diff --git a/js/src/frontend-rs/frontend-rs.h b/js/src/frontend-rs/frontend-rs.h
index 58f33c166841..f48f58f73581 100644
--- a/js/src/frontend-rs/frontend-rs.h
+++ b/js/src/frontend-rs/frontend-rs.h
@@ -3,8 +3,18 @@
 #include <cstdlib>
 #include <new>
 
+struct Bytecode {
+  uint8_t *data;
+  uintptr_t len;
+  uintptr_t capacity;
+};
+
 extern "C" {
 
 void asdf();
 
+void free_bytecode(Bytecode bytecode);
+
+Bytecode run_jsparagus(const uint8_t *text, uintptr_t text_len);
+
 } // extern "C"
diff --git a/js/src/frontend-rs/src/lib.rs b/js/src/frontend-rs/src/lib.rs
index a66db10f7cf6..d572e21a5409 100644
--- a/js/src/frontend-rs/src/lib.rs
+++ b/js/src/frontend-rs/src/lib.rs
@@ -1,10 +1,46 @@
 extern crate parser;
 
+use std::mem;
+use std::slice;
+use std::str;
+
+#[repr(C)]
+pub struct Bytecode {
+    data: *mut u8,
+    len: usize,
+    capacity: usize,
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn run_jsparagus(text: *const u8, text_len: usize) -> Bytecode {
+    let text = str::from_utf8(slice::from_raw_parts(text, text_len)).expect("Invalid UTF8");
+    let mut bytecode = jsparagus(text);
+    let result = Bytecode {
+        data: bytecode.as_mut_ptr(),
+        len: bytecode.len(),
+        capacity: bytecode.capacity(),
+    };
+    mem::forget(bytecode);
+    result
+}
+
+#[no_mangle]
+pub unsafe extern "C" fn free_bytecode(bytecode: Bytecode) {
+    Vec::from_raw_parts(bytecode.data, bytecode.len, bytecode.capacity);
+}
+
+fn jsparagus(text: &str) -> Vec<u8> {
+    vec![64, 153] // ret
+
+    //vec![64, 112] // null, throw
+}
+
 #[no_mangle]
 pub extern "C" fn asdf() {
     println!("Hiiiii!");
     println!("{:?}", parser::parse_script("2+2"));
 }
+
 #[cfg(test)]
 mod tests {
     #[test]
diff --git a/js/src/frontend/Frontend2.cpp b/js/src/frontend/Frontend2.cpp
index 84799ea62557..d1ee4b42f654 100644
--- a/js/src/frontend/Frontend2.cpp
+++ b/js/src/frontend/Frontend2.cpp
@@ -6,6 +6,7 @@
 
 #include "frontend/Frontend2.h"
 
+// #include "frontend-rs/frontend-rs.h"
 #include "gc/AllocKind.h"
 
 using JS::RootedScript;
@@ -15,8 +16,14 @@ using namespace js::gc;
 using namespace js::frontend;
 using namespace js;
 
+// https://stackoverflow.com/questions/3407012/c-rounding-up-to-the-nearest-multiple-of-a-number
+int roundUp(int numToRound, int multiple) {
+  // assert(multiple && ((multiple & (multiple - 1)) == 0));
+  return (numToRound + multiple - 1) & -multiple;
+}
+
 bool InitScript(JSContext* cx, HandleScript script,
-                HandleFunction canoicalFunction) {
+                HandleFunction canoicalFunction, const Bytecode& bytecode) {
   uint32_t natoms = 0;
   if (!script->createScriptData(cx, natoms)) {
     return false;
@@ -37,8 +44,8 @@ bool InitScript(JSContext* cx, HandleScript script,
   mozilla::Span<JS::GCCellPtr> gcthings = script->data_->gcthings();
   gcthings[0] = JS::GCCellPtr(functionProtoScope);
 
-  uint32_t codeLength = 1;
-  uint32_t noteLength = 2;
+  uint32_t codeLength = bytecode.len;
+  uint32_t noteLength = roundUp(1 + bytecode.len, 4) - (1 + bytecode.len);
   uint32_t numResumeOffsets = 0;
   uint32_t numScopeNotes = 0;
   uint32_t numTryNotes = 0;
@@ -49,32 +56,65 @@ bool InitScript(JSContext* cx, HandleScript script,
   }
 
   jsbytecode* code = script->immutableScriptData()->code();
-  code[0] = JSOP_RETRVAL;
+  for (size_t i = 0; i < codeLength; i++) {
+    code[i] = bytecode.data[i];
+  }
 
   jssrcnote* notes = script->immutableScriptData()->notes();
-  notes[0] = SRC_NULL;
-  notes[1] = SRC_NULL;
+  for (size_t i = 0; i < noteLength; i++) {
+    notes[i] = SRC_NULL;
+  }
 
