Track HALT

src/emulator/shrooms_vb_core.rs

@@ -210,7 +210,7 @@ extern "C" fn on_execute(sim: *mut VB, address: u32, code: *const u16, length: c
         }
     }
 
-    let mut stopped = data.stop_reason.is_some();
+    let mut stopped = data.stop_reason.is_some() || data.monitor.event.is_some();
     if data.step_from.is_some_and(|s| s != address) {
         data.step_from = None;
         data.stop_reason = Some(StopReason::Stepped);
@@ -247,7 +247,13 @@ extern "C" fn on_exception(sim: *mut VB, cause: *mut u16) -> c_int {
     // There is no way for the userdata to be null or otherwise invalid.
     let data: &mut VBState = unsafe { &mut *vb_get_user_data(sim).cast() };
     data.monitor.event = data.monitor.queued_event.take();
-    data.monitor.queued_event = Some(SimEvent::Interrupt(unsafe { *cause }));
+    let cause = unsafe { *cause };
+    let pc = if cause == 0xff70 {
+        0xffffff60
+    } else {
+        (cause & 0xfff0) as u32 | 0xffff0000
+    };
+    data.monitor.queued_event = Some(SimEvent::Interrupt(cause, pc));
     unsafe { vb_set_exception_callback(sim, None) };
     unsafe { vb_set_fetch_callback(sim, Some(on_fetch)) };
     if data.monitor.event.is_some() { 1 } else { 0 }
@@ -319,7 +325,8 @@ extern "C" fn on_write(
 pub enum SimEvent {
     Call(u32),
     Return,
-    Interrupt(u16),
+    Halt,
+    Interrupt(u16, u32),
     Reti,
 }
 
@@ -327,6 +334,7 @@ struct EventMonitor {
     enabled: bool,
     event: Option<SimEvent>,
     queued_event: Option<SimEvent>,
+    just_halted: bool,
 }
 
 impl EventMonitor {
@@ -335,6 +343,7 @@ impl EventMonitor {
             enabled: false,
             event: None,
             queued_event: None,
+            just_halted: false,
         }
     }
 
@@ -343,7 +352,8 @@ impl EventMonitor {
         self.queued_event.is_some()
     }
 
-    fn do_detect_event(&self, sim: *mut VB, address: u32, code: &[u16]) -> Option<SimEvent> {
+    fn do_detect_event(&mut self, sim: *mut VB, address: u32, code: &[u16]) -> Option<SimEvent> {
+        const HALT_OPCODE: u16 = 0b011010;
         const JAL_OPCODE: u16 = 0b101011;
         const JMP_OPCODE: u16 = 0b000110;
         const RETI_OPCODE: u16 = 0b011001;
@@ -359,6 +369,18 @@ impl EventMonitor {
 
         let opcode = code[0] >> 10;
 
+        if opcode == HALT_OPCODE {
+            if !self.just_halted {
+                self.just_halted = true;
+                self.event = Some(SimEvent::Halt);
+            } else {
+                self.just_halted = false;
+            }
+            // Don't _return_ an event, we want to emit this right away.
+            // If the CPU is halting, no other callbacks will run for a long time.
+            return None;
+        }
+
         if opcode == JAL_OPCODE {
             let disp = format_iv_disp(code);
             if disp != 4 {