMul_SetR15 (ARMul_State * state, ARMword value)
{
    if (ARMul_MODE32BIT)
        state->Reg[15] = value & PCBITS;
    else {
        state->Reg[15] = value;
        ARMul_R15Altered (state);
    }
    FLUSHPIPE;
}

/* This routine returns the value of the CPSR.  */

ARMword
ARMul_GetCPSR (ARMul_State * state)
{
    //chy 2003-08-20: below is from gdb20030716, maybe isn't suitable for system simulator
    //return (CPSR | state->Cpsr); for gdb20030716
    return (CPSR);		//had be tested in old skyeye with gdb5.0-5.3
}

/* This routine sets the value of the CPSR.  */

void
ARMul_SetCPSR (ARMul_State * state, ARMword value)
{
    state->Cpsr = value;
    ARMul_CPSRAltered (state);
}

/* This routine does all the nasty bits involved in a write to the CPSR,
   including updating the register bank, given a MSR instruction.  */

void
ARMul_FixCPSR (ARMul_State * state, ARMword instr, ARMword rhs)
{
    state->Cpsr = ARMul_GetCPSR (state);
    //chy 2006-02-16 , should not consider system mode, don't conside 26bit mode
    if (state->Mode != USER26MODE && state->Mode != USER32MODE ) {
        /* In user mode, only write flags.  */
        if (BIT (16))
            SETPSR_C (state->Cpsr, rhs);
        if (BIT (17))
            SETPSR_X (state->Cpsr, rhs);
        if (BIT (18))
            SETPSR_S (state->Cpsr, rhs);
    }
    if (BIT (19))
        SETPSR_F (state->Cpsr, rhs);
    ARMul_CPSRAltered (state);
}

/* Get an SPSR from the specified mode.  */

ARMword
ARMul_GetSPSR (ARMul_State * state, ARMword mode)
{
    ARMword bank = ModeToBank (mode & MODEBITS);

    if (!BANK_CAN_ACCESS_SPSR (bank))
        return ARMul_GetCPSR (state);

    return state->Spsr[bank];
}

/* This routine does a write to an SPSR.  */

void
ARMul_SetSPSR (ARMul_State * state, ARMword mode, ARMword value)
{
    ARMword bank = ModeToBank (mode & MODEBITS);

    if (BANK_CAN_ACCESS_SPSR (bank))
        state->Spsr[bank] = value;
}

/* This routine does a write to the current SPSR, given an MSR instruction.  */

void
ARMul_FixSPSR (ARMul_State * state, ARMword instr, ARMword rhs)
{
    if (BANK_CAN_ACCESS_SPSR (state->Bank)) {
        if (BIT (16))
            SETPSR_C (state->Spsr[state->Bank], rhs);
        if (BIT (17))
            SETPSR_X (state->Spsr[state->Bank], rhs);
        if (BIT (18))
            SETPSR_S (state->Spsr[state->Bank], rhs);
        if (BIT (19))
            SETPSR_F (state->Spsr[state->Bank], rhs);
    }
}

/* This routine updates the state of the emulator after the Cpsr has been
   changed.  Both the processor flags and register bank are updated.  */

void
ARMul_CPSRAltered (ARMul_State * state)
{
    ARMword oldmode;

    if (state->prog32Sig == LOW)
        state->Cpsr &= (CCBITS | INTBITS | R15MODEBITS);

    oldmode = state->Mode;

    /*if (state->Mode != (state->Cpsr & MODEBITS)) {
    	state->Mode =
    		ARMul_SwitchMode (state, state->Mode,
    				  state->Cpsr & MODEBITS);

    	state->NtransSig = (state->Mode & 3) ? HIGH : LOW;
    }*/
    //state->Cpsr &= ~MODEBITS;

    ASSIGNINT (state->Cpsr & INTBITS);
    //state->Cpsr &= ~INTBITS;
    ASSIGNN ((state->Cpsr & NBIT) != 0);
    //state->Cpsr &= ~NBIT;
    ASSIGNZ ((state->Cpsr & ZBIT) != 0);
    //state->Cpsr &= ~ZBIT;
    ASSIGNC ((state->Cpsr & CBIT) != 0);
    //state->Cpsr &= ~CBIT;
    ASSIGNV ((state->Cpsr & VBIT) != 0);
    //state->Cpsr &= ~VBIT;
    ASSIGNQ ((state->Cpsr & QBIT) != 0);
    //state->Cpsr &= ~QBIT;
    state->GEFlag = (state->Cpsr & 0x000F0000);
#ifdef MODET
    ASSIGNT ((state->Cpsr & TBIT) != 0);
    //state->Cpsr &= ~TBIT;
#endif

