Refactor address ranges

Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "rmg-001"
 version = "0.1.0"
-edition = "2018"
+edition = "2021"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 

src/bus.rs

@@ -1,40 +1,38 @@
 use crate::utils::{join_bytes};
 use crate::rom::ROM;
 
-pub enum MemoryMap {
-    BankZero,
-    BankSwitchable,
-    VideoRAM,
-    ExternalRAM,
-    WorkRAM1,
-    WorkRAM2,
-    EchoRAM,
-    SpriteAttributeTable,
-    NotUsable,
-    IORegisters,
-    HighRAM,
-    InterruptEnableRegister,
+pub struct AddressRange {
+    begin: u16,
+    end: u16,
 }
 
-impl MemoryMap {
-    pub fn get_map(address: u16) -> Self {
-        match address {
-            0x0000..=0x3FFF => Self::BankZero,
-            0x4000..=0x7FFF => Self::BankSwitchable,
-            0x8000..=0x9FFF => Self::VideoRAM,
-            0xA000..=0xBFFF => Self::ExternalRAM,
-            0xC000..=0xCFFF => Self::WorkRAM1,
-            0xD000..=0xDFFF => Self::WorkRAM2,
-            0xE000..=0xFDFF => Self::EchoRAM, // Mirror of C000~DDFF
-            0xFE00..=0xFE9F => Self::SpriteAttributeTable,
-            0xFEA0..=0xFEFF => Self::NotUsable,
-            0xFF00..=0xFF7F => Self::IORegisters,
-            0xFF80..=0xFFFE => Self::HighRAM,
-            0xFFFF => Self::InterruptEnableRegister,
-        }
+impl AddressRange {
+    pub fn begin(&self) -> u16 {
+        self.begin
+    }
+
+    pub fn end(&self) -> u16 {
+        self.end
+    }
+
+    pub fn in_range(&self, address: u16) -> bool {
+        address >= self.begin && address <= self.end
     }
 }
 
+pub const BANK_ZERO: AddressRange                 = AddressRange{begin: 0x0000, end: 0x3FFF};
+pub const BANK_SWITCHABLE: AddressRange           = AddressRange{begin: 0x4000, end: 0x7FFF};
+pub const VIDEO_RAM: AddressRange                 = AddressRange{begin: 0x8000, end: 0x9FFF};
+pub const EXTERNAL_RAM: AddressRange              = AddressRange{begin: 0xA000, end: 0xBFFF};
+pub const WORK_RAM_1: AddressRange                = AddressRange{begin: 0xC000, end: 0xCFFF};
+pub const WORK_RAM_2: AddressRange                = AddressRange{begin: 0xD000, end: 0xDFFF};
+pub const ECHO_RAM: AddressRange                  = AddressRange{begin: 0xE000, end: 0xFDFF};
+pub const SPRITE_ATTRIBUTE_TABLE: AddressRange    = AddressRange{begin: 0xFE00, end: 0xFE9F};
+pub const NOT_USABLE: AddressRange                = AddressRange{begin: 0xFEA0, end: 0xFEFF};
+pub const IO_REGISTERS: AddressRange              = AddressRange{begin: 0xFF00, end: 0xFF7F};
+pub const HIGH_RAM: AddressRange                  = AddressRange{begin: 0xFF80, end: 0xFFFE};
+pub const INTERRUPT_ENABLE_REGISTER: AddressRange = AddressRange{begin: 0xFFFF, end: 0xFFFF};
+
 pub struct Bus {
     game_rom: ROM,
     data: [u8; 0x10000],
@@ -62,49 +60,45 @@ impl Bus {
     }
 
