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feat: implement cartridge saving

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Implemented for MBC1, MBC2, MBC3 and MBC5
This commit is contained in:
Rekai Nyangadzayi Musuka
2021-09-20 04:13:25 -03:00
parent e1fe00ab64
commit ce121864d2
6 changed files with 263 additions and 8 deletions
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10
src/bus.rs
View File

@@ -90,6 +90,16 @@ impl Bus {
pub(crate) fn joyp_mut(&mut self) -> &mut Joypad {
&mut self.joypad
}
#[inline]
pub(crate) fn cart(&self) -> Option<&Cartridge> {
self.cart.as_ref()
}
#[inline]
pub(crate) fn cart_mut(&mut self) -> Option<&mut Cartridge> {
self.cart.as_mut()
}
}
impl Bus {

153
src/cartridge.rs
View File

@@ -24,6 +24,14 @@ impl Cartridge {
}
}
pub(crate) fn ext_ram(&self) -> Option<&[u8]> {
self.mbc.ext_ram()
}
pub(crate) fn write_ext_ram(&mut self, memory: Vec<u8>) {
self.mbc.write_ext_ram(memory)
}
fn detect_mbc(memory: &[u8]) -> Box<dyn MBCIo> {
let ram_size = Self::detect_ram_info(memory);
let rom_size = Self::detect_rom_info(memory);
@@ -38,13 +46,13 @@ impl Cartridge {
match mbc_kind {
MBCKind::None => Box::new(NoMBC),
MBCKind::MBC1 => Box::new(MBC1::new(ram_size, rom_size)),
MBCKind::MBC1WithBattery => Box::new(MBC1::new(ram_size, rom_size)), // TODO: Implement Saving
MBCKind::MBC1WithBattery => Box::new(MBC1::with_battery(ram_size, rom_size)), // TODO: Implement Saving
MBCKind::MBC2 => Box::new(MBC2::new(rom_cap)),
MBCKind::MBC2WithBattery => Box::new(MBC2::new(rom_cap)), // TODO: Implement Saving
MBCKind::MBC2WithBattery => Box::new(MBC2::with_battery(rom_cap)), // TODO: Implement Saving
MBCKind::MBC3 => Box::new(MBC3::new(ram_cap)),
MBCKind::MBC3WithBattery => Box::new(MBC3::new(ram_cap)), // TODO: Implement Saving
MBCKind::MBC3WithBattery => Box::new(MBC3::with_battery(ram_cap)), // TODO: Implement Saving
MBCKind::MBC5 => Box::new(MBC5::new(ram_cap, rom_cap)),
MBCKind::MBC5WithBattery => Box::new(MBC5::new(ram_cap, rom_cap)), // TDO: Implement Saving
MBCKind::MBC5WithBattery => Box::new(MBC5::with_battery(ram_cap, rom_cap)), // TDO: Implement Saving
}
}
@@ -117,6 +125,8 @@ struct MBC1 {
memory: Vec<u8>,
rom_size: RomSize,
mem_enabled: bool,
has_battery: bool,
}
impl MBC1 {
@@ -129,6 +139,20 @@ impl MBC1 {
ram_bank: Default::default(),
mode: Default::default(),
mem_enabled: Default::default(),
has_battery: Default::default(),
}
}
fn with_battery(ram_size: RamSize, rom_size: RomSize) -> Self {
Self {
rom_bank: 0x01,
memory: vec![0; ram_size.capacity() as usize],
ram_size,
rom_size,
ram_bank: Default::default(),
mode: Default::default(),
mem_enabled: Default::default(),
has_battery: true,
}
}
@@ -197,6 +221,21 @@ impl MBC1 {
}
}
impl Savable for MBC1 {
fn ext_ram(&self) -> Option<&[u8]> {
match self.has_battery {
true => Some(&self.memory),
false => None,
}
}
fn write_ext_ram(&mut self, memory: Vec<u8>) {
if self.has_battery {
self.memory.copy_from_slice(&memory);
}
}
}
impl MBCIo for MBC1 {
fn handle_read(&self, addr: u16) -> MBCResult {
use MBCResult::*;
@@ -256,6 +295,8 @@ struct MBC3 {
// RTC Data Latch Previous Write
