diff --git a/junctions/src/main/scala/addrmap.scala b/junctions/src/main/scala/addrmap.scala
index 5fa34483..275314b5 100644
--- a/junctions/src/main/scala/addrmap.scala
+++ b/junctions/src/main/scala/addrmap.scala
@@ -16,7 +16,6 @@ case object PPNBits extends Field[Int]
 case object VPNBits extends Field[Int]
 
 case object GlobalAddrMap extends Field[AddrMap]
-case object MMIOBase extends Field[BigInt]
 
 trait HasAddrMapParameters {
   implicit val p: Parameters
@@ -30,12 +29,12 @@ trait HasAddrMapParameters {
   val pgLevelBits = p(PgLevelBits)
   val asIdBits = p(ASIdBits)
 
-  val addrMap = new AddrHashMap(p(GlobalAddrMap), p(MMIOBase))
+  val addrMap = new AddrHashMap(p(GlobalAddrMap))
 }
 
 abstract class MemRegion { def size: BigInt }
 
-case class MemSize(size: BigInt, prot: Int) extends MemRegion
+case class MemSize(size: BigInt, prot: Int, cacheable: Boolean = false) extends MemRegion
 case class MemSubmap(size: BigInt, entries: AddrMap) extends MemRegion
 
 object AddrMapConsts {
@@ -55,7 +54,7 @@ class AddrMapProt extends Bundle {
 
 case class AddrMapEntry(name: String, start: Option[BigInt], region: MemRegion)
 
-case class AddrHashMapEntry(port: Int, start: BigInt, size: BigInt, prot: Int)
+case class AddrHashMapEntry(port: Int, start: BigInt, size: BigInt, prot: Int, cacheable: Boolean)
 
 class AddrMap(entries: Seq[AddrMapEntry]) extends scala.collection.IndexedSeq[AddrMapEntry] {
   
@@ -65,17 +64,19 @@ class AddrMap(entries: Seq[AddrMapEntry]) extends scala.collection.IndexedSeq[Ad
 
   def countSlaves: Int = {
     this map { entry: AddrMapEntry => entry.region match {
-      case MemSize(_, _) => 1
+      case MemSize(_, _, _) => 1
       case MemSubmap(_, submap) => submap.countSlaves
     }} reduceLeft(_ + _)
   }
+
+  override def tail: AddrMap = new AddrMap(entries.tail)
 }
 
 object AddrMap {
   def apply(elems: AddrMapEntry*): AddrMap = new AddrMap(elems)
 }
 
-class AddrHashMap(addrmap: AddrMap, start: BigInt) {
+class AddrHashMap(addrmap: AddrMap, start: BigInt = BigInt(0)) {
   val mapping = new HashMap[String, AddrHashMapEntry]
 
   private def genPairs(am: AddrMap, start: BigInt): Seq[(String, AddrHashMapEntry)] = {
@@ -84,18 +85,18 @@ class AddrHashMap(addrmap: AddrMap, start: BigInt) {
     var pairs = Seq[(String, AddrHashMapEntry)]()
     am.foreach { case AddrMapEntry(name, startOpt, region) =>
       region match {
-        case MemSize(size, prot) => {
+        case MemSize(size, prot, cacheable) => {
           if (!startOpt.isEmpty) base = startOpt.get
-          pairs = (name, AddrHashMapEntry(ind, base, size, prot)) +: pairs
+          pairs = (name, AddrHashMapEntry(ind, base, size, prot, cacheable)) +: pairs
           base += size
           ind += 1
         }
         case MemSubmap(size, submap) => {
           if (!startOpt.isEmpty) base = startOpt.get
           val subpairs = genPairs(submap, base).map {
-            case (subname, AddrHashMapEntry(subind, subbase, subsize, prot)) =>
+            case (subname, AddrHashMapEntry(subind, subbase, subsize, prot, cacheable)) =>
               (name + ":" + subname,
-                AddrHashMapEntry(ind + subind, subbase, subsize, prot))
+                AddrHashMapEntry(ind + subind, subbase, subsize, prot, cacheable))
           }
           pairs = subpairs ++ pairs
           ind += subpairs.size
@@ -111,17 +112,29 @@ class AddrHashMap(addrmap: AddrMap, start: BigInt) {
   def nEntries: Int = mapping.size
   def apply(name: String): AddrHashMapEntry = mapping(name)
   def get(name: String): Option[AddrHashMapEntry] = mapping.get(name)
-  def sortedEntries(): Seq[(String, BigInt, BigInt, Int)] = {
-    val arr = new Array[(String, BigInt, BigInt, Int)](mapping.size)
-    mapping.foreach { case (name, AddrHashMapEntry(port, base, size, prot)) =>
-      arr(port) = (name, base, size, prot)
+  def sortedEntries(): Seq[(String, BigInt, BigInt, Int, Boolean)] = {
+    val arr = new Array[(String, BigInt, BigInt, Int, Boolean)](mapping.size)
+    mapping.foreach { case (name, AddrHashMapEntry(port, base, size, prot, cacheable)) =>
+      arr(port) = (name, base, size, prot, cacheable)
     }
     arr.toSeq
   }
 
+  def isInRegion(name: String, addr: UInt): Bool = {
+    val start = mapping(name).start
+    val size = mapping(name).size
+    UInt(start) <= addr && addr < UInt(start + size)
+  }
+
+  def isCacheable(addr: UInt): Bool = {
+    sortedEntries().map { case (_, base, size, _, cacheable) =>
+      UInt(base) <= addr && addr < UInt(base + size) && Bool(cacheable)
+    }.reduce(_ || _)
+  }
+
   def isValid(addr: UInt): Bool = {
     addr < UInt(start) || sortedEntries().map {
-      case (_, base, size, _) =>
+      case (_, base, size, _, _) =>
         addr >= UInt(base) && addr < UInt(base + size)
     }.reduceLeft(_ || _)
   }
@@ -129,7 +142,7 @@ class AddrHashMap(addrmap: AddrMap, start: BigInt) {
   def getProt(addr: UInt): AddrMapProt = {
     val protBits = Mux(addr < UInt(start),
       Bits(AddrMapConsts.RWX, 3),
-      Mux1H(sortedEntries().map { case (_, base, size, prot) =>
+      Mux1H(sortedEntries().map { case (_, base, size, prot, _) =>
         (addr >= UInt(base) && addr < UInt(base + size), Bits(prot, 3))
       }))
     new AddrMapProt().fromBits(protBits)
diff --git a/junctions/src/main/scala/nasti.scala b/junctions/src/main/scala/nasti.scala
index cc2a3a98..cbb6e729 100644
--- a/junctions/src/main/scala/nasti.scala
+++ b/junctions/src/main/scala/nasti.scala
@@ -534,7 +534,7 @@ class NastiRecursiveInterconnect(
   addrmap.zip(realAddrMap).zip(xbar.io.slaves).zipWithIndex.foreach {
     case (((entry, (start, size)), xbarSlave), i) => {
       entry.region match {
-        case MemSize(_, _) =>
+        case MemSize(_, _, _) =>
           io.slaves(slaveInd) <> xbarSlave
           slaveInd += 1
         case MemSubmap(_, submap) =>