    if (oldmode > SVC26MODE) {
        if (state->Mode <= SVC26MODE) {
            state->Emulate = CHANGEMODE;
            state->Reg[15] = ECC | ER15INT | EMODE | R15PC;
        }
    } else {
        if (state->Mode > SVC26MODE) {
            state->Emulate = CHANGEMODE;
            state->Reg[15] = R15PC;
        } else
            state->Reg[15] = ECC | ER15INT | EMODE | R15PC;
    }
}

/* This routine updates the state of the emulator after register 15 has
   been changed.  Both the processor flags and register bank are updated.
   This routine should only be called from a 26 bit mode.  */

void
ARMul_R15Altered (ARMul_State * state)
{
    if (state->Mode != R15MODE) {
        state->Mode = ARMul_SwitchMode (state, state->Mode, R15MODE);
        state->NtransSig = (state->Mode & 3) ? HIGH : LOW;
    }

    if (state->Mode > SVC26MODE)
        state->Emulate = CHANGEMODE;

    ASSIGNR15INT (R15INT);

    ASSIGNN ((state->Reg[15] & NBIT) != 0);
    ASSIGNZ ((state->Reg[15] & ZBIT) != 0);
    ASSIGNC ((state->Reg[15] & CBIT) != 0);
    ASSIGNV ((state->Reg[15] & VBIT) != 0);
}

/* This routine controls the saving and restoring of registers across mode
   changes.  The regbank matrix is largely unused, only rows 13 and 14 are
   used across all modes, 8 to 14 are used for FIQ, all others use the USER
   column.  It's easier this way.  old and new parameter are modes numbers.
   Notice the side effect of changing the Bank variable.  */

ARMword
ARMul_SwitchMode (ARMul_State * state, ARMword oldmode, ARMword newmode)
{
    unsigned i;
    ARMword oldbank;
    ARMword newbank;
    static int revision_value = 53;

    oldbank = ModeToBank (oldmode);
    newbank = state->Bank = ModeToBank (newmode);

    /* Do we really need to do it?  */
    if (oldbank != newbank) {
        if (oldbank == 3 && newbank == 2) {
            //printf("icounter is %d PC is %x MODE CHANGED : %d --> %d\n", state->NumInstrs, state->pc, oldbank, newbank);
            if (state->NumInstrs >= 5832487) {
//				printf("%d, ", state->NumInstrs + revision_value);
//				printf("revision_value : %d\n", revision_value);
                revision_value ++;
            }
        }
        /* Save away the old registers.  */
        switch (oldbank) {
        case USERBANK:
        case IRQBANK:
        case SVCBANK:
        case ABORTBANK:
        case UNDEFBANK:
            if (newbank == FIQBANK)
                for (i = 8; i < 13; i++)
                    state->RegBank[USERBANK][i] =
                        state->Reg[i];
            state->RegBank[oldbank][13] = state->Reg[13];
            state->RegBank[oldbank][14] = state->Reg[14];
            break;
        case FIQBANK:
            for (i = 8; i < 15; i++)
                state->RegBank[FIQBANK][i] = state->Reg[i];
            break;
        case DUMMYBANK:
            for (i = 8; i < 15; i++)
                state->RegBank[DUMMYBANK][i] = 0;
            break;
        default:
            abort ();
        }

        /* Restore the new registers.  */
        switch (newbank) {
        case USERBANK:
        case IRQBANK:
        case SVCBANK:
        case ABORTBANK:
        case UNDEFBANK:
            if (oldbank == FIQBANK)
                for (i = 8; i < 13; i++)
                    state->Reg[i] =
                        state->RegBank[USERBANK][i];
            state->Reg[13] = state->RegBank[newbank][13];
            state->Reg[14] = state->RegBank[newbank][14];
            break;
        case FIQBANK:
            for (i = 8; i < 15; i++)
                state->Reg[i] = state->RegBank[FIQBANK][i];
            break;
        case DUMMYBANK:
            for (i = 8; i < 15; i++)
                state->Reg[i] = 0;
            break;
        default:
            abort ();
        }
    }

    return newmode;
}

/* Given a processor mode, this routine returns the
   register bank that will be accessed in that mode.  */

