first working CPU implementation with 3 op codes

src/main.rs

@@ -1,6 +1,18 @@
 mod cartridge;
 mod bus;
+mod cpu;
+
+use crate::bus::{Bus, NesBus};
+use crate::cartridge::Cartridge;
+use crate::cpu::Cpu;
 
 fn main() {
-    println!("Hello, world!");
+    let cart: Cartridge = Cartridge::from_file("roms/test/cpu/nestest/nestest.nes").unwrap();
+    let mut bus: NesBus = NesBus::new(cart);
+    let mut cpu = Cpu::new();
+    cpu.set_test_start(0xC000, 7);
+    loop {
+        println!("{}", cpu.trace(&mut bus));
+        cpu.step(&mut bus);
+    }
 }