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/* sprs.c -- Simulation of OR1K special-purpose registers

   Copyright (C) 1999 Damjan Lampret, lampret@opencores.org

This file is part of OpenRISC 1000 Architectural Simulator.

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., 675 Mass Ave, Cambridge, MA 02139, USA. */

#include <stdlib.h>

#include <stdio.h>

#include <string.h>

#include "arch.h"

#include "sprs.h"

extern int cont_run;   /* defined in toplevel.c */

extern int tt_stopped; /* defined in tick.c */

extern int GlobalMode; /* CZ 21/06/01 */

static sprword sprs[MAX_SPRS];

int temp_disable_except = 0;

int audio_cnt = 0;

static FILE *fo = 0;

/* Set a specific SPR with a value. */

void mtspr(int regno, sprword value)

{

  int ofs = regno % MAX_SPRS_PER_GRP;

  /* MM: Register hooks.  */

  switch (regno) {

  case 0xFFFD:

    fo = fopen ("audiosim.pcm", "wb+");

    if (!fo) printf("Cannot open audiosim.pcm\n");

    printf("Audio opened.\n");

    return;

  case 0xFFFE:

    if (!fo) printf("audiosim.pcm not opened\n");

    fputc (value & 0xFF, fo);

    if ((audio_cnt % 1024) == 0)

      printf("%i\n", audio_cnt);

    audio_cnt++;

    return;

  case 0xFFFF:

    fclose(fo);

    printf("Audio closed.\n");

    cont_run = 0;

    return;

  case SPR_TTMR:

    if (value & SPR_TTMR_M == 2) break;

  case SPR_TTCR:

    tt_stopped = 0;

    break;

  case 0x1234:

    printf("MTSPR(0x1234, %x);\n", value);

    break;

  }

  /* What the hell is happening here? This looks like a bug

     waiting to happen. Assume regno = 2*MAX_SPRS_PER_GRP+3,

     which presumably means I want to set register 3 in

     group 2. Instead, I calculate ofs as 3, and regno as

     2, and get a final value of 5??? Is this correct?

     Oh well...I didn't write this. Who knows what it is

     actually supposed to do. It doesn't matter if regno

     is less than MAX_SPRS_PER_GRP, which is the only

     way I use it.  CZ - 21/06/01

  */

  regno /= MAX_SPRS_PER_GRP;

  regno += ofs;

  /* CZ 21/06/01 ... the debugger wants to do this! */

  if(GlobalMode)

    {

      extern unsigned long pc;

      extern unsigned long pcnext;

      extern int delay_insn;

      extern unsigned long pcdelay;

      if(regno == SPR_PC)

        {

          sprs[SPR_PC] = value;

          /* The debugger has redirected us to a new address */

          /* This is usually done to reissue an instruction

             which just caused a breakpoint exception. */

          pcnext = value;

          if(!value)

            {

              printf("WARNING: Debugger just set us to 0!\n");

            }

          /* Clear any pending delay slot jumps also */

          delay_insn = 0;

          pcdelay = value+4;

          return;

        }

    }

  /*    printf("mtspr(%x, %x)\n", regno, value);

   */   if (regno < MAX_SPRS)

     sprs[regno] = value;

   else {

     printf("\nABORT: write out of SPR range\n");

     cont_run = 0;

   }

}

/* Get a specific SPR. */

sprword mfspr(int regno)

{

  int ofs = regno % MAX_SPRS_PER_GRP;

  regno /= MAX_SPRS_PER_GRP;

  regno += ofs;

  /* CZ 21/06/01 ... the debugger wants to do this! */

  if(GlobalMode)

    {

      extern unsigned long pc;

      if(regno == SPR_PC)

        return pc;

    }

  /* MM: l.rfe, for example, temporarly disables

     exceptions.  We will make it appear as SR bit

     is set.  */

  if (regno == SPR_SR && temp_disable_except > 0)

    return sprs[regno] | SPR_SR_EXR;

  /*  printf("mfspr(%x)%x\n", regno, sprs[regno]); */

  if (regno < MAX_SPRS)

    return sprs[regno];

  else {

    printf("\nABORT: read out of SPR range\n");

    cont_run = 0;

  }

  return 0;

}

/* Set a specific bit from SPR. LSB in a word is numbered zero. */

void setsprbit(int regno, int bitnum, unsigned long bitvalue)

{

  sprword mask;

  sprword regvalue = mfspr(regno);

  mask = ~(1 << bitnum);

  mtspr(regno, (regvalue & mask) | ((bitvalue & 0x1) << bitnum));

  return;

}

/* Get a specific bit from SPR. */

int getsprbit(int regno, int bitnum)

{

  sprword regvalue = mfspr(regno);

  return (regvalue >> bitnum) & 0x1;

}

/* Set specific SPR bit(s) identified by mask. */

void setsprbits(int regno, unsigned long mask, unsigned long value)

{

  sprword regvalue = mfspr(regno);

  sprword shifted = 0x0;

  int m, v = 0;

  /* m counts bits in valuemask */

  /* v counts bits in value */

  for (m = 0; m < 32; m++)

    if ((mask >> m) & 0x1) {

      shifted |= ((value >> v) & 0x1) << m;

      v++;

    }

  /* printf("oldvalue %x setsprbits(%x, %x, %x)  shifted %x", regvalue, regno, mask, value, shifted); */

  mtspr(regno, (regvalue & ~mask) | shifted);

  return;

}

/* Get specific SPR bit(s) identified by mask. */

unsigned long getsprbits(int regno, unsigned long mask)

{

  sprword regvalue = mfspr(regno);

  sprword shifted = 0x0;

  int m, v = 0;

  /* m counts bits in valuemask */

  /* v counts bits in regvalue */

  for (m = 0; m < 32; m++)

    if ((mask >> m) & 0x1) {

      shifted |= ((regvalue >> m) & 0x1) << v;

      v++;

    }

  return shifted;

}

/* Show status of important SPRs. */

void sprs_status()

{

  printf("VR   : 0x%.8x  UPR  : 0x%.8x\n", mfspr(SPR_VR), mfspr(SPR_UPR));

  printf("SR   : 0x%.8x\n", mfspr(SPR_SR));

  printf("MACLO: 0x%.8x  MACHI: 0x%.8x\n", mfspr(SPR_MACLO), mfspr(SPR_MACHI));

  printf("EPCR0: 0x%.8x  EPCR1: 0x%.8x\n", mfspr(SPR_EPCR_BASE), mfspr(SPR_EPCR_BASE+1));

  printf("EEAR0: 0x%.8x  EEAR1: 0x%.8x\n", mfspr(SPR_EEAR_BASE), mfspr(SPR_EEAR_BASE+1));

  printf("ESR0 : 0x%.8x  ESR1 : 0x%.8x\n", mfspr(SPR_ESR_BASE), mfspr(SPR_ESR_BASE+1));

}