prev_latch_write: Option<u8>,
has_battery: bool,
}
impl MBC3 {
@@ -267,6 +308,34 @@ impl MBC3 {
devs_enabled: Default::default(),
mapped: Default::default(),
prev_latch_write: Default::default(),
has_battery: Default::default(),
}
}
fn with_battery(ram_cap: usize) -> Self {
Self {
memory: vec![0; ram_cap],
rom_bank: Default::default(),
ram_bank: Default::default(),
devs_enabled: Default::default(),
mapped: Default::default(),
prev_latch_write: Default::default(),
has_battery: true,
}
}
}
impl Savable for MBC3 {
fn ext_ram(&self) -> Option<&[u8]> {
match self.has_battery {
true => Some(&self.memory),
false => None,
}
}
fn write_ext_ram(&mut self, memory: Vec<u8>) {
if self.has_battery {
self.memory.copy_from_slice(&memory);
}
}
}
@@ -342,9 +411,10 @@ struct MBC5 {
ram_bank: u8,
rom_cap: usize,
memory: Vec<u8>,
mem_enabled: bool,
has_battery: bool,
}
impl MBC5 {
@@ -355,6 +425,18 @@ impl MBC5 {
rom_cap,
ram_bank: Default::default(),
mem_enabled: Default::default(),
has_battery: Default::default(),
}
}
fn with_battery(ram_cap: usize, rom_cap: usize) -> Self {
Self {
rom_bank: 0x01,
memory: vec![0; ram_cap],
rom_cap,
ram_bank: Default::default(),
mem_enabled: Default::default(),
has_battery: true,
}
}
@@ -363,6 +445,21 @@ impl MBC5 {
}
}
impl Savable for MBC5 {
fn ext_ram(&self) -> Option<&[u8]> {
match self.has_battery {
true => Some(&self.memory),
false => None,
}
}
fn write_ext_ram(&mut self, memory: Vec<u8>) {
if self.has_battery {
self.memory.copy_from_slice(&memory);
}
}
}
impl MBCIo for MBC5 {
fn handle_read(&self, addr: u16) -> MBCResult {
use MBCResult::*;
@@ -401,6 +498,7 @@ struct MBC2 {
mem_enabled: bool,
rom_cap: usize,
has_battery: bool,
}
impl MBC2 {
@@ -410,8 +508,19 @@ impl MBC2 {
Self {
rom_bank: 0x01,
memory: Box::new([0; Self::RAM_SIZE]),
mem_enabled: Default::default(),
rom_cap,
mem_enabled: Default::default(),
has_battery: Default::default(),
}
}
fn with_battery(rom_cap: usize) -> Self {
Self {
rom_bank: 0x01,
memory: Box::new([0; Self::RAM_SIZE]),
rom_cap,
mem_enabled: Default::default(),
has_battery: true,
}
}
@@ -420,6 +529,21 @@ impl MBC2 {
}
}
impl Savable for MBC2 {
fn ext_ram(&self) -> Option<&[u8]> {
match self.has_battery {
true => Some(self.memory.as_ref()),
false => None,
}
}
fn write_ext_ram(&mut self, memory: Vec<u8>) {
if self.has_battery {
self.memory.copy_from_slice(&memory);
}
}
}
impl MBCIo for MBC2 {
fn handle_read(&self, addr: u16) -> MBCResult {
use MBCResult::*;
@@ -457,6 +581,16 @@ impl MBCIo for MBC2 {
#[derive(Debug)]
struct NoMBC;
impl Savable for NoMBC {
fn ext_ram(&self) -> Option<&[u8]> {
None
}
fn write_ext_ram(&mut self, _memory: Vec<u8>) {
// Nothing Happens Here
}
}
impl MBCIo for NoMBC {
fn handle_read(&self, addr: u16) -> MBCResult {
MBCResult::Address(addr as usize)
@@ -467,7 +601,7 @@ impl MBCIo for NoMBC {
}
}
trait MBCIo {
trait MBCIo: Savable {
fn handle_read(&self, addr: u16) -> MBCResult;
fn handle_write(&mut self, addr: u16, byte: u8);
}
@@ -607,3 +741,8 @@ impl Default for Box<dyn MBCIo> {
Box::new(NoMBC)
}
}
trait Savable {
fn ext_ram(&self) -> Option<&[u8]>;
fn write_ext_ram(&mut self, memory: Vec<u8>);
}

