用golang实现zmodem协议

实现ZMODEM协议可以使用Go语言的串口通信库和文件读写库。以下是一个基本的实现示例：

package main

import (
	"bytes"
	"fmt"
	"github.com/pkg/term"
	"io"
	"os"
	"time"
)

const (
	CRBREAK = 0x00000003
	CRCNEXT = 0x00000080
	CRCEOT  = 0x00000004
	CRCG    = 0x00000007
	CRCPAD  = 0x00000000
	CRCW    = 0x00000003
	CRCX    = 0x00000018
	CRCY    = 0x00000020
	CRCA    = 0x00000001
	CRCL    = 0x0000000C
	FRAME   = 1024
)

var (
	zpad  = []byte{0x2a}
	zdled = []byte{0x18}
	zdle  = []byte{0x18, 0x42}
	zbin  = []byte{0x0a}
)

func main() {
	// Open serial port
	portName := "/dev/ttyUSB0"
	baudRate := 115200
	mode := &term.SerialMode{
		BaudRate: baudRate,
		DataBits: 8,
		Parity:   term.PARITY_NONE,
		StopBits: term.STOP_BITS_1,
	}
	port, err := term.Open(portName, mode)
	if err != nil {
		fmt.Println(err)
		return
	}
	defer port.Close()

	// Send file
	fileName := "test.txt"
	file, err := os.Open(fileName)
	if err != nil {
		fmt.Println(err)
		return
	}
	defer file.Close()

	buf := make([]byte, FRAME)
	for {
		n, err := file.Read(buf)
		if err == io.EOF {
			break
		}
		if err != nil {
			fmt.Println(err)
			return
		}

		// Send data packet
		packet := bytes.Join([][]byte{
			zpad,
			zdle,
			[]byte{CRCEOT},
			zdle,
			[]byte{CRCG},
			zdle,
			[]byte{CRCW},
			buf[:n],
			[]byte{0x00},
		}, []byte{})
		_, err = port.Write(packet)
		if err != nil {
			fmt.Println(err)
			return
		}

		// Wait for ACK
		ack := make([]byte, 1)
		port.SetReadDeadline(time.Now().Add(time.Second * 10))
		_, err = port.Read(ack)
		if err != nil {
			fmt.Println(err)
			return
		}
		if ack[0] != 0 {
			fmt.Println("Failed to receive ACK")
			return
		}
	}

	fmt.Println("File sent successfully!")
}

这是一个非常基本的实现，只能发送文件，并且没有实现中断和重试机制。如果您需要更完整的实现，请参考开源的ZModem库，如 [go-zmodem](https://github.com/tarm/serial/tree/master/zmodem)。