diff --git a/.gitmodules b/.gitmodules
index 09c8055e..af688115 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -10,6 +10,9 @@
 [submodule "rocket"]
 	path = rocket
 	url = https://github.com/ucb-bar/rocket.git
+[submodule "chisel"]
+	path = chisel2
+	url = https://github.com/ucb-bar/chisel.git
 [submodule "hardfloat"]
 	path = hardfloat
 	url = https://github.com/ucb-bar/berkeley-hardfloat.git
@@ -31,3 +34,9 @@
 [submodule "torture"]
 	path = torture
 	url = https://github.com/ucb-bar/riscv-torture.git
+[submodule "chisel3"]
+	path = chisel3
+	url = https://github.com/ucb-bar/chisel3.git
+[submodule "firrtl"]
+	path = firrtl
+	url = https://github.com/ucb-bar/firrtl.git
diff --git a/Makefrag b/Makefrag
index 5b923236..33cd334e 100644
--- a/Makefrag
+++ b/Makefrag
@@ -8,10 +8,16 @@ PROJECT := rocketchip
 CXX ?= g++
 CXXFLAGS := -O1
 
-SBT := java -Xmx2048M -Xss8M -XX:MaxPermSize=256M -jar sbt-launch.jar
+CHISEL_VERSION=2
+
+SBT := CHISEL_SUBMODULE="chisel$(CHISEL_VERSION)" java -Xmx2048M -Xss8M -XX:MaxPermSize=256M -jar sbt-launch.jar
 SHELL := /bin/bash
 
+ifeq ($(CHISEL_VERSION),2)
 CHISEL_ARGS := $(PROJECT) $(MODEL) $(CONFIG) --W0W --minimumCompatibility 3.0.0 --backend $(BACKEND) --configName $(CONFIG) --compileInitializationUnoptimized --targetDir $(generated_dir)
+else
+CHISEL_ARGS := --W0W --minimumCompatibility 3.0.0 --backend $(BACKEND) --configName $(CONFIG) --compileInitializationUnoptimized --targetDir $(generated_dir)
+endif
 
 src_path = src/main/scala
 default_submodules = . junctions uncore hardfloat rocket zscale groundtest context-dependent-environments
diff --git a/chisel2 b/chisel2
new file mode 160000
index 00000000..95c889ee
--- /dev/null
+++ b/chisel2
@@ -0,0 +1 @@
+Subproject commit 95c889ee0cb9ff177e1bbfa8dc4ed09efb5364c1
diff --git a/chisel3 b/chisel3
new file mode 160000
index 00000000..e6ee1ddb
--- /dev/null
+++ b/chisel3
@@ -0,0 +1 @@
+Subproject commit e6ee1ddb79c219e313e530a029d8402274fbaebc
diff --git a/firrtl b/firrtl
new file mode 160000
index 00000000..8ae6ece9
--- /dev/null
+++ b/firrtl
@@ -0,0 +1 @@
+Subproject commit 8ae6ece99dfadb8d3dd25acc3549a975e3c40bbc
diff --git a/fsim/Makefile b/fsim/Makefile
index 8e765a34..90407690 100644
--- a/fsim/Makefile
+++ b/fsim/Makefile
@@ -15,7 +15,7 @@ mem_gen = $(base_dir)/fsim/fpga_mem_gen
 sim_dir = .
 output_dir = $(sim_dir)/output
 
-BACKEND ?= fpga
+BACKEND ?= v
 CONFIG ?= DefaultFPGAConfig
 TB ?= rocketTestHarness
 
diff --git a/project/build.scala b/project/build.scala
index 85238c0f..f1c263cb 100644
--- a/project/build.scala
+++ b/project/build.scala
@@ -15,7 +15,7 @@ object BuildSettings extends Build {
     libraryDependencies ++= Seq("org.scala-lang" % "scala-reflect" % scalaVersion.value)
   )
 
-  lazy val chisel     = project
+  lazy val chisel     = project in file(sys.env.getOrElse("CHISEL_SUBMODULE", "chisel2"))
   lazy val cde        = project in file("context-dependent-environments")
   lazy val hardfloat  = project.dependsOn(chisel)
   lazy val junctions  = project.dependsOn(chisel, cde)
diff --git a/regression/Makefile b/regression/Makefile
index cda2eaf1..8bdda86d 100644
--- a/regression/Makefile
+++ b/regression/Makefile
@@ -16,6 +16,9 @@ ifeq ($(TORTURE_CONFIG),)
 $(error Set TORTURE_CONFIG to the torture configuration to run)
 endif
 
+# The version of Chisel to use
+CHISEL_VERSION ?= 2
+
 # The top-level directory that contains rocket-chip
 TOP ?= ..
 
