The Android NDK is a companion tool to the Android SDK that lets you build performance-critical portions of your apps in native code. It provides headers and libraries that allow you to build activities, handle user input, use hardware sensors, access application resources, and more, when programming in C or C++. If you write native code, your applications are still packaged into an .apk file and they still run inside of a virtual machine on the device. The fundamental Android application model does not change.
Using native code does not result in an automatic performance increase, but always increases application complexity. If you have not run into any limitations using the Android framework APIs, you probably do not need the NDK. Read What is the NDK? for more information about what the NDK offers and whether it will be useful to you.
The NDK is designed for use only in conjunction with the Android SDK. If you have not already installed and setup the Android SDK, please do so before downloading the NDK.
Platform | Package | Size | MD5 Checksum |
---|---|---|---|
Windows | android-ndk-r5b-windows.zip | 61299831 bytes | 87745ada305ab639399161ab4faf684c |
Mac OS X (intel) | android-ndk-r5b-darwin-x86.tar.bz2 | 50210863 bytes | 019a14622a377b3727ec789af6707037 |
Linux 32/64-bit (x86) | android-ndk-r5b-linux-x86.tar.bz2 | 44138539 bytes | 4c0045ddc2bfd657be9d5177d0e0b7e7 |
The sections below provide information and notes about successive releases of the NDK, as denoted by revision number.
This release of the NDK does not include any new features compared to r5. The r5b release addresses the following problems in the r5 release:
ndk-build
issues are fixed:
cygpath -m
from GNU Make for every source or object file, which caused problems
with very large source trees. In case this doesn't work properly, define NDK_USE_CYGPATH=1
in your
environment to use cygpath -m
again.NDK_MODULE_PATH
environment variable from working properly when
it contained multiple directories separated with a colon. prebuilt-common.sh
script contains fixes to check the compiler for 64-bit
generated machine code, instead of relying on the host tag, which
allows the 32-bit toolchain to rebuild properly on Snow Leopard. The toolchain rebuild scripts now also support
using a 32-bit host toolchain.INET_ADDRSTRLEN
was added to <netinet/in.h>
.IN6_IS_ADDR_MC_NODELOCAL
and IN6_IS_ADDR_MC_GLOBAL
were added to <netinet/in6.h>
.<asm/byteorder.h>
to allow compilation with -std=c99
.This release of the NDK includes many new APIs, most of which are introduced to
support the development of games and similar applications that make extensive use
of native code. Using the APIs, developers have direct native access to events, audio,
graphics and window management, assets, and storage. Developers can also implement the
Android application lifecycle in native code with help from the new
NativeActivity
class. For detailed information describing the changes in this
release, read the CHANGES.HTML
document included in the downloaded NDK package.
.apk
file../configure && make
. See
docs/STANDALONE-TOOLCHAIN.html for the details. The binaries for GCC 4.4.0 are still provided,
but the 4.2.1 binaries were removed.cpufeatures
helper library that improves reporting
of the CPU type (some devices previously reported ARMv7 CPU when the device really was an ARMv6). We
recommend developers that use this library to rebuild their applications then
upload to Market to benefit from the improvements.native-plasma
and native-activity
,
to demonstrate how to write a native activity.Includes fixes for several issues in the NDK build and debugging scripts — if you are using NDK r4, we recommend downloading the NDK r4b build. For detailed information describing the changes in this release, read the CHANGES.TXT document included in the downloaded NDK package.
ndk-build
build
command.ndk-gdb
command.armeabi-v7a
. The new ABI extends the existing armeabi
ABI to
include these CPU instruction set extensions:
cpufeatures
static library (with sources) that lets your
app detect the host device's CPU features at runtime. Specifically, applications can
check for ARMv7-A support, as well as VFPv3-D32 and NEON support, then provide separate
code paths as needed.hello-neon
, that illustrates how to use the
cpufeatures
library to check CPU features and then provide an optimized
code path using NEON instrinsics, if supported by the CPU..apk
.Bitmap
objects from native code.hello-gl2
, that illustrates the use of
OpenGL ES 2.0 vertex and fragment shaders.Originally released as "Android 1.6 NDK, Release 1".
san-angeles
, that renders 3D graphics
through the native OpenGL ES APIs, while managing activity lifecycle with a GLSurfaceView
object.Originally released as "Android 1.5 NDK, Release 1".
Installing the NDK on your development computer is straightforward and involves extracting the NDK from its download package.
Before you get started make sure that you have downloaded the latest Android SDK and upgraded your applications and environment as needed. The NDK is compatible with older platform versions but not older versions of the SDK tools. Also, take a moment to review the System and Software Requirements for the NDK, if you haven't already.
To install the NDK, follow these steps:
android-ndk-<version>
. You can rename the NDK directory if necessary and you
can move it to any location on your computer. This documentation refers to the NDK directory as
<ndk>
.You are now ready to start working with the NDK.
Once you've installed the NDK successfully, take a few minutes to read the documentation
included in the NDK. You can find the documentation in the <ndk>/docs/
directory. In particular, please read the OVERVIEW.HTML document completely, so that you
understand the intent of the NDK and how to use it.
If you used a previous version of the NDK, take a moment to review the list of NDK changes in the CHANGES.HTML document.
Here's the general outline of how you work with the NDK tools:
<project>/jni/...
<project>/jni/Android.mk
to describe your native sources to the
NDK build system<project>/jni/Application.mk
.cd <project> <ndk>/ndk-build
The build tools copy the stripped, shared libraries needed by your application to the proper location in the application's project directory.
.apk
file.For complete information on all of the steps listed above, please see the documentation included with the NDK package.
The NDK includes sample Android applications that illustrate how to use native code in your Android applications. For more information, see Sample Applications.
If you have questions about the NDK or would like to read or contribute to discussions about it, please visit the android-ndk group and mailing list.