CLI argument to start the server at startup

src/main.rs

@@ -22,7 +22,11 @@ mod window;
 
 #[derive(Parser)]
 struct Args {
+    /// The path to a virtual boy ROM to run.
     rom: Option<PathBuf>,
+    /// Start a GDB/LLDB debug server on this port.
+    #[arg(short, long)]
+    debug_port: Option<u16>,
 }
 
 fn set_panic_handler() {
@@ -101,6 +105,6 @@ fn main() -> Result<()> {
     let event_loop = EventLoop::with_user_event().build().unwrap();
     event_loop.set_control_flow(ControlFlow::Poll);
     let proxy = event_loop.create_proxy();
-    event_loop.run_app(&mut Application::new(client, proxy))?;
+    event_loop.run_app(&mut Application::new(client, proxy, args.debug_port))?;
     Ok(())
 }