add comms handler to get MCU UID (#1212)

* cleanup first

* get uid

* add to bootstub and test

* fix pedal

* match that

Co-authored-by: Comma Device <device@comma.ai>

board/flasher.h

@@ -41,6 +41,13 @@ int comms_control_handler(ControlPacket_t *req, uint8_t *resp) {
         resp[1] = 0xff;
       }
       break;
+    // **** 0xc3: fetch MCU UID
+    case 0xc3:
+      #ifdef UID_BASE
+        (void)memcpy(resp, ((uint8_t *)UID_BASE), 12);
+        resp_len = 12;
+      #endif
+      break;
     // **** 0xd0: fetch serial number
     case 0xd0:
       #ifndef STM32F2

board/main_comms.h

@@ -147,7 +147,7 @@ int comms_control_handler(ControlPacket_t *req, uint8_t *resp) {
       resp[0] = hw_type;
       resp_len = 1;
       break;
-    // **** 0xd0: fetch serial number
+    // **** 0xc2: CAN health stats
     case 0xc2:
       COMPILE_TIME_ASSERT(sizeof(can_health_t) <= USBPACKET_MAX_SIZE);
       if (req->param1 < 3U) {
@@ -160,6 +160,12 @@ int comms_control_handler(ControlPacket_t *req, uint8_t *resp) {
         (void)memcpy(resp, &can_health[req->param1], resp_len);
       }
       break;
+    // **** 0xc3: fetch MCU UID
+    case 0xc3:
+      (void)memcpy(resp, ((uint8_t *)UID_BASE), 12);
+      resp_len = 12;
+      break;
+    // **** 0xd0: fetch serial (aka the provisioned dongle ID)
     case 0xd0:
       // addresses are OTP
       if (req->param1 == 1U) {

board/provision.h

@@ -1,3 +1,6 @@
+// this is where we manage the dongle ID assigned during our
+// manufacturing. aside from this, there's a UID for the MCU
+
 #define PROVISION_CHUNK_LEN 0x20
 
 void get_provision_chunk(uint8_t *resp) {

python/__init__.py

@@ -5,6 +5,7 @@ import time
 import usb1
 import struct
 import hashlib
+import binascii
 import datetime
 import traceback
 import warnings
@@ -588,14 +589,28 @@ class Panda:
     return self.get_type() in Panda.INTERNAL_DEVICES
 
   def get_serial(self):
+    """
+      Returns the comma-issued dongle ID from our provisioning
+    """
     dat = self._handle.controlRead(Panda.REQUEST_IN, 0xd0, 0, 0, 0x20)
     hashsig, calc_hash = dat[0x1c:], hashlib.sha1(dat[0:0x1c]).digest()[0:4]
     assert(hashsig == calc_hash)
     return [dat[0:0x10].decode("utf8"), dat[0x10:0x10 + 10].decode("utf8")]
 
   def get_usb_serial(self):
+    """
+      Returns the serial number reported from the USB descriptor;
+      matches the MCU UID
+    """
     return self._serial
 
+  def get_uid(self):
+    """
+      Returns the UID from the MCU
+    """
+    dat = self._handle.controlRead(Panda.REQUEST_IN, 0xc3, 0, 0, 12)
+    return binascii.hexlify(dat).decode()
+
   def get_secret(self):
     return self._handle.controlRead(Panda.REQUEST_IN, 0xd0, 1, 0, 0x10)
 

tests/hitl/2_health.py

@@ -53,6 +53,10 @@ def test_hw_type(p):
   mcu_type = p.get_mcu_type()
   assert mcu_type is not None
 
+  app_uid =  p.get_uid()
+  usb_serial = p.get_usb_serial()
+  assert app_uid == usb_serial
+
   p.reset(enter_bootstub=True, reconnect=True)
   p.close()
   time.sleep(3)
@@ -60,6 +64,7 @@ def test_hw_type(p):
     assert pp.bootstub
     assert pp.get_type() == hw_type, "Bootstub and app hw type mismatch"
     assert pp.get_mcu_type() == mcu_type, "Bootstub and app MCU type mismatch"
+    assert pp.get_uid() == app_uid
 
 
 @test_all_pandas