diff --git a/cmd/gomobile/bind.go b/cmd/gomobile/bind.go
index 2c70f92..8888e3b 100644
--- a/cmd/gomobile/bind.go
+++ b/cmd/gomobile/bind.go
@@ -6,6 +6,7 @@ package main
 
 import (
 	"bytes"
+	"errors"
 	"fmt"
 	"go/ast"
 	"go/build"
@@ -102,6 +103,10 @@ func runBind(cmd *command) error {
 		return fmt.Errorf("-prefix is supported only for ios target")
 	}
 
+	if ctx.GOOS == "android" && ndkRoot == "" {
+		return errors.New("no Android NDK path is set. Please run gomobile init with the ndk-bundle installed through the Android SDK manager or with the -ndk flag set.")
+	}
+
 	var pkgs []*build.Package
 	switch len(args) {
 	case 0:
diff --git a/cmd/gomobile/bind_test.go b/cmd/gomobile/bind_test.go
index de12951..d2f4d1c 100644
--- a/cmd/gomobile/bind_test.go
+++ b/cmd/gomobile/bind_test.go
@@ -37,6 +37,7 @@ func TestBindAndroid(t *testing.T) {
 	buildX = true
 	buildO = "asset.aar"
 	buildTarget = "android"
+	ndkRoot = "/NDK"
 
 	tests := []struct {
 		javaPkg    string
@@ -106,7 +107,7 @@ mkdir -p $WORK/gomobile_bind
 mkdir -p $WORK/gomobile_bind
 mkdir -p $WORK/gomobile_bind
 mkdir -p $WORK/gen/src/Java
-GOOS=android GOARCH=arm CC=$GOMOBILE/android-{{.NDK}}/arm/bin/arm-linux-androideabi-clang CXX=$GOMOBILE/android-{{.NDK}}/arm/bin/arm-linux-androideabi-clang++ CGO_CFLAGS=-target armv7a-none-linux-androideabi --sysroot $GOMOBILE/android-{{.NDK}}/arm/sysroot CGO_CPPFLAGS=-target armv7a-none-linux-androideabi --sysroot $GOMOBILE/android-{{.NDK}}/arm/sysroot CGO_LDFLAGS=-target armv7a-none-linux-androideabi --sysroot $GOMOBILE/android-{{.NDK}}/arm/sysroot CGO_ENABLED=1 GOARM=7 GOPATH=$WORK/gen:$GOPATH go install -pkgdir=$GOMOBILE/pkg_android_arm -x golang.org/x/mobile/asset
+GOOS=android GOARCH=arm CC=/NDK/toolchains/llvm/prebuilt/{{.GOOS}}-{{.NDKARCH}}/bin/clang{{.EXE}} CXX=/NDK/toolchains/llvm/prebuilt/{{.GOOS}}-{{.NDKARCH}}/bin/clang++{{.EXE}} CGO_CFLAGS=-target armv7a-none-linux-androideabi --sysroot /NDK/platforms/android-15/arch-arm -gcc-toolchain /NDK/toolchains/arm-linux-androideabi-4.9/prebuilt/{{.GOOS}}-{{.NDKARCH}} -I$GOMOBILE/include CGO_CPPFLAGS=-target armv7a-none-linux-androideabi --sysroot /NDK/platforms/android-15/arch-arm -gcc-toolchain /NDK/toolchains/arm-linux-androideabi-4.9/prebuilt/{{.GOOS}}-{{.NDKARCH}} -I$GOMOBILE/include CGO_LDFLAGS=-target armv7a-none-linux-androideabi --sysroot /NDK/platforms/android-15/arch-arm -gcc-toolchain /NDK/toolchains/arm-linux-androideabi-4.9/prebuilt/{{.GOOS}}-{{.NDKARCH}} -L/NDK/platforms/android-15/arch-arm/usr/lib -L$GOMOBILE/lib/arm CGO_ENABLED=1 GOARM=7 GOPATH=$WORK/gen:$GOPATH go install -pkgdir=$GOMOBILE/pkg_android_arm -x golang.org/x/mobile/asset
 rm -r -f "$WORK/fakegopath"
 mkdir -p $WORK/fakegopath/pkg
 cp $GOMOBILE/pkg_android_arm/golang.org/x/mobile/asset.a $WORK/fakegopath/pkg/android_arm/golang.org/x/mobile/asset.a
@@ -134,7 +135,7 @@ mkdir -p $WORK/gomobile_bind
 cp $GOPATH/src/golang.org/x/mobile/bind/seq.go.support $WORK/gomobile_bind/seq.go
 mkdir -p $WORK/gomobile_bind
 mkdir -p $WORK/android/src/main/java/go
-GOOS=android GOARCH=arm CC=$GOMOBILE/android-{{.NDK}}/arm/bin/arm-linux-androideabi-clang{{.EXE}} CXX=$GOMOBILE/android-{{.NDK}}/arm/bin/arm-linux-androideabi-clang++{{.EXE}} CGO_CFLAGS=-target armv7a-none-linux-androideabi --sysroot $GOMOBILE/android-{{.NDK}}/arm/sysroot CGO_CPPFLAGS=-target armv7a-none-linux-androideabi --sysroot $GOMOBILE/android-{{.NDK}}/arm/sysroot CGO_LDFLAGS=-target armv7a-none-linux-androideabi --sysroot $GOMOBILE/android-{{.NDK}}/arm/sysroot CGO_ENABLED=1 GOARM=7 GOPATH=$WORK/gen:$GOPATH go build -pkgdir=$GOMOBILE/pkg_android_arm -x -buildmode=c-shared -o=$WORK/android/src/main/jniLibs/armeabi-v7a/libgojni.so $WORK/androidlib/main.go
+GOOS=android GOARCH=arm CC=/NDK/toolchains/llvm/prebuilt/{{.GOOS}}-{{.NDKARCH}}/bin/clang{{.EXE}} CXX=/NDK/toolchains/llvm/prebuilt/{{.GOOS}}-{{.NDKARCH}}/bin/clang++{{.EXE}} CGO_CFLAGS=-target armv7a-none-linux-androideabi --sysroot /NDK/platforms/android-15/arch-arm -gcc-toolchain /NDK/toolchains/arm-linux-androideabi-4.9/prebuilt/{{.GOOS}}-{{.NDKARCH}} -I$GOMOBILE/include CGO_CPPFLAGS=-target armv7a-none-linux-androideabi --sysroot /NDK/platforms/android-15/arch-arm -gcc-toolchain /NDK/toolchains/arm-linux-androideabi-4.9/prebuilt/{{.GOOS}}-{{.NDKARCH}} -I$GOMOBILE/include CGO_LDFLAGS=-target armv7a-none-linux-androideabi --sysroot /NDK/platforms/android-15/arch-arm -gcc-toolchain /NDK/toolchains/arm-linux-androideabi-4.9/prebuilt/{{.GOOS}}-{{.NDKARCH}} -L/NDK/platforms/android-15/arch-arm/usr/lib -L$GOMOBILE/lib/arm CGO_ENABLED=1 GOARM=7 GOPATH=$WORK/gen:$GOPATH go build -pkgdir=$GOMOBILE/pkg_android_arm -x -buildmode=c-shared -o=$WORK/android/src/main/jniLibs/armeabi-v7a/libgojni.so $WORK/androidlib/main.go
 rm $WORK/android/src/main/java/go/Seq.java
 ln -s $GOPATH/src/golang.org/x/mobile/bind/java/Seq.java $WORK/android/src/main/java/go/Seq.java
 rm $WORK/android/src/main/java/go/LoadJNI.java
diff --git a/cmd/gomobile/build_androidapp.go b/cmd/gomobile/build_androidapp.go
index 3136d7d..8d261f3 100644
--- a/cmd/gomobile/build_androidapp.go
+++ b/cmd/gomobile/build_androidapp.go
@@ -22,6 +22,9 @@ import (
 )
 