@@ -67,7 +70,7 @@ fsim-asm-tests: stamps/$(CONFIG)/fsim-asm-tests.stamp
 fsim-bmark-tests: stamps/$(CONFIG)/fsim-bmark-tests.stamp
 fsim-torture: stamps/$(CONFIG)/fsim-torture-$(TORTURE_CONFIG).stamp
 
-submodule_names = chisel context-dependent-environments dramsim2 groundtest hardfloat junctions rocket torture uncore zscale $(ROCKETCHIP_ADDONS)
+submodule_names = chisel2 chisel3 context-dependent-environments dramsim2 groundtest hardfloat junctions rocket torture uncore zscale $(ROCKETCHIP_ADDONS)
 
 # Checks out all the rocket-chip submodules
 stamps/other-submodules.stamp:
@@ -90,28 +93,28 @@ $(RISCV)/install.stamp:
 # Builds the various simulators
 stamps/$(CONFIG)/%-verilog.stamp: stamps/other-submodules.stamp $(RISCV)/install.stamp
 	mkdir -p $(dir $@)
-	+flock -x $(dir $@)/chisel-lock $(MAKE) -C $(abspath $(TOP))/$(patsubst stamps/$(CONFIG)/%-verilog.stamp,%,$@) CONFIG=$(CONFIG) RISCV=$(abspath $(RISCV)) verilog
-	date > $@	
+	+flock -x $(dir $@)/chisel-lock $(MAKE) -C $(abspath $(TOP))/$(patsubst stamps/$(CONFIG)/%-verilog.stamp,%,$@) CONFIG=$(CONFIG) RISCV=$(abspath $(RISCV)) CHISEL_VERSION=$(CHISEL_VERSION) verilog
+	date > $@
 
 stamps/$(CONFIG)/%-ndebug.stamp: stamps/other-submodules.stamp $(RISCV)/install.stamp
 	mkdir -p $(dir $@)
-	+flock -x $(dir $@)/chisel-lock $(MAKE) -C $(abspath $(TOP))/$(patsubst stamps/$(CONFIG)/%-ndebug.stamp,%,$@) CONFIG=$(CONFIG) RISCV=$(abspath $(RISCV))
+	+flock -x $(dir $@)/chisel-lock $(MAKE) -C $(abspath $(TOP))/$(patsubst stamps/$(CONFIG)/%-ndebug.stamp,%,$@) CONFIG=$(CONFIG) RISCV=$(abspath $(RISCV)) CHISEL_VERSION=$(CHISEL_VERSION)
 	date > $@
 
 stamps/$(CONFIG)/%-debug.stamp: stamps/other-submodules.stamp $(RISCV)/install.stamp
 	mkdir -p $(dir $@)
-	+flock -x $(dir $@)/chisel-lock $(MAKE) -C $(abspath $(TOP))/$(patsubst stamps/$(CONFIG)/%-debug.stamp,%,$@) CONFIG=$(CONFIG) RISCV=$(abspath $(RISCV)) debug
+	+flock -x $(dir $@)/chisel-lock $(MAKE) -C $(abspath $(TOP))/$(patsubst stamps/$(CONFIG)/%-debug.stamp,%,$@) CONFIG=$(CONFIG) RISCV=$(abspath $(RISCV)) CHISEL_VERSION=$(CHISEL_VERSION) debug
 	date > $@
 
