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…er (#52) Stabilize the pylink-square MCP server (crashes caused by repeated J-Link DLL load / USB connect-disconnect on every tool call) by connecting all J-Link tools through a persistent localhost J-Link Remote Server on port 19020, and have mcp_server.py launch that daemon when it isn't listening. AI-authored (deepseek-v4-flash-free, 4k context) — researched SEgger KB, designed/implemented: - jlink_connection.py: shared --remote-host/--remote-port/--direct args and a connect() that opens via jlink.open(ip_addr=host:port) with direct-USB fallback. - Converted all 13 J-Link tool scripts to the shared helper. - mcp_server.py: spawns JLinkRemoteServer -Port <port> [-USB <serial>] on startup if not already listening (persists across MCP restarts), routes every tool call through it via --remote-host/--remote-port; added --device/--speed/--remote-port/--usb-serial with JLINK_MCP_* env fallbacks. - .gitignore/gotcha/PLAN/README docs. Human review: chose the localhost-server default, confirmed port 19020, provided the Remote Server launch options, and requested serial numbers not appear in examples/commits. Verified live on hardware through the tunnel: debug_target, run_for, rtt_read --continuous. Host LLVM build + all 18 unit tests pass; no C++ sources touched.
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Closes #52
Problem
The pylink-square MCP server crashes periodically. Every tool call created a
fresh
pylink.JLink(), opened USB, connected, and discarded it — repeatedJ-Link DLL load / USB connect-disconnect churn inside a long-lived process.
Change
All 13 J-Link tools now connect through a persistent localhost J-Link
Remote Server (default
127.0.0.1:19020) instead of opening USB per call.mcp_server.pylaunches the daemon on startup when nothing is listening andintentionally leaves it running across MCP restarts.
jlink_connection.py(new): shared--remote-host/--remote-port/--directargs +
connect()viajlink.open(ip_addr="host:port")with direct-USBfallback.
mcp_server.py:ensure_remote_server()spawnsJLinkRemoteServer -Port <port> [-USB <serial>]; every handler routesthrough it with
--remote-host/--remote-port; new--device/--speed/--remote-port/--usb-serialCLI withJLINK_MCP_*envfallbacks.
Verification
debug_target,run_for --seconds 2,rtt_read --continuous 4all connect/read correctly.(cross presets unaffected; CI will still validate).