diff --git a/script/src/Main.scala b/script/src/Main.scala
index 5118c1984b..13c0a45ff1 100644
--- a/script/src/Main.scala
+++ b/script/src/Main.scala
@@ -635,6 +635,18 @@ object Main:
     println(ujson.write(Map("config" -> testPlans)))
   end generateTestPlan
 
+  def nixResolvePath(attr: String): String =
+    os.proc(
+      "nix",
+      "build",
+      "--no-link",
+      "--no-warn-dirty",
+      "--print-out-paths",
+      attr
+    ).call()
+      .out
+      .trim()
+
   @main
   def generateRegressionTestPlan(runnersAmount: Int): Unit =
     // Find emulator configs
@@ -647,21 +659,9 @@ object Main:
           // but all we need is the <config> name.
           path.segments.toSeq.reverse.drop(1).head
 
-    def nixBuild(attr: String): String =
-      os.proc(
-        "nix",
-        "build",
-        "--no-link",
-        "--no-warn-dirty",
-        "--print-out-paths",
-        attr
-      ).call()
-        .out
-        .trim()
-
     import scala.util.chaining._
     val testPlans: Seq[String] = emulatorConfigs.flatMap: configName =>
-      val allCasesPath = nixBuild(s".#t1.$configName.cases.all")
+      val allCasesPath = nixResolvePath(s".#t1.$configName.cases.all")
       os.walk(os.Path(allCasesPath) / "configs")
         .filter: path =>
           path.ext == "json"
@@ -700,5 +700,50 @@ object Main:
       .pipe(println)
   end generateRegressionTestPlan
 
+  @main
+  def difftest(
+    @arg(
+      name = "config",
+      short = 'c',
+      doc = "specify the elaborate config for running test case"
+    ) config: String,
+    @arg(
+      name = "case-attr",
+      short = 'C',
+      doc = "Specify test case attribute to run diff test"
+    ) caseAttr: String,
+  ): Unit =
+    Logger.info("Building simulator")
+    val difftest = nixResolvePath(".#t1-simulator")
+
+    val fullCaseAttr = s".#t1.${config}.cases.${caseAttr}"
+    Logger.info(s"Building cases ${fullCaseAttr}")
+    val caseElf = nixResolvePath(fullCaseAttr)
+
+    import scala.util.chaining._
+    val configJson = nixResolvePath(s".#t1.${config}.elaborateConfigJson")
+      .pipe(p => os.Path(p))
+      .pipe(p => os.read(p))
+      .pipe(text => ujson.read(text))
+    val dLen = configJson.obj("parameter").obj("dLen").num.toInt
+    val vLen = configJson.obj("parameter").obj("vLen").num.toInt
+    Logger.info(s"Using DLEN ${dLen}, VLEN ${vLen}")
+
+    Logger.info(s"Running emulator to get event log")
+    val eventLog = nixResolvePath(s"${fullCaseAttr}.emu-result")
+
+    os.proc(Seq(
+      s"${difftest}/bin/t1-simulator",
+      "--vlen",
+      vLen.toString(),
+      "--dlen",
+      dLen.toString(),
+      "--elf-file",
+      s"${caseElf}/bin/${caseAttr}.elf",
+      "--log-file",
+      s"${eventLog}/rtl-event.log",
+    )).call(stdout = os.Inherit, stderr = os.Inherit)
+  end difftest
+
   def main(args: Array[String]): Unit = ParserForMethods(this).runOrExit(args)
 end Main