Add web dashboard OTA upload with live progress.

Share UART OTA logic between CLI and serve via POST /api/ota, WebSocket progress events, and a dashboard upload UI showing the running partition.

Co-authored-by: Cursor <cursoragent@cursor.com>

goTool/api_serve.go

@@ -3,12 +3,15 @@ package main
 import (
 	"encoding/json"
 	"fmt"
+	"io"
 	"net/http"
 	"strconv"
 
 	"powerpod/gotool/pb"
 )
 
+const otaMaxFirmwareSize = 2 * 1024 * 1024
+
 type deadzoneAPIResponse struct {
 	Deadzone      uint32 `json:"deadzone"`
 	ClientID      uint32 `json:"client_id"`
@@ -37,7 +40,14 @@ type unicastAPIResponse struct {
 	Error   string `json:"error,omitempty"`
 }
 
-func mountServeAPI(mux *http.ServeMux, link *managedSerial) {
+type otaAPIResponse struct {
+	Success       bool   `json:"success"`
+	BytesWritten  uint32 `json:"bytes_written,omitempty"`
+	TargetSlot    uint32 `json:"target_slot,omitempty"`
+	Error         string `json:"error,omitempty"`
+}
+
+func mountServeAPI(mux *http.ServeMux, link *managedSerial, hub *wsHub) {
 	mux.HandleFunc("/api/deadzone", func(w http.ResponseWriter, r *http.Request) {
 		switch r.Method {
 		case http.MethodGet:
@@ -55,6 +65,56 @@ func mountServeAPI(mux *http.ServeMux, link *managedSerial) {
 		}
 		serveUnicastTest(w, r, link)
 	})
+	mux.HandleFunc("/api/ota", func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != http.MethodPost {
+			http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
+			return
+		}
+		serveOTAUpload(w, r, link, hub)
+	})
+}
+
+func serveOTAUpload(w http.ResponseWriter, r *http.Request, link *managedSerial, hub *wsHub) {
+	if err := r.ParseMultipartForm(otaMaxFirmwareSize); err != nil {
+		writeJSON(w, http.StatusBadRequest, otaAPIResponse{Error: "invalid form"})
+		return
+	}
+	file, _, err := r.FormFile("firmware")
+	if err != nil {
+		writeJSON(w, http.StatusBadRequest, otaAPIResponse{Error: "firmware file required"})
+		return
+	}
+	defer file.Close()
+
+	data, err := io.ReadAll(io.LimitReader(file, otaMaxFirmwareSize))
+	if err != nil {
+		writeJSON(w, http.StatusBadRequest, otaAPIResponse{Error: err.Error()})
+		return
+	}
+	if len(data) == 0 {
+		writeJSON(w, http.StatusBadRequest, otaAPIResponse{Error: "empty firmware"})
+		return
+	}
+
+	var last OTAProgress
+	err = runOTAUpload(link, data, func(p OTAProgress) {
+		last = p
+		if hub != nil {
+			hub.broadcastRaw(p)
+		}
+	})
+	if err != nil {
+		if hub != nil {
+			hub.broadcastRaw(OTAProgress{Type: "ota_progress", Phase: "error", Message: err.Error()})
+		}
+		writeJSON(w, http.StatusServiceUnavailable, otaAPIResponse{Error: err.Error()})
+		return
+	}
+	writeJSON(w, http.StatusOK, otaAPIResponse{
+		Success:      true,
+		BytesWritten: last.Bytes,
+		TargetSlot:   last.Slot,
+	})
 }
 
 func serveDeadzoneGet(w http.ResponseWriter, r *http.Request, link *managedSerial) {

goTool/cmd_ota.go

@@ -2,29 +2,7 @@ package main
 
 import (
 	"fmt"
-	"log"
 	"os"
-	"time"
-
-	"google.golang.org/protobuf/proto"
-
-	uartframe "powerpod/gotool/uart"
-	"powerpod/gotool/pb"
-)
-
-const (
-	otaHostChunkSize  = 200
-	otaFlashBlockSize = 4096
-	otaPrepareTimeout = 120 * time.Second
-	otaDefaultTimeout = 15 * time.Second
-)
-
-const (
-	otaStPreparing = 1
-	otaStReady     = 2
-	otaStBlockAck  = 3
-	otaStSuccess   = 4
-	otaStFailed    = 5
 )
 
