chore: update README

This commit is contained in:
Rekai Nyangadzayi Musuka 2021-11-05 22:40:31 -03:00
parent 55da5a29d8
commit 6f76571d6c
3 changed files with 180 additions and 15 deletions

View File

@ -4,10 +4,10 @@
### Status
* From [Blargg Test ROMs](https://github.com/L-P/blargg-test-roms/)
* [x] cpu_instrs
* [x] instr_timing
* [ ] instr_timing (kind of)
* [x] mem_timing
* [x] mem_timing-2
* [ ] Partially dmg_sound
* [ ] dmg_sound (partial)
* [x] [dmg-acid2](https://github.com/mattcurrie/dmg-acid2)
* From [mooneye-gb](https://github.com/Gekkio/mooneye-gb):
* Cartridges:
@ -16,7 +16,7 @@
* [x] MBC2
* [x] MBC5
* Implements a cycle-accurate PPU FIFO
* Doesn't \*exactly\* work right just yet
* Doesn't \*exactly\* work just yet
Supports: ROM-only, MBC1, MBC2, MBC3 and MBC5 games.

View File

@ -73,6 +73,7 @@ impl Bus {
fn tick(&mut self, limit: u8) {
for _ in 0..limit {
self.timer.tick();
self.cart.as_mut().map(|cart| cart.tick());
self.ppu.tick();
self.apu.tick(self.timer.divider);
self.dma_tick()