 func goAndroidBuild(pkg *build.Package, androidArchs []string) (map[string]bool, error) {
+	if ndkRoot == "" {
+		return nil, errors.New("no Android NDK path is set. Please run gomobile init with the ndk-bundle installed through the Android SDK manager or with the -ndk flag set.")
+	}
 	appName := path.Base(pkg.ImportPath)
 	libName := androidPkgName(appName)
 	manifestPath := filepath.Join(pkg.Dir, "AndroidManifest.xml")
@@ -170,13 +173,11 @@ func goAndroidBuild(pkg *build.Package, androidArchs []string) (map[string]bool,
 		toolchain := ndk.Toolchain(arch)
 		if nmpkgs[arch]["golang.org/x/mobile/exp/audio/al"] {
 			dst := "lib/" + toolchain.abi + "/libopenal.so"
-			src := dst
-			if arch == "arm" {
-				src = "lib/armeabi/libopenal.so"
-			} else if arch == "arm64" {
-				src = "lib/arm64/libopenal.so"
+			src := filepath.Join(gomobilepath, dst)
+			if _, err := os.Stat(src); err != nil {
+				return nil, errors.New("the Android requires the golang.org/x/mobile/exp/audio/al, but the OpenAL libraries was not found. Please run gomobile init with the -openal flag pointing to an OpenAL source directory.")
 			}
-			if err := apkwWriteFile(dst, filepath.Join(ndk.Root(), "openal/"+src)); err != nil {
+			if err := apkwWriteFile(dst, src); err != nil {
 				return nil, err
 			}
 		}
diff --git a/cmd/gomobile/build_test.go b/cmd/gomobile/build_test.go
index 1234c7a..569441e 100644
--- a/cmd/gomobile/build_test.go
+++ b/cmd/gomobile/build_test.go
@@ -76,6 +76,7 @@ func TestAndroidBuild(t *testing.T) {
 	buildX = true
 	buildO = "basic.apk"
 	buildTarget = "android"
+	ndkRoot = "/NDK"
 	gopath = filepath.ToSlash(filepath.SplitList(os.Getenv("GOPATH"))[0])
 	if goos == "windows" {
 		os.Setenv("HOMEDRIVE", "C:")
@@ -100,7 +101,7 @@ func TestAndroidBuild(t *testing.T) {
 var androidBuildTmpl = template.Must(template.New("output").Parse(`GOMOBILE={{.GOPATH}}/pkg/gomobile
 WORK=$WORK
 mkdir -p $WORK/lib/armeabi-v7a
-GOOS=android GOARCH=arm CC=$GOMOBILE/android-{{.NDK}}/arm/bin/arm-linux-androideabi-clang{{.EXE}} CXX=$GOMOBILE/android-{{.NDK}}/arm/bin/arm-linux-androideabi-clang++{{.EXE}} CGO_CFLAGS=-target armv7a-none-linux-androideabi --sysroot $GOMOBILE/android-{{.NDK}}/arm/sysroot CGO_CPPFLAGS=-target armv7a-none-linux-androideabi --sysroot $GOMOBILE/android-{{.NDK}}/arm/sysroot CGO_LDFLAGS=-target armv7a-none-linux-androideabi --sysroot $GOMOBILE/android-{{.NDK}}/arm/sysroot CGO_ENABLED=1 GOARM=7 go build -pkgdir=$GOMOBILE/pkg_android_arm -tags tag1 -x -buildmode=c-shared -o $WORK/lib/armeabi-v7a/libbasic.so golang.org/x/mobile/example/basic
+GOOS=android GOARCH=arm CC=/NDK/toolchains/llvm/prebuilt/{{.GOOS}}-{{.NDKARCH}}/bin/clang{{.EXE}} CXX=/NDK/toolchains/llvm/prebuilt/{{.GOOS}}-{{.NDKARCH}}/bin/clang++{{.EXE}} CGO_CFLAGS=-target armv7a-none-linux-androideabi --sysroot /NDK/platforms/android-15/arch-arm -gcc-toolchain /NDK/toolchains/arm-linux-androideabi-4.9/prebuilt/{{.GOOS}}-{{.NDKARCH}} -I$GOMOBILE/include CGO_CPPFLAGS=-target armv7a-none-linux-androideabi --sysroot /NDK/platforms/android-15/arch-arm -gcc-toolchain /NDK/toolchains/arm-linux-androideabi-4.9/prebuilt/{{.GOOS}}-{{.NDKARCH}} -I$GOMOBILE/include CGO_LDFLAGS=-target armv7a-none-linux-androideabi --sysroot /NDK/platforms/android-15/arch-arm -gcc-toolchain /NDK/toolchains/arm-linux-androideabi-4.9/prebuilt/{{.GOOS}}-{{.NDKARCH}} -L/NDK/platforms/android-15/arch-arm/usr/lib -L$GOMOBILE/lib/arm CGO_ENABLED=1 GOARM=7 go build -pkgdir=$GOMOBILE/pkg_android_arm -tags tag1 -x -buildmode=c-shared -o $WORK/lib/armeabi-v7a/libbasic.so golang.org/x/mobile/example/basic
 `))
 
 func TestParseBuildTargetFlag(t *testing.T) {
diff --git a/cmd/gomobile/doc.go b/cmd/gomobile/doc.go
index fb17b6a..5405a13 100644
--- a/cmd/gomobile/doc.go
+++ b/cmd/gomobile/doc.go
@@ -123,15 +123,20 @@ Usage:
 
 	gomobile init [-u]
 
-Init installs the Android C++ compiler toolchain and builds copies
-of the Go standard library for mobile devices.
+Init builds copies of the Go standard library for mobile devices. If ANDROID_HOME
+is set and the Android NDK is available, Android support is built. If on Darwin
+and the Xcode command line utilities are installed, iOS support is built.
 
-When first run, it downloads part of the Android NDK.
-The toolchain is installed in $GOPATH/pkg/gomobile.
+The toolchains are installed in $GOPATH/pkg/gomobile.
 
-The -u option forces download and installation of the new toolchain
-even when the toolchain exists.
+Init use the Android NDK installed by the Android SDK manager by default. Use the
+-ndk flag to specify a custom location for the NDK.
 
+If the -openal flag is specified, init also builds an Android version of OpenAL
+from the source directory given. OpenAL enables support for gomobile build and
+install with mobile apps using the golang.org/x/mobile/exp/audio/al package.
+It needs cmake and, on Windows, nmake installed. If cmake is installed through
+the Android SDK manager, init will use that.
 
 Compile android APK and install on device
 
diff --git a/cmd/gomobile/env.go b/cmd/gomobile/env.go
index 89395d1..fbddaba 100644
--- a/cmd/gomobile/env.go
+++ b/cmd/gomobile/env.go
@@ -26,6 +26,10 @@ var (
 
 	androidArmNM string
 	darwinArmNM  string
+
+	ndkRoot string
+
+	archs = []string{"arm", "arm64", "386", "amd64"}
 )
 
 func buildEnvInit() (cleanup func(), err error) {
@@ -38,10 +42,6 @@ func buildEnvInit() (cleanup func(), err error) {
 		}
 	}
 
-	if err := envInit(); err != nil {
-		return nil, err
-	}
-
 	if buildX {
 		fmt.Fprintln(xout, "GOMOBILE="+gomobilepath)
 	}
@@ -51,6 +51,27 @@ func buildEnvInit() (cleanup func(), err error) {
 	if gomobilepath == "" {
 		return nil, errors.New("toolchain not installed, run `gomobile init`")
 	}
+
+	// Read the NDK root path stored by gomobile init -ndk, if any.
+	if !buildN {
+		root, err := ioutil.ReadFile(filepath.Join(gomobilepath, "android_ndk_root"))
+		if err != nil && !os.IsNotExist(err) {
+			return nil, err
+		}
+		ndkRoot = string(root)
+		if ndkRoot != "" {
+			if _, err := os.Stat(filepath.Join(ndkRoot, "toolchains")); err != nil {
+				if os.IsNotExist(err) {
+					return nil, fmt.Errorf("The ndk path %q doesn't exist. Please re-run gomobile with the ndk-bundle install through the Android SDK manager or with the -ndk flag set.", ndkRoot)
+				}
+				return nil, err
+			}
+		}
+	}
+	if err := envInit(); err != nil {
+		return nil, err
+	}
+
 	cleanupFn := func() {
 		if buildWork {
 			fmt.Printf("WORK=%s\n", tmpdir)
@@ -92,34 +113,39 @@ func envInit() (err error) {
 
 	// Setup the cross-compiler environments.
 
-	androidEnv = make(map[string][]string)
-	for arch, toolchain := range ndk {
-		if goVersion < toolchain.minGoVer {
-			continue
-		}
+	if ndkRoot != "" {
+		androidEnv = make(map[string][]string)
+		for arch, toolchain := range ndk {
+			if goVersion < toolchain.minGoVer {
+				continue
+			}
 
