diff -r 070005ab99f5 libgo/configure.ac
--- a/libgo/configure.ac	Sun Jan 05 19:00:53 2014 -0800
+++ b/libgo/configure.ac	Mon Jan 06 11:13:23 2014 -0800
@@ -174,6 +174,7 @@
 is_386=no
 is_alpha=no
 is_arm=no
+is_arm64=no
 is_m68k=no
 mips_abi=unknown
 is_ppc=no
@@ -187,6 +188,10 @@
     is_alpha=yes
     GOARCH=alpha
     ;;
+  aarch64-*-*)
+    is_arm64=yes
+    GOARCH=arm64
+    ;;
   arm*-*-* | strongarm*-*-* | ep9312*-*-* | xscale-*-*)
     is_arm=yes
     GOARCH=arm
@@ -267,6 +272,7 @@
 AM_CONDITIONAL(LIBGO_IS_386, test $is_386 = yes)
 AM_CONDITIONAL(LIBGO_IS_ALPHA, test $is_alpha = yes)
 AM_CONDITIONAL(LIBGO_IS_ARM, test $is_arm = yes)
+AM_CONDITIONAL(LIBGO_IS_ARM64, test $is_arm64 = yes)
 AM_CONDITIONAL(LIBGO_IS_M68K, test $is_m68k = yes)
 AM_CONDITIONAL(LIBGO_IS_MIPS, test $mips_abi != unknown)
 AM_CONDITIONAL(LIBGO_IS_MIPSO32, test $mips_abi = o32)
diff -r 070005ab99f5 libgo/go/go/build/build.go
--- a/libgo/go/go/build/build.go	Sun Jan 05 19:00:53 2014 -0800
+++ b/libgo/go/go/build/build.go	Mon Jan 06 11:13:23 2014 -0800
@@ -1211,6 +1211,8 @@
 		return "6", nil
 	case "arm":
 		return "5", nil
+	case "arm64":
+		return "7", nil
 	}
 	return "", errors.New("unsupported GOARCH " + goarch)
 }
diff -r 070005ab99f5 libgo/go/go/build/deps_test.go
--- a/libgo/go/go/build/deps_test.go	Sun Jan 05 19:00:53 2014 -0800
+++ b/libgo/go/go/build/deps_test.go	Mon Jan 06 11:13:23 2014 -0800
@@ -360,7 +360,7 @@
 
 var bools = []bool{false, true}
 var geese = []string{"darwin", "dragonfly", "freebsd", "linux", "netbsd", "openbsd", "plan9", "windows"}
-var goarches = []string{"386", "amd64", "arm"}
+var goarches = []string{"386", "amd64", "arm", "arm64"}
 
 type osPkg struct {
 	goos, pkg string
diff -r 070005ab99f5 libgo/go/go/build/syslist.go
--- a/libgo/go/go/build/syslist.go	Sun Jan 05 19:00:53 2014 -0800
+++ b/libgo/go/go/build/syslist.go	Mon Jan 06 11:13:23 2014 -0800
@@ -5,4 +5,4 @@
 package build
 
 const goosList = "darwin dragonfly freebsd linux netbsd openbsd plan9 windows solaris "
-const goarchList = "386 amd64 arm alpha m68k mipso32 mipsn32 mipsn64 mipso64 ppc ppc64 sparc sparc64 "
+const goarchList = "386 amd64 arm arm64 alpha m68k mipso32 mipsn32 mipsn64 mipso64 ppc ppc64 sparc sparc64 "
diff -r 070005ab99f5 libgo/go/runtime/extern.go
--- a/libgo/go/runtime/extern.go	Sun Jan 05 19:00:53 2014 -0800
+++ b/libgo/go/runtime/extern.go	Mon Jan 06 11:13:23 2014 -0800
@@ -185,5 +185,5 @@
 const GOOS string = theGoos
 
 // GOARCH is the running program's architecture target:
-// 386, amd64, or arm.
+// 386, amd64, arm or arm64.
 const GOARCH string = theGoarch