1 <!-- 2 Copyright 2010 The Android Open Source Project 3 4 Licensed under the Apache License, Version 2.0 (the "License"); 5 you may not use this file except in compliance with the License. 6 You may obtain a copy of the License at 7 8 http://www.apache.org/licenses/LICENSE-2.0 9 10 Unless required by applicable law or agreed to in writing, software 11 distributed under the License is distributed on an "AS IS" BASIS, 12 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 See the License for the specific language governing permissions and 14 limitations under the License. 15 --> 16 17 # Building the System # 18 19 The basic sequence of build commands is as follows: 20 21 ## Initialize ## 22 23 Initialize the environment with the `envsetup.sh` script. Note 24 that replacing "source" with a single dot saves a few characters, 25 and the short form is more commonly used in documentation. 26 27 $ source build/envsetup.sh 28 29 or 30 31 $ . build/envsetup.sh 32 33 ## Choose a Target ## 34 35 Choose which target to build with `lunch`. The exact configuration can be passed as 36 an argument, e.g. 37 38 $ lunch full-eng 39 40 The example above refers to a complete build for the emulator, with all debugging enabled. 41 42 If run with no arguments `lunch` will prompt you to choose a target from the menu. 43 44 All build targets take the form BUILD-BUILDTYPE, where the BUILD is a codename 45 referring to the particular feature combination: 46 47 Build name | Device | Notes 48 ------------|----------|--------------------------- 49 generic | emulator | lowest-common denominator 50 full | emulator | fully configured with all languages, apps, input methods 51 full_crespo | crespo | `full` build running on Nexus S ("crespo") 52 53 and the BUILDTYPE is one of the following: 54 55 Buildtype | Use 56 ------------|-------------------------------------- 57 user | limited access; suited for production 58 userdebug | like "user" but with root access and debuggability; preferred for debugging 59 eng | development configuration with additional debugging tools 60 61 For more information about building for and running on actual hardware, see 62 [Building for devices](building-devices.html) 63 64 ## Build the Code ## 65 66 Build everything with `make`. GNU make can handle parallel 67 tasks with a `-jN` argument, and it's common to use a number of 68 tasks N that's between 1 and 2 times the number of hardware 69 threads on the computer being used for the build. E.g. on a 70 dual-E5520 machine (2 CPUs, 4 cores per CPU, 2 threads per core), 71 the fastest builds are made with commands between `make -j16` and 72 `make -j32`. 73 74 $ make -j4 75 76 ## Run It! ## 77 78 You can either run your build on an emulator or flash it on a device. Please note that you have already selected your build target with `lunch`, and it is unlikely at best to run on a different target than it was built for. 79 80 ### Flash a Device ### 81 82 To flash a device, you will need to use `fastboot`, which should be included in your path after a successful build. Place the device in fastboot mode either manually by holding the appropriate key combination at boot, or from the shell with 83 84 $ adb reboot bootloader 85 86 Once the device is in fastboot mode, run 87 88 $ fastboot flashall -w 89 90 The `-w` option wipes the `/data` partition on the device; this is useful for your first time flashing a particular device, but is otherwise unnecessary. 91 92 For more information about building for and running on actual hardware, see 93 [Building for devices](building-devices.html) 94 95 ### Emulate an Android Device ### 96 97 The emulator is added to your path automatically by the build process. To run the emulator, type 98 99 $ emulator 100 101 # Using ccache # 102 103 ccache is a compiler cache for C and C++ that can help make builds faster. 104 In the root of the source tree, do the following: 105 106 $ export USE_CCACHE=1 107 $ export CCACHE_DIR=/<path_of_your_choice>/.ccache 108 $ prebuilt/linux-x86/ccache/ccache -M 20G 109 110 You can watch ccache being used by doing the following: 111 112 $ watch -n1 -d prebuilt/linux-x86/ccache/ccache -s 113 114 On OSX, you should replace `linux-x86` with `darwin-x86`. 115 116 # Troubleshooting Common Build Errors # 117 118 ## Wrong Java Version ## 119 120 If you are attempting to build froyo or earlier with Java 1.6, or gingerbread or later 121 with Java 1.5, `make` will abort with a message such as 122 123 ************************************************************ 124 You are attempting to build with the incorrect version 125 of java. 126 127 Your version is: WRONG_VERSION. 128 The correct version is: RIGHT_VERSION. 129 130 Please follow the machine setup instructions at 131 http://source.android.com/download 132 ************************************************************ 133 134 This may be caused by 135 136 - failing to install the correct JDK as specified on the [Initializing](initializing.html) page. Building Android requires Sun JDK 5 or 6 depending on which release you are building. 137 138 - another JDK that you previously installed appearing in your path. You can remove the offending JDK from your path with: 139 140 $ export PATH=${PATH/\/path\/to\/jdk\/dir:/} 141 142 ## Python Version 3 ## 143 144 Repo is built on particular functionality from Python 2.x and is unfortunately incompatible with Python 3. In order to use repo, please install Python 2.x: 145 146 $ apt-get install python 147 148 ## Gmake Version 3.82 ## 149 150 There is a bug in `make` version 3.82 on Mac OS that prevents building Android. 151 152 TODO: what the error looks like with GNU make 3.82 on older builds that don't explicitly detect it. 153 154 Follow the instructions on the [Initializing](initializing.html) page for reverting GNU make from 3.82 to 3.81. 155 156 ## Case Insensitive Filesystem ## 157 158 If you are building on an HFS filesystem on Mac OS X, you may encounter an error such as 159 160 ************************************************************ 161 You are building on a case-insensitive filesystem. 162 Please move your source tree to a case-sensitive filesystem. 163 ************************************************************ 164 165 Please follow the instructions on the [Initializing](initializing.html) page for creating a case-sensitive disk image. 166 167 ## No USB Permission ## 168 169 On most Linux systems, unprivileged users cannot access USB ports by default. If you see a permission denied error, follow the instructions on the [Initializing](initializing.html) page for configuring USB access. 170 171 If adb was already running and cannot connect to the device after 172 getting those rules set up, it can be killed with `adb kill-server`. 173 That will cause adb to restart with the new configuration. 174 175
