Implemented additional checks. Add force flag to flash firmware even if modem is in BIOS mode.

firmware/firmware.go

@@ -18,6 +18,7 @@ func FwExists(path string) bool {
 	return !errors.Is(err, os.ErrNotExist)
 }
 
+// ChkHeader: runs header and CRC checks on the firmware file
 func ChkHeader(fwfile string) error {
 	log.Info("checking ", fwfile)
 	// SCS has two different file layouts, one for the "Dragons", the other for any older modem
@@ -62,9 +63,7 @@ func ChkHeader(fwfile string) error {
 		size = uint32(binary.LittleEndian.Uint16(firmware[2:4])) // PTC-3 and Co
 	}
 	a := make([]byte, 4)
-	//binary.LittleEndian.PutUint32(a, crc32.ChecksumIEEE(firmware[4:size+4])) // PTC-3
 	binary.LittleEndian.PutUint32(a, crc32.ChecksumIEEE(firmware[offset:offset+size]))
-	//if bytes.Equal(a, firmware[4+size:8+size]) { // PTC-3
 	if bytes.Equal(a, firmware[offset+size:offset+size+4]) {
 		log.Info("CRC checksum ok!")
 	} else {

main.go

@@ -1,3 +1,7 @@
+// Copyright 2021 Torsten Harenberg DL1THM. All rights reserved.
+
+// A SCS PACTOR modem flashing utility written in Go. Should run anywhere Go runs.
+
 package main
 
 import (
@@ -16,8 +20,11 @@ func main() {
 	serialDevice := parser.String("s", "serialDevice", &argparse.Options{Required: false, Help: "(optional) serial device the modem is attached to, e.g. /dev/ttyUSB0. If not set, go-scsupdate will search for SCS modems."})
 	brate := parser.Int("b", "baudrate", &argparse.Options{Required: false, Help: "(optional, required when -s is set) sets the serial baudrate, e.g. 115200"})
 	f := parser.String("f", "file", &argparse.Options{Required: true, Help: "(required) the file to flash, e.g. profi41r.pro"})
+
 	debug := parser.Flag("d", "debug", &argparse.Options{Required: false, Help: "(optional) enable debug logs"})
 	dryrun := parser.Flag("n", "dryrun", &argparse.Options{Required: false, Help: "(optional) drying:  if set, modem will detected but no firmware being written"})
+	force := parser.Flag("", "force", &argparse.Options{Required: false, Help: "(optional) skip testing if firmware fits modem. Useful if the modem is bricked and you need to put it into BIOS mode. Read the manual!"})
+	sertimeout := parser.Int("t", "timeout", &argparse.Options{Required: false, Help: "(optional) Sets the read and write timeout. Default: 70. If you have handshake problems, enlarge this values, especially for older modems."})
 	err := parser.Parse(os.Args)
 	cLog := console.New(true)
 	if *debug {
@@ -27,6 +34,10 @@ func main() {
 		log.AddHandler(cLog, log.InfoLevel, log.ErrorLevel, log.AlertLevel, log.WarnLevel, log.NoticeLevel, log.PanicLevel)
 	}
 
+	if *sertimeout == 0 { // if not set, set the write / read timeout to 70
+		*sertimeout = 70
+	}
+
 	if *serialDevice != "" && *brate == 0 {
 		log.Fatal("ERROR: if you specify a device, you need to specify a baud rate as well. Cannot continue")
 	}
@@ -79,9 +90,9 @@ func main() {
 	if *dryrun != true {
 		var err error
 		if *serialDevice != "" {
-			err = update.Update(*serialDevice, baudrate, *f)
+			err = update.Update(*serialDevice, baudrate, *sertimeout, *f, *force)
 		} else {
-			err = update.Update(ports[0].Port, baudrate, *f)
+			err = update.Update(ports[0].Port, baudrate, *sertimeout, *f, *force)
 		}
 		if err != nil {
 			log.Panic(err)

update/update.go

@@ -14,22 +14,25 @@ import (
 	"regexp"
 	"strings"
 	"time"
+	"unicode"
 )
 