static ARMword
ModeToBank (ARMword mode)
{
    static ARMword bankofmode[] = {
        USERBANK, FIQBANK, IRQBANK, SVCBANK,
        DUMMYBANK, DUMMYBANK, DUMMYBANK, DUMMYBANK,
        DUMMYBANK, DUMMYBANK, DUMMYBANK, DUMMYBANK,
        DUMMYBANK, DUMMYBANK, DUMMYBANK, DUMMYBANK,
        USERBANK, FIQBANK, IRQBANK, SVCBANK,
        DUMMYBANK, DUMMYBANK, DUMMYBANK, ABORTBANK,
        DUMMYBANK, DUMMYBANK, DUMMYBANK, UNDEFBANK,
        DUMMYBANK, DUMMYBANK, DUMMYBANK, SYSTEMBANK
    };

    if (mode >= (sizeof (bankofmode) / sizeof (bankofmode[0])))
        return DUMMYBANK;

    return bankofmode[mode];
}

/* Returns the register number of the nth register in a reg list.  */

unsigned
ARMul_NthReg (ARMword instr, unsigned number)
{
    unsigned bit, upto;

    for (bit = 0, upto = 0; upto <= number; bit++)
        if (BIT (bit))
            upto++;

    return (bit - 1);
}

/* Assigns the N and Z flags depending on the value of result.  */

void
ARMul_NegZero (ARMul_State * state, ARMword result)
{
    if (NEG (result)) {
        SETN;
        CLEARZ;
    } else if (result == 0) {
        CLEARN;
        SETZ;
    } else {
        CLEARN;
        CLEARZ;
    }
}

/* Compute whether an addition of A and B, giving RESULT, overflowed.  */

int
AddOverflow (ARMword a, ARMword b, ARMword result)
{
    return ((NEG (a) && NEG (b) && POS (result))
            || (POS (a) && POS (b) && NEG (result)));
}

/* Compute whether a subtraction of A and B, giving RESULT, overflowed.  */

int
SubOverflow (ARMword a, ARMword b, ARMword result)
{
    return ((NEG (a) && POS (b) && POS (result))
            || (POS (a) && NEG (b) && NEG (result)));
}

/* Assigns the C flag after an addition of a and b to give result.  */

void
ARMul_AddCarry (ARMul_State * state, ARMword a, ARMword b, ARMword result)
{
    ASSIGNC ((NEG (a) && NEG (b)) ||
             (NEG (a) && POS (result)) || (NEG (b) && POS (result)));
}

/* Assigns the V flag after an addition of a and b to give result.  */

void
ARMul_AddOverflow (ARMul_State * state, ARMword a, ARMword b, ARMword result)
{
    ASSIGNV (AddOverflow (a, b, result));
}

/* Assigns the Q flag if the given result is considered an overflow from the addition of a and b  */
void ARMul_AddOverflowQ(ARMul_State* state, ARMword a, ARMword b)
{
    u32 result = a + b;
    if (((result ^ a) & (u32)0x80000000) && ((a ^ b) & (u32)0x80000000) == 0)
        SETQ;
}

/* Assigns the C flag after an subtraction of a and b to give result.  */

void
ARMul_SubCarry (ARMul_State * state, ARMword a, ARMword b, ARMword result)
{
    ASSIGNC ((NEG (a) && POS (b)) ||
             (NEG (a) && POS (result)) || (POS (b) && POS (result)));
}

/* Assigns the V flag after an subtraction of a and b to give result.  */

void
ARMul_SubOverflow (ARMul_State * state, ARMword a, ARMword b, ARMword result)
{
    ASSIGNV (SubOverflow (a, b, result));
}

/* This function does the work of generating the addresses used in an
   LDC instruction.  The code here is always post-indexed, it's up to the
   caller to get the input address correct and to handle base register
   modification. It also handles the Busy-Waiting.  */

void
ARMul_LDC (ARMul_State * state, ARMword instr, ARMword address)
{
    unsigned cpab;
    ARMword data;

    UNDEF_LSCPCBaseWb;
    //printf("SKYEYE ARMul_LDC, CPnum is %x, instr %x, addr %x\n",CPNum, instr, address);
    /*chy 2004-05-23 should update this function in the future,should concern dataabort*/
// chy 2004-05-25 , fix it now,so needn't printf
//  printf("SKYEYE ARMul_LDC, should update this function!!!!!\n");
    //exit(-1);

