cmd/buildlet/stage0/stage0_windows.go

// Copyright 2017 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package main

import (
	"io"
	"log"
	"os"

	"github.com/tarm/serial"
)

func init() {
	configureSerialLogOutput = configureSerialLogOutputWindows
	closeSerialLogOutput = closeSerialLogOutputWindows
}

var com1 *serial.Port

func configureSerialLogOutputWindows() {
	c := &serial.Config{Name: "COM1", Baud: 9600}
	var err error
	com1, err = serial.OpenPort(c)
	if err != nil {
		// Oh well, we tried. This empirically works
		// on Windows on GCE.
		// We can log here anyway and hope somebody sees it
		// in a GUI console:
		log.Printf("serial.OpenPort: %v", err)
		return
	}
	log.SetOutput(io.MultiWriter(com1, os.Stderr))
}

func closeSerialLogOutputWindows() {
	if com1 != nil {
		com1.Close()
		com1 = nil
		log.SetOutput(os.Stderr)
	}
}