+// Size of a "firmware packet" over the serial line
 const CHUNKSIZE = 256
 
 type modem struct {
 	port serial.Port
 }
 
-func initmodem(serport string, baudrate int) (*modem, error) {
+// initmodem: opens the serial line, returns instance of serial.Port
+func initmodem(serport string, baudrate int, sertimeout int) (*modem, error) {
 	p, err := serial.Open(serport,
 		serial.WithBaudrate(baudrate),
 		serial.WithDataBits(8),
 		serial.WithParity(serial.NoParity),
 		serial.WithStopBits(serial.OneStopBit),
-		serial.WithReadTimeout(70),
+		serial.WithReadTimeout(sertimeout),
-		serial.WithWriteTimeout(70)) // 50 was not stable, bump to 70
+		serial.WithWriteTimeout(sertimeout))
 	if err != nil {
 		fmt.Printf("ERROR: File %s could not be opened\n", serport)
 		return nil, err
@@ -38,9 +41,12 @@ func initmodem(serport string, baudrate int) (*modem, error) {
 	return m, nil
 }
 
+// write: writes to the serial ports, returns answer and logs output
 func (m *modem) write(out string, nolog ...bool) ([]byte, error) {
 	if len(nolog) == 0 {
-		log.Debug("Sending " + out)
+		log.Debug("Sending " + strings.TrimFunc(out, func(r rune) bool {
+			return !unicode.IsGraphic(r)
+		}))
 	} else {
 		if len(out) < 200 { // in other cases it's the firmware!
 			log.Debugf("Sending %d byte(s)", len(out))
@@ -67,6 +73,7 @@ func (m *modem) write(out string, nolog ...bool) ([]byte, error) {
 
 }
 
+// getSerNum: tries to find out the serial number of the modem.
 func (m *modem) getSerNum() (string, error) {
 	answer, err := m.write("\rsys sern\r")
 	if err != nil {
@@ -77,6 +84,7 @@ func (m *modem) getSerNum() (string, error) {
 	return sn, nil
 }
 
+// setDateTime: sets the current date and time (taken from the host) to the modem
 func (m *modem) setDateTime() error {
 	ct := time.Now()
 	answer, err := m.write("DATE " + ct.Format("020106\r"))
@@ -93,6 +101,7 @@ func (m *modem) setDateTime() error {
 	return nil
 }
 
+// writeUpdate: main flash utility. Writes the firmware taken from fwfile to the modem. Write progress bar.
 func (m *modem) writeUpdate(fwfile string) error {
 	_, err := m.write("UPDATE\r")
 	if err != nil {
@@ -174,6 +183,7 @@ func (m *modem) writeUpdate(fwfile string) error {
 	return nil
 }
 
+// checkFirmwareFits: checks the type of the modem and compares the file extension.
 func (m *modem) checkFirmwareFits(fwfile string) error {
 	answer, err := m.write("ver ##\r")
 	if err != nil {
@@ -215,8 +225,9 @@ func (m *modem) checkFirmwareFits(fwfile string) error {
 
 }
 
-func Update(serport string, baudrate int, fwfile string) error {
+// Update: main firmware update utility. Runs pre-checks and calls main flashing function writeUpdate
-	m, err := initmodem(serport, baudrate)
+func Update(serport string, baudrate int, sertimeout int, fwfile string, force bool) error {
+	m, err := initmodem(serport, baudrate, sertimeout)
 	defer m.port.Close()
 	if err != nil {
 		return errors.New("FEHLER in Update")
@@ -232,8 +243,12 @@ func Update(serport string, baudrate int, fwfile string) error {
 	if m.setDateTime() != nil {
 		return err
 	}
-	if m.checkFirmwareFits(fwfile) != nil {
+	if force == false {
-		return err
+		if m.checkFirmwareFits(fwfile) != nil {
+			return err
+		}
+	} else {
+		log.Noticef("Skipping checks if firmware fits modem due to force flag!")
 	}
 	if m.writeUpdate(fwfile) != nil {
 		return err