-		// Emulate the flags in the clang wrapper scripts generated
-		// by make_standalone_toolchain.py
-		s := strings.SplitN(toolchain.toolPrefix, "-", 3)
-		a, os, env := s[0], s[1], s[2]
-		if a == "arm" {
-			a = "armv7a"
-		}
-		target := strings.Join([]string{a, "none", os, env}, "-")
-		sysroot := filepath.Join(ndk.Root(), toolchain.arch, "sysroot")
-		flags := fmt.Sprintf("-target %s --sysroot %s", target, sysroot)
-		androidEnv[arch] = []string{
-			"GOOS=android",
-			"GOARCH=" + arch,
-			"CC=" + toolchain.Path("clang"),
-			"CXX=" + toolchain.Path("clang++"),
-			"CGO_CFLAGS=" + flags,
-			"CGO_CPPFLAGS=" + flags,
-			"CGO_LDFLAGS=" + flags,
-			"CGO_ENABLED=1",
-		}
-		if arch == "arm" {
-			androidEnv[arch] = append(androidEnv[arch], "GOARM=7")
+			// Emulate the flags in the clang wrapper scripts generated
+			// by make_standalone_toolchain.py
+			s := strings.SplitN(toolchain.toolPrefix, "-", 3)
+			a, os, env := s[0], s[1], s[2]
+			if a == "arm" {
+				a = "armv7a"
+			}
+			target := strings.Join([]string{a, "none", os, env}, "-")
+			sysroot := filepath.Join(ndkRoot, "platforms", toolchain.platform, "arch-"+toolchain.arch)
+			gcctoolchain := filepath.Join(ndkRoot, "toolchains", toolchain.gcc, "prebuilt", archNDK())
+			flags := fmt.Sprintf("-target %s --sysroot %s -gcc-toolchain %s", target, sysroot, gcctoolchain)
+			cflags := fmt.Sprintf("%s -I%s/include", flags, gomobilepath)
+			ldflags := fmt.Sprintf("%s -L%s/usr/lib -L%s/lib/%s", flags, sysroot, gomobilepath, arch)
+			androidEnv[arch] = []string{
+				"GOOS=android",
+				"GOARCH=" + arch,
+				"CC=" + toolchain.Path("clang"),
+				"CXX=" + toolchain.Path("clang++"),
+				"CGO_CFLAGS=" + cflags,
+				"CGO_CPPFLAGS=" + cflags,
+				"CGO_LDFLAGS=" + ldflags,
+				"CGO_ENABLED=1",
+			}
+			if arch == "arm" {
+				androidEnv[arch] = append(androidEnv[arch], "GOARM=7")
+			}
 		}
 	}
 
@@ -264,6 +290,23 @@ func pkgdir(env []string) string {
 	return gomobilepath + "/pkg_" + getenv(env, "GOOS") + "_" + getenv(env, "GOARCH")
 }
 
+func archNDK() string {
+	if runtime.GOOS == "windows" && runtime.GOARCH == "386" {
+		return "windows"
+	} else {
+		var arch string
+		switch runtime.GOARCH {
+		case "386":
+			arch = "x86"
+		case "amd64":
+			arch = "x86_64"
+		default:
+			panic("unsupported GOARCH: " + runtime.GOARCH)
+		}
+		return runtime.GOOS + "-" + arch
+	}
+}
+
 type ndkToolchain struct {
 	arch       string
 	abi        string
@@ -274,18 +317,24 @@ type ndkToolchain struct {
 }
 
 func (tc *ndkToolchain) Path(toolName string) string {
+	// The nm tool is located in the GCC directory structure.
+	isUtil := toolName == "nm"
 	if goos == "windows" {
 		toolName += ".exe"
 	}
-	return filepath.Join(ndk.Root(), tc.arch, "bin", tc.toolPrefix+"-"+toolName)
+	path := filepath.Join(ndkRoot, "toolchains")
+	if isUtil {
+		toolName = tc.toolPrefix + "-" + toolName
+		path = filepath.Join(path, tc.gcc)
+	} else {
+		path = filepath.Join(path, "llvm")
+	}
+	path = filepath.Join(path, "prebuilt")
+	return filepath.Join(path, archNDK(), "bin", toolName)
 }
 
 type ndkConfig map[string]ndkToolchain // map: GOOS->androidConfig.
 
-func (nc ndkConfig) Root() string {
-	return filepath.Join(gomobilepath, "android-"+ndkVersion)
-}
-
 func (nc ndkConfig) Toolchain(arch string) ndkToolchain {
 	tc, ok := nc[arch]
 	if !ok || tc.minGoVer > goVersion {
@@ -294,7 +343,6 @@ func (nc ndkConfig) Toolchain(arch string) ndkToolchain {
 	return tc
 }
 
-// TODO: share this with release.go
 var ndk = ndkConfig{
 	"arm": {
 		arch:       "arm",
diff --git a/cmd/gomobile/hashes.go b/cmd/gomobile/hashes.go
deleted file mode 100644
index f2fec62..0000000
--- a/cmd/gomobile/hashes.go
+++ /dev/null
@@ -1,19 +0,0 @@
-// Copyright 2015 The Go Authors.  All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package main
-
-// Hashes were computed with 'go run release.go'
-
-var fetchHashes = map[string]string{
-	"android-ndk-r12b-darwin-x86_64.zip":            "2bdef9143a2c7680fcb7c9fd54fe85013d591f106aea43831eba5e13e10db77e",
-	"gomobile-ndk-r12b-darwin-x86_64.tar.gz":        "2c4365d033fc3c9e1fbeeb6c2773f75116a0c76000ebf0dab7290506ba9acb07",
-	"android-ndk-r12b-linux-x86_64.zip":             "eafae2d614e5475a3bcfd7c5f201db5b963cc1290ee3e8ae791ff0c66757781e",
-	"gomobile-ndk-r12b-linux-x86_64.tar.gz":         "3eaeb237f89fa7ca44dbc760085a79a1efe9c6e830f3bedf68e5473bbd716fed",
-	"android-ndk-r12b-windows-x86.zip":              "4b3b522775858bdf4e5e8f7365e06fdabb9913fb7b9f45d7010232f8271fb42c",
-	"gomobile-ndk-r12b-windows-x86.tar.gz":          "2108256dac7fe7499c139915672c0f68eca1bcfe3d9660b1ef0f9c3e776459ee",
-	"android-ndk-r12b-windows-x86_64.zip":           "a201b9dad71802464823dcfc77f61445ec1bbd8a29baa154d0a6ed84f50298ae",
-	"gomobile-ndk-r12b-windows-x86_64.tar.gz":       "558b124266add3bced8591596911862fdf7949f689a79f612c3f9e48ef8a2199",
-	"gomobile-openal-soft-1.16.0.1-ndk-r12b.tar.gz": "848307aa48311a2d4f6cd05661724b121c8f8663d616dfc8c573f9e5d926cf1d",
-}
diff --git a/cmd/gomobile/init.go b/cmd/gomobile/init.go
index 769d61e..5b8a5e0 100644
--- a/cmd/gomobile/init.go
+++ b/cmd/gomobile/init.go
@@ -5,34 +5,19 @@
 package main
 
 import (
-	"archive/tar"
 	"bytes"
-	"compress/gzip"
-	"crypto/sha256"
-	"encoding/hex"
+	"errors"
 	"fmt"
 	"io"
 	"io/ioutil"
-	"net/http"
 	"os"
 	"os/exec"
-	"path"
 	"path/filepath"
 	"runtime"
 	"strings"
 	"time"
 )
 
-// useStrippedNDK determines whether the init subcommand fetches the clang
-// toolchain from the original Android NDK, or from the stripped-down NDK
-// hosted specifically for the gomobile tool.
-//
-// There is a significant size different (400MB compared to 30MB).
-var useStrippedNDK = true
-
-const ndkVersion = "ndk-r12b"
-const openALVersion = "openal-soft-1.16.0.1-" + ndkVersion
-
 var (
 	goos    = runtime.GOOS
 	goarch  = runtime.GOARCH
@@ -54,23 +39,26 @@ var cmdInit = &command{
 	run:   runInit,
 	Name:  "init",
 	Usage: "[-u]",
-	Short: "install android compiler toolchain",
+	Short: "install mobile compiler toolchain",
 	Long: `
-Init installs the Android C++ compiler toolchain and builds copies
-of the Go standard library for mobile devices.
-
-When first run, it downloads part of the Android NDK.
-The toolchain is installed in $GOPATH/pkg/gomobile.
-
-The -u option forces download and installation of the new toolchain
-even when the toolchain exists.
+Init builds copies of the Go standard library for mobile devices.
+It uses Xcode, if available, to build for iOS and uses the Android
+NDK from the ndk-bundle SDK package or from the -ndk flag, to build
+for Android.
+If a OpenAL source directory is specified with -openal, init will
+also build an Android version of OpenAL for use with gomobile build
+and gomobile install.
 `,
 }
 
-var initU bool // -u
+var (
+	initNDK    string // -ndk
+	initOpenAL string // -openal
+)
 
 func init() {
-	cmdInit.flag.BoolVar(&initU, "u", false, "force toolchain download")
+	cmdInit.flag.StringVar(&initNDK, "ndk", "", "Android NDK path")
+	cmdInit.flag.StringVar(&initOpenAL, "openal", "", "OpenAL source path")
 }
 
 func runInit(cmd *command) error {
@@ -84,9 +72,9 @@ func runInit(cmd *command) error {
 	if buildX || buildN {
 		fmt.Fprintln(xout, "GOMOBILE="+gomobilepath)
 	}
-	removeGomobilepkg()
+	removeAll(gomobilepath)
 
-	if err := mkdir(ndk.Root()); err != nil {
+	if err := mkdir(gomobilepath); err != nil {
 		return err
 	}
 
@@ -110,17 +98,49 @@ func runInit(cmd *command) error {
 		removeAll(tmpdir)
 	}()
 