 # Runs tests on one of the simulators
 stamps/$(CONFIG)/%-asm-tests.stamp: stamps/$(CONFIG)/%-ndebug.stamp
 	mkdir -p $(dir $@)
-	$(MAKE) -C $(abspath $(TOP))/$(patsubst stamps/$(CONFIG)/%-asm-tests.stamp,%,$@) CONFIG=$(CONFIG) RISCV=$(abspath $(RISCV)) run-asm-tests
+	$(MAKE) -C $(abspath $(TOP))/$(patsubst stamps/$(CONFIG)/%-asm-tests.stamp,%,$@) CONFIG=$(CONFIG) RISCV=$(abspath $(RISCV)) CHISEL_VERSION=$(CHISEL_VERSION) run-asm-tests
 	date > $@
 
 stamps/$(CONFIG)/%-bmark-tests.stamp: stamps/$(CONFIG)/%-ndebug.stamp
 	mkdir -p $(dir $@)
-	$(MAKE) -C $(abspath $(TOP))/$(patsubst stamps/$(CONFIG)/%-bmark-tests.stamp,%,$@) CONFIG=$(CONFIG) RISCV=$(abspath $(RISCV)) run-bmark-tests
+	$(MAKE) -C $(abspath $(TOP))/$(patsubst stamps/$(CONFIG)/%-bmark-tests.stamp,%,$@) CONFIG=$(CONFIG) RISCV=$(abspath $(RISCV)) CHISEL_VERSION=$(CHISEL_VERSION) run-bmark-tests
 	date > $@
 
 # The torture tests run subtly differently on the different targets, so they
diff --git a/src/main/scala/Backends.scala b/src/main/scala/Backends.scala
deleted file mode 100644
index 348d29e5..00000000
--- a/src/main/scala/Backends.scala
+++ /dev/null
@@ -1,55 +0,0 @@
-// See LICENSE for license details.
-
-package rocketchip
-
-import Chisel._
-import RocketChipBackend._
-import scala.collection.mutable.HashMap
-
-object RocketChipBackend {
-  val initMap = new HashMap[Module, Bool]()
-}
-
-class RocketChipBackend extends VerilogBackend
-{
-  initMap.clear()
-  override def emitPortDef(m: MemAccess, idx: Int) = {
-    val res = new StringBuilder()
-    for (node <- m.mem.inputs) {
-      if(node.name.contains("init"))
-         res.append("    .init(" + node.name + "),\n")
-    }
-    (if (idx == 0) res.toString else "") + super.emitPortDef(m, idx)
-  }
-
-  def addMemPin(c: Module) = {
-    for (m <- Driver.components) {
-      m bfs { _ match {
-        case mem: Mem[_] if mem.seqRead =>
-          connectMemPin(m, mem)
-        case _ =>
-      } }
-    }
-  }
-
-  def connectInitPin(c: Module) {
-    initMap(c) = c.addPin(Bool(INPUT), "init")
-    if (!(initMap contains c.parent)) connectInitPin(c.parent)
-    initMap(c) := initMap(c.parent)
-  }
-
-  def connectMemPin(c: Module, mem: Mem[_]) {
-    if (!(initMap contains c)) connectInitPin(c)
-    mem.inputs += initMap(c)
-  }
-
-  def addTopLevelPin(c: Module) = {
-    initMap(c) = c.addPin(Bool(INPUT), "init")
-  }
-
-  transforms += addTopLevelPin
-  transforms += addMemPin
-}
-
-class Fame1RocketChipBackend extends RocketChipBackend with Fame1Transform
-
diff --git a/vsim/Makefile b/vsim/Makefile
index 956d1ca4..9ea52b2c 100644
--- a/vsim/Makefile
+++ b/vsim/Makefile
@@ -15,7 +15,7 @@ mem_gen = $(base_dir)/vsim/vlsi_mem_gen
 sim_dir = .
 output_dir = $(sim_dir)/output
 
-BACKEND ?= rocketchip.RocketChipBackend
+BACKEND ?= v
 CONFIG ?= DefaultVLSIConfig
 TB ?= rocketTestHarness
 
diff --git a/vsim/Makefrag-verilog b/vsim/Makefrag-verilog
index 39ed5472..66034bc2 100644
--- a/vsim/Makefrag-verilog
+++ b/vsim/Makefrag-verilog
@@ -2,23 +2,53 @@
 # Verilog Generation
 #--------------------------------------------------------------------
 
