mirror of
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
111 lines
2.6 KiB
C++
111 lines
2.6 KiB
C++
#pragma once
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#include "stdafx.h"
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#include "IMemoryHandler.h"
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#include "Sa1Cpu.h"
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#include "Sa1Types.h"
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#include "Sa1.h"
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//Manages BWRAM access from the SA-1 CPU, for regions that can enable bitmap mode. e.g:
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//00-3F:6000-7FFF + 80-BF:6000-7FFF (optional bitmap mode + bank select)
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//60-6F:0000-FFFF (always bitmap mode)
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class Sa1BwRamHandler : public IMemoryHandler
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{
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private:
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uint8_t * _ram;
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uint32_t _mask;
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Sa1State* _state;
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uint32_t GetBwRamAddress(uint32_t addr)
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{
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return ((_state->Sa1BwBank * 0x2000) | (addr & 0x1FFF));
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}
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__forceinline uint8_t InternalRead(uint32_t addr)
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{
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if((addr & 0x600000) == 0x600000) {
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return ReadBitmapMode(addr - 0x600000);
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} else {
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addr = GetBwRamAddress(addr);
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if(_state->Sa1BwMode) {
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//Bitmap mode is enabled
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return ReadBitmapMode(addr);
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} else {
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//Return regular memory content
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return _ram[addr & _mask];
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}
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}
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}
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public:
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Sa1BwRamHandler(uint8_t* bwRam, uint32_t bwRamSize, Sa1State* state) : IMemoryHandler(SnesMemoryType::SaveRam)
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{
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_ram = bwRam;
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_mask = bwRamSize - 1;
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_state = state;
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}
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uint8_t Read(uint32_t addr) override
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{
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return InternalRead(addr);
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}
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uint8_t Peek(uint32_t addr) override
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{
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return InternalRead(addr);
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}
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void PeekBlock(uint32_t addr, uint8_t *output) override
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{
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for(int i = 0; i < 0x1000; i++) {
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output[i] = InternalRead(addr + i);
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}
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}
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void Write(uint32_t addr, uint8_t value) override
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{
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if((addr & 0x600000) == 0x600000) {
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WriteBitmapMode(addr - 0x600000, value);
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} else {
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addr = GetBwRamAddress(addr);
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if(_state->Sa1BwMode) {
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WriteBitmapMode(addr, value);
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} else {
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_ram[addr & _mask] = value;
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}
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}
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}
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uint8_t ReadBitmapMode(uint32_t addr)
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{
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if(_state->BwRam2BppMode) {
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return (_ram[(addr >> 2) & _mask] >> ((addr & 0x03) * 2)) & 0x03;
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} else {
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return (_ram[(addr >> 1) & _mask] >> ((addr & 0x01) * 4)) & 0x0F;
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}
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}
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void WriteBitmapMode(uint32_t addr, uint8_t value)
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{
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if(_state->BwRam2BppMode) {
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uint8_t shift = (addr & 0x03) * 2;
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addr = (addr >> 2) & _mask;
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_ram[addr] = (_ram[addr] & ~(0x03 << shift)) | ((value & 0x03) << shift);
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} else {
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uint8_t shift = (addr & 0x01) * 4;
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addr = (addr >> 1) & _mask;
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_ram[addr] = (_ram[addr] & ~(0x0F << shift)) | ((value & 0x0F) << shift);
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}
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}
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AddressInfo GetAbsoluteAddress(uint32_t addr) override
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{
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AddressInfo info;
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if((addr & 0x600000) == 0x600000) {
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info.Address = ((addr - 0x600000) >> (_state->BwRam2BppMode ? 2 : 1)) & _mask;
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} else {
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info.Address = GetBwRamAddress(addr) & _mask;
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}
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info.Type = SnesMemoryType::SaveRam;
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return info;
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}
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}; |