bsnes/higan/sfc/slot/bsmemory/bsmemory.cpp

125 lines
2.5 KiB
C++

#include <sfc/sfc.hpp>
namespace SuperFamicom {
BSMemory bsmemory;
auto BSMemory::init() -> void {
}
auto BSMemory::load() -> void {
if(memory.size() == 0) {
memory.allocate(1024 * 1024);
}
}
auto BSMemory::unload() -> void {
memory.reset();
}
auto BSMemory::power() -> void {
regs.command = 0;
regs.writeOld = 0x00;
regs.writeNew = 0x00;
regs.flashEnable = false;
regs.readEnable = false;
regs.writeEnable = false;
memory.writeProtect(!regs.writeEnable);
}
auto BSMemory::size() const -> uint {
return memory.size();
}
auto BSMemory::read(uint24 addr, uint8 data) -> uint8 {
if(readonly) {
return memory.read(bus.mirror(addr, memory.size()), data);
}
if(addr == 0x0002) {
if(regs.flashEnable) return 0x80;
}
if(addr == 0x5555) {
if(regs.flashEnable) return 0x80;
}
if(regs.readEnable && addr >= 0xff00 && addr <= 0xff13) {
//read flash cartridge vendor information
switch(addr - 0xff00) {
case 0x00: return 0x4d;
case 0x01: return 0x00;
case 0x02: return 0x50;
case 0x03: return 0x00;
case 0x04: return 0x00;
case 0x05: return 0x00;
case 0x06: return 0x2a; //0x2a = 8mbit, 0x2b = 16mbit (not known to exist, though BIOS recognizes ID)
case 0x07: return 0x00;
default: return 0x00;
}
}
return memory.read(addr, data);
}
auto BSMemory::write(uint24 addr, uint8 data) -> void {
if(readonly) {
return;
}
if((addr & 0xff0000) == 0) {
regs.writeOld = regs.writeNew;
regs.writeNew = data;
if(regs.writeEnable && regs.writeOld == regs.writeNew) {
return memory.write(addr, data);
}
} else {
if(regs.writeEnable) {
return memory.write(addr, data);
}
}
if(addr == 0x0000) {
regs.command <<= 8;
regs.command |= data;
if((regs.command & 0xffff) == 0x38d0) {
regs.flashEnable = true;
regs.readEnable = true;
}
}
if(addr == 0x2aaa) {
regs.command <<= 8;
regs.command |= data;
}
if(addr == 0x5555) {
regs.command <<= 8;
regs.command |= data;
if((regs.command & 0xffffff) == 0xaa5570) {
regs.writeEnable = false;
}
if((regs.command & 0xffffff) == 0xaa55a0) {
regs.writeOld = 0x00;
regs.writeNew = 0x00;
regs.flashEnable = true;
regs.writeEnable = true;
}
if((regs.command & 0xffffff) == 0xaa55f0) {
regs.flashEnable = false;
regs.readEnable = false;
regs.writeEnable = false;
}
memory.writeProtect(!regs.writeEnable);
}
}
}