feat: emulator now sucessfully runs boot rom

src/bus.rs

@@ -112,6 +112,7 @@ impl Bus {
                     0xFF0F => self.interrupt.flag.into(),
                     0xFF11 => self.sound.ch1.sound_duty.into(),
                     0xFF12 => self.sound.ch1.vol_envelope.into(),
+                    0xFF14 => self.sound.ch1.freq.get_hi(),
                     0xFF24 => self.sound.control.channel.into(),
                     0xFF25 => self.sound.control.select.into(),
                     0xFF26 => self.sound.control.status.into(),
@@ -180,6 +181,8 @@ impl Bus {
                     0xFF0F => self.interrupt.flag = byte.into(),
                     0xFF11 => self.sound.ch1.sound_duty = byte.into(),
                     0xFF12 => self.sound.ch1.vol_envelope = byte.into(),
+                    0xFF13 => self.sound.ch1.freq.set_lo(byte),
+                    0xFF14 => self.sound.ch1.freq.set_hi(byte),
                     0xFF24 => self.sound.control.channel = byte.into(),
                     0xFF25 => self.sound.control.select = byte.into(),
                     0xFF26 => self.sound.control.status = byte.into(), // FIXME: Should we control which bytes are written to here?
@@ -189,6 +192,12 @@ impl Bus {
                     0xFF43 => self.ppu.pos.scroll_x = byte,
                     0xFF44 => self.ppu.pos.line_y = byte,
                     0xFF47 => self.ppu.monochrome.bg_palette = byte.into(),
+                    0xFF50 => {
+                        // Disable Boot ROM
+                        if byte != 0 {
+                            self.boot = None;
+                        }
+                    }
                     _ => unimplemented!("Unable to write to {:#06X} in I/O Registers", addr),
                 };
             }

src/main.rs

@@ -54,17 +54,6 @@ fn main() -> Result<()> {
             // window.request_redraw();
         }
     });
-
-    // loop {
-    //     let pc = game_boy.register_pair(gb::cpu::RegisterPair::PC);
-    //     let opcode = game_boy.fetch();
-    //     let instruction = game_boy.decode(opcode);
-
-    //     let _cycles = game_boy.execute(instruction);
-
-    //     let ppu = game_boy.get_ppu();
-    //     ppu.step();
-    // }
 }
 
 pub fn create_window(event_loop: &EventLoop<()>) -> Result<Window> {

src/ppu.rs

@@ -1,5 +1,7 @@
 use crate::instruction::Cycles;
 
+const GB_WIDTH: usize = 160;
+const GB_HEIGHT: usize = 144;
 #[derive(Debug, Clone)]
 pub struct PPU {
     pub lcd_control: LCDControl,
@@ -7,32 +9,60 @@ pub struct PPU {
     pub pos: ScreenPosition,
     pub vram: Box<[u8]>,
     pub oam: Box<[u8]>,
+    frame_buf: [u8; GB_WIDTH * GB_HEIGHT * 4],
     pub stat: LCDStatus,
     cycles: Cycles,
-    mode: PPUMode,
+    mode: Mode,
 }
 
 impl PPU {
     pub fn step(&mut self, cycles: Cycles) {
         self.cycles += cycles;
 
+        // let smth: u32 = self.cycles.into();
+        // println!("Mode: {:?} | Cycles: {}", self.mode, smth);
+
         match self.mode {
-            PPUMode::OAMScan => {
+            Mode::OAMScan => {
                 if self.cycles >= 80.into() {
-                    self.cycles = cycles % 80;
+                    self.cycles %= 80;
+                    self.mode = Mode::Draw;
+                }
+            }
+            Mode::Draw => {
+                if self.cycles >= 172.into() {
+                    // 172 -> 129 Cycles
+                    // self.cycles %= 172;
+                    self.mode = Mode::HBlank;
+                }
+            }
+            Mode::HBlank => {
+                // The 80 comes from the 80 cycles we made disappear in OAMScan above.
+                if self.cycles >= (456 - 80).into() {
+                    self.cycles %= 456 - 80;
+                    self.pos.line_y += 1;
+
+                    if self.pos.line_y >= 144 {
+                        self.mode = Mode::VBlank;
+                    }
+                }
+            }
+            Mode::VBlank => {
+                if self.cycles >= 456.into() {
+                    self.cycles %= 456;
+                    self.pos.line_y += 1;
+
+                    if self.pos.line_y == 154 {
+                        self.mode = Mode::OAMScan;
+                        self.pos.line_y = 0;
+                    }
                 }
             }
-            PPUMode::Draw => {}
-            PPUMode::HBlank => {}
-            PPUMode::VBlank => {}
         }
     }
 
