Merge pull request #809 from ucb-bar/better-multirocc

Add WithMultiRoCCFromBuildRoCC to make heterogeneous accelerator configs easier

generators/chipyard/src/main/scala/ConfigFragments.scala

@@ -83,6 +83,17 @@ class WithMultiRoCC extends Config((site, here, up) => {
   case BuildRoCC => site(MultiRoCCKey).getOrElse(site(TileKey).hartId, Nil)
 })
 
+/**
+ * Assigns what was previously in the BuildRoCC key to specific harts with MultiRoCCKey
+ * Must be paired with WithMultiRoCC
+ */
+class WithMultiRoCCFromBuildRoCC(harts: Int*) extends Config((site, here, up) => {
+  case BuildRoCC => Nil
+  case MultiRoCCKey => up(MultiRoCCKey, site) ++ harts.distinct.map { i =>
+    (i -> up(BuildRoCC, site))
+  }
+})
+
 /**
  * Config fragment to add Hwachas to cores based on hart
  *