+	if buildN {
+		initNDK = "$NDK_PATH"
+		initOpenAL = "$OPENAL_PATH"
+	} else {
+		toolsDir := filepath.Join("prebuilt", archNDK(), "bin")
+		// Try the ndk-bundle SDK package package, if installed.
+		if initNDK == "" {
+			if sdkHome := os.Getenv("ANDROID_HOME"); sdkHome != "" {
+				path := filepath.Join(sdkHome, "ndk-bundle")
+				if st, err := os.Stat(filepath.Join(path, toolsDir)); err == nil && st.IsDir() {
+					initNDK = path
+				}
+			}
+		}
+		if initNDK != "" {
+			var err error
+			if initNDK, err = filepath.Abs(initNDK); err != nil {
+				return err
+			}
+			// Check if the platform directory contains a known subdirectory.
+			if _, err := os.Stat(filepath.Join(initNDK, toolsDir)); err != nil {
+				if os.IsNotExist(err) {
+					return fmt.Errorf("%q does not point to an Android NDK.", initNDK)
+				}
+				return err
+			}
+			ndkFile := filepath.Join(gomobilepath, "android_ndk_root")
+			if err := ioutil.WriteFile(ndkFile, []byte(initNDK), 0644); err != nil {
+				return err
+			}
+		}
+		if initOpenAL != "" {
+			var err error
+			if initOpenAL, err = filepath.Abs(initOpenAL); err != nil {
+				return err
+			}
+		}
+	}
+	ndkRoot = initNDK
 	if err := envInit(); err != nil {
 		return err
 	}
 
-	if err := fetchNDK(); err != nil {
-		return err
-	}
-	if err := fetchOpenAL(); err != nil {
-		return err
-	}
-
 	if runtime.GOOS == "darwin" {
 		// Install common x/mobile packages for local development.
 		// These are often slow to compile (due to cgo) and easy to forget.
@@ -154,6 +174,10 @@ func runInit(cmd *command) error {
 		return err
 	}
 
+	if err := installOpenAL(gomobilepath); err != nil {
+		return err
+	}
+
 	if buildX || buildN {
 		printcmd("go version > %s", verpath)
 	}
@@ -169,6 +193,121 @@ func runInit(cmd *command) error {
 	return nil
 }
 
+func installOpenAL(gomobilepath string) error {
+	if ndkRoot == "" || initOpenAL == "" {
+		return nil
+	}
+	sdkRoot := os.Getenv("ANDROID_HOME")
+	if sdkRoot == "" {
+		return nil
+	}
+	var cmake string
+	if buildN {
+		cmake = "cmake"
+	} else {
+		var err error
+		cmake, err = exec.LookPath("cmake")
+		if err != nil {
+			cmakePath := filepath.Join(sdkRoot, "cmake")
+			cmakeDir, err := os.Open(cmakePath)
+			if err != nil {
+				if os.IsNotExist(err) {
+					// Skip OpenAL install if the cmake package is not installed.
+					return errors.New("cmake was not found in the PATH. Please install it through the Android SDK manager.")
+				}
+				return err
+			}
+			defer cmakeDir.Close()
+			// There might be multiple versions of CMake installed. Use any one for now.
+			cmakeVers, err := cmakeDir.Readdirnames(1)
+			if err != nil || len(cmakeVers) == 0 {
+				return errors.New("cmake was not found in the PATH. Please install it through the Android SDK manager.")
+			}
+			cmake = filepath.Join(cmakePath, cmakeVers[0], "bin", "cmake")
+		}
+	}
+	var alTmpDir string
+	if buildN {
+		alTmpDir = filepath.Join(gomobilepath, "work")
+	} else {
+		var err error
+		alTmpDir, err = ioutil.TempDir(gomobilepath, "openal-release-")
+		if err != nil {
+			return err
+		}
+		defer removeAll(alTmpDir)
+	}
+
+	for _, f := range []string{"include/AL/al.h", "include/AL/alc.h"} {
+		dst := filepath.Join(gomobilepath, f)
+		src := filepath.Join(initOpenAL, f)
+		if err := copyFile(dst, src); err != nil {
+			return err
+		}
+	}
+
+	toolsDir := filepath.Join(ndkRoot, "prebuilt", archNDK(), "bin")
+	py27 := filepath.Join(toolsDir, "python2.7")
+	var make string
+	if !buildN && runtime.GOOS == "windows" {
+		var err error
+		make, err = exec.LookPath("nmake")
+		if err != nil {
+			return nil
+		}
+	} else {
+		make = filepath.Join(toolsDir, "make")
+	}
+	for _, arch := range archs {
+		t := ndk[arch]
+		abi := t.arch
+		if abi == "arm" {
+			abi = "armeabi"
+		}
+		// Split android-XX to get the api version.
+		platform := strings.SplitN(t.platform, "-", 2)
+		api := platform[1]
+		buildDir := alTmpDir + "/build/" + abi
+		toolchain := buildDir + "/toolchain"
+		// standalone ndk toolchains make openal-soft's build config easier.
+		cmd := exec.Command(py27,
+			"build/tools/make_standalone_toolchain.py",
+			"--arch="+t.arch,
+			"--api="+api,
+			"--install-dir="+toolchain)
+		cmd.Dir = ndkRoot
+		if err := runCmd(cmd); err != nil {
+			return err
+		}
+
+		cmd = exec.Command(cmake,
+			initOpenAL,
+			"-DCMAKE_TOOLCHAIN_FILE="+initOpenAL+"/XCompile-Android.txt",
+			"-DHOST="+t.toolPrefix)
+		cmd.Dir = buildDir
+		orgPath := os.Getenv("PATH")
+		if !buildN {
+			cmd.Env = []string{"PATH=" + toolchain + "/bin" + string(os.PathListSeparator) + orgPath}
+		}
+		if err := runCmd(cmd); err != nil {
+			return err
+		}
+
+		cmd = exec.Command(make)
+		cmd.Dir = buildDir
+		if err := runCmd(cmd); err != nil {
+			return err
+		}
+
+		dst := filepath.Join(gomobilepath, "lib", t.abi, "libopenal.so")
+		src := filepath.Join(alTmpDir, "build", abi, "libopenal.so")
+		if err := copyFile(dst, src); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
 var commonPkgs = []string{
 	"golang.org/x/mobile/gl",
 	"golang.org/x/mobile/app",
@@ -225,44 +364,6 @@ func installPkg(pkg string, env []string, args ...string) error {
 	return runCmd(cmd)
 }
 
-func removeGomobilepkg() {
-	dir, err := os.Open(gomobilepath)
-	if err != nil {
-		return
-	}
-	names, err := dir.Readdirnames(-1)
-	if err != nil {
-		return
-	}
-	for _, name := range names {
-		if name == "dl" {
-			continue
-		}
-		removeAll(filepath.Join(gomobilepath, name))
-	}
-}
-
-func move(dst, src string, names ...string) error {
-	for _, name := range names {
-		srcf := filepath.Join(src, name)
-		dstf := filepath.Join(dst, name)
-		if buildX || buildN {
-			printcmd("mv %s %s", srcf, dstf)
-		}
-		if buildN {
-			continue
-		}
-		if goos == "windows" {
-			// os.Rename fails if dstf already exists.
-			removeAll(dstf)
-		}
-		if err := os.Rename(srcf, dstf); err != nil {
-			return err
-		}
-	}
-	return nil
-}
-
 func mkdir(dir string) error {
 	if buildX || buildN {
 		printcmd("mkdir -p %s", dir)
@@ -296,280 +397,6 @@ func rm(name string) error {
 	return os.Remove(name)
 }
 
