diff --git a/generators/chipyard/src/main/scala/config/fragments/TileFragments.scala b/generators/chipyard/src/main/scala/config/fragments/TileFragments.scala
index c9493e785..b61b99f38 100644
--- a/generators/chipyard/src/main/scala/config/fragments/TileFragments.scala
+++ b/generators/chipyard/src/main/scala/config/fragments/TileFragments.scala
@@ -131,3 +131,8 @@ class WithRocketBoundaryBuffers(buffers: Option[RocketTileBoundaryBufferParams]
 class WithSV48IfPossible extends Config((site, here, up) => {
   case PgLevels => if (site(XLen) == 64) 4 /* Sv48 */ else up(PgLevels)
 })
+
+// Uses SV39 if possible, otherwise default to the Rocket Chip core default
+class WithSV39 extends Config((site, here, up) => {
+  case PgLevels => { require(site(XLen) == 64); 3; }
+})
diff --git a/generators/firechip/src/main/scala/TargetConfigs.scala b/generators/firechip/src/main/scala/TargetConfigs.scala
index fd3bb381b..8533d80bd 100644
--- a/generators/firechip/src/main/scala/TargetConfigs.scala
+++ b/generators/firechip/src/main/scala/TargetConfigs.scala
@@ -370,3 +370,11 @@ class FireSimLargeBoomCospikeConfig extends Config(
   new WithDefaultMemModel ++
   new WithFireSimConfigTweaks++
   new chipyard.LargeBoomV3Config)
+
+class FireSimLargeBoomSV39CospikeConfig extends Config(
+  new firesim.firesim.WithCospikeBridge ++
+  new WithDefaultFireSimBridges ++
+  new WithDefaultMemModel ++
+  new WithFireSimConfigTweaks++
+  new chipyard.config.WithSV39 ++
+  new chipyard.LargeBoomV3Config)