51
src/emu.rs
View File

@@ -2,7 +2,11 @@ use crate::apu::gen::SampleProducer;
use crate::cpu::Cpu;
use crate::joypad::{self, Joypad};
use crate::{Cycle, GB_HEIGHT, GB_WIDTH};
use clap::crate_name;
use gilrs::Gilrs;
use std::fs::File;
use std::io::{Read, Write};
use std::path::PathBuf;
use std::time::Duration;
use winit_input_helper::WinitInputHelper;
@@ -50,7 +54,7 @@ impl Emulator {
}
fn load_cart(&mut self, rom: Vec<u8>) {
self.cpu.bus_mut().load_cart(rom)
self.cpu.bus_mut().load_cart(rom);
}
#[inline]
@@ -65,6 +69,51 @@ impl Emulator {
pub fn title(&self) -> &str {
self.cpu.bus().cart_title().unwrap_or(DEFAULT_TITLE)
}
pub fn try_write_sav(&self) -> std::io::Result<()> {
if let Some(ext_ram) = self.cpu.bus().cart().map(|c| c.ext_ram()).flatten() {
if let Some(title) = self.cpu.bus().cart_title() {
let mut save_path = Self::data_path().unwrap_or_else(|| PathBuf::from("."));
save_path.push(title);
save_path.set_extension("sav");
let mut file = File::create(save_path)?;
file.write_all(ext_ram)?;
}
}
Ok(())
}
pub fn try_load_sav(&mut self) -> std::io::Result<()> {
if let Some(cart) = self.cpu.bus_mut().cart_mut() {
if let Some(title) = cart.title() {
let mut save_path = Self::data_path().unwrap_or_else(|| PathBuf::from("."));
save_path.push(title);
save_path.set_extension("sav");
if let Ok(mut file) = File::open(save_path) {
let mut memory = Vec::new();
file.read_to_end(&mut memory)?;
cart.write_ext_ram(memory);
}
}
}
Ok(())
}
fn data_path() -> Option<PathBuf> {
match directories_next::ProjectDirs::from("dev", "musuka", crate_name!()) {
Some(dirs) => {
let data_local = dirs.data_local_dir();
std::fs::create_dir_all(data_local).ok()?;
Some(data_local.to_path_buf())
}
None => None,
}
}
}
pub mod build {

7
src/main.rs
View File

@@ -49,6 +49,9 @@ fn main() -> Result<()> {
}
let mut emu = emu_build.finish();
// Load Save file if it exists
emu.try_load_sav().expect("Load save if exists");
let rom_title = emu.title();
let mut gamepad = Gilrs::new().expect("Initialize Controller Support");
@@ -96,6 +99,8 @@ fn main() -> Result<()> {
.map_err(|e| anyhow!("pixels.render() failed: {}", e))
.is_err()
{
emu.try_write_sav().expect("Write game save if need be");
*control_flow = ControlFlow::Exit;
return;
}
@@ -103,6 +108,8 @@ fn main() -> Result<()> {
if input.update(&event) {
if input.key_pressed(VirtualKeyCode::Escape) || input.quit() {
emu.try_write_sav().expect("Write game save if need be");
*control_flow = ControlFlow::Exit;
return;
}