-func fetchOpenAL() error {
-	url := "https://dl.google.com/go/mobile/gomobile-" + openALVersion + ".tar.gz"
-	archive, err := fetch(url)
-	if err != nil {
-		return err
-	}
-	if err := extract("openal", archive); err != nil {
-		return err
-	}
-	if goos == "windows" {
-		resetReadOnlyFlagAll(filepath.Join(tmpdir, "openal"))
-	}
-	ndkroot := ndk.Root()
-	src := filepath.Join(tmpdir, "openal/include/AL")
-	for arch := range androidEnv {
-		toolchain := ndk.Toolchain(arch)
-		dst := filepath.Join(ndkroot, toolchain.arch+"/sysroot/usr/include/AL")
-		if buildX || buildN {
-			printcmd("cp -r %s %s", src, dst)
-		}
-		if buildN {
-			continue
-		}
-		if err := doCopyAll(dst, src); err != nil {
-			return err
-		}
-	}
-	libDst := filepath.Join(ndkroot, "openal")
-	libSrc := filepath.Join(tmpdir, "openal")
-	if err := mkdir(libDst); err != nil {
-		return nil
-	}
-	if err := move(libDst, libSrc, "lib"); err != nil {
-		return err
-	}
-	return nil
-}
-
-func extract(dst, src string) error {
-	if buildX || buildN {
-		printcmd("tar xfz %s", src)
-	}
-	if buildN {
-		return nil
-	}
-	tf, err := os.Open(src)
-	if err != nil {
-		return err
-	}
-	defer tf.Close()
-	zr, err := gzip.NewReader(tf)
-	if err != nil {
-		return err
-	}
-	tr := tar.NewReader(zr)
-	for {
-		hdr, err := tr.Next()
-		if err == io.EOF {
-			break
-		}
-		if err != nil {
-			return err
-		}
-		dst := filepath.Join(tmpdir, dst+"/"+hdr.Name)
-		if hdr.Typeflag == tar.TypeSymlink {
-			if err := symlink(hdr.Linkname, dst); err != nil {
-				return err
-			}
-			continue
-		}
-		if err := os.MkdirAll(filepath.Dir(dst), 0755); err != nil {
-			return err
-		}
-		f, err := os.OpenFile(dst, os.O_CREATE|os.O_EXCL|os.O_WRONLY, os.FileMode(hdr.Mode)&0777)
-		if err != nil {
-			return err
-		}
-		if _, err := io.Copy(f, tr); err != nil {
-			return err
-		}
-		if err := f.Close(); err != nil {
-			return err
-		}
-	}
-	return nil
-}
-
-func fetchNDK() error {
-	if useStrippedNDK {
-		if err := fetchStrippedNDK(); err != nil {
-			return err
-		}
-	} else {
-		if err := fetchFullNDK(); err != nil {
-			return err
-		}
-	}
-	if goos == "windows" {
-		resetReadOnlyFlagAll(filepath.Join(tmpdir, "android-"+ndkVersion))
-	}
-
-	// Copy the cross compiling clang and clang++ compilers
-	llvmsrc := filepath.Join(tmpdir, fmt.Sprintf(
-		"android-%s/toolchains/llvm/prebuilt", ndkVersion))
-	if goos == "windows" && ndkarch == "x86" {
-		llvmsrc = filepath.Join(llvmsrc, "windows")
-	} else {
-		llvmsrc = filepath.Join(llvmsrc, goos+"-"+ndkarch)
-	}
-	llvmdst := filepath.Join(ndk.Root(), "llvm")
-	if err := mkdir(llvmdst); err != nil {
-		return err
-	}
-	if err := move(llvmdst, llvmsrc, "lib64", "bin"); err != nil {
-		return err
-	}
-
-	for arch := range androidEnv {
-		toolchain := ndk.Toolchain(arch)
-		dst := filepath.Join(ndk.Root(), toolchain.arch)
-		dstSysroot := filepath.Join(dst, "sysroot")
-		if err := mkdir(dstSysroot); err != nil {
-			return err
-		}
-
-		srcSysroot := filepath.Join(tmpdir, fmt.Sprintf(
-			"android-%s/platforms/%s/arch-%s", ndkVersion, toolchain.platform, toolchain.arch))
-		if err := move(dstSysroot, srcSysroot, "usr"); err != nil {
-			return err
-		}
-
-		ndkpath := filepath.Join(tmpdir, fmt.Sprintf(
-			"android-%s/toolchains/%s/prebuilt", ndkVersion, toolchain.gcc))
-		if goos == "windows" && ndkarch == "x86" {
-			ndkpath = filepath.Join(ndkpath, "windows")
-		} else {
-			ndkpath = filepath.Join(ndkpath, goos+"-"+ndkarch)
-		}
-		if err := move(dst, ndkpath, "bin", "lib"); err != nil {
-			return err
-		}
-
-		linkpath := filepath.Join(dst, toolchain.toolPrefix+"/bin")
-		if err := mkdir(linkpath); err != nil {
-			return err
-		}
-
-		for _, name := range []string{"ld", "as", "nm"} {
-			if goos == "windows" {
-				name += ".exe"
-			}
-			if err := symlink(filepath.Join(dst, "bin", toolchain.toolPrefix+"-"+name), filepath.Join(linkpath, name)); err != nil {
-				return err
-			}
-		}
-		for _, toname := range []string{"clang", "clang++"} {
-			fromname := toname
-			if goos == "windows" {
-				if goarch == "386" {
-					if toname == "clang++" {
-						// there is no 32-bit version of clang++
-						continue
-					}
-					fromname += "_32"
-				}
-				fromname += ".exe"
-				toname += ".exe"
-			}
-			if err := symlink(filepath.Join(llvmdst, "bin", fromname), filepath.Join(dst, "bin", toolchain.toolPrefix+"-"+toname)); err != nil {
-				return err
-			}
-		}
-		if err := symlink(filepath.Join(llvmdst, "lib64"), filepath.Join(dst, "lib64")); err != nil {
-			return err
-		}
-	}
-	return nil
-}
-
-func fetchStrippedNDK() error {
-	url := "https://dl.google.com/go/mobile/gomobile-" + ndkVersion + "-" + goos + "-" + ndkarch + ".tar.gz"
-	archive, err := fetch(url)
-	if err != nil {
-		return err
-	}
-	return extract("", archive)
-}
-
-func fetchFullNDK() error {
-	url := "https://dl.google.com/android/repository/android-" + ndkVersion + "-" + goos + "-" + ndkarch + ".zip"
-	archive, err := fetch(url)
-	if err != nil {
-		return err
-	}
-	var inflate *exec.Cmd
-	if goos != "windows" {
-		inflate = exec.Command("unzip", archive)
-	} else {
-		inflate = exec.Command("unzip.exe", archive)
-	}
-	inflate.Dir = tmpdir
-	return runCmd(inflate)
-}
-
-// fetch reads a URL into $GOPATH/pkg/gomobile/dl and returns the path
-// to the downloaded file. Downloading is skipped if the file is
-// already present.
-func fetch(url string) (dst string, err error) {
-	if err := mkdir(filepath.Join(gomobilepath, "dl")); err != nil {
-		return "", err
-	}
-	name := path.Base(url)
-	dst = filepath.Join(gomobilepath, "dl", name)
-
-	// Use what's in the cache if force update is not required.
-	if !initU {
-		if buildX {
-			printcmd("stat %s", dst)
-		}
-		if _, err = os.Stat(dst); err == nil {
-			return dst, nil
-		}
-	}
-	if buildX {
-		printcmd("curl -o%s %s", dst, url)
-	}
-	if buildN {
-		return dst, nil
-	}
-
-	if buildV {
-		fmt.Fprintf(os.Stderr, "Downloading %s.\n", url)
-	}
-
-	f, err := ioutil.TempFile(tmpdir, "partial-"+name)
-	if err != nil {
-		return "", err
-	}
-	defer func() {
-		if err != nil {
-			f.Close()
-			os.Remove(f.Name())
-		}
-	}()
-	hashw := sha256.New()
-
-	resp, err := http.Get(url)
-	if err != nil {
-		return "", err
-	}
-	if resp.StatusCode != http.StatusOK {
-		err = fmt.Errorf("error fetching %v, status: %v", url, resp.Status)
-	} else {
-		_, err = io.Copy(io.MultiWriter(hashw, f), resp.Body)
-	}
-	if err2 := resp.Body.Close(); err == nil {
-		err = err2
-	}
-	if err != nil {
-		return "", err
-	}
-	if err = f.Close(); err != nil {
-		return "", err
-	}
-	hash := hex.EncodeToString(hashw.Sum(nil))
-	if fetchHashes[name] != hash {
-		return "", fmt.Errorf("sha256 for %q: %v, want %v. Try 'gomobile clean'", name, hash, fetchHashes[name])
-	}
-	if err = os.Rename(f.Name(), dst); err != nil {
-		return "", err
-	}
-	return dst, nil
-}
-
 func doCopyAll(dst, src string) error {
 	return filepath.Walk(src, func(path string, info os.FileInfo, errin error) (err error) {
 		if errin != nil {
diff --git a/cmd/gomobile/init_test.go b/cmd/gomobile/init_test.go
index cdb6024..43384ce 100644
--- a/cmd/gomobile/init_test.go
+++ b/cmd/gomobile/init_test.go
@@ -22,13 +22,11 @@ func TestInit(t *testing.T) {
 		xout = os.Stderr
 		buildN = false
 		buildX = false
-		initU = false
 		os.Setenv("GOPATH", gopathorig)
 	}()
 	xout = buf
 	buildN = true
 	buildX = true
-	initU = true
 
