add wait

python/tvm/micro/contrib/zephyr.py

@@ -30,6 +30,8 @@
 import shutil
 import subprocess
 import sys
+import threading
+import queue
 
 import yaml
 
@@ -630,6 +632,8 @@ def __init__(self, base_dir, startup_timeout_sec=5.0, qemu_debugger=None, **kwar
         self.fd_transport = None
         self.pipe_dir = None
         self.qemu_debugger = qemu_debugger
+        self._queue = queue.Queue()
+        self._qemu_ready_msg = "Qready"
 
     def timeouts(self):
         return TransportTimeouts(
@@ -658,7 +662,9 @@ def open(self):
             ["make", "run", f"QEMU_PIPE={self.pipe}"],
             cwd=self.base_dir,
             **self.kwargs,
+            stdout=subprocess.PIPE,
         )
+        self._wait_for_qemu()
 
         if self.qemu_debugger is not None:
             self.qemu_debugger.start()
@@ -703,6 +709,21 @@ def write(self, data, timeout_sec):
             raise TransportClosedError()
         return self.fd_transport.write(data, timeout_sec)
 
+    def _qemu_check_stdout(self):
+        for line in self.proc.stdout:
+            line = str(line)
+            _LOG.debug(line)
+            if "[QEMU] CPU" in line:
+                self._queue.put(self._qemu_ready_msg)
+                return
+
+    def _wait_for_qemu(self):
+        threading.Thread(target=self._qemu_check_stdout, daemon=True).start()
+        while True:
+            item = self._queue.get()
+            if item == self._qemu_ready_msg:
+                return True
+
 
 class ZephyrDebugger(debugger.GdbDebugger):
     """A Zephyr debugger implementation."""