 func runOTA(sp *serialPort, args []string) error {
@@ -35,170 +13,20 @@ func runOTA(sp *serialPort, args []string) error {
 	if err != nil {
 		return err
 	}
-	if len(data) == 0 {
-		return fmt.Errorf("empty firmware file")
-	}
-
-	if err := sp.port.SetReadTimeout(otaPrepareTimeout); err != nil {
-		return err
-	}
-	defer sp.port.SetReadTimeout(readTimeout)
 
 	sp.mu.Lock()
 	defer sp.mu.Unlock()
-
+	m := &managedSerial{quiet: false, sp: sp}
-	fmt.Printf("OTA start: %d bytes firmware\n", len(data))
+	return runOTAOnPortUnlocked(m, data, func(p OTAProgress) {
-	if err := writeUartMessageLocked(sp, &pb.UartMessage{
+		switch p.Phase {
-		Type: pb.MessageType_OTA_START,
+		case "preparing", "ready":
-		Payload: &pb.UartMessage_OtaStart{
+			fmt.Println(p.Message)
-			OtaStart: &pb.OtaStartPayload{TotalSize: uint32(len(data))},
+		case "uploading":
-		},
+			if p.Percent%10 == 0 {
-	}, "OTA_START"); err != nil {
+				fmt.Printf("  %s (%d%%)\n", p.Message, p.Percent)
-		return err
-	}
-	if _, err := waitOtaStatusLocked(sp, otaStReady, otaPrepareTimeout); err != nil {
-		return err
-	}
-
-	if err := sp.port.SetReadTimeout(otaDefaultTimeout); err != nil {
-		return err
-	}
-
-	var seq uint32
-	blockNum := 0
-	for offset := 0; offset < len(data); {
-		bytesInBlock := 0
-		for bytesInBlock < otaFlashBlockSize && offset < len(data) {
-			n := otaHostChunkSize
-			room := otaFlashBlockSize - bytesInBlock
-			if n > room {
-				n = room
 			}
-			if offset+n > len(data) {
+		case "done", "error":
-				n = len(data) - offset
+			fmt.Println(p.Message)
-			}
-			chunk := data[offset : offset+n]
-
-			if err := writeUartMessageLocked(sp, &pb.UartMessage{
-				Type: pb.MessageType_OTA_PAYLOAD,
-				Payload: &pb.UartMessage_OtaPayload{
-					OtaPayload: &pb.OtaPayload{Seq: seq, Data: chunk},
-				},
-			}, "OTA_PAYLOAD"); err != nil {
-				return err
-			}
-			seq++
-			offset += n
-			bytesInBlock += n
 		}
-
+	})
-		if bytesInBlock == otaFlashBlockSize {
-			blockNum++
-			st, err := waitOtaStatusLocked(sp, otaStBlockAck, otaDefaultTimeout)
-			if err != nil {
-				return err
-			}
-			fmt.Printf("  block %d ack (%d bytes in flash, %d%%)\n",
-				blockNum, st.GetBytesWritten(), offset*100/len(data))
-		}
-	}
-
-	if err := writeUartMessageLocked(sp, &pb.UartMessage{
-		Type: pb.MessageType_OTA_END,
-		Payload: &pb.UartMessage_OtaEnd{
-			OtaEnd: &pb.OtaEndPayload{},
-		},
-	}, "OTA_END"); err != nil {
-		return err
-	}
-	st, err := readOtaStatusLocked(sp)
-	if err != nil {
-		return err
-	}
-	if st.GetStatus() != otaStSuccess {
-		return fmt.Errorf("OTA failed: status=%d error=%d written=%d",
-			st.GetStatus(), st.GetError(), st.GetBytesWritten())
-	}
-	fmt.Printf("OTA success: %d bytes written (slot %d) — reboot to boot new image\n",
-		st.GetBytesWritten(), st.GetTargetSlot())
-	return nil
-}
-
-func writeUartMessageLocked(sp *serialPort, msg *pb.UartMessage, cmdName string) error {
-	frame, err := encodeUartMessage(msg)
-	if err != nil {
-		return err
-	}
-	if !sp.quiet {
-		log.Printf("sending %s (%d frame bytes)", cmdName, len(frame))
-	}
-	_, err = sp.port.Write(frame)
-	return err
-}
-
-func encodeUartMessage(msg *pb.UartMessage) ([]byte, error) {
-	body, err := proto.Marshal(msg)
-	if err != nil {
-		return nil, err
-	}
-	payload := append([]byte{byte(msg.Type)}, body...)
-	return uartframe.EncodeFrame(payload)
-}
-
-func decodeUartPayload(payload []byte) (*pb.UartMessage, error) {
-	if len(payload) == 0 {
-		return nil, fmt.Errorf("empty response")
-	}
-	var msg pb.UartMessage
-	if err := proto.Unmarshal(payload[1:], &msg); err != nil {
-		return nil, err
-	}
-	msg.Type = pb.MessageType(payload[0])
-	return &msg, nil
-}
-
-func waitOtaStatusLocked(sp *serialPort, want uint32, timeout time.Duration) (*pb.OtaStatusPayload, error) {
-	deadline := time.Now().Add(timeout)
-	for {
-		if time.Now().After(deadline) {
-			return nil, fmt.Errorf("timeout waiting for OTA status %d", want)
-		}
-		if err := sp.port.SetReadTimeout(time.Until(deadline)); err != nil {
-			return nil, err
-		}
-		st, err := readOtaStatusLocked(sp)
-		if err != nil {
-			return nil, err
-		}
-		switch st.GetStatus() {
-		case want:
-			if want == otaStReady {
-				fmt.Printf("OTA ready: inactive slot %d\n", st.GetTargetSlot())
-			}
-			return st, nil
-		case otaStPreparing:
-			fmt.Printf("OTA preparing partition (erase may take ~30s)…\n")
-		case otaStFailed:
-			return nil, fmt.Errorf("OTA failed (error=%d)", st.GetError())
-		}
-	}
-}
-
-func readOtaStatusLocked(sp *serialPort) (*pb.OtaStatusPayload, error) {
-	payload, err := uartframe.ReadFrame(sp.port, nil)
-	if err != nil {
-		return nil, fmt.Errorf("read response: %w", err)
-	}
-	msg, err := decodeUartPayload(payload)
-	if err != nil {
-		return nil, err
-	}
-	if msg.GetType() != pb.MessageType_OTA_STATUS {
-		return nil, fmt.Errorf("unexpected response type %v", msg.GetType())
-	}
-	st := msg.GetOtaStatus()
-	if st == nil {
-		return nil, fmt.Errorf("missing ota_status")
-	}
-	return st, nil
 }