 	// Test that first GOPATH element is chosen correctly.
 	gopath = "/GOPATH1"
@@ -75,7 +73,6 @@ func diffOutput(got string, wantTmpl *template.Template) (string, error) {
 }
 
 type outputData struct {
-	NDK       string
 	GOOS      string
 	GOARCH    string
 	GOPATH    string
@@ -88,7 +85,6 @@ type outputData struct {
 
 func defaultOutputData() outputData {
 	data := outputData{
-		NDK:       ndkVersion,
 		GOOS:      goos,
 		GOARCH:    goarch,
 		GOPATH:    gopath,
@@ -104,38 +100,40 @@ func defaultOutputData() outputData {
 }
 
 var initTmpl = template.Must(template.New("output").Parse(`GOMOBILE={{.GOPATH}}/pkg/gomobile
-mkdir -p $GOMOBILE/android-{{.NDK}}
-WORK={{.GOPATH}}/pkg/gomobile/work
-mkdir -p $GOMOBILE/dl
-curl -o$GOMOBILE/dl/gomobile-{{.NDK}}-{{.GOOS}}-{{.NDKARCH}}.tar.gz https://dl.google.com/go/mobile/gomobile-{{.NDK}}-{{.GOOS}}-{{.NDKARCH}}.tar.gz
-tar xfz $GOMOBILE/dl/gomobile-{{.NDK}}-{{.GOOS}}-{{.NDKARCH}}.tar.gz
-mkdir -p $GOMOBILE/android-{{.NDK}}/llvm
-mv $WORK/android-{{.NDK}}/toolchains/llvm/prebuilt/{{.GOOS}}-{{.NDKARCH}}/lib64 $GOMOBILE/android-{{.NDK}}/llvm/lib64
-mv $WORK/android-{{.NDK}}/toolchains/llvm/prebuilt/{{.GOOS}}-{{.NDKARCH}}/bin $GOMOBILE/android-{{.NDK}}/llvm/bin
-mkdir -p $GOMOBILE/android-{{.NDK}}/arm/sysroot
-mv $WORK/android-{{.NDK}}/platforms/android-15/arch-arm/usr $GOMOBILE/android-{{.NDK}}/arm/sysroot/usr
-mv $WORK/android-{{.NDK}}/toolchains/arm-linux-androideabi-4.9/prebuilt/{{.GOOS}}-{{.NDKARCH}}/bin $GOMOBILE/android-{{.NDK}}/arm/bin
-mv $WORK/android-{{.NDK}}/toolchains/arm-linux-androideabi-4.9/prebuilt/{{.GOOS}}-{{.NDKARCH}}/lib $GOMOBILE/android-{{.NDK}}/arm/lib
-mkdir -p $GOMOBILE/android-{{.NDK}}/arm/arm-linux-androideabi/bin
-ln -s $GOMOBILE/android-{{.NDK}}/arm/bin/arm-linux-androideabi-ld{{.EXE}} $GOMOBILE/android-{{.NDK}}/arm/arm-linux-androideabi/bin/ld{{.EXE}}
-ln -s $GOMOBILE/android-{{.NDK}}/arm/bin/arm-linux-androideabi-as{{.EXE}} $GOMOBILE/android-{{.NDK}}/arm/arm-linux-androideabi/bin/as{{.EXE}}
-ln -s $GOMOBILE/android-{{.NDK}}/arm/bin/arm-linux-androideabi-nm{{.EXE}} $GOMOBILE/android-{{.NDK}}/arm/arm-linux-androideabi/bin/nm{{.EXE}}
-ln -s $GOMOBILE/android-{{.NDK}}/llvm/bin/clang $GOMOBILE/android-{{.NDK}}/arm/bin/arm-linux-androideabi-clang
-ln -s $GOMOBILE/android-{{.NDK}}/llvm/bin/clang++ $GOMOBILE/android-{{.NDK}}/arm/bin/arm-linux-androideabi-clang++
-ln -s $GOMOBILE/android-{{.NDK}}/llvm/lib64 $GOMOBILE/android-{{.NDK}}/arm/lib64
-mkdir -p $GOMOBILE/dl
-curl -o$GOMOBILE/dl/gomobile-openal-soft-1.16.0.1-{{.NDK}}.tar.gz https://dl.google.com/go/mobile/gomobile-openal-soft-1.16.0.1-{{.NDK}}.tar.gz
-tar xfz $GOMOBILE/dl/gomobile-openal-soft-1.16.0.1-{{.NDK}}.tar.gz
-cp -r $WORK/openal/include/AL $GOMOBILE/android-{{.NDK}}/arm/sysroot/usr/include/AL
-mkdir -p $GOMOBILE/android-{{.NDK}}/openal
-mv $WORK/openal/lib $GOMOBILE/android-{{.NDK}}/openal/lib{{if eq .GOOS "darwin"}}
+rm -r -f "$GOMOBILE"
+mkdir -p $GOMOBILE
+WORK={{.GOPATH}}/pkg/gomobile/work{{if eq .GOOS "darwin"}}
 go install -x golang.org/x/mobile/gl
 go install -x golang.org/x/mobile/app
 go install -x golang.org/x/mobile/exp/app/debug{{end}}
-GOOS=android GOARCH=arm CC=$GOMOBILE/android-{{.NDK}}/arm/bin/arm-linux-androideabi-clang{{.EXE}} CXX=$GOMOBILE/android-{{.NDK}}/arm/bin/arm-linux-androideabi-clang++{{.EXE}} CGO_CFLAGS=-target armv7a-none-linux-androideabi --sysroot $GOMOBILE/android-{{.NDK}}/arm/sysroot CGO_CPPFLAGS=-target armv7a-none-linux-androideabi --sysroot $GOMOBILE/android-{{.NDK}}/arm/sysroot CGO_LDFLAGS=-target armv7a-none-linux-androideabi --sysroot $GOMOBILE/android-{{.NDK}}/arm/sysroot CGO_ENABLED=1 GOARM=7 go install -pkgdir=$GOMOBILE/pkg_android_arm -x std
+GOOS=android GOARCH=arm CC=$NDK_PATH/toolchains/llvm/prebuilt/{{.GOOS}}-{{.NDKARCH}}/bin/clang{{.EXE}} CXX=$NDK_PATH/toolchains/llvm/prebuilt/{{.GOOS}}-{{.NDKARCH}}/bin/clang++{{.EXE}} CGO_CFLAGS=-target armv7a-none-linux-androideabi --sysroot $NDK_PATH/platforms/android-15/arch-arm -gcc-toolchain $NDK_PATH/toolchains/arm-linux-androideabi-4.9/prebuilt/{{.GOOS}}-{{.NDKARCH}} -I$GOMOBILE/include CGO_CPPFLAGS=-target armv7a-none-linux-androideabi --sysroot $NDK_PATH/platforms/android-15/arch-arm -gcc-toolchain $NDK_PATH/toolchains/arm-linux-androideabi-4.9/prebuilt/{{.GOOS}}-{{.NDKARCH}} -I$GOMOBILE/include CGO_LDFLAGS=-target armv7a-none-linux-androideabi --sysroot $NDK_PATH/platforms/android-15/arch-arm -gcc-toolchain $NDK_PATH/toolchains/arm-linux-androideabi-4.9/prebuilt/{{.GOOS}}-{{.NDKARCH}} -L$NDK_PATH/platforms/android-15/arch-arm/usr/lib -L$GOMOBILE/lib/arm CGO_ENABLED=1 GOARM=7 go install -pkgdir=$GOMOBILE/pkg_android_arm -x std
 {{if eq .GOOS "darwin"}}GOOS=darwin GOARCH=arm GOARM=7 CC=clang-iphoneos CXX=clang-iphoneos CGO_CFLAGS=-isysroot=iphoneos -miphoneos-version-min=6.1 -arch armv7 CGO_LDFLAGS=-isysroot=iphoneos -miphoneos-version-min=6.1 -arch armv7 CGO_ENABLED=1 go install -pkgdir=$GOMOBILE/pkg_darwin_arm -x std
 GOOS=darwin GOARCH=arm64 CC=clang-iphoneos CXX=clang-iphoneos CGO_CFLAGS=-isysroot=iphoneos -miphoneos-version-min=6.1 -arch arm64 CGO_LDFLAGS=-isysroot=iphoneos -miphoneos-version-min=6.1 -arch arm64 CGO_ENABLED=1 go install -pkgdir=$GOMOBILE/pkg_darwin_arm64 -x std
 GOOS=darwin GOARCH=amd64 CC=clang-iphonesimulator CXX=clang-iphonesimulator CGO_CFLAGS=-isysroot=iphonesimulator -mios-simulator-version-min=6.1 -arch x86_64 CGO_LDFLAGS=-isysroot=iphonesimulator -mios-simulator-version-min=6.1 -arch x86_64 CGO_ENABLED=1 go install -tags=ios -pkgdir=$GOMOBILE/pkg_darwin_amd64 -x std
-{{end}}go version > $GOMOBILE/version
+{{end}}cp $OPENAL_PATH/include/AL/al.h $GOMOBILE/include/AL/al.h
+mkdir -p $GOMOBILE/include/AL
+cp $OPENAL_PATH/include/AL/alc.h $GOMOBILE/include/AL/alc.h
+mkdir -p $GOMOBILE/include/AL
+PWD=$NDK_PATH $NDK_PATH/prebuilt/{{.GOOS}}-{{.NDKARCH}}/bin/python2.7 build/tools/make_standalone_toolchain.py --arch=arm --api=15 --install-dir=$WORK/build/armeabi/toolchain
+PWD=$WORK/build/armeabi cmake $OPENAL_PATH -DCMAKE_TOOLCHAIN_FILE=$OPENAL_PATH/XCompile-Android.txt -DHOST=arm-linux-androideabi
+PWD=$WORK/build/armeabi $NDK_PATH/prebuilt/{{.GOOS}}-{{.NDKARCH}}/bin/make
+cp $WORK/build/armeabi/libopenal.so $GOMOBILE/lib/armeabi-v7a/libopenal.so
+mkdir -p $GOMOBILE/lib/armeabi-v7a
+PWD=$NDK_PATH $NDK_PATH/prebuilt/{{.GOOS}}-{{.NDKARCH}}/bin/python2.7 build/tools/make_standalone_toolchain.py --arch=arm64 --api=21 --install-dir=$WORK/build/arm64/toolchain