View File

@ -1,4 +1,8 @@
use bitfield::bitfield;
use crate::bus::BusIo;
use crate::emu::SM83_CLOCK_SPEED;
use crate::Cycle;
const RAM_SIZE_ADDRESS: usize = 0x0149;
const ROM_SIZE_ADDRESS: usize = 0x0148;
@ -33,6 +37,10 @@ impl Cartridge {
self.mbc.write_ext_ram(memory)
}
pub(crate) fn tick(&mut self) {
self.mbc.tick()
}
fn detect_mbc(memory: &[u8]) -> Box<dyn MBCIo> {
let ram_size = Self::detect_ram_info(memory);
let rom_size = Self::detect_rom_info(memory);
@ -281,10 +289,120 @@ impl MBCIo for MBC1 {
}
}
impl RtcTick for MBC1 {
fn tick(&mut self) {}
}
#[derive(Debug, Default, Clone, Copy)]
struct Rtc {
/// 6-bit unsigned integer
sec: u8,
/// 6-bit unsigned integer
min: u8,
/// 6-bit unsigned integer
hr: u8,
day_low: u8,
day_high: DayHigh,
cycles: Cycle,
}
impl Rtc {
fn inc_day(&mut self) {
// TODO: Figure out order of operations, the brackets are a bit too defenseive here
let days: u16 = (((self.day_high.ninth() as u16) << 8) | self.day_low as u16) + 1;
if days > 0x1FF {
self.day_high.set_carry(true);
}
self.day_high.set_ninth(((days >> 8) & 0x01) == 0x01);
self.day_low = days as u8;
}
}
impl RtcTick for Rtc {
fn tick(&mut self) {
// This is the sort of situation where you'd want to use a scheduler.
if self.day_high.halt() {
return;
}
self.cycles += 1;
if self.cycles >= SM83_CLOCK_SPEED {
self.cycles %= SM83_CLOCK_SPEED;
self.sec += 1;
if self.sec == 60 {
self.sec = 0;
self.min += 1;
}
if self.min == 60 {
self.min = 0;
self.hr += 1;
}
if self.hr == 24 {
self.hr = 0;
self.inc_day();
}
}
}
}
trait RtcTick {
fn tick(&mut self);
}
bitfield! {
struct DayHigh(u8);
impl Debug;
_, set_carry: 7;
halt, _: 6;
ninth, set_ninth: 0;
}
impl Copy for DayHigh {}
impl Clone for DayHigh {
fn clone(&self) -> Self {
*self
}
}
impl Default for DayHigh {
fn default() -> Self {
Self(0)
}
}
impl From<u8> for DayHigh {
fn from(byte: u8) -> Self {
Self(byte)
}
}
impl From<DayHigh> for u8 {
fn from(dh: DayHigh) -> Self {
dh.0
}
}
#[derive(Debug, Clone, Copy)]
enum MBC3Device {
ExternalRam,
RealTimeClock,
Rtc(RtcRegister),
}
#[derive(Debug, Clone, Copy)]
enum RtcRegister {
Second,
Minute,
Hour,
DayLow,
DayHigh,
}
#[derive(Debug)]
@ -302,6 +420,8 @@ struct MBC3 {
prev_latch_write: Option<u8>,
has_battery: bool,
rtc: Rtc,
rtc_latch: Option<Rtc>,
}
impl MBC3 {
@ -314,6 +434,8 @@ impl MBC3 {
mapped: Default::default(),
prev_latch_write: Default::default(),
has_battery: Default::default(),
rtc: Default::default(),
rtc_latch: Default::default(),
}
}
@ -325,6 +447,8 @@ impl MBC3 {
devs_enabled: Default::default(),
mapped: Default::default(),
prev_latch_write: Default::default(),
rtc: Default::default(),
rtc_latch: Default::default(),
has_battery: true,
}
}
@ -348,6 +472,7 @@ impl Savable for MBC3 {
impl MBCIo for MBC3 {
fn handle_read(&self, addr: u16) -> MBCResult {
use MBCResult::*;
use RtcRegister::*;
let res = match addr {
0x0000..=0x3FFF => Address(addr as usize),
@ -356,9 +481,21 @@ impl MBCIo for MBC3 {
Some(MBC3Device::ExternalRam) if self.devs_enabled => {
Value(self.memory[0x2000 * self.ram_bank as usize + (addr as usize - 0xA000)])
}
Some(MBC3Device::RealTimeClock) if self.devs_enabled => {
todo!("Return Latched value of register")
}
Some(MBC3Device::Rtc(rtc_reg)) if self.devs_enabled => Value(match rtc_reg {
Second => self.rtc_latch.as_ref().map(|rtc| rtc.sec).unwrap_or(0xFF),
Minute => self.rtc_latch.as_ref().map(|rtc| rtc.min).unwrap_or(0xFF),
Hour => self.rtc_latch.as_ref().map(|rtc| rtc.hr).unwrap_or(0xFF),
DayLow => self
.rtc_latch
.as_ref()
.map(|rtc| rtc.day_low)
.unwrap_or(0xFF),
DayHigh => self
.rtc_latch
.as_ref()
.map(|rtc| rtc.day_high.into())
.unwrap_or(0xFF),
}),
_ => Value(0xFF),
},
_ => unreachable!("A read from {:#06X} should not be handled by MBC3", addr),
@ -368,6 +505,8 @@ impl MBCIo for MBC3 {
}
fn handle_write(&mut self, addr: u16, byte: u8) {
use RtcRegister::*;
match addr {
0x000..=0x1FFF => self.devs_enabled = (byte & 0x0F) == 0x0A, // Enable External RAM and Access to RTC if there is one
0x2000..=0x3FFF => {
@ -381,15 +520,18 @@ impl MBCIo for MBC3 {
self.ram_bank = byte & 0x03;
self.mapped = Some(MBC3Device::ExternalRam);
}
0x08 | 0x09 | 0x0A | 0x0B | 0x0C => {
self.mapped = Some(MBC3Device::RealTimeClock);
}
0x08 => self.mapped = Some(MBC3Device::Rtc(Second)),
0x09 => self.mapped = Some(MBC3Device::Rtc(Minute)),
0x0A => self.mapped = Some(MBC3Device::Rtc(Hour)),
0x0B => self.mapped = Some(MBC3Device::Rtc(DayLow)),
0x0C => self.mapped = Some(MBC3Device::Rtc(DayHigh)),
_ => {}
},
0x6000..=0x7FFF => {
if let Some(0x00) = self.prev_latch_write {
if byte == 0x01 {
todo!("Perform Data Latch")
self.rtc_latch = Some(self.rtc);
}
}
self.prev_latch_write = Some(byte);
@ -398,9 +540,13 @@ impl MBCIo for MBC3 {
Some(MBC3Device::ExternalRam) if self.devs_enabled => {
self.memory[0x2000 * self.ram_bank as usize + (addr as usize - 0xA000)] = byte
}
Some(MBC3Device::RealTimeClock) if self.devs_enabled => {
todo!("Write to RTC")
}
Some(MBC3Device::Rtc(rtc_reg)) if self.devs_enabled => match rtc_reg {
Second => self.rtc.sec = byte & 0x3F,
Minute => self.rtc.min = byte & 0x3F,
Hour => self.rtc.hr = byte & 0x1F,
DayLow => self.rtc.day_low = byte & 0xFF,
DayHigh => self.rtc.day_high = (byte & 0xC1).into(),
},
_ => {}
},
_ => unreachable!("A write to {:#06X} should not be handled by MBC3", addr),
@ -408,6 +554,12 @@ impl MBCIo for MBC3 {
}
}
impl RtcTick for MBC3 {
fn tick(&mut self) {
self.rtc.tick();
}
}
#[derive(Debug)]
struct MBC5 {
/// 9-bit number
@ -495,6 +647,10 @@ impl MBCIo for MBC5 {
}
}
impl RtcTick for MBC5 {
fn tick(&mut self) {}
}
#[derive(Debug)]
struct MBC2 {
/// 4-bit number
@ -583,6 +739,10 @@ impl MBCIo for MBC2 {
}
}
impl RtcTick for MBC2 {
fn tick(&mut self) {}
}
#[derive(Debug)]
struct NoMBC;
@ -606,7 +766,11 @@ impl MBCIo for NoMBC {
}
}
trait MBCIo: Savable {
impl RtcTick for NoMBC {
fn tick(&mut self) {}
}
trait MBCIo: Savable + RtcTick {
fn handle_read(&self, addr: u16) -> MBCResult;
fn handle_write(&mut self, addr: u16, byte: u8);
}