internal static bool goodchecksum(IList <byte> romdata, RomMapMode mode, int size)
{
int snestopc(int snesAddress) => RomUtil.ConvertSnesToPc(snesAddress, mode, size);
var checksum = (int)getchecksum(romdata);
return(((romdata[snestopc(0x00FFDE)] ^ romdata[snestopc(0x00FFDC)]) == 0xFF) &&
((romdata[snestopc(0x00FFDF)] ^ romdata[snestopc(0x00FFDD)]) == 0xFF) &&
((romdata[snestopc(0x00FFDE)] & 0xFF) == (checksum & 0xFF)) &&
((romdata[snestopc(0x00FFDF)] & 0xFF) == ((checksum >> 8) & 0xFF)));
}
public ImportRomSettings CreateSettings()
{
ImportSettings.InitialLabels = RomUtil.GenerateVectorLabels(
VectorTableEntriesEnabled, ImportSettings.RomSettingsOffset, ImportSettings.RomBytes, ImportSettings.RomMapMode);
if (ShouldCheckHeader)
{
ImportSettings.InitialHeaderFlags =
RomUtil.GenerateHeaderFlags(ImportSettings.RomSettingsOffset, ImportSettings.RomBytes);
}
return(ImportSettings);
}
internal static void fixchecksum(IList <byte> romdata, RomMapMode mode, int size)
{
int snestopc(int snesAddress) => RomUtil.ConvertSnesToPc(snesAddress, mode, size);
// randomdude999: clear out checksum bytes before recalculating checksum, this should make it correct on roms that don't have a checksum yet
romdata.writeromdata(snestopc(0x00FFDC), 0xFFFF0000);
var checksum = getchecksum(romdata);
romdata.writeromdata_byte(snestopc(0x00FFDE), (byte)(checksum & 255));
romdata.writeromdata_byte(snestopc(0x00FFDF), (byte)((checksum >> 8) & 255));
romdata.writeromdata_byte(snestopc(0x00FFDC), (byte)((checksum & 255) ^ 255));
romdata.writeromdata_byte(snestopc(0x00FFDD), (byte)(((checksum >> 8) & 255) ^ 255));
}
public void Init(string romFilename)
{
var rawRomBytes = RomUtil.ReadRomFileBytes(romFilename);
ImportSettings = new ImportRomSettings
{
RomFilename = romFilename,
RomBytes = rawRomBytes,
RomMapMode = RomUtil.DetectRomMapMode(rawRomBytes, out var detectedMapModeSuccess),
};
ImportSettings.RomSpeed = RomUtil.GetRomSpeed(ImportSettings.RomSettingsOffset, rawRomBytes);
if (detectedMapModeSuccess)
{
DetectedMapMode = ImportSettings.RomMapMode;
}
VectorTableEntriesEnabled = GenerateVectors();
}
public static int ConvertSnesToPc(int address, RomMapMode mode, int size)
{
if (address < 0)
{
return(-1);
}
int UnmirroredOffset(int offset) => RomUtil.UnmirroredOffset(offset, size);
// WRAM is N/A to PC addressing
if ((address & 0xFE0000) == 0x7E0000)
{
return(-1);
}
// WRAM mirror & PPU regs are N/A to PC addressing
if (((address & 0x400000) == 0) && ((address & 0x8000) == 0))
{
return(-1);
}
switch (mode)
{
case RomMapMode.LoRom:
{
// SRAM is N/A to PC addressing
if (((address & 0x700000) == 0x700000) && ((address & 0x8000) == 0))
{
return(-1);
}
return(UnmirroredOffset(((address & 0x7F0000) >> 1) | (address & 0x7FFF)));
}
case RomMapMode.HiRom:
{
return(UnmirroredOffset(address & 0x3FFFFF));
}
case RomMapMode.SuperMmc:
{
return(UnmirroredOffset(address & 0x3FFFFF)); // todo, treated as hirom atm
}
case RomMapMode.Sa1Rom:
case RomMapMode.ExSa1Rom:
{
// BW-RAM is N/A to PC addressing
if (address >= 0x400000 && address <= 0x7FFFFF)
{
return(-1);
}
if (address >= 0xC00000)
{
return(mode == RomMapMode.ExSa1Rom ? UnmirroredOffset(address & 0x7FFFFF) : UnmirroredOffset(address & 0x3FFFFF));
}
if (address >= 0x800000)
{
address -= 0x400000;
}
// SRAM is N/A to PC addressing
if (((address & 0x8000) == 0))
{
return(-1);
}
return(UnmirroredOffset(((address & 0x7F0000) >> 1) | (address & 0x7FFF)));
}
case RomMapMode.SuperFx:
{
// BW-RAM is N/A to PC addressing
if (address >= 0x600000 && address <= 0x7FFFFF)
{
return(-1);
}
if (address < 0x400000)
{
return(UnmirroredOffset(((address & 0x7F0000) >> 1) | (address & 0x7FFF)));
}
if (address < 0x600000)
{
return(UnmirroredOffset(address & 0x3FFFFF));
}
if (address < 0xC00000)
{
return(0x200000 + UnmirroredOffset(((address & 0x7F0000) >> 1) | (address & 0x7FFF)));
}
return(0x400000 + UnmirroredOffset(address & 0x3FFFFF));
}
case RomMapMode.ExHiRom:
{
return(UnmirroredOffset(((~address & 0x800000) >> 1) | (address & 0x3FFFFF)));
}
case RomMapMode.ExLoRom:
{
// SRAM is N/A to PC addressing
if (((address & 0x700000) == 0x700000) && ((address & 0x8000) == 0))
{
return(-1);
}
return(UnmirroredOffset((((address ^ 0x800000) & 0xFF0000) >> 1) | (address & 0x7FFF)));
}
default:
{
return(-1);
}
}
}