    //if (!CP_ACCESS_ALLOWED (state, CPNum)) {
    if (!state->LDC[CPNum]) {
        /*
           printf
           ("SKYEYE ARMul_LDC,NOT ALLOW, underinstr, CPnum is %x, instr %x, addr %x\n",
           CPNum, instr, address);
         */
        ARMul_UndefInstr (state, instr);
        return;
    }

    /*if (ADDREXCEPT (address))
          INTERNALABORT (address);*/

    cpab = (state->LDC[CPNum]) (state, ARMul_FIRST, instr, 0);
    while (cpab == ARMul_BUSY) {
        ARMul_Icycles (state, 1, 0);

        if (IntPending (state)) {
            cpab = (state->LDC[CPNum]) (state, ARMul_INTERRUPT,
                                        instr, 0);
            return;
        } else
            cpab = (state->LDC[CPNum]) (state, ARMul_BUSY, instr,
                                        0);
    }
    if (cpab == ARMul_CANT) {
        /*
           printf
           ("SKYEYE ARMul_LDC,NOT CAN, underinstr, CPnum is %x, instr %x, addr %x\n",
           CPNum, instr, address);
         */
        CPTAKEABORT;
        return;
    }

    cpab = (state->LDC[CPNum]) (state, ARMul_TRANSFER, instr, 0);
    data = ARMul_LoadWordN (state, address);
    //chy 2004-05-25
    if (state->abortSig || state->Aborted)
        goto L_ldc_takeabort;

    BUSUSEDINCPCN;
//chy 2004-05-25
    /*
      if (BIT (21))
        LSBase = state->Base;
    */

    cpab = (state->LDC[CPNum]) (state, ARMul_DATA, instr, data);

    while (cpab == ARMul_INC) {
        address += 4;
        data = ARMul_LoadWordN (state, address);
        //chy 2004-05-25
        if (state->abortSig || state->Aborted)
            goto L_ldc_takeabort;

        cpab = (state->LDC[CPNum]) (state, ARMul_DATA, instr, data);
    }

//chy 2004-05-25
L_ldc_takeabort:
    if (BIT (21)) {
        if (!
                ((state->abortSig || state->Aborted)
                 && state->lateabtSig == LOW))
            LSBase = state->Base;
    }

    if (state->abortSig || state->Aborted)
        TAKEABORT;
}

/* This function does the work of generating the addresses used in an
   STC instruction.  The code here is always post-indexed, it's up to the
   caller to get the input address correct and to handle base register
   modification. It also handles the Busy-Waiting.  */

void
ARMul_STC (ARMul_State * state, ARMword instr, ARMword address)
{
    unsigned cpab;
    ARMword data;

    UNDEF_LSCPCBaseWb;

    //printf("SKYEYE ARMul_STC, CPnum is %x, instr %x, addr %x\n",CPNum, instr, address);
    /*chy 2004-05-23 should update this function in the future,should concern dataabort */
//  skyeye_instr_debug=0;printf("SKYEYE  debug end!!!!\n");
// chy 2004-05-25 , fix it now,so needn't printf
//  printf("SKYEYE ARMul_STC, should update this function!!!!!\n");

    //exit(-1);
    //if (!CP_ACCESS_ALLOWED (state, CPNum)) {
    if (!state->STC[CPNum]) {
        /*
           printf
           ("SKYEYE ARMul_STC,NOT ALLOW, undefinstr,  CPnum is %x, instr %x, addr %x\n",
           CPNum, instr, address);
         */
        ARMul_UndefInstr (state, instr);
        return;
    }

    /*if (ADDREXCEPT (address) || VECTORACCESS (address))
          INTERNALABORT (address);*/

    cpab = (state->STC[CPNum]) (state, ARMul_FIRST, instr, &data);
    while (cpab == ARMul_BUSY) {
        ARMul_Icycles (state, 1, 0);
        if (IntPending (state)) {
            cpab = (state->STC[CPNum]) (state, ARMul_INTERRUPT,
                                        instr, 0);
            return;
        } else
            cpab = (state->STC[CPNum]) (state, ARMul_BUSY, instr,
                                        &data);
    }

