Index: llvm/trunk/lib/Target/AMDGPU/MCTargetDesc/AMDGPUAsmBackend.cpp
===================================================================
--- llvm/trunk/lib/Target/AMDGPU/MCTargetDesc/AMDGPUAsmBackend.cpp
+++ llvm/trunk/lib/Target/AMDGPU/MCTargetDesc/AMDGPUAsmBackend.cpp
@@ -11,6 +11,7 @@
 #include "MCTargetDesc/AMDGPUFixupKinds.h"
 #include "MCTargetDesc/AMDGPUMCTargetDesc.h"
 #include "llvm/ADT/StringRef.h"
+#include "llvm/BinaryFormat/ELF.h"
 #include "llvm/MC/MCAsmBackend.h"
 #include "llvm/MC/MCAssembler.h"
 #include "llvm/MC/MCContext.h"
@@ -167,14 +168,29 @@
 class ELFAMDGPUAsmBackend : public AMDGPUAsmBackend {
   bool Is64Bit;
   bool HasRelocationAddend;
+  uint8_t OSABI = ELF::ELFOSABI_NONE;
 
 public:
   ELFAMDGPUAsmBackend(const Target &T, const Triple &TT) :
       AMDGPUAsmBackend(T), Is64Bit(TT.getArch() == Triple::amdgcn),
-      HasRelocationAddend(TT.getOS() == Triple::AMDHSA) { }
+      HasRelocationAddend(TT.getOS() == Triple::AMDHSA) {
+    switch (TT.getOS()) {
+    case Triple::AMDHSA:
+      OSABI = ELF::ELFOSABI_AMDGPU_HSA;
+      break;
+    case Triple::AMDPAL:
+      OSABI = ELF::ELFOSABI_AMDGPU_PAL;
+      break;
+    case Triple::Mesa3D:
+      OSABI = ELF::ELFOSABI_AMDGPU_MESA3D;
+      break;
+    default:
+      break;
+    }
+  }
 
   MCObjectWriter *createObjectWriter(raw_pwrite_stream &OS) const override {
-    return createAMDGPUELFObjectWriter(Is64Bit, HasRelocationAddend, OS);
+    return createAMDGPUELFObjectWriter(Is64Bit, OSABI, HasRelocationAddend, OS);
   }
 };
 
Index: llvm/trunk/lib/Target/AMDGPU/MCTargetDesc/AMDGPUELFObjectWriter.cpp
===================================================================
--- llvm/trunk/lib/Target/AMDGPU/MCTargetDesc/AMDGPUELFObjectWriter.cpp
+++ llvm/trunk/lib/Target/AMDGPU/MCTargetDesc/AMDGPUELFObjectWriter.cpp
@@ -22,7 +22,7 @@
 
 class AMDGPUELFObjectWriter : public MCELFObjectTargetWriter {
 public:
-  AMDGPUELFObjectWriter(bool Is64Bit, bool HasRelocationAddend);
+  AMDGPUELFObjectWriter(bool Is64Bit, uint8_t OSABI, bool HasRelocationAddend);
 
 protected:
   unsigned getRelocType(MCContext &Ctx, const MCValue &Target,
@@ -33,10 +33,9 @@
 } // end anonymous namespace
 
 AMDGPUELFObjectWriter::AMDGPUELFObjectWriter(bool Is64Bit,
+                                             uint8_t OSABI,
                                              bool HasRelocationAddend)
-  : MCELFObjectTargetWriter(Is64Bit,
-                            ELF::ELFOSABI_AMDGPU_HSA,
-                            ELF::EM_AMDGPU,
+  : MCELFObjectTargetWriter(Is64Bit, OSABI, ELF::EM_AMDGPU,
                             HasRelocationAddend) {}
 
 unsigned AMDGPUELFObjectWriter::getRelocType(MCContext &Ctx,
@@ -83,9 +82,10 @@
 }
 
