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https://github.com/SourMesen/Mesen-S.git
synced 2024-06-23 14:52:12 -04:00
6539b92502
Memory handlers did not have the _memoryType value set, which caused some memory accesses to be much faster than expected
98 lines
2.2 KiB
C++
98 lines
2.2 KiB
C++
#include "stdafx.h"
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#include "Obc1.h"
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#include "Console.h"
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#include "MemoryManager.h"
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#include "MemoryMappings.h"
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Obc1::Obc1(Console* console, uint8_t* saveRam, uint32_t saveRamSize) : BaseCoprocessor(SnesMemoryType::Register)
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{
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MemoryMappings *mappings = console->GetMemoryManager()->GetMemoryMappings();
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mappings->RegisterHandler(0x00, 0x3F, 0x6000, 0x7FFF, this);
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mappings->RegisterHandler(0x80, 0xBF, 0x6000, 0x7FFF, this);
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_ram = saveRam;
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_mask = saveRamSize - 1;
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}
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void Obc1::Reset()
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{
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}
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uint8_t Obc1::ReadRam(uint16_t addr)
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{
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return _ram[addr & _mask];
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}
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void Obc1::WriteRam(uint16_t addr, uint8_t value)
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{
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_ram[addr & _mask] = value;
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}
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uint8_t Obc1::Read(uint32_t addr)
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{
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addr &= 0x1FFF;
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switch(addr) {
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case 0x1FF0: return ReadRam(GetLowAddress());
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case 0x1FF1: return ReadRam(GetLowAddress() + 1);
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case 0x1FF2: return ReadRam(GetLowAddress() + 2);
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case 0x1FF3: return ReadRam(GetLowAddress() + 3);
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case 0x1FF4: return ReadRam(GetHighAddress());
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}
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return ReadRam(addr);
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}
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void Obc1::Write(uint32_t addr, uint8_t value)
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{
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addr &= 0x1FFF;
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switch(addr) {
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case 0x1FF0: WriteRam(GetLowAddress(), value); break;
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case 0x1FF1: WriteRam(GetLowAddress() + 1, value); break;
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case 0x1FF2: WriteRam(GetLowAddress() + 2, value); break;
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case 0x1FF3: WriteRam(GetLowAddress() + 3, value); break;
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case 0x1FF4: {
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uint8_t shift = (ReadRam(0x1FF6) & 0x03) << 1;
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WriteRam(GetHighAddress(), ((value & 0x03) << shift) | (ReadRam(GetHighAddress()) & ~(0x03 << shift)));
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break;
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}
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default: WriteRam(addr, value); break;
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}
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}
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//$1FF5: Base address in bit 0 (0 = $1C00, 1 = $1800)
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//$1FF6: "OAM" index (0-127) in first 7 bits
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uint16_t Obc1::GetBaseAddress()
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{
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return 0x1800 | ((~ReadRam(0x1FF5) & 0x01) << 10);
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}
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uint16_t Obc1::GetLowAddress()
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{
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return GetBaseAddress() | ((ReadRam(0x1FF6) & 0x7F) << 2);
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}
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uint16_t Obc1::GetHighAddress()
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{
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return (GetBaseAddress() | ((ReadRam(0x1FF6) & 0x7F) >> 2)) + 0x200;
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}
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void Obc1::Serialize(Serializer &s)
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{
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}
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uint8_t Obc1::Peek(uint32_t addr)
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{
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return 0;
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}
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void Obc1::PeekBlock(uint32_t addr, uint8_t *output)
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{
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memset(output, 0, 0x1000);
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}
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AddressInfo Obc1::GetAbsoluteAddress(uint32_t address)
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{
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return { -1, SnesMemoryType::Register };
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} |