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Mappers: Fixed issue where unallocated memory could be used for work/save ram when size smaller than 8kb (Fixes Gradius II and Crisis Force)

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This commit is contained in:
Souryo 2016-08-18 23:41:58 -04:00
parent c099fdcd18
commit f979a0679c
2 changed files with 25 additions and 18 deletions
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40
Core/BaseMapper.cpp
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@ -9,19 +9,13 @@ uint8_t BaseMapper::ReadRegister(uint16_t addr) { return 0; }
void BaseMapper::InitMapper(RomData &romData) { }
void BaseMapper::Reset(bool softReset) { }
uint16_t BaseMapper::InternalGetPrgPageSize()
{
//Make sure the page size is no bigger than the size of the ROM itself
//Otherwise we will end up reading from unallocated memory
return std::min((uint32_t)GetPRGPageSize(), _prgSize);
}
uint16_t BaseMapper::InternalGetChrPageSize()
{
//Make sure the page size is no bigger than the size of the ROM itself
//Otherwise we will end up reading from unallocated memory
return std::min((uint32_t)GetCHRPageSize(), _chrRomSize);
}
//Make sure the page size is no bigger than the size of the ROM itself
//Otherwise we will end up reading from unallocated memory
uint16_t BaseMapper::InternalGetPrgPageSize() { return std::min((uint32_t)GetPRGPageSize(), _prgSize); }
uint16_t BaseMapper::InternalGetSaveRamPageSize() { return std::min((uint32_t)GetSaveRamPageSize(), _saveRamSize); }
uint16_t BaseMapper::InternalGetWorkRamPageSize() { return std::min((uint32_t)GetWorkRamPageSize(), _workRamSize); }
uint16_t BaseMapper::InternalGetChrPageSize() { return std::min((uint32_t)GetCHRPageSize(), _chrRomSize); }
uint16_t BaseMapper::InternalGetChrRamPageSize() { return std::min((uint32_t)GetChrRamPageSize(), _chrRamSize); }
void BaseMapper::SetCpuMemoryMapping(uint16_t startAddr, uint16_t endAddr, int16_t pageNumber, PrgMemoryType type, int8_t accessType)
{
@ -43,14 +37,14 @@ void BaseMapper::SetCpuMemoryMapping(uint16_t startAddr, uint16_t endAddr, int16
break;
case PrgMemoryType::SaveRam:
source = _saveRam;
pageCount = _saveRamSize / GetSaveRamPageSize();
pageSize = GetSaveRamPageSize();
pageCount = _saveRamSize / InternalGetSaveRamPageSize();
pageSize = InternalGetSaveRamPageSize();
defaultAccessType |= MemoryAccessType::Write;
break;
case PrgMemoryType::WorkRam:
source = _workRam;
pageCount = _workRamSize / GetWorkRamPageSize();
pageSize = GetWorkRamPageSize();
pageCount = _workRamSize / InternalGetWorkRamPageSize();
pageSize = InternalGetWorkRamPageSize();
defaultAccessType |= MemoryAccessType::Write;
break;
default:
@ -73,6 +67,16 @@ void BaseMapper::SetCpuMemoryMapping(uint16_t startAddr, uint16_t endAddr, int16
source = &source[pageNumber * pageSize];
accessType = accessType != -1 ? accessType : defaultAccessType;
if((uint16_t)(endAddr - startAddr) >= pageSize) {
#ifdef _DEBUG
MessageManager::DisplayMessage("Debug", "Tried to map undefined prg - page size too small for selected range.");
#endif
//Make sure the range is no bigger than a single page, else we could read from unallocated memory
endAddr = startAddr + pageSize - 1;
}
SetCpuMemoryMapping(startAddr, endAddr, source, accessType);
}
@ -123,7 +127,7 @@ void BaseMapper::SetPpuMemoryMapping(uint16_t startAddr, uint16_t endAddr, uint1
break;
case ChrMemoryType::ChrRam:
pageSize = GetChrRamPageSize();
pageSize = InternalGetChrRamPageSize();
pageCount = _chrRamSize / pageSize;
sourceMemory = _chrRam;
defaultAccessType |= MemoryAccessType::Write;

3
Core/BaseMapper.h
View File

@ -46,7 +46,10 @@ private:
string _batteryFilename;
uint16_t InternalGetPrgPageSize();
uint16_t InternalGetSaveRamPageSize();
uint16_t InternalGetWorkRamPageSize();
uint16_t InternalGetChrPageSize();
uint16_t InternalGetChrRamPageSize();
uint8_t *_nesNametableRam[2];
uint8_t *_cartNametableRam[10];