 MCObjectWriter *llvm::createAMDGPUELFObjectWriter(bool Is64Bit,
+                                                  uint8_t OSABI,
                                                   bool HasRelocationAddend,
                                                   raw_pwrite_stream &OS) {
   MCELFObjectTargetWriter *MOTW =
-      new AMDGPUELFObjectWriter(Is64Bit, HasRelocationAddend);
+      new AMDGPUELFObjectWriter(Is64Bit, OSABI, HasRelocationAddend);
   return createELFObjectWriter(MOTW, OS, true);
 }
Index: llvm/trunk/lib/Target/AMDGPU/MCTargetDesc/AMDGPUMCTargetDesc.h
===================================================================
--- llvm/trunk/lib/Target/AMDGPU/MCTargetDesc/AMDGPUMCTargetDesc.h
+++ llvm/trunk/lib/Target/AMDGPU/MCTargetDesc/AMDGPUMCTargetDesc.h
@@ -48,6 +48,7 @@
                                      const MCTargetOptions &Options);
 
 MCObjectWriter *createAMDGPUELFObjectWriter(bool Is64Bit,
+                                            uint8_t OSABI,
                                             bool HasRelocationAddend,
                                             raw_pwrite_stream &OS);
 } // End llvm namespace
Index: llvm/trunk/test/CodeGen/AMDGPU/elf-header.ll
===================================================================
--- llvm/trunk/test/CodeGen/AMDGPU/elf-header.ll
+++ llvm/trunk/test/CodeGen/AMDGPU/elf-header.ll
@@ -0,0 +1,43 @@
+; RUN: llc -march=r600 -filetype=obj < %s | llvm-readobj -file-headers - | FileCheck --check-prefix=R600 --check-prefix=R600-OSABI-NONE %s
+; RUN: llc -mtriple=r600-- -filetype=obj < %s | llvm-readobj -file-headers - | FileCheck --check-prefix=R600 --check-prefix=R600-OSABI-NONE %s
+; RUN: llc -mtriple=r600-amd- -filetype=obj < %s | llvm-readobj -file-headers - | FileCheck --check-prefix=R600 --check-prefix=R600-OSABI-NONE %s
+; RUN: llc -mtriple=r600-amd-unknown -filetype=obj < %s | llvm-readobj -file-headers - | FileCheck --check-prefix=R600 --check-prefix=R600-OSABI-NONE %s
+; RUN: llc -mtriple=r600-unknown-unknown -filetype=obj < %s | llvm-readobj -file-headers - | FileCheck --check-prefix=R600 --check-prefix=R600-OSABI-NONE %s
+
+; RUN: llc -march=amdgcn -filetype=obj < %s | llvm-readobj -file-headers - | FileCheck --check-prefix=GCN --check-prefix=GCN-OSABI-NONE %s
+; RUN: llc -mtriple=amdgcn-- -filetype=obj < %s | llvm-readobj -file-headers - | FileCheck --check-prefix=GCN --check-prefix=GCN-OSABI-NONE %s
+; RUN: llc -mtriple=amdgcn-amd- -filetype=obj < %s | llvm-readobj -file-headers - | FileCheck --check-prefix=GCN --check-prefix=GCN-OSABI-NONE %s
+; RUN: llc -mtriple=amdgcn-amd-unknown -filetype=obj < %s | llvm-readobj -file-headers - | FileCheck --check-prefix=GCN --check-prefix=GCN-OSABI-NONE %s
+; RUN: llc -mtriple=amdgcn-unknown-unknown -filetype=obj < %s | llvm-readobj -file-headers - | FileCheck --check-prefix=GCN --check-prefix=GCN-OSABI-NONE %s
+
+; RUN: llc -mtriple=amdgcn--amdhsa -filetype=obj < %s | llvm-readobj -file-headers - | FileCheck --check-prefix=GCN --check-prefix=GCN-OSABI-HSA %s
