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paoda:refactor
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compare: paoda:de0d1476857365bee7c565b81817a6f05cec9303
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paoda:main
paoda:refactor

3 Commits
32b597a328 ... de0d147685

Author SHA1 Message Date
Rekai Nyangadzayi Musuka de0d147685 fix(cartridge): put a bit more detail into the MBC3 RTC stub
continuous-integration/drone/push Build is failing Details
2021-08-03 15:19:08 -05:00
Rekai Nyangadzayi Musuka dd8339e8de chore(cartridge): consistently capitalize MBC 2021-08-03 15:06:06 -05:00
Rekai Nyangadzayi Musuka 05d6475015 fix(cartridge): Use default title instead of empty string 2021-08-03 14:53:30 -05:00
1 changed files with 72 additions and 60 deletions
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132
src/cartridge.rs
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@ -7,12 +7,13 @@ use crate::bus::BusIo;
const RAM_SIZE_ADDRESS: usize = 0x0149; const RAM_SIZE_ADDRESS: usize = 0x0149;
const ROM_SIZE_ADDRESS: usize = 0x0148; const ROM_SIZE_ADDRESS: usize = 0x0148;
const MBC_TYPE_ADDRESS: usize = 0x0147; const MBC_TYPE_ADDRESS: usize = 0x0147;
const ROM_TITLE_RANGE: std::ops::RangeInclusive<usize> = 0x0134..=0x0143;
#[derive(Debug, Default)] #[derive(Debug, Default)]
pub(crate) struct Cartridge { pub(crate) struct Cartridge {
memory: Vec<u8>, memory: Vec<u8>,
title: Option<String>, title: Option<String>,
mbc: Box<dyn MemoryBankController>, mbc: Box<dyn MBCIo>,
} }
impl Cartridge { impl Cartridge {
@ -31,7 +32,7 @@ impl Cartridge {
}) })
} }
fn detect_mbc(memory: &[u8]) -> Box<dyn MemoryBankController> { fn detect_mbc(memory: &[u8]) -> Box<dyn MBCIo> {
let ram_size = Self::find_ram_size(memory); let ram_size = Self::find_ram_size(memory);
let bank_count = Self::find_bank_count(memory); let bank_count = Self::find_bank_count(memory);
let mbc_kind = Self::find_mbc(memory); let mbc_kind = Self::find_mbc(memory);
@ -42,9 +43,9 @@ impl Cartridge {
eprintln!("MBC Type: {:?}", mbc_kind); eprintln!("MBC Type: {:?}", mbc_kind);
match mbc_kind { match mbc_kind {
MbcKind::None => Box::new(NoMbc {}), MBCKind::None => Box::new(NoMBC {}),
MbcKind::Mbc1 => { MBCKind::MBC1 => {
let mbc = Mbc1 { let mbc = MBC1 {
ram_size, ram_size,
ram: vec![0; ram_byte_count as usize], ram: vec![0; ram_byte_count as usize],
bank_count, bank_count,
@ -53,9 +54,9 @@ impl Cartridge {
Box::new(mbc) Box::new(mbc)
} }
MbcKind::Mbc1WithBattery => { MBCKind::MBC1WithBattery => {
// TODO: Implement Saving // TODO: Implement Saving
let mbc = Mbc1 { let mbc = MBC1 {
ram_size, ram_size,
ram: vec![0; ram_byte_count as usize], ram: vec![0; ram_byte_count as usize],
bank_count, bank_count,
@ -64,7 +65,7 @@ impl Cartridge {
Box::new(mbc) Box::new(mbc)
} }
MbcKind::Mbc3WithBattery => { MBCKind::MBC3WithBattery => {
// TODO: Implement Saving // TODO: Implement Saving
let mbc = MBC3 { let mbc = MBC3 {
ram_size, ram_size,
@ -74,7 +75,7 @@ impl Cartridge {
Box::new(mbc) Box::new(mbc)
} }
MbcKind::Mbc3 => { MBCKind::MBC3 => {
let mbc = MBC3 { let mbc = MBC3 {
ram_size, ram_size,
ram: vec![0; ram_byte_count as usize], ram: vec![0; ram_byte_count as usize],
@ -83,19 +84,19 @@ impl Cartridge {
Box::new(mbc) Box::new(mbc)
} }
MbcKind::Mbc5 => todo!("Implement MBC5"), MBCKind::MBC5 => todo!("Implement MBC5"),
} }
} }
fn find_title(memory: &[u8]) -> Option<String> { fn find_title(memory: &[u8]) -> Option<String> {
// FIXME: Get rid of magic values and handle cases let slice = &memory[ROM_TITLE_RANGE];
// where 0x134..0x143 reads past the length of the let with_nulls = std::str::from_utf8(slice).ok();
// string let trimmed = with_nulls.map(|s| s.trim_matches('\0'));