goTool/cmd_serve.go

@@ -40,7 +40,7 @@ func runServe(portName string, baud int, args []string) error {
 	go runPoller(link, portName, hub, *interval, stop)
 
 	mux := http.NewServeMux()
-	mountServeAPI(mux, link)
+	mountServeAPI(mux, link, hub)
 	mux.HandleFunc("/ws", func(w http.ResponseWriter, r *http.Request) {
 		conn, err := wsUpgrader.Upgrade(w, r, nil)
 		if err != nil {

goTool/dashboard.go

@@ -14,11 +14,12 @@ import (
 )
 
 type MasterView struct {
-	Version  uint32 `json:"version"`
+	Version           uint32 `json:"version"`
-	GitHash  string `json:"git_hash"`
+	GitHash           string `json:"git_hash"`
-	Deadzone uint32 `json:"deadzone,omitempty"`
+	RunningPartition  string `json:"running_partition,omitempty"`
-	OK       bool   `json:"ok"`
+	Deadzone          uint32 `json:"deadzone,omitempty"`
-	Error    string `json:"error,omitempty"`
+	OK                bool   `json:"ok"`
+	Error             string `json:"error,omitempty"`
 }
 
 type ClientView struct {
@@ -87,6 +88,23 @@ func (h *wsHub) unregister(c *websocket.Conn) {
 	h.mu.Unlock()
 }
 