    if (cpab == ARMul_CANT) {
        /*
           printf
           ("SKYEYE ARMul_STC,CANT, undefinstr,  CPnum is %x, instr %x, addr %x\n",
           CPNum, instr, address);
         */
        CPTAKEABORT;
        return;
    }
    /*#ifndef MODE32
    	if (ADDREXCEPT (address) || VECTORACCESS (address))
    		INTERNALABORT (address);
                    #endif*/
    BUSUSEDINCPCN;
//chy 2004-05-25
    /*
      if (BIT (21))
        LSBase = state->Base;
    */
    cpab = (state->STC[CPNum]) (state, ARMul_DATA, instr, &data);
    ARMul_StoreWordN (state, address, data);
    //chy 2004-05-25
    if (state->abortSig || state->Aborted)
        goto L_stc_takeabort;

    while (cpab == ARMul_INC) {
        address += 4;
        cpab = (state->STC[CPNum]) (state, ARMul_DATA, instr, &data);
        ARMul_StoreWordN (state, address, data);
        //chy 2004-05-25
        if (state->abortSig || state->Aborted)
            goto L_stc_takeabort;
    }
//chy 2004-05-25
L_stc_takeabort:
    if (BIT (21)) {
        if (!
                ((state->abortSig || state->Aborted)
                 && state->lateabtSig == LOW))
            LSBase = state->Base;
    }

    if (state->abortSig || state->Aborted)
        TAKEABORT;
}

/* This function does the Busy-Waiting for an MCR instruction.  */

void
ARMul_MCR (ARMul_State * state, ARMword instr, ARMword source)
{
    unsigned cpab;
    int cm = BITS(0, 3) & 0xf;
    int cp = BITS(5, 7) & 0x7;
    int rd = BITS(12, 15) & 0xf;
    int cn = BITS(16, 19) & 0xf;
    int cpopc = BITS(21, 23) & 0x7;

    if (CPNum == 15 && source == 0) //Cache flush
    {
        return;
    }

    //printf("SKYEYE ARMul_MCR, CPnum is %x, source %x\n",CPNum, source);
    //if (!CP_ACCESS_ALLOWED (state, CPNum)) {
    if (!state->MCR[CPNum]) {
        //chy 2004-07-19 should fix in the future ????!!!!
        LOG_ERROR(Core_ARM11, "SKYEYE ARMul_MCR, ACCESS_not ALLOWed, UndefinedInstr  CPnum is %x, source %x",CPNum, source);
        ARMul_UndefInstr (state, instr);
        return;
    }

    //DEBUG("SKYEYE ARMul_MCR p%d, %d, r%d, c%d, c%d, %d\n", CPNum, cpopc, rd, cn, cm, cp);
    //DEBUG("plutoo: MCR not implemented\n");
    //exit(1);
    //return;

    cpab = (state->MCR[CPNum]) (state, ARMul_FIRST, instr, source);

    while (cpab == ARMul_BUSY) {
        ARMul_Icycles (state, 1, 0);

        if (IntPending (state)) {
            cpab = (state->MCR[CPNum]) (state, ARMul_INTERRUPT,
                                        instr, 0);
            return;
        } else
            cpab = (state->MCR[CPNum]) (state, ARMul_BUSY, instr,
                                        source);
    }

    if (cpab == ARMul_CANT) {
        LOG_ERROR(Core_ARM11, "SKYEYE ARMul_MCR, CANT, UndefinedInstr %x CPnum is %x, source %x", instr, CPNum, source); //ichfly todo
        //ARMul_Abort (state, ARMul_UndefinedInstrV);
    } else {
        BUSUSEDINCPCN;
        ARMul_Ccycles (state, 1, 0);
    }
}

/* This function does the Busy-Waiting for an MCRR instruction.  */

void
ARMul_MCRR (ARMul_State * state, ARMword instr, ARMword source1, ARMword source2)
{
    unsigned cpab;

    //if (!CP_ACCESS_ALLOWED (state, CPNum)) {
    if (!state->MCRR[CPNum]) {
        ARMul_UndefInstr (state, instr);
        return;
    }

    cpab = (state->MCRR[CPNum]) (state, ARMul_FIRST, instr, source1, source2);

    while (cpab == ARMul_BUSY) {
        ARMul_Icycles (state, 1, 0);

        if (IntPending (state)) {
            cpab = (state->MCRR[CPNum]) (state, ARMul_INTERRUPT,
                                         instr, 0, 0);
            return;
        } else
            cpab = (state->MCRR[CPNum]) (state, ARMul_BUSY, instr,
                                         source1, source2);
    }
    if (cpab == ARMul_CANT) {
        printf ("In %s, CoProcesscor returned CANT, CPnum is %x, instr %x, source %x %x\n", __FUNCTION__, CPNum, instr, source1, source2);
        ARMul_Abort (state, ARMul_UndefinedInstrV);
    } else {
        BUSUSEDINCPCN;
        ARMul_Ccycles (state, 1, 0);
    }
}