+PWD=$WORK/build/arm64 cmake $OPENAL_PATH -DCMAKE_TOOLCHAIN_FILE=$OPENAL_PATH/XCompile-Android.txt -DHOST=aarch64-linux-android
+PWD=$WORK/build/arm64 $NDK_PATH/prebuilt/{{.GOOS}}-{{.NDKARCH}}/bin/make
+cp $WORK/build/arm64/libopenal.so $GOMOBILE/lib/arm64-v8a/libopenal.so
+mkdir -p $GOMOBILE/lib/arm64-v8a
+PWD=$NDK_PATH $NDK_PATH/prebuilt/{{.GOOS}}-{{.NDKARCH}}/bin/python2.7 build/tools/make_standalone_toolchain.py --arch=x86 --api=15 --install-dir=$WORK/build/x86/toolchain
+PWD=$WORK/build/x86 cmake $OPENAL_PATH -DCMAKE_TOOLCHAIN_FILE=$OPENAL_PATH/XCompile-Android.txt -DHOST=i686-linux-android
+PWD=$WORK/build/x86 $NDK_PATH/prebuilt/{{.GOOS}}-{{.NDKARCH}}/bin/make
+cp $WORK/build/x86/libopenal.so $GOMOBILE/lib/x86/libopenal.so
+mkdir -p $GOMOBILE/lib/x86
+PWD=$NDK_PATH $NDK_PATH/prebuilt/{{.GOOS}}-{{.NDKARCH}}/bin/python2.7 build/tools/make_standalone_toolchain.py --arch=x86_64 --api=21 --install-dir=$WORK/build/x86_64/toolchain
+PWD=$WORK/build/x86_64 cmake $OPENAL_PATH -DCMAKE_TOOLCHAIN_FILE=$OPENAL_PATH/XCompile-Android.txt -DHOST=x86_64-linux-android
+PWD=$WORK/build/x86_64 $NDK_PATH/prebuilt/{{.GOOS}}-{{.NDKARCH}}/bin/make
+cp $WORK/build/x86_64/libopenal.so $GOMOBILE/lib/x86_64/libopenal.so
+mkdir -p $GOMOBILE/lib/x86_64
+go version > $GOMOBILE/version
 rm -r -f "$WORK"
 `))
diff --git a/cmd/gomobile/release.go b/cmd/gomobile/release.go
deleted file mode 100644
index 589a124..0000000
--- a/cmd/gomobile/release.go
+++ /dev/null
@@ -1,489 +0,0 @@
-// Copyright 2015 The Go Authors.  All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-//+build ignore
-
-// Release is a tool for building the NDK tarballs hosted on dl.google.com.
-//
-// The Go toolchain only needs the gcc compiler and headers, which are ~10MB.
-// The entire NDK is ~400MB. Building smaller toolchain binaries reduces the
-// run time of gomobile init significantly.
-package main
-
-import (
-	"archive/tar"
-	"bufio"
-	"compress/gzip"
-	"crypto/sha256"
-	"encoding/hex"
-	"flag"
-	"fmt"
-	"hash"
-	"io"
-	"io/ioutil"
-	"log"
-	"net/http"
-	"os"
-	"os/exec"
-	"path/filepath"
-	"runtime"
-	"strconv"
-)
-
-const ndkVersion = "ndk-r12b"
-
-type version struct {
-	os   string
-	arch string
-}
-
-var hosts = []version{
-	{"darwin", "x86_64"},
-	{"linux", "x86_64"},
-	{"windows", "x86"},
-	{"windows", "x86_64"},
-}
-
-type target struct {
-	arch       string
-	platform   int
-	gcc        string
-	toolPrefix string
-}
-
-var targets = []target{
-	{"arm", 15, "arm-linux-androideabi-4.9", "arm-linux-androideabi"},
-	{"arm64", 21, "aarch64-linux-android-4.9", "aarch64-linux-android"},
-	{"x86", 15, "x86-4.9", "i686-linux-android"},
-	{"x86_64", 21, "x86_64-4.9", "x86_64-linux-android"},
-}
-
-var (
-	ndkdir = flag.String("ndkdir", "", "Directory for the downloaded NDKs for caching")
-	tmpdir string
-)
-
-func main() {
-	flag.Parse()
-	var err error
-	tmpdir, err = ioutil.TempDir("", "gomobile-release-")
-	if err != nil {
-		log.Panic(err)
-	}
-	defer os.RemoveAll(tmpdir)
-
-	fmt.Println("var fetchHashes = map[string]string{")
-	for _, host := range hosts {
-		if err := mkpkg(host); err != nil {
-			log.Panic(err)
-		}
-	}
-	if err := mkALPkg(); err != nil {
-		log.Panic(err)
-	}
-
-	fmt.Println("}")
-}
-
-func run(dir, path string, args ...string) error {
-	cmd := exec.Command(path, args...)
-	cmd.Dir = dir
-	buf, err := cmd.CombinedOutput()
-	if err != nil {
-		fmt.Printf("%s\n", buf)
-	}
-	return err
-}
-
-func mkALPkg() (err error) {
-	ndkPath, _, err := fetchNDK(version{os: hostOS, arch: hostArch})
-	if err != nil {
-		return err
-	}
-	ndkRoot := tmpdir + "/android-" + ndkVersion
-	if err := inflate(tmpdir, ndkPath); err != nil {
-		return err
-	}
-
-	alTmpDir, err := ioutil.TempDir("", "openal-release-")
-	if err != nil {
-		return err
-	}
-	defer os.RemoveAll(alTmpDir)
-
-	if err := run(alTmpDir, "git", "clone", "-v", "git://repo.or.cz/openal-soft.git", alTmpDir); err != nil {
-		return err
-	}
-	// TODO: use more recent revision?
-	if err := run(alTmpDir, "git", "checkout", "19f79be57b8e768f44710b6d26017bc1f8c8fbda"); err != nil {
-		return err
-	}
-
-	files := map[string]string{
-		"include/AL/al.h":  "include/AL/al.h",
-		"include/AL/alc.h": "include/AL/alc.h",
-		"COPYING":          "include/AL/COPYING",
-	}
-
-	for _, t := range targets {
-		abi := t.arch
-		if abi == "arm" {
-			abi = "armeabi"
-		}
-		buildDir := alTmpDir + "/build/" + abi
-		toolchain := buildDir + "/toolchain"
-		// standalone ndk toolchains make openal-soft's build config easier.
-		if err := run(ndkRoot, "env",
-			"build/tools/make_standalone_toolchain.py",
-			"--arch="+t.arch,
-			"--api="+strconv.Itoa(t.platform),
-			"--install-dir="+toolchain); err != nil {
-			return fmt.Errorf("make_standalone_toolchain.py failed: %v", err)
-		}
-
-		orgPath := os.Getenv("PATH")
-		os.Setenv("PATH", toolchain+"/bin"+string(os.PathListSeparator)+orgPath)
-		if err := run(buildDir, "cmake",
-			"../../",
-			"-DCMAKE_TOOLCHAIN_FILE=../../XCompile-Android.txt",
-			"-DHOST="+t.toolPrefix); err != nil {
-			return fmt.Errorf("cmake failed: %v", err)
-		}
-		os.Setenv("PATH", orgPath)
-
-		if err := run(buildDir, "make"); err != nil {
-			return fmt.Errorf("make failed: %v", err)
-		}
-
-		files["build/"+abi+"/libopenal.so"] = "lib/" + abi + "/libopenal.so"
-	}
-
-	// Build the tarball.
-	aw := newArchiveWriter("gomobile-openal-soft-1.16.0.1-" + ndkVersion + ".tar.gz")
-	defer func() {
-		err2 := aw.Close()
-		if err == nil {
-			err = err2
-		}
-	}()
-
-	for src, dst := range files {
-		f, err := os.Open(filepath.Join(alTmpDir, src))
-		if err != nil {
-			return err
-		}
-		fi, err := f.Stat()
-		if err != nil {
-			return err
-		}
-		aw.WriteHeader(&tar.Header{
-			Name: dst,
-			Mode: int64(fi.Mode()),
-			Size: fi.Size(),
-		})
-		io.Copy(aw, f)
-		f.Close()
-	}
-	return nil
-}
-
-func fetchNDK(host version) (binPath, url string, err error) {
-	ndkName := "android-" + ndkVersion + "-" + host.os + "-" + host.arch + ".zip"
-
-	url = "https://dl.google.com/android/repository/" + ndkName
-	binPath = *ndkdir
-	if binPath == "" {
-		binPath = tmpdir
-	}
-	binPath += "/" + ndkName
-
-	if _, err := os.Stat(binPath); err == nil {
-		log.Printf("\t%q: using cached NDK\n", ndkName)
-		return binPath, url, nil
-	}
-
-	log.Printf("%s\n", url)
-	binHash, err := fetch(binPath, url)
-	if err != nil {
-		return "", "", err
-	}
-
