Small refactor and define rom trait

snes-core/src/cpu/instructions.rs

@@ -1,5 +1,5 @@
 use super::cpu::CPU;
-use crate::bus::Bus;
+use crate::cpu::bus::Bus;
 use crate::utils::addressing::{AddressingMode, IndexRegister};
 use crate::utils::alu;
 use crate::utils::num_trait::SnesNum;
@@ -1098,6 +1098,11 @@ impl CPU {
         self.increment_cycles_test(addressing_mode);
     }
 
+    pub fn run(&mut self, bus: &mut Bus) {
+        let opcode = bus.read(self.registers.get_pc_address());
+        self.execute_opcode(opcode, bus);
+    }
+
     pub fn execute_opcode(&mut self, opcode: u8, bus: &mut Bus) {
         type A = AddressingMode;
         type I = IndexRegister;

snes-core/src/cpu/mod.rs

@@ -1,4 +1,6 @@
 pub mod cpu;
+pub use cpu::CPU;
+pub mod bus;
 pub mod registers;
 pub mod instructions;
 pub mod cycles;

snes-core/src/emulator.rs

@@ -0,0 +1,24 @@
+use crate::cpu::CPU;
+use crate::cpu::bus::Bus;
+use crate::rom::ROM;
+use crate::rom::lo_rom::LoROM;
+
+pub struct Emulator {
+    cpu: CPU,
+    bus: Bus,
+    pub rom: Box<dyn ROM>,
+}
+
+impl Emulator {
+    pub fn new() -> Self {
+        Self {
+            cpu: CPU::new(),
+            bus: Bus::new(),
+            rom: Box::new(LoROM::new()),
+        }
+    }
+
+    pub fn run(&mut self) {
+        self.cpu.run(&mut self.bus);
+    }
+}

snes-core/src/lib.rs

@@ -1,4 +1,5 @@
 pub mod cpu;
-pub mod bus;
+pub mod rom;
 pub mod utils;
 pub mod common;
+pub mod emulator;

snes-core/src/rom/lo_rom.rs

@@ -0,0 +1,28 @@
+use super::{ROM, load_rom};
+
+pub struct LoROM {
+    data: Vec<u8>,
+}
+
+impl LoROM {
+    pub fn new() -> Self {
+        Self {
+            data: vec![],
+        }
+    }
+}
+
+impl ROM for LoROM {
+    fn load(&mut self, filename: &String) -> std::io::Result<bool> {
+        load_rom(filename, &mut self.data)
+    }
+
+    fn read(&self, address: u32) -> u8 {
+        match self.data.get(address as usize) {
+            Some(byte) => *byte,
+            None => 0xFF,
+        }
+    }
+
+    fn write(&mut self, _address: u32, _value: u8) {}
+}

snes-core/src/rom/mod.rs

@@ -0,0 +1,17 @@
+pub mod lo_rom;
+
+use std::fs::File;
+use std::io::Read;
+
+pub fn load_rom(filename: &String, target: &mut Vec<u8>) -> std::io::Result<bool> {
+    let mut file = File::open(filename)?;
+    file.read_to_end(target)?;
+    // TODO: header checksum here
+    Ok(true)
+}
+
+pub trait ROM {
+    fn load(&mut self, filename: &String) -> std::io::Result<bool>;
+    fn read(&self, address: u32) -> u8;
+    fn write(&mut self, address: u32, value: u8);
+}

snes-core/src/utils/addressing.rs

@@ -1,4 +1,4 @@
-use crate::bus::Bus;
+use crate::cpu::bus::Bus;
 
 /// OPCODE #const
 pub fn immediate(pc_addr: u32) -> u32 {