ffx-uart-driver

This directory contains the ffx-uart-driver host tool. It acts as a background daemon that handles communication between ffx client tools (like ffx-uart) and Fuchsia devices connected via UART.

The driver runs as a background process, manages multiplexing, provides reliability protocols (like acknowledgments and retransmissions), and exposes metrics via a control UNIX socket.

Directory Structure and Files

• BUILD.gn: Defines the GN build rules for compiling the ffx_uart_host_driver library and the ffx-uart-driver binary.
• src/main.rs: The entry point for the ffx-uart-driver executable. It initializes the build version info and runs the driver.
• src/lib.rs: Contains the CLI driver execution framework. It handles argument parsing, background execution supervision, setting up log sinks, managing log rotation, binding the main UNIX socket, writing connection metadata, and invoking the core driver implementation.
• impl/BUILD.gn: Compiles the core driver logic into the uart_driver_impl library.
• impl/src/adapters.rs: Implements FDomainTransport, providing packetized message framing over asynchronous Tokio streams for the fdomain-client library.
• impl/src/lib.rs: The implementation core of the driver daemon. Handles socket creation, orphaned process detection and cleanup, routing messages between clients and the serial port, executing the ResendSP protocol framing and reliability state machines, querying target identity over FDomain, and serving metrics on a .control socket.