+func (h *wsHub) broadcastRaw(v any) {
+	h.mu.RLock()
+	conns := make([]*websocket.Conn, 0, len(h.clients))
+	for c := range h.clients {
+		conns = append(conns, c)
+	}
+	h.mu.RUnlock()
+
+	data, err := json.Marshal(v)
+	if err != nil {
+		return
+	}
+	for _, c := range conns {
+		_ = c.WriteMessage(websocket.TextMessage, data)
+	}
+}
+
 func pollDashboard(link *managedSerial, portName string) DashboardState {
 	st := DashboardState{
 		UpdatedAt:  time.Now().Format(time.RFC3339),
@@ -101,9 +119,10 @@ func pollDashboard(link *managedSerial, portName string) DashboardState {
 	st.UARTConnected = true
 	st.SerialOK = true
 	st.Master = MasterView{
-		Version: ver.GetVersion(),
+		Version:          ver.GetVersion(),
-		GitHash: ver.GetGitHash(),
+		GitHash:          ver.GetGitHash(),
-		OK:      true,
+		RunningPartition: ver.GetRunningPartition(),
+		OK:               true,
 	}
 	if dz, err := readDeadzone(link, 0); err == nil {
 		st.Master.Deadzone = dz

goTool/ota_upload.go

@@ -0,0 +1,252 @@
+package main
+
+import (
+	"fmt"
+	"log"
+	"time"
+
+	"google.golang.org/protobuf/proto"
+
+	uartframe "powerpod/gotool/uart"
+	"powerpod/gotool/pb"
+)
+
+const (
+	otaHostChunkSize  = 200
+	otaFlashBlockSize = 4096
+	otaPrepareTimeout = 120 * time.Second
+	otaDefaultTimeout = 15 * time.Second
+)
+
+const (
+	otaStPreparing = 1
+	otaStReady     = 2
+	otaStBlockAck  = 3
+	otaStSuccess   = 4
+	otaStFailed    = 5
+)
+
+// OTAProgress is pushed to the dashboard during web uploads.
+type OTAProgress struct {
+	Type    string `json:"type"` // always "ota_progress"
+	Phase   string `json:"phase"` // preparing, ready, uploading, done, error
+	Percent int    `json:"percent"`
+	Message string `json:"message"`
+	Bytes   uint32 `json:"bytes_written,omitempty"`
+	Slot    uint32 `json:"target_slot,omitempty"`
+}
+
+type otaProgressFn func(OTAProgress)
+
+func runOTAUpload(m *managedSerial, firmware []byte, onProgress otaProgressFn) error {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	err := runOTAOnPortUnlocked(m, firmware, onProgress)
+	if err != nil {
+		m.invalidateLocked(err)
+	}
+	return err
+}
+
+func runOTAOnPortUnlocked(m *managedSerial, firmware []byte, onProgress otaProgressFn) error {
+	if len(firmware) == 0 {
+		return fmt.Errorf("empty firmware")
+	}
+	notify := func(phase string, percent int, msg string, extra ...OTAProgress) {
+		if onProgress == nil {
+			return
+		}
+		p := OTAProgress{Type: "ota_progress", Phase: phase, Percent: percent, Message: msg}
+		if len(extra) > 0 {
+			p.Bytes = extra[0].Bytes
+			p.Slot = extra[0].Slot
+		}
+		onProgress(p)
+	}
+
+	if m.sp == nil {
+		if err := m.openLocked(); err != nil {
+			notify("error", 0, err.Error())
+			return err
+		}
+	}
+
+	sp := m.sp
+	if err := sp.port.SetReadTimeout(otaPrepareTimeout); err != nil {
+		notify("error", 0, err.Error())
+		return err
+	}
+	defer sp.port.SetReadTimeout(readTimeout)
+
+	notify("preparing", 0, fmt.Sprintf("OTA start (%d bytes)…", len(firmware)))
+
+	if err := writeUartMessage(sp, &pb.UartMessage{
+		Type: pb.MessageType_OTA_START,
+		Payload: &pb.UartMessage_OtaStart{
+			OtaStart: &pb.OtaStartPayload{TotalSize: uint32(len(firmware))},
+		},
+	}, false); err != nil {
+		notify("error", 0, err.Error())
+		return err
+	}
+
+	ready, err := waitOtaStatus(sp, otaStReady, otaPrepareTimeout, func(msg string) {
+		notify("preparing", 2, msg)
+	})
+	if err != nil {
+		notify("error", 0, err.Error())
+		return err
+	}
+	notify("ready", 5, fmt.Sprintf("Ziel-Slot %d bereit", ready.GetTargetSlot()))
+
+	if err := sp.port.SetReadTimeout(otaDefaultTimeout); err != nil {
+		notify("error", 0, err.Error())
+		return err
+	}
+
+	var seq uint32
+	for offset := 0; offset < len(firmware); {
+		bytesInBlock := 0
+		for bytesInBlock < otaFlashBlockSize && offset < len(firmware) {
+			n := otaHostChunkSize
+			room := otaFlashBlockSize - bytesInBlock