     pub fn draw(&self, frame: &mut [u8]) {
-        for (_i, pixel) in frame.chunks_exact_mut(4).enumerate() {
+        frame.copy_from_slice(&self.frame_buf);
-            let rgba: [u8; 4] = [0xFF, 0xFF, 0xFF, 0xFF];
-            pixel.copy_from_slice(&rgba);
-        }
     }
 }
 
@@ -46,13 +76,14 @@ impl Default for PPU {
             vram: vec![0; 8192].into_boxed_slice(),
             oam: vec![0; 160].into_boxed_slice(),
             cycles: 0.into(),
-            mode: PPUMode::OAMScan,
+            frame_buf: [0; GB_WIDTH * GB_HEIGHT * 4],
+            mode: Mode::OAMScan,
         }
     }
 }
 
 #[derive(Debug, Clone, Copy)]
-enum PPUMode {
+enum Mode {
     OAMScan,
     Draw,
     HBlank,

src/sound.rs

@@ -19,6 +19,72 @@ pub struct SoundControl {
     pub status: SoundStatus,
 }
 
+#[derive(Debug, Clone, Copy, Default)]
+pub struct Frequency {
+    initial: bool,
+    freq_type: FrequencyType,
+    lo: u8, // Bottom 8 bits
+    hi: u8, // Top 3 bits (11 bits total)
+}
+
+#[derive(Debug, Clone, Copy)]
+enum FrequencyType {
+    Counter,
+    Consequtive,
+}
+
+impl From<u8> for FrequencyType {
+    fn from(byte: u8) -> Self {
+        match byte {
+            0b00 => Self::Counter,
+            0b01 => Self::Consequtive,
+            _ => unreachable!("{} is not a valid number for FreuquencyType"),
+        }
+    }
+}
+
+impl From<FrequencyType> for u8 {
+    fn from(freq_type: FrequencyType) -> Self {
+        match freq_type {
+            FrequencyType::Counter => 0b00,
+            FrequencyType::Consequtive => 0b01,
+        }
+    }
+}
+
+impl Default for FrequencyType {
+    fn default() -> Self {
+        Self::Counter
+    }
+}
+
+impl Frequency {
+    fn get_11bit_freq(&self) -> u16 {
+        (self.hi as u16) << 8 | self.lo as u16
+    }
+
+    pub fn set_lo(&mut self, byte: u8) {
+        self.lo = byte;
+    }
+
+    pub fn get_lo(&self) -> u8 {
+        self.lo
+    }
+
+    pub fn set_hi(&mut self, byte: u8) {
+        *self = Self {
+            initial: byte >> 7 == 0x01,
+            freq_type: ((byte >> 6) & 0x01).into(),
+            lo: self.lo,
+            hi: byte & 0x07,
+        };
+    }
+
+    pub fn get_hi(&self) -> u8 {
+        (self.initial as u8) << 7 | (self.freq_type as u8) << 6 | self.hi
+    }
+}
+
 #[derive(Debug, Clone, Copy, Default)]
 pub struct SoundStatus {
     pub all_enabled: bool, // You can actually write to this one.
@@ -54,6 +120,7 @@ impl From<SoundStatus> for u8 {
 pub struct Channel1 {
     pub sound_duty: SoundDuty,
     pub vol_envelope: VolumeEnvelope,
+    pub freq: Frequency,
 }
 
 #[derive(Debug, Clone, Copy, Default)]