tilelink: make bus xbar protected so it can be suggestNamed

src/main/scala/coreplex/MemoryBus.scala

@@ -44,6 +44,8 @@ case object MemoryBusParams extends Field[MemoryBusParams]
 
 /** Wrapper for creating TL nodes from a bus connected to the back of each mem channel */
 class MemoryBus(params: MemoryBusParams)(implicit p: Parameters) extends TLBusWrapper(params)(p) {
+  xbar.suggestName("MemoryBus")
+
   def fromCoherenceManager: TLInwardNode = inwardBufNode
   def toDRAMController: TLOutwardNode = outwardBufNode
   def toVariableWidthSlave: TLOutwardNode = outwardFragNode

src/main/scala/coreplex/PeripheryBus.scala

@@ -22,6 +22,8 @@ case class PeripheryBusParams(
 case object PeripheryBusParams extends Field[PeripheryBusParams]
 
 class PeripheryBus(params: PeripheryBusParams)(implicit p: Parameters) extends TLBusWrapper(params) {
+  xbar.suggestName("PeripheryBus")
+
   def toFixedWidthSingleBeatSlave(widthBytes: Int) = {
     TLFragmenter(widthBytes, params.blockBytes)(outwardWWNode)
   }

src/main/scala/coreplex/SystemBus.scala

@@ -18,6 +18,8 @@ case class SystemBusParams(
 case object SystemBusParams extends Field[SystemBusParams]
 
 class SystemBus(params: SystemBusParams)(implicit p: Parameters) extends TLBusWrapper(params) {
+  xbar.suggestName("SystemBus")
+
   private val master_splitter = LazyModule(new TLSplitter)  // Allows cycle-free connection to external networks
   inwardNode :=* master_splitter.node
   def busView = master_splitter.node.edgesIn.head

src/main/scala/tilelink/Bus.scala

@@ -30,7 +30,7 @@ abstract class TLBusWrapper(params: TLBusParams)(implicit p: Parameters) extends
   private val delayProb = p(TLBusDelayProbability)
 
   private val delayer = if (delayProb > 0.0) Some(LazyModule(new TLDelayer(delayProb))) else None
-  private val xbar = LazyModule(new TLXbar)
+  protected val xbar = LazyModule(new TLXbar)
   private val master_buffer = LazyModule(new TLBuffer(masterBuffering))
   private val slave_buffer = LazyModule(new TLBuffer(slaveBuffering))
   private val slave_frag = LazyModule(new TLFragmenter(beatBytes, blockBytes))