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Rework for a cleaner code for ROM Bank 0, 1 and 2 address calculation

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This commit is contained in:
Godzil 2019-09-20 16:29:21 +01:00
parent b662fc05a1
commit c8f731c9f9
1 changed files with 18 additions and 4 deletions
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22
oswan/source/memory.cpp
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@ -161,8 +161,9 @@ BYTE cpu_readmem20(DWORD addr)
{
uint32 offset=addr&0xffff;
uint32 bank=addr>>16;
uint16 romBank;
//uint16 romBank;
uint8_t hwReg;
uint32_t temp;
BYTE ret;
switch (bank)
@ -183,8 +184,18 @@ BYTE cpu_readmem20(DWORD addr)
return ws_staticRam[offset&sramAddressMask];
case 2:
// Bank 2
hwReg = ws_ioRam[0xC2];
temp = hwReg << 16;
temp += offset;
temp &= (romSize - 1);
return ws_rom[temp];
case 3:
return ws_rom[offset+((ws_ioRam[IO_ROM_BANK_BASE_SELECTOR+bank]&((romSize>>16)-1))<<16)];
hwReg = ws_ioRam[0xC3];
temp = hwReg << 16;
temp += offset;
temp &= (romSize - 1);
return ws_rom[temp];
case 0xF:
hwReg = ws_ioRam[0xA0];
@ -211,8 +222,11 @@ BYTE cpu_readmem20(DWORD addr)
// fall through
default:
romBank = (256-(((ws_ioRam[IO_ROM_BANK_BASE_SELECTOR]&0xf)<<4)|(bank&0xf)));
return ws_rom[(unsigned)(offset+romSize-(romBank<<16))];
hwReg = ws_ioRam[0xC0];
temp = hwReg << 20;
temp += addr & 0xFFFFF;
temp &= (romSize - 1);
return ws_rom[temp];
}
return(0xff);