flashtool: use recommended asyncio entry point

Signed-off-by:  Eric Callahan <arksine.code@gmail.com>

scripts/flashtool.py

@@ -17,6 +17,7 @@ import hashlib
 import pathlib
 import shutil
 import shlex
+import contextlib
 from typing import Dict, List, Optional, Union
 HAS_SERIAL = True
 try:
@@ -586,9 +587,12 @@ class SerialSocket:
             pid = fd_dir.parent.name
             if not pid.isdigit():
                 continue
-            try:
+            with contextlib.suppress(OSError):
                 for item in fd_dir.iterdir():
-                    item_st = item.stat()
+                    try:
+                        item_st = item.stat()
+                    except OSError:
+                        continue
                     item_id = (item_st.st_dev, item_st.st_ino)
                     if item_id == dev_id:
                         proc_name = await self._lookup_proc_name(pid)
@@ -598,8 +602,6 @@ class SerialSocket:
                             f"Process {proc_name}"
                         )
                         raise FlashError(f"Serial device {dev_path} in use")
-            except PermissionError:
-                continue
 
     async def run(self, intf: str, baud: int, fw_path: pathlib.Path) -> None:
         if not fw_path.is_file():
@@ -633,7 +635,59 @@ class SerialSocket:
         self.serial.close()
         self.serial = None
 
-def main():
+async def main(args: argparse.Namespace) -> int:
+    if not args.verbose:
+        logging.getLogger().setLevel(logging.ERROR)
+    intf = args.interface
+    fpath = pathlib.Path(args.firmware).expanduser().resolve()
+    loop = asyncio.get_running_loop()
+    iscan = args.device is None
+    req_only = args.request_bootloader
+    sock: CanSocket | SerialSocket | None = None
+    try:
+        if iscan:
+            sock = CanSocket(loop)
+            if args.query:
+                await sock.run_query(intf)
+            else:
+                if args.uuid is None:
+                    raise FlashError(
+                        "The 'uuid' option must be specified to flash a device"
+                    )
+                output_line(f"Flashing CAN UUID {args.uuid} on interface {intf}")
+                uuid = int(args.uuid, 16)
+                await sock.run(intf, uuid, fpath, req_only)
+        else:
+            if not HAS_SERIAL:
+                ser_inst_cmd = "pip3 install serial"
+                if shutil.which("apt") is not None:
+                    ser_inst_cmd = "sudo apt install python3-serial"
+                raise FlashError(
+                    "The pyserial python package was not found.  To install "
+                    "run the following command in a terminal: \n\n"
+                    f"   {ser_inst_cmd}\n\n"
+                )
+            if args.device is None:
+                raise FlashError(
+                    "The 'device' option must be specified to flash a device"
+                )
+            output_line(f"Flashing Serial Device {args.device}, baud {args.baud}")
+            sock = SerialSocket(loop)
+            await sock.run(args.device, args.baud, fpath)
+    except Exception:
+        logging.exception("Flash Error")
+        return -1
+    finally:
+        if sock is not None:
+            sock.close()
+    if args.query:
+        output_line("Query Complete")
+    else:
+        output_line("Flash Success")
+    return 0
+
+
+if __name__ == '__main__':
     parser = argparse.ArgumentParser(
         description="Katapult Flash Tool")
     parser.add_argument(
@@ -670,55 +724,4 @@ def main():
     )
 
     args = parser.parse_args()
-    if not args.verbose:
-        logging.getLogger().setLevel(logging.ERROR)
-    intf = args.interface
-    fpath = pathlib.Path(args.firmware).expanduser().resolve()
-    loop = asyncio.get_event_loop()
-    iscan = args.device is None
-    req_only = args.request_bootloader
-    sock = None
-    try:
-        if iscan:
-            sock = CanSocket(loop)
-            if args.query:
-                loop.run_until_complete(sock.run_query(intf))
-            else:
-                if args.uuid is None:
-                    raise FlashError(
-                        "The 'uuid' option must be specified to flash a device"
-                    )
-                output_line(f"Flashing CAN UUID {args.uuid} on interface {intf}")
-                uuid = int(args.uuid, 16)
-                loop.run_until_complete(sock.run(intf, uuid, fpath, req_only))
-        else:
-            if not HAS_SERIAL:
-                ser_inst_cmd = "pip3 install serial"
-                if shutil.which("apt") is not None:
-                    ser_inst_cmd = "sudo apt install python3-serial"
-                raise FlashError(
-                    "The pyserial python package was not found.  To install "
-                    "run the following command in a terminal: \n\n"
-                    f"   {ser_inst_cmd}\n\n"
-                )
-            if args.device is None:
-                raise FlashError(
-                    "The 'device' option must be specified to flash a device"
-                )
-            output_line(f"Flashing Serial Device {args.device}, baud {args.baud}")
-            sock = SerialSocket(loop)
-            loop.run_until_complete(sock.run(args.device, args.baud, fpath))
-    except Exception:
-        logging.exception("Flash Error")
-        sys.exit(-1)
-    finally:
-        if sock is not None:
-            sock.close()
-    if args.query:
-        output_line("Query Complete")
-    else:
-        output_line("Flash Success")
-
-
-if __name__ == '__main__':
-    main()
+    exit(asyncio.run(main(args)))