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

server/test_client.py

@@ -0,0 +1,111 @@
+#!/usr/bin/env python3
+"""
+Simuliert einen Pico, der den OTA-Server anfragt. Damit testen wir das
+Protokoll ohne echtes Geraet.
+
+Usage:
+  test_client.py <pico_id> [--current-binary PATH] [--host HOST] [--port PORT]
+
+Beispiele:
+  # so tun, als laege auf dem Pico ein leerer Slot (alles 0xFF):
+  test_client.py 1
+
+  # so tun, als laege auf dem Pico schon pico_1.bin:
+  test_client.py 1 --current-binary firmware/pico_1.bin
+
+  # unbekannte Pico-ID:
+  test_client.py 99
+"""
+
+import argparse
+import hashlib
+import socket
+import struct
+import sys
+from pathlib import Path
+
+MAGIC = 0xC0FFEE01
+APP_SLOT_SIZE = 3584 * 1024
+SHA256_SIZE = 32
+
+
+def slot_hash(binary_path: Path | None) -> bytes:
+    if binary_path is None:
+        # Leerer Slot: 3.5 MB 0xFF.
+        padded = b"\xff" * APP_SLOT_SIZE
+    else:
+        data = binary_path.read_bytes()
+        if len(data) > APP_SLOT_SIZE:
+            raise ValueError(f"{binary_path}: zu gross ({len(data)})")
+        padded = data + b"\xff" * (APP_SLOT_SIZE - len(data))
+    return hashlib.sha256(padded).digest()
+
+
+def recv_exact(sock: socket.socket, n: int) -> bytes:
+    buf = b""
+    while len(buf) < n:
+        chunk = sock.recv(n - len(buf))
+        if not chunk:
+            raise ConnectionError(f"Server-Disconnect nach {len(buf)}/{n}")
+        buf += chunk
+    return buf
+
+
+def main() -> int:
+    ap = argparse.ArgumentParser()
+    ap.add_argument("pico_id", type=int)
+    ap.add_argument("--current-binary", type=Path, default=None,
+                    help="Pfad einer Binary, die wir 'als bereits installiert' simulieren")
+    ap.add_argument("--host", default="127.0.0.1")
+    ap.add_argument("--port", type=int, default=9000)
+    ap.add_argument("--save-update", type=Path, default=None,
+                    help="Falls Server ein Update sendet, hier speichern")
+    args = ap.parse_args()
+
+    current_hash = slot_hash(args.current_binary)
+    print(f"-> pico_id={args.pico_id}  hash={current_hash.hex()[:16]}...")
+
+    req = struct.pack("<II", MAGIC, args.pico_id) + current_hash
+    assert len(req) == 40
+
+    with socket.create_connection((args.host, args.port), timeout=5.0) as sock:
+        sock.sendall(req)
+
+        status_byte = recv_exact(sock, 1)
+        status = status_byte[0]
+        print(f"<- status=0x{status:02x}")
+
+        if status == 0x00:
+            print("   no update — boot the existing app")
+            return 0
+
+        if status != 0x01:
+            print(f"   FEHLER: unerwartetes Status-Byte 0x{status:02x}")
+            return 1
+
+        size_bytes = recv_exact(sock, 4)
+        size = struct.unpack("<I", size_bytes)[0]
+        new_hash = recv_exact(sock, SHA256_SIZE)
+        print(f"   size={size}  new_hash={new_hash.hex()[:16]}...")
+
+        payload = recv_exact(sock, size)
+        actual_slot_hash = hashlib.sha256(
+            payload + b"\xff" * (APP_SLOT_SIZE - len(payload))
+        ).digest()
+        match = actual_slot_hash == new_hash
+        print(f"   payload empfangen ({len(payload)} bytes)  "
+              f"hash-match={match}")
+
+        if not match:
+            print("   FEHLER: gepaddeter Payload-Hash passt nicht zum angekuendigten Slot-Hash")
+            return 2
+
+        if args.save_update:
+            args.save_update.write_bytes(payload)
+            print(f"   gespeichert: {args.save_update}")
+
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())