Index: lib/Target/AVR/MCTargetDesc/AVRELFStreamer.h
===================================================================
--- /dev/null
+++ lib/Target/AVR/MCTargetDesc/AVRELFStreamer.h
@@ -0,0 +1,27 @@
+//===----- AVRELFStreamer.h - AVR Target Streamer --------------*- C++ -*--===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_AVR_ELF_STREAMER_H
+#define LLVM_AVR_ELF_STREAMER_H
+
+#include "AVRTargetStreamer.h"
+
+#include "llvm/MC/MCELFStreamer.h"
+
+/// A target streamer for an AVR ELF object file.
+class AVRELFStreamer : public AVRTargetStreamer {
+public:
+  AVRELFStreamer(MCStreamer &S, const MCSubtargetInfo &STI);
+
+  MCELFStreamer &getStreamer() {
+    return static_cast<MCELFStreamer &>(Streamer);
+  }
+};
+
+#endif
Index: lib/Target/AVR/MCTargetDesc/AVRELFStreamer.cpp
===================================================================
--- /dev/null
+++ lib/Target/AVR/MCTargetDesc/AVRELFStreamer.cpp
@@ -0,0 +1,60 @@
+#include "AVRELFStreamer.h"
+
+#include "llvm/Support/ELF.h"
+#include "llvm/Support/FormattedStream.h"
+
+static unsigned getEFlagsForFeatureSet(const FeatureBitset &Features) {
+  unsigned EFlags = 0;
+
+  // Set architecture
+  if (Features[AVR::ELFArchAVR1])
+    EFlags |= ELF::EF_AVR_ARCH_AVR1;
+  else if (Features[AVR::ELFArchAVR2])
+    EFlags |= ELF::EF_AVR_ARCH_AVR2;
+  else if (Features[AVR::ELFArchAVR25])
+    EFlags |= ELF::EF_AVR_ARCH_AVR25;
+  else if (Features[AVR::ELFArchAVR3])
+    EFlags |= ELF::EF_AVR_ARCH_AVR3;
+  else if (Features[AVR::ELFArchAVR31])
+    EFlags |= ELF::EF_AVR_ARCH_AVR31;
+  else if (Features[AVR::ELFArchAVR35])
+    EFlags |= ELF::EF_AVR_ARCH_AVR35;
+  else if (Features[AVR::ELFArchAVR4])
+    EFlags |= ELF::EF_AVR_ARCH_AVR4;
+  else if (Features[AVR::ELFArchAVR5])
+    EFlags |= ELF::EF_AVR_ARCH_AVR5;
+  else if (Features[AVR::ELFArchAVR51])
+    EFlags |= ELF::EF_AVR_ARCH_AVR51;
+  else if (Features[AVR::ELFArchAVR6])
+    EFlags |= ELF::EF_AVR_ARCH_AVR6;
+  else if (Features[AVR::ELFArchAVRTiny])
+    EFlags |= ELF::EF_AVR_ARCH_AVRTINY;
+  else if (Features[AVR::ELFArchXMEGA1])
+    EFlags |= ELF::EF_AVR_ARCH_XMEGA1;
+  else if (Features[AVR::ELFArchXMEGA2])
+    EFlags |= ELF::EF_AVR_ARCH_XMEGA2;
+  else if (Features[AVR::ELFArchXMEGA3])
+    EFlags |= ELF::EF_AVR_ARCH_XMEGA3;
+  else if (Features[AVR::ELFArchXMEGA4])
+    EFlags |= ELF::EF_AVR_ARCH_XMEGA4;
+  else if (Features[AVR::ELFArchXMEGA5])
+    EFlags |= ELF::EF_AVR_ARCH_XMEGA5;
+  else if (Features[AVR::ELFArchXMEGA6])
+    EFlags |= ELF::EF_AVR_ARCH_XMEGA6;
+  else if (Features[AVR::ELFArchXMEGA7])
+    EFlags |= ELF::EF_AVR_ARCH_XMEGA7;
+
+  return EFlags;
+}
+
+AVRELFStreamer::AVRELFStreamer(MCStreamer &S,
+                               const MCSubtargetInfo &STI)
+    : AVRTargetStreamer(S) {
+
+  MCAssembler &MCA = getStreamer().getAssembler();
+  unsigned EFlags = MCA.getELFHeaderEFlags(Features);
+
+  EFlags |= getEFlagsForFeatureSet(STI.getFeatureBits())
+
+  MCA.setELFHeaderEFlags(EFlags);
+}
Index: lib/Target/AVR/MCTargetDesc/AVRTargetStreamer.h
===================================================================
--- /dev/null
+++ lib/Target/AVR/MCTargetDesc/AVRTargetStreamer.h
@@ -0,0 +1,30 @@
+//===-- AVRTargetStreamer.h - AVR Target Streamer --------------*- C++ -*--===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_AVR_TARGET_STREAMER_H
+#define LLVM_AVR_TARGET_STREAMER_H
+
+namespace llvm {
+class MCStreamer;
+
+/// A generic AVR target output stream.
+class AVRTargetStreamer : public MCTargetStreamer {
+public:
+  explicit AVRTargetStreamer(MCStreamer &S);
+};
+
+/// A target streamer for textual AVR assembly code.
+class AVRTargetAsmStreamer : public AVRTargetStreamer {
+public:
+  explicit AVRTargetAsmStreamer(MCStreamer &S);
+};
+
+} // end namespace llvm
+
+#endif // LLVM_AVR_TARGET_STREAMER_H
Index: lib/Target/AVR/MCTargetDesc/CMakeLists.txt
===================================================================
--- /dev/null
+++ lib/Target/AVR/MCTargetDesc/CMakeLists.txt
@@ -0,0 +1,7 @@
+add_llvm_library(LLVMAVRDesc
+  AVRTargetStreamer.cpp
+  AVRELFStreamer.cpp
+)
+
+add_dependencies(LLVMAVRDesc AVRCommonTableGen)
+
Index: lib/Target/AVR/MCTargetDesc/LLVMBuild.txt
===================================================================
--- /dev/null
+++ lib/Target/AVR/MCTargetDesc/LLVMBuild.txt
@@ -0,0 +1,23 @@
+;===- ./lib/Target/AVR/MCTargetDesc/LLVMBuild.txt --------------*- Conf -*--===;
+;
+;                     The LLVM Compiler Infrastructure
+;
+; This file is distributed under the University of Illinois Open Source
+; License. See LICENSE.TXT for details.
+;
+;===------------------------------------------------------------------------===;
+;
+; This is an LLVMBuild description file for the components in this subdirectory.
+;
+; For more information on the LLVMBuild system, please see:
+;
+;   http://llvm.org/docs/LLVMBuild.html
+;
+;===------------------------------------------------------------------------===;
+
+[component_0]
+type = Library
+name = AVRDesc
+parent = AVR
+required_libraries = MC AVRInfo Support
+add_to_library_groups = AVR