-	fmt.Printf("\t%q: %q,\n", ndkName, binHash)
-	return binPath, url, nil
-}
-
-func mkpkg(host version) error {
-	binPath, url, err := fetchNDK(host)
-	if err != nil {
-		return err
-	}
-
-	src := tmpdir + "/" + host.os + "-" + host.arch + "-src"
-	dst := tmpdir + "/" + host.os + "-" + host.arch + "-dst"
-	defer os.RemoveAll(src)
-	defer os.RemoveAll(dst)
-
-	if err := os.Mkdir(src, 0755); err != nil {
-		return err
-	}
-
-	if err := inflate(src, binPath); err != nil {
-		return err
-	}
-
-	// The NDK is unpacked into tmpdir/linux-x86_64-src/android-{{ndkVersion}}.
-	// Move the files we want into tmpdir/linux-x86_64-dst/android-{{ndkVersion}}.
-	// We preserve the same file layout to make the full NDK interchangable
-	// with the cut down file.
-	for _, t := range targets {
-		usr := fmt.Sprintf("android-%s/platforms/android-%d/arch-%s/usr/", ndkVersion, t.platform, t.arch)
-		gcc := fmt.Sprintf("android-%s/toolchains/%s/prebuilt/", ndkVersion, t.gcc)
-
-		if host.os == "windows" && host.arch == "x86" {
-			gcc += "windows"
-		} else {
-			gcc += host.os + "-" + host.arch
-		}
-
-		if err := os.MkdirAll(dst+"/"+usr, 0755); err != nil {
-			return err
-		}
-		if err := os.MkdirAll(dst+"/"+gcc+"/bin", 0755); err != nil {
-			return err
-		}
-
-		subdirs := []string{"include", "lib"}
-		switch t.arch {
-		case "x86_64":
-			subdirs = append(subdirs, "lib64", "libx32")
-		}
-		if err := move(dst+"/"+usr, src+"/"+usr, subdirs...); err != nil {
-			return err
-		}
-
-		if err := move(dst+"/"+gcc, src+"/"+gcc, "lib", "COPYING", "COPYING.LIB"); err != nil {
-			return err
-		}
-		for _, exe := range []string{"as", "ld", "nm"} {
-			if host.os == "windows" {
-				exe += ".exe"
-			}
-			if err := move(dst+"/"+gcc+"/bin", src+"/"+gcc+"/bin", t.toolPrefix+"-"+exe); err != nil {
-				return err
-			}
-		}
-	}
-
-	// Copy the LLVM clang and clang++ compilers
-	llvm := fmt.Sprintf("android-%s/toolchains/llvm/prebuilt/", ndkVersion)
-
-	if host.os == "windows" && host.arch == "x86" {
-		llvm += "windows"
-	} else {
-		llvm += host.os + "-" + host.arch
-	}
-
-	if err := os.MkdirAll(dst+"/"+llvm, 0755); err != nil {
-		return err
-	}
-
-	if err := move(dst+"/"+llvm, src+"/"+llvm, "bin", "lib64", "NOTICE"); err != nil {
-		return err
-	}
-
-	// Build the tarball.
-	aw := newArchiveWriter("gomobile-" + ndkVersion + "-" + host.os + "-" + host.arch + ".tar.gz")
-	defer func() {
-		err2 := aw.Close()
-		if err == nil {
-			err = err2
-		}
-	}()
-
-	readme := "Stripped down copy of:\n\n\t" + url + "\n\nGenerated by golang.org/x/mobile/cmd/gomobile/release.go."
-	aw.WriteHeader(&tar.Header{
-		Name: "README",
-		Mode: 0644,
-		Size: int64(len(readme)),
-	})
-	io.WriteString(aw, readme)
-
-	return filepath.Walk(dst, func(path string, fi os.FileInfo, err error) error {
-		defer func() {
-			if err != nil {
-				err = fmt.Errorf("%s: %v", path, err)
-			}
-		}()
-		if err != nil {
-			return err
-		}
-		if path == dst {
-			return nil
-		}
-		name := path[len(dst)+1:]
-		if fi.IsDir() {
-			return nil
-		}
-		if fi.Mode()&os.ModeSymlink != 0 {
-			dst, err := os.Readlink(path)
-			if err != nil {
-				log.Printf("bad symlink: %s", name)
-				return nil
-			}
-			aw.WriteHeader(&tar.Header{
-				Name:     name,
-				Linkname: dst,
-				Typeflag: tar.TypeSymlink,
-			})
-			return nil
-		}
-		aw.WriteHeader(&tar.Header{
-			Name: name,
-			Mode: int64(fi.Mode()),
-			Size: fi.Size(),
-		})
-		f, err := os.Open(path)
-		if err != nil {
-			return err
-		}
-		io.Copy(aw, f)
-		f.Close()
-		return nil
-	})
-}
-
-func fetch(dst, url string) (string, error) {
-	f, err := os.OpenFile(dst, os.O_CREATE|os.O_EXCL|os.O_WRONLY, 0755)
-	if err != nil {
-		return "", err
-	}
-	resp, err := http.Get(url)
-	if err != nil {
-		return "", err
-	}
-	if sc := resp.StatusCode; sc != http.StatusOK {
-		return "", fmt.Errorf("invalid HTTP status %d", sc)
-	}
-	hashw := sha256.New()
-	_, err = io.Copy(io.MultiWriter(hashw, f), resp.Body)
-	err2 := resp.Body.Close()
-	err3 := f.Close()
-	if err != nil {
-		return "", err
-	}
-	if err2 != nil {
-		return "", err2
-	}
-	if err3 != nil {
-		return "", err3
-	}
-	return hex.EncodeToString(hashw.Sum(nil)), nil
-}
-
-func inflate(dst, path string) error {
-	unzip := "unzip"
-	cmd := exec.Command(unzip, path)
-	cmd.Dir = dst
-	out, err := cmd.CombinedOutput()
-	if err != nil {
-		os.Stderr.Write(out)
-		return err
-	}
-	return nil
-}
-
-func move(dst, src string, names ...string) error {
-	for _, name := range names {
-		if err := os.Rename(src+"/"+name, dst+"/"+name); err != nil {
-			return err
-		}
-	}
-	return nil
-}
-
-// archiveWriter writes a .tar.gz archive and prints its SHA256 to stdout.
-// If any error occurs, it continues as a no-op until Close, when it is reported.
-type archiveWriter struct {
-	name  string
-	hashw hash.Hash
-	f     *os.File
-	zw    *gzip.Writer
-	bw    *bufio.Writer
-	tw    *tar.Writer
-	err   error
-}
-
-func (aw *archiveWriter) WriteHeader(h *tar.Header) {
-	if aw.err != nil {
-		return
-	}
-	aw.err = aw.tw.WriteHeader(h)
-}
-
-func (aw *archiveWriter) Write(b []byte) (n int, err error) {
-	if aw.err != nil {
-		return len(b), nil
-	}
-	n, aw.err = aw.tw.Write(b)
-	return n, nil
-}
-
-func (aw *archiveWriter) Close() (err error) {
-	err = aw.tw.Close()
-	if aw.err == nil {
-		aw.err = err
-	}
-	err = aw.zw.Close()
-	if aw.err == nil {
-		aw.err = err
-	}
-	err = aw.bw.Flush()
-	if aw.err == nil {
-		aw.err = err
-	}
-	err = aw.f.Close()
-	if aw.err == nil {
-		aw.err = err
-	}
-	if aw.err != nil {
-		return aw.err
-	}
-	hash := hex.EncodeToString(aw.hashw.Sum(nil))
-	fmt.Printf("\t%q: %q,\n", aw.name, hash)
-	return nil
-}
-
-func newArchiveWriter(name string) *archiveWriter {
-	aw := &archiveWriter{name: name}
-	aw.f, aw.err = os.Create(name)
-	if aw.err != nil {
-		return aw
-	}
-	aw.hashw = sha256.New()
-	aw.bw = bufio.NewWriter(io.MultiWriter(aw.f, aw.hashw))
-	aw.zw, aw.err = gzip.NewWriterLevel(aw.bw, gzip.BestCompression)
-	if aw.err != nil {
-		return aw
-	}
-	aw.tw = tar.NewWriter(aw.zw)
-	return aw
-}
-
-var hostOS, hostArch string
-
-func init() {
-	switch runtime.GOOS {
-	case "linux", "darwin":
-		hostOS = runtime.GOOS
-	}
-	switch runtime.GOARCH {
-	case "386":
-		hostArch = "x86"
-	case "amd64":
-		hostArch = "x86_64"
-	}
-	if hostOS == "" || hostArch == "" {
-		panic(fmt.Sprintf("cannot run release from OS/Arch: %s/%s", hostOS, hostArch))
-	}
-}