let slice = &memory[0x134..0x143]; match trimmed {
Some("") | None => None,
let str_with_nulls = std::str::from_utf8(slice).ok(); Some(_) => trimmed.map(String::from),
str_with_nulls.map(|s| s.trim_matches('\0').to_string()) }
} }
pub(crate) fn title(&self) -> Option<&str> { pub(crate) fn title(&self) -> Option<&str> {
@ -112,18 +113,18 @@ impl Cartridge {
id.into() id.into()
} }
fn find_mbc(memory: &[u8]) -> MbcKind { fn find_mbc(memory: &[u8]) -> MBCKind {
let id = memory[MBC_TYPE_ADDRESS]; let id = memory[MBC_TYPE_ADDRESS];
// TODO: Refactor this to match the other enums in this module // TODO: Refactor this to match the other enums in this module
match id { match id {
0x00 => MbcKind::None, 0x00 => MBCKind::None,
0x01 => MbcKind::Mbc1, 0x01 => MBCKind::MBC1,
0x02 => MbcKind::Mbc1, 0x02 => MBCKind::MBC1,
0x03 => MbcKind::Mbc1WithBattery, 0x03 => MBCKind::MBC1WithBattery,
0x19 => MbcKind::Mbc5, 0x19 => MBCKind::MBC5,
0x13 => MbcKind::Mbc3WithBattery, 0x13 => MBCKind::MBC3WithBattery,
0x11 => MbcKind::Mbc3, 0x11 => MBCKind::MBC3,
_ => unimplemented!("id {:#04X} is an unsupported MBC", id), _ => unimplemented!("id {:#04X} is an unsupported MBC", id),
} }
} }
@ -131,7 +132,7 @@ impl Cartridge {
impl BusIo for Cartridge { impl BusIo for Cartridge {
fn read_byte(&self, addr: u16) -> u8 { fn read_byte(&self, addr: u16) -> u8 {
use MbcResult::*; use MBCResult::*;
match self.mbc.handle_read(addr) { match self.mbc.handle_read(addr) {
Address(addr) => self.memory[addr], Address(addr) => self.memory[addr],
@ -145,7 +146,7 @@ impl BusIo for Cartridge {
} }
#[derive(Debug)] #[derive(Debug)]
struct Mbc1 { struct MBC1 {
/// 5-bit number /// 5-bit number
rom_bank: u8, rom_bank: u8,
/// 2-bit number /// 2-bit number
@ -157,7 +158,7 @@ struct Mbc1 {
ram_enabled: bool, ram_enabled: bool,
} }
impl Default for Mbc1 { impl Default for MBC1 {
fn default() -> Self { fn default() -> Self {
Self { Self {
rom_bank: 0x01, rom_bank: 0x01,
@ -171,7 +172,7 @@ impl Default for Mbc1 {
} }
} }
impl Mbc1 { impl MBC1 {
fn zero_bank(&self) -> u8 { fn zero_bank(&self) -> u8 {
use BankCount::*; use BankCount::*;
@ -237,9 +238,9 @@ impl Mbc1 {
} }
} }
impl MemoryBankController for Mbc1 { impl MBCIo for MBC1 {
fn handle_read(&self, addr: u16) -> MbcResult { fn handle_read(&self, addr: u16) -> MBCResult {
use MbcResult::*; use MBCResult::*;
match addr { match addr {
0x0000..=0x3FFF => { 0x0000..=0x3FFF => {
@ -304,11 +305,14 @@ struct MBC3 {
currently_mapped: Option<MBC3Device>, currently_mapped: Option<MBC3Device>,
ram_size: RamSize, ram_size: RamSize,
ram: Vec<u8>, ram: Vec<u8>,
// RTC Data Latch Previous Write
prev_latch_write: Option<u8>,
} }
impl MemoryBankController for MBC3 { impl MBCIo for MBC3 {
fn handle_read(&self, addr: u16) -> MbcResult { fn handle_read(&self, addr: u16) -> MBCResult {
use MbcResult::*; use MBCResult::*;
let res = match addr { let res = match addr {
0x0000..=0x3FFF => Address(addr as usize), 0x0000..=0x3FFF => Address(addr as usize),
@ -318,7 +322,7 @@ impl MemoryBankController for MBC3 {
Value(self.ram[0x2000 * self.ram_bank as usize + (addr as usize - 0xA000)]) Value(self.ram[0x2000 * self.ram_bank as usize + (addr as usize - 0xA000)])
} }
Some(MBC3Device::RealTimeClock) if self.devices_enabled => { Some(MBC3Device::RealTimeClock) if self.devices_enabled => {
unimplemented!("Reading from MBC3 RTC is currently unsupported") todo!("Return Latched value of register")
} }
_ => Value(0xFF), _ => Value(0xFF),
}, },
@ -331,10 +335,12 @@ impl MemoryBankController for MBC3 {
fn handle_write(&mut self, addr: u16, byte: u8) { fn handle_write(&mut self, addr: u16, byte: u8) {
match addr { match addr {
