diff --git a/.gitignore b/.gitignore
index 32ea314..a507599 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,8 +1,22 @@
+*.*
+*
+!*/
+!Makefile
+!*.mk
+!*.scala
+!*.[cSh]
+!*.v
+!*.cpp
+!*.cc
+!.gitignore
+!.scalafmt.conf
+!build.sc
+!README.md
+build/
+
 # mill
 out/
 .bsp/
 .idea/
 .idea_modules/
 test_run_dir/
-
-build/
diff --git a/Makefile b/Makefile
index fa6b95c..8a92776 100644
--- a/Makefile
+++ b/Makefile
@@ -1,10 +1,15 @@
 BUILD_DIR = ./build
 
+export PATH := $(PATH):$(abspath ./utils)
+
+$(BUILD_DIR):
+	mkdir -p $@
+
 test:
 	mill -i __.test
 
-verilog:
-	mkdir -p $(BUILD_DIR)
+verilog: $(BUILD_DIR)
+	$(call git_commit, "generate verilog")
 	mill -i __.test.runMain Elaborate -td $(BUILD_DIR)
 
 help:
@@ -26,3 +31,9 @@ clean:
 	-rm -rf $(BUILD_DIR)
 
 .PHONY: test verilog help compile bsp reformat checkformat clean
+
+sim:
+	$(call git_commit, "sim RTL") # DO NOT REMOVE THIS LINE!!!
+	@echo "Write this Makefile by yourself."
+
+-include ../Makefile
diff --git a/README.md b/README.md
index 0a27c83..906c4e2 100644
--- a/README.md
+++ b/README.md
@@ -29,3 +29,9 @@ To generate Verilog:
 ```bash
 make verilog
 ```
+
+## Change FIRRTL Compiler
+
+You can change the FIRRTL compiler between SFC (Scala-based FIRRTL compiler) and
+MFC (MLIR-based FIRRTL compiler) by modifying the `useMFC` variable in `playground/src/Elaborate.scala`.
+The latter one requires `firtool`, which is included under `utils/`.
diff --git a/build.sc b/build.sc
index 7ef4e51..11a432b 100644
--- a/build.sc
+++ b/build.sc
@@ -7,24 +7,33 @@ import mill.scalalib.TestModule.Utest
 import mill.bsp._
 
 object playground extends ScalaModule with ScalafmtModule { m =>
-  override def scalaVersion = "2.13.8"
+  val useChisel5 = true
+  override def scalaVersion = "2.13.10"
   override def scalacOptions = Seq(
     "-language:reflectiveCalls",
     "-deprecation",
     "-feature",
-    "-Xcheckinit",
-    "-P:chiselplugin:genBundleElements"
+    "-Xcheckinit"
   )
   override def ivyDeps = Agg(
-    ivy"edu.berkeley.cs::chisel3:3.5.4",
+    if (useChisel5) ivy"org.chipsalliance::chisel:5.0.0" else
+    ivy"edu.berkeley.cs::chisel3:3.6.0",
   )
   override def scalacPluginIvyDeps = Agg(
-    ivy"edu.berkeley.cs:::chisel3-plugin:3.5.4",
+    if (useChisel5) ivy"org.chipsalliance:::chisel-plugin:5.0.0" else
+    ivy"edu.berkeley.cs:::chisel3-plugin:3.6.0",
   )
-  object test extends Tests with Utest {
+  object test extends Tests with Utest with ScalafmtModule {
     override def ivyDeps = m.ivyDeps() ++ Agg(
-      ivy"com.lihaoyi::utest:0.7.10",
-      ivy"edu.berkeley.cs::chiseltest:0.5.4",
+      ivy"com.lihaoyi::utest:0.8.1",
+      if (useChisel5) ivy"edu.berkeley.cs::chiseltest:5.0-SNAPSHOT" else
+      ivy"edu.berkeley.cs::chiseltest:0.6.0",
     )
   }
+  def repositoriesTask = T.task { Seq(
+    coursier.MavenRepository("https://maven.aliyun.com/repository/central"),
+    coursier.MavenRepository("https://repo.scala-sbt.org/scalasbt/maven-releases"),
+    coursier.MavenRepository("https://oss.sonatype.org/content/repositories/releases"),
+    coursier.MavenRepository("https://oss.sonatype.org/content/repositories/snapshots"),
+  ) ++ super.repositoriesTask() }
 }
diff --git a/playground/src/Elaborate.scala b/playground/src/Elaborate.scala
index 67345a1..6a95895 100644
--- a/playground/src/Elaborate.scala
+++ b/playground/src/Elaborate.scala
@@ -1,3 +1,7 @@
+import circt.stage._
+
 object Elaborate extends App {
-  (new chisel3.stage.ChiselStage).execute(args, Seq(chisel3.stage.ChiselGeneratorAnnotation(() => new GCD())))
+  def top = new GCD()
+  val generator = Seq(chisel3.stage.ChiselGeneratorAnnotation(() => top))
+  (new ChiselStage).execute(args, generator :+ CIRCTTargetAnnotation(CIRCTTarget.Verilog))
 }
diff --git a/utils/firtool b/utils/firtool
new file mode 100755
index 0000000..1ece37d
--- /dev/null
+++ b/utils/firtool
@@ -0,0 +1,2 @@
+#!/usr/bin/env bash
+firtool.elf.strip --lowering-options=disallowLocalVariables,disallowPackedArrays,locationInfoStyle=wrapInAtSquareBracket $@
diff --git a/utils/firtool.elf.strip b/utils/firtool.elf.strip
new file mode 100755
index 0000000..749b297
Binary files /dev/null and b/utils/firtool.elf.strip differ