When writing a value to IO 0 to force emulator exit, the exit status …

…code will be taken from the value written

Cargo.toml

@@ -2,7 +2,7 @@
 members = ["agon-light-emulator-debugger"]
 
 [workspace.package]
-version = "0.9.74"
+version = "0.9.75"
 edition = "2021"
 authors = ["Tom Morton <[email protected]>"]
 license = "GPL-3.0"

README.md

@@ -68,11 +68,11 @@ emulator from), type `help` for instructions on the use of the debugger.
 Some IO addresses unused by the EZ80F92 are used by the emulator for debugging
 purposes:
 
-| IO addresses  | Function                              |
-| ------------- | ------------------------------------- |
-| 0x00          | Terminate emulator                    |
-| 0x10-0x1f     | Breakpoint (requires --debugger)      |
-| 0x20-0x2f     | Print CPU state (requires --debugger) |
+| IO addresses  | Function                                                           |
+| ------------- | ------------------------------------------------------------------ |
+| 0x00          | Terminate emulator (exit code will be the value written to IO 0x0) |
+| 0x10-0x1f     | Breakpoint (requires --debugger)                                   |
+| 0x20-0x2f     | Print CPU state (requires --debugger)                              |
 
 These functions are activated by write (not read), and the upper 8-bits of the
 IO address are ignored. ie:

agon-ez80-emulator/src/agon_machine.rs

@@ -33,6 +33,7 @@ pub struct AgonMachine {
     paused: Arc<std::sync::atomic::AtomicBool>,
     soft_reset: Arc<std::sync::atomic::AtomicBool>,
     emulator_shutdown: Arc<std::sync::atomic::AtomicBool>,
+    exit_status: Arc<std::sync::atomic::AtomicI32>,
     clockspeed_hz: u64,
     prt_timers: [prt_timer::PrtTimer; 6],
     gpios: Arc<Mutex<gpio::GpioSet>>,
@@ -464,10 +465,16 @@ impl Machine for AgonMachine {
                 // Discard high byte of address, so we can use `out (n),a`
                 // for debugging
                 if address & 0xff == 0 {
-                    println!("Emulator shutdown triggered by write to IO 0x0");
+                    println!(
+                        "Emulator shutdown triggered by writing 0x{:x} IO 0x0",
+                        value
+                    );
+                    self.exit_status
+                        .store(value as i32, std::sync::atomic::Ordering::Relaxed);
                     self.emulator_shutdown
                         .store(true, std::sync::atomic::Ordering::Relaxed);
                 } else {
+                    // the debugger will handle some of these
                     self.io_unhandled.set(Some(address));
                 }
             }
@@ -480,6 +487,7 @@ pub struct AgonMachineConfig {
     pub uart1_link: Box<dyn uart::SerialLink>,
     pub soft_reset: Arc<std::sync::atomic::AtomicBool>,
     pub emulator_shutdown: Arc<std::sync::atomic::AtomicBool>,
+    pub exit_status: Arc<std::sync::atomic::AtomicI32>,
     pub paused: Arc<std::sync::atomic::AtomicBool>,
     pub clockspeed_hz: u64,
     pub ram_init: RamInit,
@@ -505,6 +513,7 @@ impl AgonMachine {
             mos_current_dir: MosPath(std::path::PathBuf::new()),
             soft_reset: config.soft_reset,
             emulator_shutdown: config.emulator_shutdown,
+            exit_status: config.exit_status,
             clockspeed_hz: config.clockspeed_hz,
             prt_timers: [
                 prt_timer::PrtTimer::new(),

src/main.rs

@@ -51,8 +51,14 @@ pub fn firmware_paths(
     paths
 }
 
-pub fn main() -> Result<(), pico_args::Error> {
-    let args = parse_args()?;
+pub fn main() -> () {
+    let args = match parse_args() {
+        Ok(a) => a,
+        Err(e) => {
+            eprintln!("Error parsing arguments: {}", e);
+            std::process::exit(-1);
+        }
+    };
     let vdp_interface = vdp_interface::init(
         firmware_paths(args.firmware, args.vdp_dll, false),
         args.verbose,
@@ -71,6 +77,7 @@ pub fn main() -> Result<(), pico_args::Error> {
     let ez80_paused = std::sync::Arc::new(std::sync::atomic::AtomicBool::new(false));
     let emulator_shutdown = std::sync::Arc::new(std::sync::atomic::AtomicBool::new(false));
     let soft_reset = std::sync::Arc::new(std::sync::atomic::AtomicBool::new(false));
+    let exit_status = std::sync::Arc::new(std::sync::atomic::AtomicI32::new(0));
 
     for breakpoint in &args.breakpoints {
         let trigger = Trigger {
@@ -124,6 +131,7 @@ pub fn main() -> Result<(), pico_args::Error> {
         });
 
     let _cpu_thread = {
+        let _exit_status = exit_status.clone();
         let _ez80_paused = ez80_paused.clone();
         let _emulator_shutdown = emulator_shutdown.clone();
         let soft_reset_ez80 = soft_reset.clone();
@@ -181,6 +189,7 @@ pub fn main() -> Result<(), pico_args::Error> {
                     gpios: gpios_,
                     soft_reset: soft_reset_ez80,
                     emulator_shutdown: _emulator_shutdown,
+                    exit_status: _exit_status,
                     paused: _ez80_paused,
                     clockspeed_hz: if args.unlimited_cpu {
                         1000_000_000
@@ -617,7 +626,7 @@ pub fn main() -> Result<(), pico_args::Error> {
     }
     std::thread::sleep(std::time::Duration::from_millis(200));
 
-    Ok(())
+    std::process::exit(exit_status.load(std::sync::atomic::Ordering::Relaxed))
 }
 
 fn calc_int_scale(canvas_size: (u32, u32), agon_size: (u32, u32)) -> (u32, u32) {