0x000..=0x1FFF => self.devices_enabled = (byte & 0x0F) == 0x0A, // Enable External RAM and Access to RTC if there is one 0x000..=0x1FFF => self.devices_enabled = (byte & 0x0F) == 0x0A, // Enable External RAM and Access to RTC if there is one
0x2000..=0x3FFF => match byte { 0x2000..=0x3FFF => {
0x00 => self.rom_bank = 0x01, self.rom_bank = match byte {
byte => self.rom_bank = byte & 0x7F, 0x00 => 0x01,
}, byte => byte & 0x7F,
}
}
0x4000..=0x5FFF => match byte { 0x4000..=0x5FFF => match byte {
0x00 | 0x01 | 0x02 | 0x03 => { 0x00 | 0x01 | 0x02 | 0x03 => {
self.ram_bank = byte & 0x03; self.ram_bank = byte & 0x03;
@ -342,17 +348,23 @@ impl MemoryBankController for MBC3 {
} }
0x08 | 0x09 | 0x0A | 0x0B | 0x0C => { 0x08 | 0x09 | 0x0A | 0x0B | 0x0C => {
self.currently_mapped = Some(MBC3Device::RealTimeClock); self.currently_mapped = Some(MBC3Device::RealTimeClock);
unimplemented!("RTC in MBC3 is currently unimplemented")
} }
_ => {} _ => {}
}, },
0x6000..=0x7FFF => unimplemented!("RTC Data Latch is currently unimplemented"), 0x6000..=0x7FFF => {
if let Some(0x00) = self.prev_latch_write {
if byte == 0x01 {
todo!("Perform Data Latch")
}
}
self.prev_latch_write = Some(byte);
}
0xA000..=0xBFFF => match self.currently_mapped { 0xA000..=0xBFFF => match self.currently_mapped {
Some(MBC3Device::ExternalRam) if self.devices_enabled => { Some(MBC3Device::ExternalRam) if self.devices_enabled => {
self.ram[0x2000 * self.ram_bank as usize + (addr as usize - 0xA000)] = byte self.ram[0x2000 * self.ram_bank as usize + (addr as usize - 0xA000)] = byte
} }
Some(MBC3Device::RealTimeClock) if self.devices_enabled => { Some(MBC3Device::RealTimeClock) if self.devices_enabled => {
unimplemented!("Writing to MBC3 RTC is currently unsupported") todo!("Write to RTC")
} }
_ => {} _ => {}
}, },
@ -362,11 +374,11 @@ impl MemoryBankController for MBC3 {
} }
#[derive(Debug)] #[derive(Debug)]
struct NoMbc {} struct NoMBC {}
impl MemoryBankController for NoMbc { impl MBCIo for NoMBC {
fn handle_read(&self, addr: u16) -> MbcResult { fn handle_read(&self, addr: u16) -> MBCResult {
MbcResult::Address(addr as usize) MBCResult::Address(addr as usize)
} }
fn handle_write(&mut self, _addr: u16, _byte: u8) { fn handle_write(&mut self, _addr: u16, _byte: u8) {
@ -374,28 +386,28 @@ impl MemoryBankController for NoMbc {
} }
} }
trait MemoryBankController { trait MBCIo {
fn handle_read(&self, addr: u16) -> MbcResult; fn handle_read(&self, addr: u16) -> MBCResult;
fn handle_write(&mut self, addr: u16, byte: u8); fn handle_write(&mut self, addr: u16, byte: u8);
} }
#[derive(Debug, Clone, Copy)] #[derive(Debug, Clone, Copy)]
enum MbcResult { enum MBCResult {
Address(usize), Address(usize),
Value(u8), Value(u8),
} }
#[derive(Debug, Clone, Copy)] #[derive(Debug, Clone, Copy)]
enum MbcKind { enum MBCKind {
None, None,
Mbc1, MBC1,
Mbc1WithBattery, MBC1WithBattery,
Mbc5, MBC5,
Mbc3WithBattery, MBC3WithBattery,
Mbc3, MBC3,
} }
impl Default for MbcKind { impl Default for MBCKind {
fn default() -> Self { fn default() -> Self {
Self::None Self::None
} }
@ -514,14 +526,14 @@ impl From<u8> for BankCount {
} }
} }
impl std::fmt::Debug for Box<dyn MemoryBankController> { impl std::fmt::Debug for Box<dyn MBCIo> {
fn fmt(&self, _f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result { fn fmt(&self, _f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
todo!("Implement Debug for Box<dyn MBC> Trait Object"); todo!("Implement Debug for Box<dyn MBC> Trait Object");
} }
} }
impl Default for Box<dyn MemoryBankController> { impl Default for Box<dyn MBCIo> {
fn default() -> Self { fn default() -> Self {
Box::new(Mbc1::default()) Box::new(MBC1::default())
} }
} }