avr: re-introduce UID to new VALUE messages, set UID in VALUE response messages.

avr/modules/com2/main.asm

@@ -220,6 +220,25 @@ COM2_BeginMsgWithVariablePayload_l1:
   lsr r3                                   ; shift out COM2_PAYLOAD_FLAGS_UID
   brcc COM2_BeginMsgWithVariablePayload_l2
   ; write uid
+  rcall COM2_AddUidToBuffer
+COM2_BeginMsgWithVariablePayload_l2:
+  ret
+
+
+
+; ---------------------------------------------------------------------------
+; @routine COM2_AddUidToBuffer @global
+;
+; Write UID into buffer given by X.
+;
+; @return X   points to behind written uid
+; @param  R16 destination address
+; @param  R17 flags
+; @param  R18 command (e.g. CPRO_CMD_PING)
+; @param  X   pointer to packet buffer
+; @clobbers: r18, r19, r20, r21 (r16)
+
+COM2_AddUidToBuffer:
   push xh
     push xl
       rcall Utils_ReadUid                  ; (R16, X)
@@ -229,8 +248,8 @@ COM2_BeginMsgWithVariablePayload_l1:
   st X+, r19
   st X+, r20
   st X+, r21
-COM2_BeginMsgWithVariablePayload_l2:
   ret
+; @end