-$(generated_dir)/$(MODEL).$(CONFIG).v $(generated_dir)/$(MODEL).$(CONFIG).d : $(chisel_srcs)
+ifeq ($(CHISEL_VERSION),2)
+$(generated_dir)/$(MODEL).$(CONFIG).v $(generated_dir)/$(MODEL).$(CONFIG).d $(generated_dir)/$(MODEL).$(CONFIG).prm : $(chisel_srcs)
 	cd $(base_dir) && mkdir -p $(generated_dir) && $(SBT) "run $(CHISEL_ARGS) --configDump --noInlineMem"
 	cd $(generated_dir) && \
 	if [ -a $(MODEL).$(CONFIG).conf ]; then \
 	  $(mem_gen) $(generated_dir)/$(MODEL).$(CONFIG).conf >> $(generated_dir)/$(MODEL).$(CONFIG).v; \
 	fi
 
-$(generated_dir)/consts.$(CONFIG).vh: $(generated_dir)/$(MODEL).$(CONFIG).v
+$(generated_dir)/memdessertMemDessert.$(CONFIG).v $(generated_dir)/memdessertMemDessert.$(CONFIG).d: $(base_dir)/$(src_path)/*.scala $(base_dir)/uncore/$(src_path)/*.scala
+	cd $(base_dir) && mkdir -p $(generated_dir) && $(SBT) "run $(PROJECT) MemDessert $(CONFIG) --backend v --targetDir $(generated_dir) --W0W --moduleNamePrefix memdessert --configName $(CONFIG)"
+
+else
+
+FIRRTL ?= $(base_dir)/firrtl/utils/bin/firrtl
+
+$(FIRRTL):
+	$(MAKE) -C $(base_dir)/firrtl root_dir=$(base_dir)/firrtl build
+
+# If I don't mark these as .SECONDARY then make will delete these internal
+# files.
+.SECONDARY: $(generated_dir)/$(MODEL).$(CONFIG).fir
+.SECONDARY: $(generated_dir)/MemDessert.$(CONFIG).fir
+
+$(generated_dir)/%.$(CONFIG).fir: $(chisel_srcs)
+	mkdir -p $(dir $@)
+	cd $(base_dir) && $(SBT) "run $(PROJECT) $(patsubst %.$(CONFIG).fir,%,$(notdir $@)) $(CONFIG) $(CHISEL_ARGS) --configDump --noInlineMem"
+	mv $(patsubst %.$(CONFIG).fir,%.fir,$@) $@
+
+$(generated_dir)/%.v $(generated_dir)/%.prm: $(generated_dir)/%.fir $(FIRRTL)
+	mkdir -p $(dir $@)
+	$(FIRRTL) $(patsubst %,-i %,$(filter %.fir,$^)) -o $@ -X verilog
+
+$(generated_dir)/memdessertMemDessert.$(CONFIG).v: $(generated_dir)/MemDessert.$(CONFIG).v
+	cat $(filter %.v,$^) \
+		| sed 's@MemDessert@memdessertMemDessert@g' \
+		| sed 's@Queue@memdessetQueue@g' \
+		> $@
+
+endif
+
+$(generated_dir)/consts.$(CONFIG).vh: $(generated_dir)/$(MODEL).$(CONFIG).prm
 	echo "\`ifndef CONST_VH" > $@
 	echo "\`define CONST_VH" >> $@
 	sed -r 's/\(([A-Za-z0-9_]+),([A-Za-z0-9_]+)\)/`define \1 \2/' $(patsubst %.v,%.prm,$<) >> $@
 	echo "\`define TBVFRAG \"$(MODEL).$(CONFIG).tb.vfrag\"" >> $@
 	echo "\`endif // CONST_VH" >> $@
 
-$(generated_dir)/memdessertMemDessert.$(CONFIG).v $(generated_dir)/memdessertMemDessert.$(CONFIG).d: $(base_dir)/$(src_path)/*.scala $(base_dir)/uncore/$(src_path)/*.scala
-	cd $(base_dir) && mkdir -p $(generated_dir) && $(SBT) "run $(PROJECT) MemDessert $(CONFIG) --backend v --targetDir $(generated_dir) --W0W --moduleNamePrefix memdessert --configName $(CONFIG)"
-
 #--------------------------------------------------------------------
 # Run
 #--------------------------------------------------------------------