fpgaZeroMCP

Instructions

Implementation Reference

• tools/litex.py:82-88 (handler)

  Main handler function for litex_flow tool - a generic LiteX flow runner that accepts board, args, and timeout parameters and delegates to _run_litex helper

  def litex_flow(
      board: str,
      args: list[str] | None = None,
      timeout: int = 600,
  ) -> dict:
      """Generic LiteX flow runner with caller-provided args."""
      return _run_litex(board, args or [], timeout)

• tools/litex.py:17-32 (helper)

  Core helper function _run_litex that executes the LiteX command using subprocess, handles errors, timeouts, and returns structured results

  def _run_litex(board: str, args: list[str] | None, timeout: int) -> dict:
      cmd = _build_litex_cmd(board, args)
      try:
          result = subprocess.run(
              cmd, capture_output=True, text=True, timeout=timeout
          )
          return {
              "success": result.returncode == 0,
              "cmd": cmd,
              "stdout": result.stdout,
              "stderr": result.stderr,
          }
      except FileNotFoundError:
          return {"success": False, "error": "LiteX entrypoint not found."}
      except subprocess.TimeoutExpired:
          return {"success": False, "error": f"LiteX timed out after {timeout} s."}

• tools/litex.py:11-14 (helper)

  Helper function _build_litex_cmd that constructs the LiteX command line invocation

  def _build_litex_cmd(board: str, args: list[str] | None) -> list[str]:
      if not board:
          raise ValueError("board is required")
      return [sys.executable, "-m", f"litex_boards.targets.{board}"] + (args or [])

• server.py:377-397 (registration)

  Tool registration defining litex_flow with its input schema (board, args, timeout parameters) and description

  types.Tool(
      name="litex_flow",
      description="Run a generic LiteX board target with caller-provided args.",
      inputSchema={
          "type": "object",
          "properties": {
              "board": {"type": "string", "description": "LiteX board target"},
              "args": {
                  "type": "array",
                  "items": {"type": "string"},
                  "description": "Extra LiteX CLI args",
              },
              "timeout": {
                  "type": "integer",
                  "default": 600,
                  "description": "Timeout in seconds",
              },
          },
          "required": ["board"],
      },
  ),

• server.py:510-516 (handler)

  Tool dispatch handler that invokes litex_flow via asyncio.to_thread with arguments from the MCP request

  case "litex_flow":
      result = await asyncio.to_thread(
          litex_flow,
          board=arguments["board"],
          args=arguments.get("args"),
          timeout=arguments.get("timeout", 600),
      )