Kompletter OTA Flash-Prozess mit Server (hab zwischencommits vergessen ups)

2026-05-15 23:33:10 +02:00
parent 5d9d3e205b
commit ad05cef1bf
16 changed files with 1797 additions and 0 deletions
@@ -0,0 +1,146 @@
+#!/usr/bin/env python3
+"""
+OTA-Update-Server fuer den Pico-Bootloader.
+
+Wire-Protokoll:
+  Pico -> Server (40 bytes):
+    [0:4]   magic 0xC0FFEE01 (LE)
+    [4:8]   pico_id (LE u32)
+    [8:40]  SHA256 des aktuellen App-Slots (3.5 MB, 0xFF-gepaddet)
+
+  Server -> Pico:
+    [0:1]   status: 0x00 = no update, 0x01 = update follows
+    falls status == 0x01:
+      [1:5]   size der Binary in bytes (LE u32)
+      [5:37]  SHA256 des neuen App-Slots (auch 0xFF-gepaddet auf 3.5 MB)
+      [37:]   Binary-Payload (size Bytes)
+"""
+
+import hashlib
+import socket
+import struct
+import sys
+from pathlib import Path
+
+MAGIC = 0xC0FFEE01
+APP_SLOT_SIZE = 3584 * 1024  # 3.5 MB
+SHA256_SIZE = 32
+REQUEST_SIZE = 4 + 4 + SHA256_SIZE  # 40
+
+STATUS_NO_UPDATE = 0x00
+STATUS_UPDATE = 0x01
+
+LISTEN_HOST = "0.0.0.0"
+LISTEN_PORT = 9000
+RECV_TIMEOUT_S = 5.0
+
+FIRMWARE_DIR = Path(__file__).parent / "firmware"
+
+# pico_id -> binary path. Picos, die hier nicht gelistet sind, bekommen
+# immer status=no_update (server kennt das Geraet nicht).
+MANIFEST = {
+    1: FIRMWARE_DIR / "pico_2.bin",
+    2: FIRMWARE_DIR / "pico_1.bin",
+}
+
+
+def slot_hash(binary_path: Path) -> bytes:
+    """Hash der Datei, gepaddet mit 0xFF bis 3.5 MB — exakt das,
+    was der Pico auf seinem App-Slot berechnet."""
+    data = binary_path.read_bytes()
+    if len(data) > APP_SLOT_SIZE:
+        raise ValueError(
+            f"{binary_path}: {len(data)} bytes > app slot ({APP_SLOT_SIZE})"
+        )
+    padded = data + b"\xff" * (APP_SLOT_SIZE - len(data))
+    return hashlib.sha256(padded).digest()
+
+
+def recv_exact(conn: socket.socket, n: int) -> bytes:
+    buf = b""
+    while len(buf) < n:
+        chunk = conn.recv(n - len(buf))
+        if not chunk:
+            raise ConnectionError(
+                f"Verbindung geschlossen nach {len(buf)}/{n} Bytes"
+            )
+        buf += chunk
+    return buf
+
+
+def handle_client(conn: socket.socket, addr) -> None:
+    conn.settimeout(RECV_TIMEOUT_S)
+
+    try:
+        request = recv_exact(conn, REQUEST_SIZE)
+    except (ConnectionError, socket.timeout) as exc:
+        print(f"[{addr}] Request-Abbruch: {exc}")
+        return
+
+    magic, pico_id = struct.unpack("<II", request[:8])
+    current_hash = request[8:]
+
+    print(
+        f"[{addr}] pico_id={pico_id} hash={current_hash.hex()[:16]}... magic=0x{magic:08x}"
+    )
+
+    if magic != MAGIC:
+        print(f"[{addr}] FEHLER: ungueltiges Magic")
+        return
+
+    binary_path = MANIFEST.get(pico_id)
+    if binary_path is None:
+        print(f"[{addr}] pico_id {pico_id} nicht im Manifest -> no_update")
+        conn.sendall(bytes([STATUS_NO_UPDATE]))
+        return
+
+    if not binary_path.exists():
+        print(f"[{addr}] Manifest-Eintrag fehlt: {binary_path} -> no_update")
+        conn.sendall(bytes([STATUS_NO_UPDATE]))
+        return
+
+    target_hash = slot_hash(binary_path)
+
+    if current_hash == target_hash:
+        print(f"[{addr}] aktuell -> no_update")
+        conn.sendall(bytes([STATUS_NO_UPDATE]))
+        return
+
+    binary = binary_path.read_bytes()
+    print(
+        f"[{addr}] update -> {binary_path.name} ({len(binary)} bytes, "
+        f"hash {target_hash.hex()[:16]}...)"
+    )
+    conn.sendall(bytes([STATUS_UPDATE]))
+    conn.sendall(struct.pack("<I", len(binary)))
+    conn.sendall(target_hash)
+    conn.sendall(binary)
+
+
+def main() -> int:
+    if not FIRMWARE_DIR.exists():
+        FIRMWARE_DIR.mkdir(parents=True)
+        print(f"firmware/ angelegt: {FIRMWARE_DIR}")
+
+    with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as srv:
+        srv.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+        srv.bind((LISTEN_HOST, LISTEN_PORT))
+        srv.listen(4)
+        print(f"OTA-Server hoert auf {LISTEN_HOST}:{LISTEN_PORT}")
+        print(f"Manifest: {[(k, str(v.name)) for k, v in MANIFEST.items()]}")
+        try:
+            while True:
+                conn, addr = srv.accept()
+                try:
+                    handle_client(conn, addr)
+                except Exception as exc:
+                    print(f"[{addr}] Exception: {exc}")
+                finally:
+                    conn.close()
+        except KeyboardInterrupt:
+            print("\nbeendet")
+            return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())