✨ feat(uart): add UART availability check, inter-step delays, and post-download Zynq status verification

- Add check_uart_available() to serial_monitor.py — detects port availability
- Add verify_zynq_status() to boot_verifier.py — lightweight post-download check
- Add uart_delay / inter_step_delay config fields (defaults: 3s / 2s)
- Step 1: Check UART availability, show non-blocking 'UART 不可用' notification
- Step 4: Add post-download Zynq status check (ping + serial) after TFTP
- _run_steps_worker: Add configurable inter-step delays between all steps
- Update step labels (4a→4b→4c→4d) for clarity

src/gui/main_window.py

@@ -21,8 +21,8 @@ from bitstream_programmer import full_bitstream_program, BitstreamResult
 from ip_verifier import ping_ip
 from tftp_manager import tftp_upload_verify, TftpResult
 from reboot_manager import reboot_zynq, RebootResult
-from boot_verifier import verify_boot, BootVerificationResult
-from serial_monitor import detect_serial_ports, parse_boot_output
+from boot_verifier import verify_boot, verify_zynq_status, BootVerificationResult
+from serial_monitor import detect_serial_ports, parse_boot_output, check_uart_available
 from gui.styles import (
     WINDOW_WIDTH,
     WINDOW_HEIGHT,
@@ -73,6 +73,8 @@ class MainWindow(ctk.CTk):
         self._step_statuses: dict[int, str] = {}
         self._is_running = False
         self._worker_thread: threading.Thread | None = None
+        self._uart_available: bool = False
+        self._uart_message: str = ""
 
         self._load_config()
         self._build_ui()
@@ -471,7 +473,7 @@ class MainWindow(ctk.CTk):
     # ── Step Implementations ───────────────────────────────────
 
     def _run_step_1_check_environment(self) -> bool:
-        """Step 1: Check environment (Vitis/Vivado tools + Zynq IP)."""
+        """Step 1: Check environment (Vitis/Vivado tools + Zynq IP + UART)."""
         self._log_message("Step 1: Checking environment...")
 
         if not self._config:
@@ -507,8 +509,35 @@ class MainWindow(ctk.CTk):
             self._ip_status.configure(text=f"IP: {ip} ✗", text_color=DANGER_COLOR)
             return False
 
+        # Check UART availability
+        self._log_message("  Checking UART serial port...")
+        port = self._config.serial_port
+        if port:
+            available, reason = check_uart_available(port, self._config.serial_baudrate)
+            self._uart_available = available
+            self._uart_message = reason
+            if available:
+                self._log_message(f"  ✓ UART available: {reason}")
+            else:
+                self._log_message(f"  ✗ UART unavailable: {reason}")
+                self._show_uart_notification(reason)
+        else:
+            self._uart_available = False
+            self._uart_message = "No serial port configured"
+            self._log_message("  ✗ No serial port configured")
+            self._show_uart_notification(self._uart_message)
+
         return True
 
+    def _show_uart_notification(self, reason: str) -> None:
+        """Show a non-blocking UART unavailable notification in the status panel.
+
+        Args:
+            reason: Why UART is unavailable.
+        """
+        msg = f"UART 不可用 ({reason})，日志分析及检查将禁用"
+        self.after(0, lambda: self._status.set_status(msg, "warning"))
+
     def _run_step_2_program_flash(self) -> bool:
         """Step 2: Program and verify Flash."""
         if not self._config:
@@ -606,8 +635,21 @@ class MainWindow(ctk.CTk):
             self._log_message("  Skipping reboot & boot verify (TFTP failed)")
             return False
 
-        # 4b: Reboot
-        self._log_message("Step 4b: Rebooting Zynq...")
+        # 4a2: Post-download Zynq status check
+        self._log_message("Step 4b: Checking Zynq status after download...")
+        try:
+            zynq_status = verify_zynq_status(
+                self._config,
+                uart_available=self._uart_available,
+                callback=self._zynq_status_callback,
+            )
+            status = "✓" if zynq_status.success else "✗"
+            self._log_message(f"  {status} {zynq_status.message}")
+        except Exception as e:
+            self._log_message(f"  ✗ Zynq status check error: {e}")
+
+        # 4c: Reboot
+        self._log_message("Step 4c: Rebooting Zynq...")
         try:
             reboot_result = reboot_zynq(
                 self._config,
@@ -625,8 +667,8 @@ class MainWindow(ctk.CTk):
             self._log_message("  Skipping boot verify (reboot failed)")
             return False
 
-        # 4c: Verify boot
-        self._log_message("Step 4c: Verifying boot...")
+        # 4d: Verify boot
+        self._log_message("Step 4d: Verifying boot...")
         try:
             boot_result = verify_boot(
                 self._config,
@@ -659,6 +701,10 @@ class MainWindow(ctk.CTk):
         """Callback for boot verification progress."""
         self._log_message(f"  [{status}] {message}")
 
+    def _zynq_status_callback(self, status: str, message: str) -> None:
+        """Callback for post-download Zynq status check."""
+        self._log_message(f"  [{status}] {message}")
+
     # ── Run All Steps ──────────────────────────────────────────
 
     def _update_step_dependencies(self) -> None:
@@ -781,6 +827,12 @@ class MainWindow(ctk.CTk):
             if start_index == 0 and not success:
                 break
 
+            # Inter-step delay (skip after last step)
+            if i < len(step_funcs) - 1:
+                delay = self._config.inter_step_delay if self._config else 2
+                self._log_message(f"  ⏳ Waiting {delay}s before next step...")
+                time.sleep(delay)
+
         self._progress.set_value(1.0)
         self._is_running = False
         self._run_btn.configure(state="normal", text="▶ Run All Steps")