+; RUN: llc -mtriple=amdgcn-amd-amdhsa -filetype=obj < %s | llvm-readobj -file-headers - | FileCheck --check-prefix=GCN --check-prefix=GCN-OSABI-HSA %s
+; RUN: llc -mtriple=amdgcn-unknown-amdhsa -filetype=obj < %s | llvm-readobj -file-headers - | FileCheck --check-prefix=GCN --check-prefix=GCN-OSABI-HSA %s
+
+; RUN: llc -mtriple=amdgcn--amdpal -filetype=obj < %s | llvm-readobj -file-headers - | FileCheck --check-prefix=GCN --check-prefix=GCN-OSABI-PAL %s
+; RUN: llc -mtriple=amdgcn-amd-amdpal -filetype=obj < %s | llvm-readobj -file-headers - | FileCheck --check-prefix=GCN --check-prefix=GCN-OSABI-PAL %s
+; RUN: llc -mtriple=amdgcn-unknown-amdpal -filetype=obj < %s | llvm-readobj -file-headers - | FileCheck --check-prefix=GCN --check-prefix=GCN-OSABI-PAL %s
+
+; RUN: llc -mtriple=amdgcn--mesa3d -filetype=obj < %s | llvm-readobj -file-headers - | FileCheck --check-prefix=GCN --check-prefix=GCN-OSABI-MESA3D %s
+; RUN: llc -mtriple=amdgcn-amd-mesa3d -filetype=obj < %s | llvm-readobj -file-headers - | FileCheck --check-prefix=GCN --check-prefix=GCN-OSABI-MESA3D %s
+; RUN: llc -mtriple=amdgcn-unknown-mesa3d -filetype=obj < %s | llvm-readobj -file-headers - | FileCheck --check-prefix=GCN --check-prefix=GCN-OSABI-MESA3D %s
+
+; R600: Format: ELF32-amdgpu
+; R600: Arch: unknown
+; R600: AddressSize: 32bit
+; GCN: Format: ELF64-amdgpu
+; GCN: Arch: amdgcn
+; GCN: AddressSize: 64bit
+
+; R600-OSABI-NONE:  OS/ABI: SystemV (0x0)
+; GCN-OSABI-NONE:   OS/ABI: SystemV (0x0)
+; GCN-OSABI-HSA:    OS/ABI: AMDGPU_HSA (0x40)
+; GCN-OSABI-PAL:    OS/ABI: AMDGPU_PAL (0x41)
+; GCN-OSABI-MESA3D: OS/ABI: AMDGPU_MESA3D (0x42)
+
+; R600: Machine: EM_AMDGPU (0xE0)
+; GCN: Machine: EM_AMDGPU (0xE0)
+
+define amdgpu_kernel void @elf_header() {
+  ret void
+}
\ No newline at end of file
Index: llvm/trunk/test/CodeGen/AMDGPU/elf.ll
===================================================================
--- llvm/trunk/test/CodeGen/AMDGPU/elf.ll
+++ llvm/trunk/test/CodeGen/AMDGPU/elf.ll
@@ -8,8 +8,8 @@
 ; Test that we don't try to produce a COFF file on windows
 ; RUN: llc < %s -mtriple=amdgcn-pc-mingw -verify-machineinstrs -filetype=obj | llvm-readobj -s -symbols -file-headers - | FileCheck --check-prefix=ELF %s
 
-; ELF: Format: ELF64
-; ELF: OS/ABI: AMDGPU_HSA (0x40)
+; ELF: Format: ELF64-amdgpu
+; ELF: OS/ABI: SystemV (0x0)
 ; ELF: Machine: EM_AMDGPU (0xE0)
 ; ELF: Name: .AMDGPU.config
 ; ELF: Type: SHT_PROGBITS
Index: llvm/trunk/test/CodeGen/AMDGPU/elf.r600.ll
===================================================================
--- llvm/trunk/test/CodeGen/AMDGPU/elf.r600.ll
+++ llvm/trunk/test/CodeGen/AMDGPU/elf.r600.ll
@@ -1,7 +1,7 @@
 ; RUN: llc < %s -march=r600 -mcpu=redwood -filetype=obj | llvm-readobj -s - | FileCheck --check-prefix=ELF %s
 ; RUN: llc < %s -march=r600 -mcpu=redwood -o - | FileCheck --check-prefix=CONFIG %s
 
-; ELF: Format: ELF32
+; ELF: Format: ELF32-amdgpu
 ; ELF: Name: .AMDGPU.config
 
 ; CONFIG: .section .AMDGPU.config