Manage ESP32 OTA (#133)

Author: mirkokurt

Diff for: command/ota/generate.go

@@ -22,13 +22,14 @@ import (
 	"fmt"
 	"io/ioutil"
 	"os"
+	"strings"
 
 	inota "github.com/arduino/arduino-cloud-cli/internal/ota"
 )
 
 var (
-	arduinoVendorID = "2341"
-	fqbnToPID       = map[string]string{
+	arduinoVendorID  = "2341"
+	arduinoFqbnToPID = map[string]string{
 		"arduino:samd:nano_33_iot":            "8057",
 		"arduino:samd:mkr1000":                "804E",
 		"arduino:samd:mkrgsm1400":             "8052",
@@ -39,13 +40,31 @@ var (
 		"arduino:mbed_nicla:nicla_vision":     "025F",
 		"arduino:mbed_opta:opta":              "0064",
 	}
+	esp32MagicNumberPart1 = "4553"
+	esp32MagicNumberPart2 = "5033"
 )
 
 // Generate takes a .bin file and generates a .ota file.
 func Generate(binFile string, outFile string, fqbn string) error {
-	productID, ok := fqbnToPID[fqbn]
-	if !ok {
-		return errors.New("fqbn not valid")
+
+	// We are going to put a magic number in the ota .bin file, the fw will check the magic number once the binary is received
+	var magicNumberPart1, magicNumberPart2 string
+
+	// The ota update is available for Arduino boards and ESP32 boards
+
+	// Esp32 boards have a wide range of vid and pid, we don't map all of them
+	// If the fqbn is the one of an ESP32 board, we force a default magic number that matches the same default expected on the fw side
+	if strings.HasPrefix(fqbn, "esp32") {
+		magicNumberPart1 = esp32MagicNumberPart1
+		magicNumberPart2 = esp32MagicNumberPart2
+	} else {
+		//For Arduino Boards we use vendorId and productID to form the magic number
+		magicNumberPart1 = arduinoVendorID
+		productID, ok := arduinoFqbnToPID[fqbn]
+		if !ok {
+			return errors.New("fqbn not valid")
+		}
+		magicNumberPart2 = productID
 	}
 
 	data, err := ioutil.ReadFile(binFile)
@@ -59,7 +78,7 @@ func Generate(binFile string, outFile string, fqbn string) error {
 	}
 	defer out.Close()
 
-	enc := inota.NewEncoder(out, arduinoVendorID, productID)
+	enc := inota.NewEncoder(out, magicNumberPart1, magicNumberPart2)
 	err = enc.Encode(data)
 	if err != nil {
 		return fmt.Errorf("failed to encode binary file: %w", err)

Diff for: internal/ota/encoder.go

@@ -33,18 +33,18 @@ type Encoder struct {
 	w io.Writer
 
 	// vendorID is the ID of the board vendor.
-	vendorID string
+	magicNumberPart1 string
 
 	// productID is the ID of the board model.
-	productID string
+	magicNumberPart2 string
 }
 
 // NewEncoder creates a new ota encoder.
-func NewEncoder(w io.Writer, vendorID, productID string) *Encoder {
+func NewEncoder(w io.Writer, magicNumberPart1, magicNumberPart2 string) *Encoder {
 	return &Encoder{
-		w:         w,
-		vendorID:  vendorID,
-		productID: productID,
+		w:                w,
+		magicNumberPart1: magicNumberPart1,
+		magicNumberPart2: magicNumberPart2,
 	}
 }
 
@@ -53,17 +53,17 @@ func NewEncoder(w io.Writer, vendorID, productID string) *Encoder {
 func (e *Encoder) Encode(data []byte) error {
 	// Compute the magic number (VID/PID)
 	magicNumber := make([]byte, 4)
-	vid, err := strconv.ParseUint(e.vendorID, 16, 16)
+	magicNumberPart1, err := strconv.ParseUint(e.magicNumberPart1, 16, 16)
 	if err != nil {
 		return fmt.Errorf("cannot parse vendorID: %w", err)
 	}
-	pid, err := strconv.ParseUint(e.productID, 16, 16)
+	magicNumberPart2, err := strconv.ParseUint(e.magicNumberPart2, 16, 16)
 	if err != nil {
 		return fmt.Errorf("cannot parse productID: %w", err)
 	}
 
-	binary.LittleEndian.PutUint16(magicNumber[0:2], uint16(pid))
-	binary.LittleEndian.PutUint16(magicNumber[2:4], uint16(vid))
+	binary.LittleEndian.PutUint16(magicNumber[0:2], uint16(magicNumberPart2))
+	binary.LittleEndian.PutUint16(magicNumber[2:4], uint16(magicNumberPart1))
 
 	// Version field (byte array of size 8)
 	version := Version{