     pub fn read(&self, address: u16) -> u8 {
-        match MemoryMap::get_map(address) {
-            MemoryMap::BankZero => self.game_rom.read(address),
-            MemoryMap::BankSwitchable => self.game_rom.read(address),
-            MemoryMap::WorkRAM1 | MemoryMap::WorkRAM2 | MemoryMap::InterruptEnableRegister => self.data[address as usize],
-            MemoryMap::IORegisters => match address {
+        if BANK_ZERO.in_range(address) || BANK_SWITCHABLE.in_range(address) {
+            return self.game_rom.read(address);
+        } else if IO_REGISTERS.in_range(address) {
+            return match address {
                 0xFF44 => 0x90,
                 0xFF4D => 0xFF,
                 _ => self.data[address as usize],
             }
-            _ => self.data[address as usize],
         }
+        self.data[address as usize]
     }
 
     pub fn read_16bit(&self, address: u16) -> u16 {
-        join_bytes(self.read(address + 1), self.read(address))
+        join_bytes(self.read(address.wrapping_add(1)), self.read(address))
     }
 
     pub fn write(&mut self, address: u16, data: u8) {
         if address == 0xFF01 {
             print!("{}", data as char); 
         }
-        match MemoryMap::get_map(address) {
-            MemoryMap::BankZero | MemoryMap::BankSwitchable => {
-                // println!("WRITING TO ROM");
-            },
-            MemoryMap::WorkRAM1 | MemoryMap::WorkRAM2 => {
+
+        if BANK_ZERO.in_range(address) || BANK_SWITCHABLE.in_range(address) {
+            println!("WRITING TO ROM");
+        } else if WORK_RAM_1.in_range(address) || WORK_RAM_2.in_range(address) {
             self.data[address as usize] = data;
             // Copy to the ECHO RAM
             if address <= 0xDDFF {
-                    // self.data[(0xE000 + (address - 0xC000)) as usize] = data;
+                self.data[(ECHO_RAM.begin() + (address - WORK_RAM_1.begin())) as usize] = data;
+            }
+        } else if ECHO_RAM.in_range(address) {
+            self.data[address as usize] = data;
+            self.data[(WORK_RAM_1.begin() + (address - ECHO_RAM.begin())) as usize] = data; // Copy to the working RAM
         }
-            },
-            MemoryMap::EchoRAM => {
         self.data[address as usize] = data;
-                // self.data[(0xC000 + (address - 0xE000)) as usize] = data; // Copy to the working RAM
-            },
-            _ => self.data[address as usize] = data,
-        };
     }
 
     pub fn write_16bit(&mut self, address: u16, data: u16) {
         let bytes = data.to_le_bytes();
         self.write(address, bytes[0]);
-        self.write(address + 1, bytes[1]);
+        self.write(address.wrapping_add(1), bytes[1]);
     }
 }

src/cpu.rs

@@ -227,9 +227,9 @@ impl OpcodeParameterBytes {
     pub fn from_address(address: u16, bus: &Bus)-> OpcodeParameterBytes {
         OpcodeParameterBytes(
             bus.read(address),
-            bus.read(address + 1),
-            bus.read(address + 2),
-            bus.read(address + 3),
+            bus.read(address.wrapping_add(1)),
+            bus.read(address.wrapping_add(2)),
+            bus.read(address.wrapping_add(3)),
         )
     }
 
@@ -872,7 +872,7 @@ impl CPU {
         // self.log(parameter_bytes);
         self.increment_cycles(cycles);
         self.exec(opcode, bus);
-        self.increment_exec_calls_count();
+        // self.increment_exec_calls_count();
     }
 
     pub fn exec(&mut self, opcode: Opcode, bus: &mut Bus) {
@@ -1716,7 +1716,6 @@ impl CPU {
                 self.registers.increment(Register::PC, 2);
             },
             Opcode::NOP => self.registers.increment(Register::PC, 1),
-            // _ => println!("Illegal instruction"),
             Opcode::IllegalInstruction => {panic!("Illegal instruction");},
             _ => {panic!("Illegal instruction");},
         };

src/ppu.rs

@@ -1,7 +1,177 @@
-pub struct PPU;
+use crate::utils::{
+    BitIndex,
+    get_bit,
+    set_bit,
+};
+use crate::bus::{Bus, BANK_ZERO};
 
