nestopia/source/core/board/NstBoardMmc2.cpp
2012-09-02 13:13:55 -04:00

130 lines
3.2 KiB
C++

////////////////////////////////////////////////////////////////////////////////////////
//
// Nestopia - NES/Famicom emulator written in C++
//
// Copyright (C) 2003-2008 Martin Freij
//
// This file is part of Nestopia.
//
// Nestopia 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.
//
// Nestopia 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 Nestopia; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
//
////////////////////////////////////////////////////////////////////////////////////////
#include "NstBoard.hpp"
#include "NstBoardMmc2.hpp"
namespace Nes
{
namespace Core
{
namespace Boards
{
#ifdef NST_MSVC_OPTIMIZE
#pragma optimize("s", on)
#endif
void Mmc2::SubReset(const bool hard)
{
if (hard)
{
selector[0] = 0;
selector[1] = 2;
banks[0] = 0;
banks[1] = 0;
banks[2] = 0;
banks[3] = 0;
prg.SwapBank<SIZE_32K,0x0000>(~0U);
}
chr.SetAccessor( this, &Mmc2::Access_Chr );
Map( 0xA000U, 0xAFFFU, PRG_SWAP_8K_0 );
Map( 0xB000U, 0xEFFFU, &Mmc2::Poke_B000 );
Map( 0xF000U, 0xFFFFU, NMT_SWAP_HV );
}
void Mmc2::SubLoad(State::Loader& state,const dword baseChunk)
{
NST_VERIFY( baseChunk == (AsciiId<'M','M','2'>::V) );
if (baseChunk == AsciiId<'M','M','2'>::V)
{
while (const dword subId = state.Begin())
{
if (subId == AsciiId<'R','E','G'>::V)
{
State::Loader::Data<4+1> data( state );
banks[0] = data[0];
banks[1] = data[1];
banks[2] = data[2];
banks[3] = data[3];
selector[0] = 0 + (data[4] >> 0 & 0x1);
selector[1] = 2 + (data[4] >> 1 & 0x1);
}
state.End();
}
}
}
void Mmc2::SubSave(State::Saver& state) const
{
const byte data[4+1] =
{
banks[0],
banks[1],
banks[2],
banks[3],
selector[0] | (selector[1] - 2) << 1
};
state.Begin( AsciiId<'M','M','2'>::V ).Begin( AsciiId<'R','E','G'>::V ).Write( data ).End().End();
}
#ifdef NST_MSVC_OPTIMIZE
#pragma optimize("", on)
#endif
NES_ACCESSOR(Mmc2,Chr)
{
const uint data = chr.Peek( address );
uint bank;
switch (address & 0xFF8)
{
case 0xFD8: bank = (address >> 11 & 0x2) | 0x0; break;
case 0xFE8: bank = (address >> 11 & 0x2) | 0x1; break;
default: return data;
}
selector[address >> 12] = bank;
chr.SwapBank<SIZE_4K>( address & 0x1000, banks[bank] );
return data;
}
NES_POKE_AD(Mmc2,B000)
{
ppu.Update();
banks[(address - 0xB000) >> 12] = data;
chr.SwapBanks<SIZE_4K,0x0000>( banks[selector[0]], banks[selector[1]] );
}
}
}
}