+			if n > room {
+				n = room
+			}
+			if offset+n > len(firmware) {
+				n = len(firmware) - offset
+			}
+			chunk := firmware[offset : offset+n]
+
+			if err := writeUartMessage(sp, &pb.UartMessage{
+				Type: pb.MessageType_OTA_PAYLOAD,
+				Payload: &pb.UartMessage_OtaPayload{
+					OtaPayload: &pb.OtaPayload{Seq: seq, Data: chunk},
+				},
+			}, false); err != nil {
+				notify("error", 0, err.Error())
+				return err
+			}
+			seq++
+			offset += n
+			bytesInBlock += n
+
+			pct := 5 + (offset * 90 / len(firmware))
+			notify("uploading", pct, fmt.Sprintf("%d / %d bytes", offset, len(firmware)))
+		}
+
+		if bytesInBlock == otaFlashBlockSize {
+			st, err := waitOtaStatus(sp, otaStBlockAck, otaDefaultTimeout, nil)
+			if err != nil {
+				notify("error", 0, err.Error())
+				return err
+			}
+			pct := 5 + (offset * 90 / len(firmware))
+			notify("uploading", pct, fmt.Sprintf("Block geschrieben (%d bytes in flash)", st.GetBytesWritten()),
+				OTAProgress{Bytes: st.GetBytesWritten()})
+		}
+	}
+
+	if err := writeUartMessage(sp, &pb.UartMessage{
+		Type: pb.MessageType_OTA_END,
+		Payload: &pb.UartMessage_OtaEnd{
+			OtaEnd: &pb.OtaEndPayload{},
+		},
+	}, false); err != nil {
+		notify("error", 0, err.Error())
+		return err
+	}
+
+	st, err := readOtaStatus(sp)
+	if err != nil {
+		notify("error", 0, err.Error())
+		return err
+	}
+	if st.GetStatus() != otaStSuccess {
+		err := fmt.Errorf("OTA failed: status=%d error=%d", st.GetStatus(), st.GetError())
+		notify("error", 0, err.Error())
+		return err
+	}
+
+	notify("done", 100, fmt.Sprintf("Erfolg — %d bytes auf Slot %d (Neustart)", st.GetBytesWritten(), st.GetTargetSlot()),
+		OTAProgress{Bytes: st.GetBytesWritten(), Slot: st.GetTargetSlot()})
+	return nil
+}
+
+func writeUartMessage(sp *serialPort, msg *pb.UartMessage, logFrame bool) error {
+	frame, err := encodeUartMessage(msg)
+	if err != nil {
+		return err
+	}
+	if logFrame {
+		log.Printf("sending %s (%d frame bytes)", msg.Type, len(frame))
+	}
+	_, err = sp.port.Write(frame)
+	return err
+}
+
+func waitOtaStatus(sp *serialPort, want uint32, timeout time.Duration, onPreparing func(string)) (*pb.OtaStatusPayload, error) {
+	deadline := time.Now().Add(timeout)
+	for {
+		if time.Now().After(deadline) {
+			return nil, fmt.Errorf("timeout waiting for OTA status %d", want)
+		}
+		if err := sp.port.SetReadTimeout(time.Until(deadline)); err != nil {
+			return nil, err
+		}
+		st, err := readOtaStatus(sp)
+		if err != nil {
+			return nil, err
+		}
+		switch st.GetStatus() {
+		case want:
+			return st, nil
+		case otaStPreparing:
+			if onPreparing != nil {
+				onPreparing("Partition wird vorbereitet (~30s)…")
+			}
+		case otaStFailed:
+			return nil, fmt.Errorf("OTA failed (error=%d)", st.GetError())
+		}
+	}
+}
+
+func readOtaStatus(sp *serialPort) (*pb.OtaStatusPayload, error) {
+	payload, err := uartframe.ReadFrame(sp.port, nil)
+	if err != nil {
+		return nil, fmt.Errorf("read response: %w", err)
+	}
+	msg, err := decodeUartPayload(payload)
+	if err != nil {
+		return nil, err
+	}
+	if msg.GetType() != pb.MessageType_OTA_STATUS {
+		return nil, fmt.Errorf("unexpected response type %v", msg.GetType())
+	}
+	st := msg.GetOtaStatus()
+	if st == nil {
+		return nil, fmt.Errorf("missing ota_status")
+	}
+	return st, nil
+}
+
+func encodeUartMessage(msg *pb.UartMessage) ([]byte, error) {
+	body, err := proto.Marshal(msg)
+	if err != nil {
+		return nil, err
+	}
+	payload := append([]byte{byte(msg.Type)}, body...)
+	return uartframe.EncodeFrame(payload)
+}
+
+func decodeUartPayload(payload []byte) (*pb.UartMessage, error) {
+	if len(payload) == 0 {
+		return nil, fmt.Errorf("empty response")
+	}
+	var msg pb.UartMessage
+	if err := proto.Unmarshal(payload[1:], &msg); err != nil {
+		return nil, err
+	}
+	msg.Type = pb.MessageType(payload[0])
+	return &msg, nil
+}