   return script->shareScriptData(cx);
 }
 
-bool Create(JSContext* cx, const char* bytes, size_t length) {
+static bool Execute(JSContext* cx, HandleScript script) {
+  RootedValue result(cx);
+  result.setUndefined();
+  if (!JS_ExecuteScript(cx, script, &result)) {
+    return false;
+  }
+
+  if (!result.isUndefined()) {
+    // Print.
+    RootedString str(cx, JS_ValueToSource(cx, result));
+    if (!str) {
+      return false;
+    }
+
+    UniqueChars utf8chars = JS_EncodeStringToUTF8(cx, str);
+    if (!utf8chars) {
+      return false;
+    }
+    printf("%s\n", utf8chars.get());
+  }
+  return true;
+}
+
+bool Create(JSContext* cx, const uint8_t* bytes, size_t length) {
+  // void free_bytecode(Bytecode bytecode);
+
+  // Bytecode run_jsparagus(const uint8_t *text, uintptr_t text_len);
+
+  Bytecode bytecode = run_jsparagus(bytes, length);
+
   JS::CompileOptions options(cx);
   options.setIntroductionType("js shell interactive")
       .setIsRunOnce(true)
       .setFileAndLine("typein", 1);
 
-  JS::SourceText<Utf8Unit> srcBuf;
-  if (!srcBuf.init(cx, bytes, length, JS::SourceOwnership::Borrowed)) {
-    return false;
-  }
+  // JS::SourceText<Utf8Unit> srcBuf;
+  // if (!srcBuf.init(cx, (const char*)bytes, length,
+  //                  JS::SourceOwnership::Borrowed)) {
+  //   return false;
+  // }
 
   ScriptSource* ss = cx->new_<ScriptSource>();
   if (!ss) {
     return false;
   }
 
-  ScriptSourceHolder ssHolder(ss);
+  ScriptSourceHolder ssHolder(ss);  // TODO
 
   if (!ss->initFromOptions(cx, options, mozilla::Nothing())) {
     return false;
@@ -105,14 +145,15 @@ bool Create(JSContext* cx, const char* bytes, size_t length) {
   RootedScript script(cx,
                       JSScript::Create(cx, options, sso, 0, length, 0, length));
 
-  if (!InitScript(cx, script, nullptr)) {
+  if (!InitScript(cx, script, canoicalFunction, bytecode)) {
     return false;
   }
 
-  RootedValue result(cx);
-  if (!JS_ExecuteScript(cx, script, &result)) {
+  if (!Execute(cx, script)) {
     return false;
   }
 
+  free_bytecode(bytecode);
+
   return true;
 }
diff --git a/js/src/frontend/Frontend2.h b/js/src/frontend/Frontend2.h
index 41dacb72f593..5bab24d5b11b 100644
--- a/js/src/frontend/Frontend2.h
+++ b/js/src/frontend/Frontend2.h
@@ -17,6 +17,6 @@
 
 bool InitScript(JSContext* cx, JS::HandleScript script,
                 JS::HandleFunction functionProto);
-bool Create(JSContext* cx, const char* bytes, size_t length);
+bool Create(JSContext* cx, const uint8_t* bytes, size_t length);
 
 #endif /* frontend_Frontend2_h */
diff --git a/js/src/frontend/Parser.cpp b/js/src/frontend/Parser.cpp
index d595ffccab77..64e79f4cee32 100644
--- a/js/src/frontend/Parser.cpp
+++ b/js/src/frontend/Parser.cpp
@@ -36,7 +36,6 @@
 
 #include "builtin/ModuleObject.h"
 #include "builtin/SelfHostingDefines.h"
-#include "frontend-rs/frontend-rs.h"
 #include "frontend/BytecodeCompiler.h"
 #include "frontend/FoldConstants.h"
 #include "frontend/ModuleSharedContext.h"
diff --git a/js/src/shell/js.cpp b/js/src/shell/js.cpp
index 38ff11b4c3d9..8a8ce7a773d5 100644
--- a/js/src/shell/js.cpp
+++ b/js/src/shell/js.cpp
@@ -10051,7 +10051,8 @@ static MOZ_MUST_USE bool ProcessArgs(JSContext* cx, OptionParser* op) {
 #endif  // JS_BUILD_BINAST
 
   if (op->getBoolOption("rust-frontend")) {
-    return Create(cx, "x", 1);
+    AutoReportException are(cx);
+    return Create(cx, (const unsigned char*)"x", 1);
   }
 
   if (filePaths.empty() && utf8FilePaths.empty() && codeChunks.empty() &&
diff --git a/js/src/vm/JSScript.h b/js/src/vm/JSScript.h
index 8b30e2d5faee..f93cb9c7c417 100644
--- a/js/src/vm/JSScript.h
+++ b/js/src/vm/JSScript.h
@@ -25,6 +25,7 @@
 
 #include "jstypes.h"
 
+#include "frontend-rs/frontend-rs.h"
 #include "frontend/BinASTRuntimeSupport.h"
 #include "frontend/NameAnalysisTypes.h"
 #include "gc/Barrier.h"
@@ -2226,7 +2227,8 @@ class JSScript : public js::BaseScript {
       js::MutableHandle<JS::GCVector<js::Scope*>> scopes);
 
   friend bool InitScript(JSContext* cx, JS::HandleScript script,
-                         JS::HandleFunction functionProto);
+                         JS::HandleFunction canoicalFunction,
+                         const Bytecode& bytecode);
 
  private:
   JSScript(JS::Realm* realm, uint8_t* stubEntry,