Add M5Stack CoreS3 support

pio-scripts/cores3_upload_watchdog_reset.py

@@ -0,0 +1,51 @@
+# M5Stack CoreS3 upload reset stabilization
+#
+# Purpose:
+#   ESP32-S3 native USB / USB-Serial-JTAG uploads can occasionally remain
+#   in download mode after PlatformIO's default RTS hard reset.
+#
+# PlatformIO's ESP32 builder constructs esptool's --after argument from:
+#   board.get("upload.after_reset", "hard_reset")
+#
+# Set that board option early, before the platform builder creates
+# UPLOADERFLAGS. This changes only the post-upload reset method.
+#
+# Expected esptool behavior:
+#   --after watchdog-reset
+#
+# No firmware source, build flag, partition, PSRAM, flash, or runtime
+# behavior is modified by this script.
+
+Import("env")
+
+TARGET_RESET_METHOD = "watchdog-reset"
+
+
+def configure_upload_reset():
+    board = env.BoardConfig()
+    previous = board.get("upload.after_reset", "hard_reset")
+
+    if previous == TARGET_RESET_METHOD:
+        print(
+            "[CoreS3 Upload] post-upload reset already set to "
+            f"{TARGET_RESET_METHOD}"
+        )
+        return
+
+    board.update("upload.after_reset", TARGET_RESET_METHOD)
+
+    effective = board.get("upload.after_reset", "")
+    if effective != TARGET_RESET_METHOD:
+        raise RuntimeError(
+            "CoreS3 upload reset configuration failed: "
+            f"expected {TARGET_RESET_METHOD}, got {effective}"
+        )
+
+    print(
+        "[CoreS3 Upload] post-upload reset: "
+        f"{previous} -> {TARGET_RESET_METHOD}"
+    )
+
+
+if not env.IsIntegrationDump():
+    configure_upload_reset()