do this

common/params.cc

@@ -255,7 +255,6 @@ std::unordered_map<std::string, uint32_t> keys = {
     {"EnforceTorqueLateral", PERSISTENT | BACKUP},
     {"EnhancedScc", PERSISTENT | BACKUP},
     {"FeatureStatus", PERSISTENT | BACKUP},
-    {"Fingerprints", CLEAR_ON_MANAGER_START | CLEAR_ON_ONROAD_TRANSITION},
     {"FleetManagerPin", PERSISTENT},
     {"ForceOffroad", CLEAR_ON_MANAGER_START},
     {"GmapKey", PERSISTENT | BACKUP},

selfdrive/car/car_helpers.py

@@ -169,7 +169,6 @@ def fingerprint(logcan, sendcan, num_pandas):
   # drain CAN socket so we get the latest messages
   messaging.drain_sock_raw(logcan)
   car_fingerprint, finger = can_fingerprint(lambda: get_one_can(logcan))
-  params.put("Fingerprints", repr(finger))
 
   exact_match = True
   source = car.CarParams.FingerprintSource.can

selfdrive/car/hyundai/interface.py

@@ -1,8 +1,7 @@
-import ast
-
 from cereal import car
 from panda import Panda
 from openpilot.common.params import Params
+from openpilot.selfdrive.car.sunnypilot.fingerprinting import can_fingerprint, get_one_can
 from openpilot.selfdrive.car.hyundai.enable_radar_tracks import enable_radar_tracks
 from openpilot.selfdrive.car.hyundai.hyundaicanfd import CanBus
 from openpilot.selfdrive.car.hyundai.values import HyundaiFlags, HyundaiFlagsSP, CAR, DBC, CANFD_CAR, CAMERA_SCC_CAR, CANFD_RADAR_SCC_CAR, \
@@ -208,9 +207,10 @@ class CarInterface(CarInterfaceBase):
       rt_avail_cache = params.get_bool("HyundaiRadarTracksAvailableCache")
       if rt_avail and rt_avail_cache:
         pass
+      elif rt_avail != rt_avail_cache:
+        params.put_bool_nonblocking("HyundaiRadarTracksAvailableCache", rt_avail)
       else:
-        params.put_bool_nonblocking("HyundaiRadarTracksAvailableCache", bool(rt_avail))
-        fingerprint = ast.literal_eval(params.get("Fingerprints", encoding="utf8"))
+        _, fingerprint = can_fingerprint(lambda: get_one_can(logcan))
         if RADAR_START_ADDR in fingerprint[1] and DBC[CP.carFingerprint]["radar"] is not None:
           params.put_bool_nonblocking("HyundaiRadarTracksAvailable", True)
         elif RADAR_START_ADDR not in fingerprint[1] or DBC[CP.carFingerprint]["radar"] is None:

selfdrive/car/sunnypilot/fingerprinting.py

@@ -0,0 +1,54 @@
+from collections.abc import Callable
+
+from openpilot.selfdrive.car.fingerprints import eliminate_incompatible_cars, all_legacy_fingerprint_cars
+import cereal.messaging as messaging
+from openpilot.selfdrive.car import gen_empty_fingerprint
+
+FRAME_FINGERPRINT = 100  # 1s
+
+
+def get_one_can(logcan):
+  while True:
+    can = messaging.recv_one_retry(logcan)
+    if len(can.can) > 0:
+      return can
+
+
+def can_fingerprint(next_can: Callable) -> tuple[str | None, dict[int, dict]]:
+  finger = gen_empty_fingerprint()
+  candidate_cars = {i: all_legacy_fingerprint_cars() for i in [0, 1]}  # attempt fingerprint on both bus 0 and 1
+  frame = 0
+  car_fingerprint = None
+  done = False
+
+  while not done:
+    a = next_can()
+
+    for can in a.can:
+      # The fingerprint dict is generated for all buses, this way the car interface
+      # can use it to detect a (valid) multipanda setup and initialize accordingly
+      if can.src < 128:
+        if can.src not in finger:
+          finger[can.src] = {}
+        finger[can.src][can.address] = len(can.dat)
+
+      for b in candidate_cars:
+        # Ignore extended messages and VIN query response.
+        if can.src == b and can.address < 0x800 and can.address not in (0x7df, 0x7e0, 0x7e8):
+          candidate_cars[b] = eliminate_incompatible_cars(can, candidate_cars[b])
+
+    # if we only have one car choice and the time since we got our first
+    # message has elapsed, exit
+    for b in candidate_cars:
+      if len(candidate_cars[b]) == 1 and frame > FRAME_FINGERPRINT:
+        # fingerprint done
+        car_fingerprint = candidate_cars[b][0]
+
+    # bail if no cars left or we've been waiting for more than 2s
+    failed = (all(len(cc) == 0 for cc in candidate_cars.values()) and frame > FRAME_FINGERPRINT) or frame > 200
+    succeeded = car_fingerprint is not None
+    done = failed or succeeded
+
+    frame += 1
+
+  return car_fingerprint, finger