//
// Copyright (c) 2004 K. Wilkins
//
// This software is provided 'as-is', without any express or implied warranty.
// In no event will the authors be held liable for any damages arising from
// the use of this software.
//
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it
// freely, subject to the following restrictions:
//
// 1. The origin of this software must not be misrepresented; you must not
//    claim that you wrote the original software. If you use this software
//    in a product, an acknowledgment in the product documentation would be
//    appreciated but is not required.
//
// 2. Altered source versions must be plainly marked as such, and must not
//    be misrepresented as being the original software.
//
// 3. This notice may not be removed or altered from any source distribution.
//

//////////////////////////////////////////////////////////////////////////////
//                       Handy - An Atari Lynx Emulator                     //
//                          Copyright (c) 1996,1997                         //
//                                 K. Wilkins                               //
//////////////////////////////////////////////////////////////////////////////
// Lynx memory map class                                                    //
//////////////////////////////////////////////////////////////////////////////
//                                                                          //
// This class provides the register $FFF9 functionality to the emulator, it //
// sets which devices can be seen by the CPU.                               //
//                                                                          //
//    K. Wilkins                                                            //
// August 1997                                                              //
//                                                                          //
//////////////////////////////////////////////////////////////////////////////
// Revision History:                                                        //
// -----------------                                                        //
//                                                                          //
// 01Aug1997 KW Document header added & class documented.                   //
//                                                                          //
//////////////////////////////////////////////////////////////////////////////

#define MEMMAP_CPP

#include <stdlib.h>
#include <string.h>
#include "system.h"
#include "memmap.h"


// IGNORE THIS TEXT, now overridden by new system
//
// We will hold 16 different memory maps for the "top" area which are selected
// on the basis of mMemMap->mSelector:
//
//				Code	Vect	ROM		Mikie	Susie
//----------------------------------------------------
//	(Default)	0000	V		R		M		S
//				0001	V		R		M		RAM
//				0001	V		R		RAM		S
//				0011	V		R		RAM		RAM
//				0100	V		RAM		M		S
//				..
//				..
//				1111	RAM		RAM		RAM		RAM
//
// Get it.....
//
// We can then index with mMemoryHandlers[mMemMap->mSelector][addr] for speed
//

   CMemMap::CMemMap(CSystem& parent)
:mSystem(parent)
{
   Reset();
}


void CMemMap::Reset(void)
{

   // Initialise ALL pointers to RAM then overload to correct
   for(int loop=0;loop<SYSTEM_SIZE;loop++) mSystem.mMemoryHandlers[loop]=mSystem.mRam;

   // Special case for ourselves.
   mSystem.mMemoryHandlers[0xFFF8]=mSystem.mRam;
   mSystem.mMemoryHandlers[0xFFF9]=mSystem.mMemMap;

   mSusieEnabled=-1;
   mMikieEnabled=-1;
   mRomEnabled=-1;
   mVectorsEnabled=-1;

   // Initialise everything correctly
   Poke(0,0);

}

bool CMemMap::ContextSave(LSS_FILE *fp)
{	
   if(!lss_printf(fp,"CMemMap::ContextSave")) return 0;
   if(!lss_write(&mMikieEnabled,sizeof(ULONG),1,fp)) return 0;
   if(!lss_write(&mSusieEnabled,sizeof(ULONG),1,fp)) return 0;
   if(!lss_write(&mRomEnabled,sizeof(ULONG),1,fp)) return 0;
   if(!lss_write(&mVectorsEnabled,sizeof(ULONG),1,fp)) return 0;
   return 1;
}

bool CMemMap::ContextLoad(LSS_FILE *fp)
{
   char teststr[100]="XXXXXXXXXXXXXXXXXXXX";

   // First put everything to a known state
   Reset();

   // Read back our parameters
   if(!lss_read(teststr,sizeof(char),20,fp)) return 0;
   if(strcmp(teststr,"CMemMap::ContextSave")!=0) return 0;
   if(!lss_read(&mMikieEnabled,sizeof(ULONG),1,fp)) return 0;
   if(!lss_read(&mSusieEnabled,sizeof(ULONG),1,fp)) return 0;
   if(!lss_read(&mRomEnabled,sizeof(ULONG),1,fp)) return 0;
   if(!lss_read(&mVectorsEnabled,sizeof(ULONG),1,fp)) return 0;

   // The peek will give us the correct value to put back
   UBYTE mystate=Peek(0);

   // Now set to un-initialised so the poke will set correctly
   mSusieEnabled=-1;
   mMikieEnabled=-1;
   mRomEnabled=-1;
   mVectorsEnabled=-1;

   // Set banks correctly
   Poke(0,mystate);

   return 1;
}

inline void CMemMap::Poke(ULONG addr, UBYTE data)
{
   int newstate,loop;

   // FC00-FCFF Susie area
   newstate=(data&0x01)?FALSE:TRUE;
   if(newstate!=mSusieEnabled) {
      mSusieEnabled=newstate;

      if(mSusieEnabled) {
         for(loop=SUSIE_START;loop<SUSIE_START+SUSIE_SIZE;loop++) mSystem.mMemoryHandlers[loop]=mSystem.mSusie;
      } else {
         for(loop=SUSIE_START;loop<SUSIE_START+SUSIE_SIZE;loop++) mSystem.mMemoryHandlers[loop]=mSystem.mRam;
      }
   }

   // FD00-FCFF Mikie area
   newstate=(data&0x02)?FALSE:TRUE;
   if(newstate!=mMikieEnabled) {
      mMikieEnabled=newstate;

      if(mMikieEnabled) {
         for(loop=MIKIE_START;loop<MIKIE_START+MIKIE_SIZE;loop++) mSystem.mMemoryHandlers[loop]=mSystem.mMikie;
      } else {
         for(loop=MIKIE_START;loop<MIKIE_START+MIKIE_SIZE;loop++) mSystem.mMemoryHandlers[loop]=mSystem.mRam;
      }
   }

   // FE00-FFF7 Rom area
   newstate=(data&0x04)?FALSE:TRUE;
   if(newstate!=mRomEnabled) {
      mRomEnabled=newstate;

      if(mRomEnabled) {
         for(loop=BROM_START;loop<BROM_START+(BROM_SIZE-8);loop++) mSystem.mMemoryHandlers[loop]=mSystem.mRom;
      } else {
         for(loop=BROM_START;loop<BROM_START+(BROM_SIZE-8);loop++) mSystem.mMemoryHandlers[loop]=mSystem.mRam;
      }
   }

   // FFFA-FFFF Vector area - Overload ROM space
   newstate=(data&0x08)?FALSE:TRUE;
   if(newstate!=mVectorsEnabled) {
      mVectorsEnabled=newstate;

      if(mVectorsEnabled) {
         for(loop=VECTOR_START;loop<VECTOR_START+VECTOR_SIZE;loop++) mSystem.mMemoryHandlers[loop]=mSystem.mRom;
      } else {
         for(loop=VECTOR_START;loop<VECTOR_START+VECTOR_SIZE;loop++) mSystem.mMemoryHandlers[loop]=mSystem.mRam;
      }
   }


}

inline UBYTE CMemMap::Peek(ULONG addr)
{
   UBYTE retval=0;

   retval+=(mSusieEnabled)?0:0x01;
   retval+=(mMikieEnabled)?0:0x02;
   retval+=(mRomEnabled)?0:0x04;
   retval+=(mVectorsEnabled)?0:0x08;
   return retval;
}

//END OF FILE