-impl PPU {
+struct ColorPalette(u8, u8, u8, u8);
+
+struct Tile {
+
+}
+
+struct Sprite {
+}
+
+
+pub enum LCDControl {
+    DisplayEnable,
+    WindowTileMapAddress,
+    WindowEnable,
+    BackgroundWindowTileAddress,
+    BackgroundTileMapAddress,
+    ObjectSize,
+    ObjectEnable,
+    BackgroundPriority,
+}
+
+pub enum LCDStatusModeFlag {
+    HBlank,
+    VBlank,
+    SearchingOAM,
+    TransferringToLCD,
+}
+
+pub enum LCDStatus {
+    LYCInterrupt,
+    Mode2OAMInterrupt,
+    Mode1VBlankInterrupt,
+    Mode0HBlankInterrupt,
+    LYCFlag,
+    ModeFlag(LCDStatusModeFlag),
+}
+
+const LCD_CONTROL_ADDRESS: u16 = 0xFF40;
+const LCD_STATUS_ADDRESS: u16 = 0xFF41;
+
+const SCROLL_X_ADDRESS: u16 = 0xFF42;
+const SCROLL_Y_ADDRESS: u16 = 0xFF43;
+const LCD_Y_ADDRESS: u16 = 0xFF44;
+const LCD_Y_COMPARE_ADDRESS: u16 = 0xFF45;
+const DMA_ADDRESS: u16 = 0xFF46;
+const BACKGROUND_PALETTE_ADDRESS: u16 = 0xFF47;
+const OBJECT_PALETTE_0_ADDRESS: u16 = 0xFF48;
+const OBJECT_PALETTE_1_ADDRESS: u16 = 0xFF49;
+const WINDOW_X_ADDRESS: u16 = 0xFF4A;
+const WINDOW_Y_ADDRESS: u16 = 0xFF4B;
+
+pub struct Window {}
+
+impl Window {
     pub fn new() -> Self {
         Self {}
     }
+
+    fn get_x(bus: &Bus) -> u8 {
+        bus.read(WINDOW_X_ADDRESS)
+    }
+
+    fn set_x(bus: &mut Bus, val: u8) {
+        bus.write(WINDOW_X_ADDRESS, val);
+    }
+
+    fn get_y(bus: &Bus) -> u8 {
+        bus.read(WINDOW_Y_ADDRESS)
+    }
+
+    fn set_y(bus: &mut Bus, val: u8) {
+        bus.write(WINDOW_Y_ADDRESS, val);
+    }
+}
+
+pub struct PPU {
+    window: Window,
+}
+
+impl PPU {
+    pub fn new() -> Self {
+        Self {
+            window: Window::new(),
+        }
+    }
+
+    fn get_sprite(address: u16) {
+
+    }
+
+    fn get_scroll_x(bus: &Bus) -> u8 {
+        bus.read(SCROLL_X_ADDRESS)
+    }
+
+    fn set_scroll_x(bus: &mut Bus, val: u8) {
+        bus.write(SCROLL_X_ADDRESS, val);
+    }
+
+    fn get_scroll_y(bus: &Bus) -> u8 {
+        bus.read(SCROLL_Y_ADDRESS)
+    }
+
+    fn set_scroll_y(bus: &mut Bus, val: u8) {
+        bus.write(SCROLL_Y_ADDRESS, val);
+    }
+
+    fn get_lcd_control(bus: &Bus, control: LCDControl) -> bool {
+        let byte = bus.read(LCD_CONTROL_ADDRESS);
+        match control {
+            LCDControl::DisplayEnable => get_bit(byte, BitIndex::I7),
+            LCDControl::WindowTileMapAddress => get_bit(byte, BitIndex::I6),
+            LCDControl::WindowEnable =>  get_bit(byte, BitIndex::I5),
+            LCDControl::BackgroundWindowTileAddress =>  get_bit(byte, BitIndex::I4),
+            LCDControl::BackgroundTileMapAddress =>  get_bit(byte, BitIndex::I3),
+            LCDControl::ObjectSize =>  get_bit(byte, BitIndex::I2),
+            LCDControl::ObjectEnable =>  get_bit(byte, BitIndex::I1),
