diff options
| -rw-r--r-- | Cargo.lock | 2 | ||||
| -rw-r--r-- | Cargo.toml | 2 | ||||
| -rw-r--r-- | src/apu.rs | 41 | ||||
| -rw-r--r-- | src/bin.rs | 24 | ||||
| -rw-r--r-- | src/lib.rs | 4 | ||||
| -rw-r--r-- | src/memory.rs | 50 | ||||
| -rw-r--r-- | src/mos6502.rs | 24 | ||||
| -rw-r--r-- | src/ppu.rs | 57 |
8 files changed, 130 insertions, 74 deletions
@@ -134,7 +134,7 @@ dependencies = [ [[package]] name = "runes" -version = "0.1.4" +version = "0.1.5" dependencies = [ "clap 2.29.0 (registry+https://github.com/rust-lang/crates.io-index)", "sdl2 0.31.0 (registry+https://github.com/rust-lang/crates.io-index)", @@ -1,6 +1,6 @@ [package] name = "runes" -version = "0.1.4" +version = "0.1.5" authors = ["Determinant <[email protected]>"] description = "No-std NES emulator library and minimal emulator written purely in Rust." repository = "https://github.com/Determinant/runes" @@ -1,24 +1,33 @@ #![allow(dead_code)] -use mos6502::{CPU_FREQ, CPU}; +use mos6502::CPU_FREQ; use memory::CPUBus; struct LPFilter { prev_out: i16 } -const AUDIO_LEVEL_MAX: i32 = 65536; +const AUDIO_LEVEL_MAX: i32 = 32768; const LP_FACTOR: i32 = (0.815686 * AUDIO_LEVEL_MAX as f32) as i32; const HP_FACTOR1: i32 = (0.996039 * AUDIO_LEVEL_MAX as f32) as i32; const HP_FACTOR2: i32 = (0.999835 * AUDIO_LEVEL_MAX as f32) as i32; +fn cutoff(mut x: i32) -> i16 { + if x < -32768 { + x = -32768 + } else if x > 32767 { + x = 32767 + } + x as i16 +} + impl LPFilter { fn new() -> Self { LPFilter { prev_out: 0 } } fn output(&mut self, input: i16) -> i16 { - let out = ((input as i32 - self.prev_out as i32) - * LP_FACTOR / AUDIO_LEVEL_MAX) as i16; + let out = cutoff((input as i32 - self.prev_out as i32) + * LP_FACTOR / AUDIO_LEVEL_MAX); self.prev_out = out; out } @@ -40,8 +49,9 @@ impl HPFilter { } fn output(&mut self, input: i16) -> i16 { - let out = (self.prev_out as i32 * self.hp_factor / AUDIO_LEVEL_MAX + - input as i32 - self.prev_in as i32) as i16; + let out = cutoff( + self.prev_out as i32 * self.hp_factor / AUDIO_LEVEL_MAX + + input as i32 - self.prev_in as i32); self.prev_in = input; self.prev_out = out; out @@ -603,10 +613,10 @@ impl DMC { self.rem_len = self.sample_len; } - fn try_refill(&mut self, cpu: &mut CPU) { + fn try_refill(&mut self, bus: &CPUBus) { if self.rem_len > 0 && self.dmc_cnt == 0 { - cpu.cycle += 4; - self.shift_reg = cpu.mem.read_without_tick(self.cur_addr); + bus.cpu_stall(4); + self.shift_reg = bus.get_cpu().mem.read_without_tick(self.cur_addr); self.dmc_cnt = 8; self.cur_addr = self.cur_addr.wrapping_add(1); if self.cur_addr == 0x0 { @@ -617,7 +627,7 @@ impl DMC { if self.dmc_loop { self.restart() } else if self.irq_enabled { - cpu.trigger_irq() + bus.get_cpu().trigger_irq() } } } @@ -638,9 +648,9 @@ impl DMC { self.dmc_cnt -= 1; } - fn tick_timer(&mut self, cpu: &mut CPU) { + fn tick_timer(&mut self, bus: &CPUBus) { if !self.enabled { return } - self.try_refill(cpu); + self.try_refill(bus); if self.timer_lvl == 0 { self.timer_lvl = self.timer_period; self.shift(); @@ -716,7 +726,7 @@ impl<'a> APU<'a> { let sample = self.output(); self.spkr.queue(sample); } - self.tick_timer(bus.get_cpu()); + self.tick_timer(bus); self.cycle_even = !self.cycle_even; irq } @@ -727,6 +737,7 @@ impl<'a> APU<'a> { let tnd_out = TND_TABLE[(self.triangle.output() * 3 + self.noise.output() * 2 + self.dmc.output()) as usize]; + //(pulse_out + tnd_out).wrapping_sub(0x8000) as i16 self.lp_filter.output( self.hp_filter2.output( self.hp_filter1.output( @@ -778,12 +789,12 @@ impl<'a> APU<'a> { } } - fn tick_timer(&mut self, cpu: &mut CPU) { + fn tick_timer(&mut self, bus: &CPUBus) { if self.cycle_even { self.pulse1.tick_timer(); self.pulse2.tick_timer(); self.noise.tick_timer(); - self.dmc.tick_timer(cpu); + self.dmc.tick_timer(bus); } self.triangle.tick_timer(); } @@ -269,8 +269,8 @@ impl<'a> sdl2::audio::AudioCallback for SDLAudioPlayback<'a> { let mut m = self.0.buffer.lock().unwrap(); { let b = &mut m.0; - let l1 = (b.tail + b.buffer.len() - b.head) % b.buffer.len(); - //print!("{} ", l1); + /*let l1 = (b.tail + b.buffer.len() - b.head) % b.buffer.len(); + print!("{} ", l1); */ for x in out.iter_mut() { *x = b.deque() @@ -282,7 +282,7 @@ impl<'a> sdl2::audio::AudioCallback for SDLAudioPlayback<'a> { self.0.time_barrier.notify_one(); } else { m.1 = 0; - //println!("audio frame skipping"); + println!("audio frame skipping"); } } } @@ -326,12 +326,13 @@ fn print_cpu_trace(cpu: &CPU) { } println!("0x{:04x} {} a:{:02x} x:{:02x} y:{:02x} s: {:02x} sp: {:02x}", pc, disasm::parse(opcode as u8, &code[1..]), - cpu.get_a(), cpu.get_x(), cpu.get_y(), cpu.get_status(), cpu.get_sp()); + cpu.get_a(), cpu.get_x(), cpu.get_y(), + cpu.get_status(), cpu.get_sp()); } fn main() { let matches = App::new("RuNES") - .version("0.1.4") + .version("0.1.5") .author("Ted Yin <[email protected]>") .about("A Rust NES emulator") .arg(Arg::with_name("scale") @@ -349,10 +350,13 @@ fn main() { .required(true) .index(1)) .get_matches(); + let scale = std::cmp::min(8, std::cmp::max(1, - value_t!(matches, "scale", u32).unwrap_or(4))); + value_t!(matches, "scale", u32).unwrap_or(3))); let full = matches.is_present("full"); + + /* load and parse iNES file */ let fname = matches.value_of("INPUT").unwrap(); let mut file = File::open(fname).unwrap(); let mut rheader = [0; 16]; @@ -383,6 +387,7 @@ fn main() { if chr_len == 0 { chr_len = 0x2000; } + let mut prg_rom = vec![0; prg_len]; let mut chr_rom = vec![0; chr_len]; let sram = vec![0; 0x4000]; @@ -404,8 +409,9 @@ fn main() { let device = audio_subsystem.open_playback(None, &desired_spec, |_| { SDLAudioPlayback(&audio_sync) }).unwrap(); - + /* P1 controller */ let p1ctl = stdctl::Joystick::new(); + /* cartridge & mapper */ let cart = SimpleCart::new(chr_rom, prg_rom, sram, mirror); let mut win = Box::new(SDLWindow::new(&sdl_context, &p1ctl, scale, full)); let mut m: Box<mapper::Mapper> = match mapper_id { @@ -416,7 +422,7 @@ fn main() { }; let