Flash.cpp

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/* ES40 emulator.
 * Copyright (C) 2007-2008 by the ES40 Emulator Project
 *
 * Website: http://sourceforge.net/projects/es40
 * E-mail : camiel@camicom.com
 * 
 * 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 * 
 * Although this is not required, the author would appreciate being notified of, 
 * and receiving any modifications you may make to the source code that might serve
 * the general public.
 */

#include "StdAfx.h"
#include "Flash.h"
#include "System.h"
#include "AlphaCPU.h"

// These are the modes for our flash-state-machine.
#define MODE_READ         0
#define MODE_STEP1        1
#define MODE_STEP2        2
#define MODE_AUTOSEL      3
#define MODE_PROGRAM      4
#define MODE_ERASE_STEP3  5
#define MODE_ERASE_STEP4  6
#define MODE_ERASE_STEP5  7
#define MODE_CONFIRM_0    8
#define MODE_CONFIRM_1    9

extern CAlphaCPU*   cpu[4];

CFlash::CFlash(CConfigurator* cfg, CSystem* c) : CSystemComponent(cfg, c)
{
  if(theSROM)
    FAILURE(Configuration, "More than one Flash");
  theSROM = this;
  c->RegisterMemory(this, 0, U64(0x0000080100000000), 0x8000000); // 2MB
  memset(state.Flash, 0xff, 2 * 1024 * 1024);
  RestoreStateF();
  state.mode = MODE_READ;

  printf("%s: $Id: Flash.cpp,v 1.19 2008/03/24 22:11:50 iamcamiel Exp $\n",
         devid_string);
}

CFlash::~CFlash()
{ }

u64 CFlash::ReadMem(int index, u64 address, int dsize)
{
  u64 data = 0;
  int a = (int) (address >> 6);

  switch(state.mode)
  {
  case MODE_AUTOSEL:
    switch(a)
    {
    case 0:   data = 1;     // manufacturer
      break;
    case 1:   data = 0xad;  // device
      break;
    default:  data = 0;
    }
    break;

  case MODE_CONFIRM_0:
    data = 0x80;
    state.mode = MODE_READ;
    break;

  case MODE_CONFIRM_1:
    data = 0x80;
    state.mode = MODE_CONFIRM_0;
    break;

  default:
    data = state.Flash[a];
  }

  return data;
}

void CFlash::WriteMem(int index, u64 address, int dsize, u64 data)
{
  int a = (int) (address >> 6);

  switch(state.mode)
  {
  case MODE_READ:
  case MODE_AUTOSEL:
    if((a == 0x5555) && (data == 0xaa))
    {
      state.mode = MODE_STEP1;
      return;
    }

    state.mode = MODE_READ;
    return;

  case MODE_STEP1:
    if((a == 0x2aaa) && (data == 0x55))
    {
      state.mode = MODE_STEP2;
      return;
    }

    state.mode = MODE_READ;
    return;

  case MODE_STEP2:
    if(a != 0x5555)
    {
      state.mode = MODE_READ;
      return;
    }

    switch(data)
    {
    case 0x90:  state.mode = MODE_AUTOSEL; return;
    case 0xa0:  state.mode = MODE_PROGRAM; return;
    case 0x80:  state.mode = MODE_ERASE_STEP3; return;
    }

    state.mode = MODE_READ;
    return;

  case MODE_ERASE_STEP3:
    if((a == 0x5555) && (data == 0xaa))
    {
      state.mode = MODE_ERASE_STEP4;
      return;
    }

    state.mode = MODE_READ;
    return;

  case MODE_ERASE_STEP4:
    if((a == 0x2aaa) && (data == 0x55))
    {
      state.mode = MODE_ERASE_STEP5;
      return;
    }

    state.mode = MODE_READ;
    return;

  case MODE_ERASE_STEP5:
    if((a == 0x5555) && (data == 0x10))
    {
      memset(state.Flash, 0xff, 1 << 21);
      state.mode = MODE_CONFIRM_1;
      return;
    }

    if(data == 0x30)
    {
      memset(&state.Flash[(a >> 16) << 16], 0xff, 1 << 16);
      state.mode = MODE_CONFIRM_1;
      return;
    }

    state.mode = MODE_READ;
    return;
  }

  // we must now be in mode program...
  state.Flash[a] = (u8) data;
  state.mode = MODE_READ;
}

void CFlash::SaveStateF(char* fn)
{
  FILE*   ff;
  ff = fopen(fn, "wb");
  if(ff)
  {
    SaveState(ff);
    fclose(ff);
    printf("%%FLS-I-SAVEST: Flash state saved to %s\n", fn);
  }
  else
  {
    printf("%%FLS-F-NOSAVE: Flash could not be saved to %s\n", fn);
  }
}

void CFlash::SaveStateF()
{
  SaveStateF(myCfg->get_text_value("rom.flash", "flash.rom"));
}

void CFlash::RestoreStateF(char* fn)
{
  FILE*   ff;
  ff = fopen(fn, "rb");
  if(ff)
  {
    RestoreState(ff);
    fclose(ff);
    printf("%%FLS-I-RESTST: Flash state restored from %s\n", fn);
  }
  else
  {
    printf("%%FLS-F-NOREST: Flash could not be restored from %s\n", fn);
  }
}

void CFlash::RestoreStateF()
{
  RestoreStateF(myCfg->get_text_value("rom.flash", "flash.rom"));
}

static u32  flash_magic1 = 0xFF3E3FF3;
static u32  flash_magic2 = 0x3FF3E3FF;

int CFlash::SaveState(FILE* f)
{
  long  ss = sizeof(state);
  fwrite(&flash_magic1, sizeof(u32), 1, f);
  fwrite(&ss, sizeof(long), 1, f);
  fwrite(&state, sizeof(state), 1, f);
  fwrite(&flash_magic2, sizeof(u32), 1, f);
  printf("flash: %d bytes saved.\n", ss);
  return 0;
}

int CFlash::RestoreState(FILE* f)
{
  long    ss;
  u32     m1;
  u32     m2;
  size_t  r;

  r = fread(&m1, sizeof(u32), 1, f);
  if(r != 1)
  {
    printf("flash: unexpected end of file!\n");
    return -1;
  }

  if(m1 != flash_magic1)
  {
    printf("flash: MAGIC 1 does not match!\n");
    return -1;
  }

  fread(&ss, sizeof(long), 1, f);
  if(r != 1)
  {
    printf("flash: unexpected end of file!\n");
    return -1;
  }

  if(ss != sizeof(state))
  {
    printf("flash: STRUCT SIZE does not match!\n");
    return -1;
  }

  fread(&state, sizeof(state), 1, f);
  if(r != 1)
  {
    printf("flash: unexpected end of file!\n");
    return -1;
  }

  r = fread(&m2, sizeof(u32), 1, f);
  if(r != 1)
  {
    printf("flash: unexpected end of file!\n");
    return -1;
  }

  if(m2 != flash_magic2)
  {
    printf("flash: MAGIC 1 does not match!\n");
    return -1;
  }

  printf("flash: %d bytes restored.\n", ss);
  return 0;
}

CFlash*   theSROM = 0;

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