fix: remove manual hw_server management — let Vivado handle it internally

External hw_server start via Popen was unreliable on Windows (Vivado
has its own hw_server lifecycle via open_hw_manager). Simplified to
just run Vivado TCL directly — tested working on Linux (6.9s).

Also bumped default check_env timeout from 120s to 180s for Windows
where Vivado cold-start can take significantly longer.

Removed: _port_open, socket import, manual hw_server Popen/kill logic.

src/config_manager.py

@@ -35,7 +35,7 @@ DEFAULT_CONFIG: dict[str, Any] = {
     "inter_step_delay": 2,
     "boot_wait_delay": 10,
     "step_timeouts": {
-        "check_env": 120,
+        "check_env": 180,
         "flash_erase": 120,
         "flash_program": 600,
         "bitstream": 60,

src/zynq_checker.py

@@ -7,16 +7,14 @@ returning device names, IDCODEs, and PS/PL presence.
 from __future__ import annotations
 
 import re
-import socket
 import subprocess
 import tempfile
-import time
 from dataclasses import dataclass, field
 from pathlib import Path
 from typing import Callable
 
 from config_manager import Config
-from vitis_checker import get_vivado_path, get_hw_server_path, build_tool_command
+from vitis_checker import get_vivado_path, build_tool_command
 
 
 @dataclass
@@ -68,17 +66,6 @@ _ARM_DAP_RE = re.compile(r"^arm_dap", re.IGNORECASE)
 HW_SERVER_PORT = 3121
 
 
-# ── Helpers ───────────────────────────────────────────────────────────
-
-def _port_open(host: str = "localhost", port: int = HW_SERVER_PORT) -> bool:
-    """Check if a TCP port is accepting connections."""
-    try:
-        with socket.create_connection((host, port), timeout=1):
-            return True
-    except OSError:
-        return False
-
-
 def _idcode_to_hex(binary_str: str) -> str:
     """Convert Vivado's binary IDCODE to uppercase hex."""
     try:
@@ -94,10 +81,9 @@ def check_zynq_jtag(
 ) -> ZynqCheckResult:
     """Check for Zynq devices on the JTAG chain via Vivado + hw_server.
 
-    Lifecycle:
+    Vivado manages hw_server internally — open_hw_manager auto-starts
-      1. If hw_server is already running (port 3121 open) → reuse it
+    the hardware server and connect_hw_server connects to it. No manual
-      2. If not running → start it, kill it when done
+    hw_server lifecycle needed.
-      3. Run Vivado batch TCL to enumerate JTAG devices
 
     Args:
         config: Application configuration.
@@ -112,7 +98,7 @@ def check_zynq_jtag(
     if callback:
         callback("start", "Connecting to hw_server...")
 
-    # ── 1. Find tools ──────────────────────────────────────────
+    # ── 1. Find Vivado ──────────────────────────────────────────
     vivado_path = get_vivado_path(xilinx_root=xilinx_root)
     if not vivado_path:
         return ZynqCheckResult(
@@ -122,46 +108,7 @@ def check_zynq_jtag(
             error="Vivado not found",
         )
 
-    hw_server_path = get_hw_server_path(xilinx_root=xilinx_root)
+    # ── 2. Run Vivado TCL (manages hw_server internally) ────────
-    hw_server_was_running = _port_open()
-
-    # ── 2. Start hw_server if needed ───────────────────────────
-    hw_proc: subprocess.Popen | None = None
-    if not hw_server_was_running:
-        if not hw_server_path:
-            return ZynqCheckResult(
-                devices=[], jtag_chain=[], is_present=False,
-                ps_detected=False, pl_detected=False,
-                hw_server_url=hw_server_url,
-                error="hw_server not found — install Vivado/Vitis",
-            )
-        try:
-            hw_proc = subprocess.Popen(
-                build_tool_command(hw_server_path),
-                stdout=subprocess.DEVNULL,
-                stderr=subprocess.DEVNULL,
-            )
-            # Wait for port to become available
-            for _ in range(30):  # 3s max
-                if _port_open():
-                    break
-                time.sleep(0.1)
-            else:
-                return ZynqCheckResult(
-                    devices=[], jtag_chain=[], is_present=False,
-                    ps_detected=False, pl_detected=False,
-                    hw_server_url=hw_server_url,
-                    error="hw_server started but port 3121 not open",
-                )
-        except OSError as e:
-            return ZynqCheckResult(
-                devices=[], jtag_chain=[], is_present=False,
-                ps_detected=False, pl_detected=False,
-                hw_server_url=hw_server_url,
-                error=f"Failed to start hw_server: {e}",
-            )
-
-    # ── 3. Run Vivado TCL ──────────────────────────────────────
     try:
         tcl = _build_jtag_query_tcl()
         if callback:
@@ -216,17 +163,6 @@ def check_zynq_jtag(
             hw_server_url=hw_server_url,
             error=f"OS error: {e}",
         )
-    finally:
-        # ── 4. Kill hw_server only if WE started it ────────────
-        if hw_proc is not None and hw_proc.poll() is None:
-            try:
-                hw_proc.terminate()
-                hw_proc.wait(timeout=3)
-            except subprocess.TimeoutExpired:
-                hw_proc.kill()
-                hw_proc.wait()
-            except OSError:
-                pass
 
 
 # ── TCL builder ────────────────────────────────────────────────────────