/* This function does the Busy-Waiting for an MRC instruction.  */

ARMword ARMul_MRC (ARMul_State * state, ARMword instr)
{
    int cm = BITS(0, 3) & 0xf;
    int cp = BITS(5, 7) & 0x7;
    int rd = BITS(12, 15) & 0xf;
    int cn = BITS(16, 19) & 0xf;
    int cpopc = BITS(21, 23) & 0x7;

    if (cn == 13 && cm == 0 && cp == 3) { //c13,c0,3; returns CPU svc buffer
	ARMword result = Memory::KERNEL_MEMORY_VADDR;

	if (result != -1) {
		return result;
	}
    }

    //DEBUG("SKYEYE ARMul_MRC p%d, %d, r%d, c%d, c%d, %d\n", CPNum, cpopc, rd, cn, cm, cp);
    //DEBUG("plutoo: MRC not implemented\n");
    //return;

    unsigned cpab;
    ARMword result = 0;

    //printf("SKYEYE ARMul_MRC, CPnum is %x, instr %x\n",CPNum, instr);
    //if (!CP_ACCESS_ALLOWED (state, CPNum)) {
    if (!state->MRC[CPNum]) {
        //chy 2004-07-19 should fix in the future????!!!!
        LOG_ERROR(Core_ARM11, "SKYEYE ARMul_MRC,NOT ALLOWed UndefInstr  CPnum is %x, instr %x", CPNum, instr);
        ARMul_UndefInstr (state, instr);
        return -1;
    }

    cpab = (state->MRC[CPNum]) (state, ARMul_FIRST, instr, &result);
    while (cpab == ARMul_BUSY) {
        ARMul_Icycles (state, 1, 0);
        if (IntPending (state)) {
            cpab = (state->MRC[CPNum]) (state, ARMul_INTERRUPT,
                                        instr, 0);
            return (0);
        } else
            cpab = (state->MRC[CPNum]) (state, ARMul_BUSY, instr,
                                        &result);
    }
    if (cpab == ARMul_CANT) {
        printf ("SKYEYE ARMul_MRC,CANT UndefInstr  CPnum is %x, instr %x\n", CPNum, instr);
        ARMul_Abort (state, ARMul_UndefinedInstrV);
        /* Parent will destroy the flags otherwise.  */
        result = ECC;
    } else {
        BUSUSEDINCPCN;
        ARMul_Ccycles (state, 1, 0);
        ARMul_Icycles (state, 1, 0);
    }

    return result;
}

/* This function does the Busy-Waiting for an MRRC instruction. (to verify) */

void
ARMul_MRRC (ARMul_State * state, ARMword instr, ARMword * dest1, ARMword * dest2)
{
    unsigned cpab;
    ARMword result1 = 0;
    ARMword result2 = 0;

    //if (!CP_ACCESS_ALLOWED (state, CPNum)) {
    if (!state->MRRC[CPNum]) {
        ARMul_UndefInstr (state, instr);
        return;
    }

    cpab = (state->MRRC[CPNum]) (state, ARMul_FIRST, instr, &result1, &result2);
    while (cpab == ARMul_BUSY) {
        ARMul_Icycles (state, 1, 0);
        if (IntPending (state)) {
            cpab = (state->MRRC[CPNum]) (state, ARMul_INTERRUPT,
                                         instr, 0, 0);
            return;
        } else
            cpab = (state->MRRC[CPNum]) (state, ARMul_BUSY, instr,
                                         &result1, &result2);
    }
    if (cpab == ARMul_CANT) {
        printf ("In %s, CoProcesscor returned CANT, CPnum is %x, instr %x\n", __FUNCTION__, CPNum, instr);
        ARMul_Abort (state, ARMul_UndefinedInstrV);
    } else {
        BUSUSEDINCPCN;
        ARMul_Ccycles (state, 1, 0);
        ARMul_Icycles (state, 1, 0);
    }

    *dest1 = result1;
    *dest2 = result2;
}

/* This function does the Busy-Waiting for an CDP instruction.  */

void
ARMul_CDP (ARMul_State * state, ARMword instr)
{
    unsigned cpab;

