Silence some warnings

rtl/serv_rf_if.v

@@ -119,6 +119,8 @@ module serv_rf_if
 
       assign o_rs1 = i_rdata0;
       assign o_rs2 = i_rdata1;
+      assign o_csr = 1'b0;
+      assign o_csr_pc = 1'b0;
    end // else: !if(WITH_CSR)
    endgenerate
 endmodule

rtl/serv_state.v

@@ -155,6 +155,8 @@ module serv_state
 	misalign_trap_sync <= 1'b0;
    end // always @ (posedge i_clk)
       end else begin
+	 assign o_trap_taken = 0;
+	 assign o_ctrl_trap = 0;
 	 always @(*)
 	   o_pending_irq = 1'b0;
       end