+            LCDControl::BackgroundPriority =>  get_bit(byte, BitIndex::I0),
+        }
+    }
+
+    fn set_lcd_control(bus: &mut Bus, control: LCDControl, val: bool) {
+        let mut byte = bus.read(LCD_CONTROL_ADDRESS);
+        byte = match control {
+            LCDControl::DisplayEnable => set_bit(byte, val, BitIndex::I7),
+            LCDControl::WindowTileMapAddress => set_bit(byte, val, BitIndex::I6),
+            LCDControl::WindowEnable => set_bit(byte, val, BitIndex::I5),
+            LCDControl::BackgroundWindowTileAddress => set_bit(byte, val, BitIndex::I4),
+            LCDControl::BackgroundTileMapAddress => set_bit(byte, val, BitIndex::I3),
+            LCDControl::ObjectSize => set_bit(byte, val, BitIndex::I2),
+            LCDControl::ObjectEnable => set_bit(byte, val, BitIndex::I1),
+            LCDControl::BackgroundPriority => set_bit(byte, val, BitIndex::I0),
+        };
+        bus.write(LCD_CONTROL_ADDRESS, byte);
+    }
+
+    fn get_lcd_status(bus: &Bus, status: LCDStatus) -> bool {
+        let byte = bus.read(LCD_STATUS_ADDRESS);
+        match status {
+            LCDStatus::LYCInterrupt => get_bit(byte, BitIndex::I6),
+            LCDStatus::Mode2OAMInterrupt => get_bit(byte, BitIndex::I5),
+            LCDStatus::Mode1VBlankInterrupt => get_bit(byte, BitIndex::I4),
+            LCDStatus::Mode0HBlankInterrupt => get_bit(byte, BitIndex::I3),
+            LCDStatus::LYCFlag => get_bit(byte, BitIndex::I2),
+            LCDStatus::ModeFlag(mode) => match mode {
+                LCDStatusModeFlag::HBlank => (byte & 0b00000011) == 0,
+                LCDStatusModeFlag::VBlank => (byte & 0b00000011) == 1,
+                LCDStatusModeFlag::SearchingOAM => (byte & 0b00000011) == 2,
+                LCDStatusModeFlag::TransferringToLCD => (byte & 0b00000011) == 3,
+            },
+        }
+    }
+
+    fn set_lcd_status(bus: &mut Bus, status: LCDStatus, val: bool) {
+        let mut byte = bus.read(LCD_STATUS_ADDRESS);
+        byte = match status {
+            LCDStatus::LYCInterrupt => set_bit(byte, val, BitIndex::I6),
+            LCDStatus::Mode2OAMInterrupt => set_bit(byte, val, BitIndex::I5),
+            LCDStatus::Mode1VBlankInterrupt => set_bit(byte, val, BitIndex::I4),
+            LCDStatus::Mode0HBlankInterrupt => set_bit(byte, val, BitIndex::I3),
+            LCDStatus::LYCFlag => set_bit(byte, val, BitIndex::I2),
+            LCDStatus::ModeFlag(mode) => match mode {
+                LCDStatusModeFlag::HBlank => (byte & 0b11111100) | 0,
+                LCDStatusModeFlag::VBlank => (byte & 0b11111100) | 1,
+                LCDStatusModeFlag::SearchingOAM => (byte & 0b11111100) | 2,
+                LCDStatusModeFlag::TransferringToLCD => (byte & 0b11111100) | 3,
+            },
+        };
+        bus.write(LCD_STATUS_ADDRESS, byte);
+    }
 }