goTool/webui/index.html

@@ -124,6 +124,20 @@
       margin-top: 1rem;
       padding-top: 1rem;
     }
+    .progress {
+      background: var(--pp-surface-raised);
+      border: 1px solid var(--pp-border);
+    }
+    .progress-bar {
+      background: #2d6cdf;
+    }
+    .form-control[type="file"]::file-selector-button {
+      background: var(--pp-border);
+      border: none;
+      color: var(--pp-text);
+      margin-right: 0.5rem;
+      padding: 0.25rem 0.5rem;
+    }
   </style>
 </head>
 <body x-data="dashboard()" x-init="connect()">
@@ -168,6 +182,8 @@
                 <dd class="col-7" x-text="state.master.version"></dd>
                 <dt class="col-5 text-muted">Git</dt>
                 <dd class="col-7 text-break" x-text="state.master.git_hash"></dd>
+                <dt class="col-5 text-muted">Partition</dt>
+                <dd class="col-7" x-text="state.master.running_partition || '—'"></dd>
                 <dt class="col-5 text-muted">Deadzone</dt>
                 <dd class="col-7" x-text="state.master.deadzone != null ? state.master.deadzone + ' LSB' : '—'"></dd>
               </dl>
@@ -281,6 +297,43 @@
           </div>
         </div>
       </section>
+
+      <section class="col-12">
+        <div class="card">
+          <div class="card-header">Firmware OTA (A/B)</div>
+          <div class="card-body">
+            <p class="text-muted small mb-3">
+              Lädt eine <code>.bin</code> auf die inaktive OTA-Partition (wie <code>gotool ota</code>).
+              Während des Uploads pausiert das Live-Polling.
+            </p>
+            <div class="mb-3">
+              <input type="file" class="form-control form-control-sm" accept=".bin,application/octet-stream"
+                     @change="otaFile = $event.target.files[0]"
+                     :disabled="ota.active || busy || !state.uart_connected">
+            </div>
+            <div class="d-flex flex-wrap gap-2 align-items-center mb-2">
+              <button type="button" class="btn btn-primary btn-sm"
+                      @click="uploadOTA()"
+                      :disabled="ota.active || busy || !state.uart_connected || !otaFile">
+                Firmware hochladen
+              </button>
+              <span class="text-muted small" x-show="otaFile"
+                    x-text="otaFile ? otaFile.name + ' (' + formatSize(otaFile.size) + ')' : ''"></span>
+            </div>
+            <template x-if="ota.active || ota.phase === 'done' || ota.phase === 'error'">
+              <div class="progress mb-2" style="height: 1.25rem;">
+                <div class="progress-bar" role="progressbar"
+                     :style="'width: ' + ota.percent + '%'"
+                     :class="ota.phase === 'error' ? 'bg-danger' : (ota.phase === 'done' ? 'bg-success' : '')"
+                     x-text="ota.percent + '%'"></div>
+              </div>
+              <p class="small mb-0"
+                 :class="ota.phase === 'error' ? 'text-danger' : (ota.phase === 'done' ? 'text-success' : 'text-muted')"
+                 x-text="ota.message"></p>
+            </template>
+          </div>
+        </div>
+      </section>
     </div>
   </main>
 