    //if (!CP_ACCESS_ALLOWED (state, CPNum)) {
    if (!state->CDP[CPNum]) {
        ARMul_UndefInstr (state, instr);
        return;
    }
    cpab = (state->CDP[CPNum]) (state, ARMul_FIRST, instr);
    while (cpab == ARMul_BUSY) {
        ARMul_Icycles (state, 1, 0);
        if (IntPending (state)) {
            cpab = (state->CDP[CPNum]) (state, ARMul_INTERRUPT,
                                        instr);
            return;
        } else
            cpab = (state->CDP[CPNum]) (state, ARMul_BUSY, instr);
    }
    if (cpab == ARMul_CANT)
        ARMul_Abort (state, ARMul_UndefinedInstrV);
    else
        BUSUSEDN;
}

/* This function handles Undefined instructions, as CP isntruction.  */

void
ARMul_UndefInstr (ARMul_State * state, ARMword instr)
{
    std::string disasm = ARM_Disasm::Disassemble(state->pc, instr);
    LOG_ERROR(Core_ARM11, "Undefined instruction!! Disasm: %s Opcode: 0x%x", disasm.c_str(), instr);
    ARMul_Abort (state, ARMul_UndefinedInstrV);
}

/* Return TRUE if an interrupt is pending, FALSE otherwise.  */

unsigned
IntPending (ARMul_State * state)
{
    /* Any exceptions.  */
    if (state->NresetSig == LOW) {
        ARMul_Abort (state, ARMul_ResetV);
        return TRUE;
    } else if (!state->NfiqSig && !FFLAG) {
        ARMul_Abort (state, ARMul_FIQV);
        return TRUE;
    } else if (!state->NirqSig && !IFLAG) {
        ARMul_Abort (state, ARMul_IRQV);
        return TRUE;
    }

    return FALSE;
}

/* Align a word access to a non word boundary.  */

ARMword
ARMul_Align (ARMul_State* state, ARMword address, ARMword data)
{
    /* This code assumes the address is really unaligned,
       as a shift by 32 is undefined in C.  */

    address = (address & 3) << 3;	/* Get the word address.  */
    return ((data >> address) | (data << (32 - address)));	/* rot right */
}

/* This routine is used to call another routine after a certain number of
   cycles have been executed. The first parameter is the number of cycles
   delay before the function is called, the second argument is a pointer
   to the function. A delay of zero doesn't work, just call the function.  */

void
ARMul_ScheduleEvent (ARMul_State * state, unsigned int delay,
                     unsigned (*what) (ARMul_State *))
{
    unsigned int when;
    struct EventNode *event;

    if (state->EventSet++ == 0)
        state->Now = ARMul_Time (state);
    when = (state->Now + delay) % EVENTLISTSIZE;
    event = (struct EventNode *) malloc (sizeof (struct EventNode));
    if (!event) {
        printf ("SKYEYE:ARMul_ScheduleEvent: malloc event error\n");
        exit(-1);
        //skyeye_exit (-1);
    }
    event->func = what;
    event->next = *(state->EventPtr + when);
    *(state->EventPtr + when) = event;
}

/* This routine is called at the beginning of
   every cycle, to envoke scheduled events.  */

void
ARMul_EnvokeEvent (ARMul_State * state)
{
    static unsigned int then;

    then = state->Now;
    state->Now = ARMul_Time (state) % EVENTLISTSIZE;
    if (then < state->Now)
        /* Schedule events.  */
        EnvokeList (state, then, state->Now);
    else if (then > state->Now) {
        /* Need to wrap around the list.  */
        EnvokeList (state, then, EVENTLISTSIZE - 1L);
        EnvokeList (state, 0L, state->Now);
    }
}

/* Envokes all the entries in a range.  */

static void
EnvokeList (ARMul_State * state, unsigned int from, unsigned int to)
{
    for (; from <= to; from++) {
        struct EventNode *anevent;

        anevent = *(state->EventPtr + from);
        while (anevent) {
            (anevent->func) (state);
            state->EventSet--;
            anevent = anevent->next;
        }
        *(state->EventPtr + from) = NULL;
    }
}

/* This routine is returns the number of clock ticks since the last reset.  */

unsigned int
ARMul_Time (ARMul_State * state)
{
    return (state->NumScycles + state->NumNcycles +
            state->NumIcycles + state->NumCcycles + state->NumFcycles);
}