mapper = RefCell::new(&mut (*m) as &mut mapper::Mapper); - let mut cpu = CPU::new(CPUMemory::new(&mapper, Some(&p1ctl), None)/*, &mut f*/); + let mut cpu = CPU::new(CPUMemory::new(&mapper, Some(&p1ctl), None)); let mut ppu = PPU::new(PPUMemory::new(&mapper), &mut (*win)); let mut apu = APU::new(&mut spkr); let cpu_ptr = &mut cpu as *mut CPU; @@ -426,7 +432,7 @@ fn main() { loop { /* consume the leftover cycles from the last instruction */ while cpu.cycle > 0 { - cpu.mem.bus.tick(); + cpu.mem.bus.tick() } //print_cpu_trace(&cpu); cpu.step(); @@ -1,5 +1,5 @@ -#![no_std] -//extern crate core; +//#![no_std] +extern crate core; mod memory; #[macro_use] mod mos6502; mod ppu; diff --git a/src/memory.rs b/src/memory.rs index 8954c91..985070f 100644 --- a/src/memory.rs +++ b/src/memory.rs @@ -5,7 +5,7 @@ use mos6502::{CPU, CPU_FREQ}; use cartridge::MirrorType; use mapper::Mapper; use controller::Controller; -use core::cell::RefCell; +use core::cell::{RefCell, Cell}; use core::ptr::null_mut; pub trait VMem { @@ -18,6 +18,8 @@ pub struct CPUBus<'a> { ppu: *mut PPU<'a>, apu: *mut APU<'a>, ppu_sampler: RefCell<Sampler>, + nmi_after_tick: Cell<bool>, + cpu_stall: Cell<u32> } impl<'a> CPUBus<'a> { @@ -26,6 +28,8 @@ impl<'a> CPUBus<'a> { cpu: null_mut(), apu: null_mut(), ppu_sampler: RefCell::new(Sampler::new(CPU_FREQ, 60)), + nmi_after_tick: Cell::new(false), + cpu_stall: Cell::new(0) } } @@ -41,17 +45,41 @@ impl<'a> CPUBus<'a> { #[inline(always)] pub fn get_ppu(&self) -> &'a mut PPU<'a> {unsafe{&mut *self.ppu}} #[inline(always)] pub fn get_apu(&self) -> &'a mut APU<'a> {unsafe{&mut *self.apu}} + pub fn cpu_stall(&self, delta: u32) { + self.cpu_stall.set(self.cpu_stall.get() + delta) + } + pub fn tick(&self) { let cpu = self.get_cpu(); let ppu = self.get_ppu(); let apu = self.get_apu(); - cpu.tick(); + + let cpu_stall = self.cpu_stall.get(); + if cpu_stall == 0 { + cpu.tick() + } else { + self.cpu_stall.set(cpu_stall - 1) + } if apu.tick(self) { cpu.trigger_irq() } - if ppu.tick(self) || ppu.tick(self) || ppu.tick(self) { - cpu.trigger_nmi() + + let first = ppu.tick(self); + let second = ppu.tick(self); + let third = ppu.tick(self); + let mut nmi_after_tick = false; + + if first || second || third { + nmi_after_tick = !first; + if cpu.cycle == 0 && nmi_after_tick { + cpu.trigger_delayed_nmi() + } else { + cpu.trigger_nmi() + } + //println!("nmi"); } + self.nmi_after_tick.set(nmi_after_tick); + //println!("tick {} {}", ppu.scanline, ppu.cycle); if let (true, _) = self.ppu_sampler.borrow_mut().tick() { ppu.scr.frame() } @@ -88,7 +116,12 @@ impl<'a> CPUMemory<'a> { self.sram[(addr & 0x07ff) as usize] } else if addr < 0x4000 { match addr & 0x7 { - 0x2 => ppu.read_status(cpu), + 0x2 => { + if ppu.cycle == 2 || ppu.cycle == 3 { + cpu.suppress_nmi() + } /* race condition when status is read near vbl/nmi */ + ppu.read_status() + }, 0x4 => ppu.read_oamdata(), 0x7 => ppu.read_data(), _ => 0 @@ -119,7 +152,10 @@ impl<'a> CPUMemory<'a> { 0x0 => { let old = ppu.get_flag_nmi(); ppu.write_ctl(data); - if !old && ppu.try_nmi() && ppu.vblank { + if !ppu.try_nmi() && self.bus.nmi_after_tick.get() { + cpu.suppress_nmi() + } /* NMI could be suppressed if disabled near set */ + if !old && ppu.try_nmi() && ppu.vblank_lines { cpu.trigger_delayed_nmi() } /* toggle NMI flag can generate multiple ints */ }, @@ -155,7 +191,7 @@ impl<'a> CPUMemory<'a> { 0x4013 => apu.dmc.write_reg4(data), 0x4015 => apu.write_status(data), 0x4017 => apu.write_frame_counter(data), - 0x4014 => ppu.write_oamdma(data, cpu), + 0x4014 => ppu.write_oamdma(data, &self.bus), 0x4016 => { if let Some(c) = self.ctl1 { c.write(data) } if let Some(c) = self.ctl2 { c.write(data) } diff --git a/src/mos6502.rs b/src/mos6502.rs index 5f64b59..848dd1f 100644 --- a/src/mos6502.rs +++ b/src/mos6502.rs @@ -605,7 +605,6 @@ pub struct CPU<'a> { //pub elapsed: u32, int: Option<IntType>, pub mem: CPUMemory<'a>, - //sec_callback: &'a mut FnMut(), } macro_rules! make_int { @@ -639,8 +638,7 @@ impl<'a> CPU<'a> { #[inline(always)] pub fn get_over(&self) -> u8 { (self.status >> 6) & 1 } #[inline(always)] pub fn get_neg(&self) -> u8 { (self.status >> 7) & 1 } - pub fn new(mem: CPUMemory<'a>/*, - sec_callback: &'a mut FnMut()*/) -> Self { + pub fn new(mem: CPUMemory<'a>) -> Self { let pc = 0; /* nes power up state */ let a = 0; @@ -650,12 +648,14 @@ impl<'a> CPU<'a> { let status = 0x34; let cycle = 0; - CPU{a, x, y, + CPU {a, x, y, pc, sp, status, cycle, opr: 0, ea: 0, imm_val: 0, int: None, acc: false, - mem, /*elapsed: 0, sec_callback*/} + mem, + //elapsed: 0 + } } pub fn powerup(&mut self) { @@ -667,7 +667,6 @@ impl<'a> CPU<'a> { make_int!(irq, IRQ_VECTOR); pub fn step(&mut self) { - //let cycle0 = self.cycle; if self.int.is_some() { match self.int { Some(IntType::NMI) => {self.nmi(); self.int = None; return}, @@ -676,7 +675,7 @@ impl<'a> CPU<'a> { _ => () } } - self.cycle += 1; + self.cycle += 0xff; let pc = self.pc; let opcode = self.mem.read(pc) as usize; /* update opr pointing to operands of current inst */ @@ -685,7 +684,8 @@ impl<'a> CPU<'a> { self.pc = pc.wrapping_add(INST_LENGTH[opcode] as u16); /* get effective address based on addressing mode */ self.acc = false; - self.cycle += INST_CYCLE[opcode] as u32 - 1; + self.cycle += INST_CYCLE[opcode] as u32; + self.cycle -= 0xff; self.cycle += (addr::ADDR_MODES[opcode](self) * INST_EXTRA_CYCLE[opcode]) as u32; /* execute the inst */ ops::OPS[opcode](self); @@ -694,13 +694,7 @@ impl<'a> CPU<'a> { pub fn tick(&mut self) { self.cycle -= 1; - /* - self.elapsed += 1; - if self.elapsed == CPU_FREQ { - self.elapsed = 0; - (self.sec_callback)(); - } - */ + //self.elapsed += 1; } pub fn reset(&mut self) { @@ -1,6 +1,5 @@ #![allow(dead_code)] use memory::{VMem, PPUMemory, CPUBus}; -use mos6502::CPU; use core::intrinsics::transmute; pub trait Screen { @@ -48,12 +47,14 @@ pub struct PPU<'a> { sp_pixel: [u32; 8], sp_idx: [usize; 8], sp_cnt: [u8; 