@@ -293,6 +346,8 @@
         masterDz: 100,
         allDz: 100,
         slaveDz: {},
+        otaFile: null,
+        ota: { active: false, phase: '', percent: 0, message: '' },
         busy: false,
         configMsg: '',
         configMsgOk: false,
@@ -308,12 +363,16 @@
             };
             this.ws.onmessage = (e) => {
               try {
-                const st = JSON.parse(e.data);
+                const msg = JSON.parse(e.data);
-                this.state = st;
+                if (msg.type === 'ota_progress') {
-                if (st.master?.deadzone != null) {
+                  this.applyOTAProgress(msg);
-                  this.masterDz = st.master.deadzone;
+                  return;
                 }
-                for (const c of (st.clients || [])) {
+                this.state = msg;
+                if (msg.master?.deadzone != null) {
+                  this.masterDz = msg.master.deadzone;
+                }
+                for (const c of (msg.clients || [])) {
                   if (c.deadzone != null && this.slaveDz[c.id] == null) {
                     this.slaveDz[c.id] = c.deadzone;
                   }
@@ -327,6 +386,53 @@
           if (!hex || hex.length !== 12) return hex || '';
           return hex.match(/.{2}/g).join(':');
         },
+        formatSize(n) {
+          if (n == null) return '';
+          if (n < 1024) return n + ' B';
+          if (n < 1024 * 1024) return (n / 1024).toFixed(1) + ' KiB';
+          return (n / (1024 * 1024)).toFixed(2) + ' MiB';
+        },
+        applyOTAProgress(p) {
+          this.ota.phase = p.phase || '';
+          this.ota.percent = p.percent ?? 0;
+          this.ota.message = p.message || '';
+          if (p.phase === 'preparing' || p.phase === 'ready' || p.phase === 'uploading') {
+            this.ota.active = true;
+          }
+          if (p.phase === 'done' || p.phase === 'error') {
+            this.ota.active = false;
+          }
+        },
+        async uploadOTA() {
+          if (!this.otaFile) return;
+          this.ota = { active: true, phase: 'preparing', percent: 0, message: 'Upload startet…' };
+          this.busy = true;
+          const form = new FormData();
+          form.append('firmware', this.otaFile);
+          try {
+            const r = await fetch('/api/ota', { method: 'POST', body: form });
+            const data = await r.json();
+            if (!r.ok || !data.success) {
+              this.applyOTAProgress({
+                phase: 'error',
+                percent: 0,
+                message: data.error || 'OTA fehlgeschlagen'
+              });
+              return;
+            }
+            const slot = data.target_slot != null ? 'ota_' + data.target_slot : '?';
+            this.applyOTAProgress({
+              phase: 'done',
+              percent: 100,
+              message: `OK — ${data.bytes_written} Bytes nach ${slot} (Neustart zum Booten)`
+            });
+          } catch (e) {
+            this.applyOTAProgress({ phase: 'error', percent: 0, message: String(e) });
+          } finally {
+            this.busy = false;
+            this.ota.active = false;
+          }
+        },
         flash(msg, ok) {
           this.configMsg = msg;
           this.configMsgOk = ok;