8], - pub vblank: bool, + vblank: bool, + pub vblank_lines: bool, buffered_read: u8, early_read: bool, /* IO */ mem: PPUMemory<'a>, pub scr: &'a mut Screen, + //pub elapsed: u32, } impl<'a> PPU<'a> { @@ -71,16 +72,12 @@ impl<'a> PPU<'a> { } #[inline] - pub fn read_status(&mut self, cpu: &mut CPU) -> u8 { + pub fn read_status(&mut self) -> u8 { let res = (self.ppustatus & !0x1fu8) | (self.reg & 0x1f); self.ppustatus &= !PPU::FLAG_VBLANK; self.w = false; - if self.scanline == 241 { - match self.cycle { - 1 => self.early_read = true, /* read before cycle 1 */ - 2 | 3 => cpu.suppress_nmi(), - _ => () - } + if self.scanline == 241 && self.cycle == 1 { + self.early_read = true /* read before cycle 1 */ } res } @@ -166,19 +163,20 @@ impl<'a> PPU<'a> { } #[inline] - pub fn write_oamdma(&mut self, data: u8, cpu: &mut CPU) { + pub fn write_oamdma(&mut self, data: u8, bus: &CPUBus) { + let cpu = bus.get_cpu(); self.reg = data; let mut addr = (data as u16) << 8; - let cycle = 1 + (cpu.cycle & 1) + 256; - cpu.cycle += cycle; + let stall = 1 + (cpu.cycle & 1) + 512; + bus.cpu_stall(stall); let mut oamaddr = self.oamaddr; - for _ in 0..cycle - 0x100 { + for _ in 0..stall - 0x100 { cpu.mem.bus.tick() } { let oam_raw = self.get_oam_raw_mut(); for _ in 0..0x100 { - oam_raw[oamaddr as usize] = cpu.mem.read(addr); + oam_raw[oamaddr as usize] = cpu.mem.read_without_tick(addr); addr = addr.wrapping_add(1); oamaddr = oamaddr.wrapping_add(1); } @@ -457,8 +455,8 @@ impl<'a> PPU<'a> { let ppustatus = 0xa0; let oamaddr = 0x00; let buffered_read = 0x00; - let cycle = 340; - let scanline = 240; + let cycle = 0; + let scanline = 241; PPU { scanline, ppuctl, @@ -476,9 +474,11 @@ impl<'a> PPU<'a> { sp_pixel: [0; 8], sp_cnt: [0; 8], vblank: false, + vblank_lines: true, buffered_read, early_read: false, - mem, scr + mem, scr, + //elapsed: 0, } } @@ -488,8 +488,9 @@ impl<'a> PPU<'a> { self.ppustatus = self.ppustatus & 0x80; self.w = false; self.buffered_read = 0x00; - self.cycle = 340; - self.scanline = 240; + self.cycle = 0; + self.scanline = 241; + self.vblank_lines = true; } #[inline(always)] @@ -504,6 +505,12 @@ impl<'a> PPU<'a> { } fn _tick(&mut self) -> bool { + if self.scanline == 240 { + self.vblank_lines = true + } else if self.scanline == 261 { + self.vblank_lines = false + } + //self.elapsed += 1; let cycle = self.cycle; if cycle == 0 { self.cycle = 1; @@ -551,11 +558,11 @@ impl<'a> PPU<'a> { self.cycle = 258; return false } - if pre_line && cycle == 339 && self.f { - self.scanline = 0; - self.cycle = 0; - self.f = !self.f; - return false; + /* skip at 338 because of 10-even_odd_timing test indicates an undocumented + * behavior of NES */ + if pre_line && cycle == 338 && self.f { + self.cycle = 340; + return false; } } } else { @@ -564,6 +571,8 @@ impl<'a> PPU<'a> { if !self.early_read { self.ppustatus |= PPU::FLAG_VBLANK } + //self.elapsed = 0; + //println!("vbl"); self.early_read = false; self.vblank = true; self.scr.render(); |