1 page.title=Building Kernels 2 @jd:body 3 4 <!-- 5 Copyright 2010 The Android Open Source Project 6 7 Licensed under the Apache License, Version 2.0 (the "License"); 8 you may not use this file except in compliance with the License. 9 You may obtain a copy of the License at 10 11 http://www.apache.org/licenses/LICENSE-2.0 12 13 Unless required by applicable law or agreed to in writing, software 14 distributed under the License is distributed on an "AS IS" BASIS, 15 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 16 See the License for the specific language governing permissions and 17 limitations under the License. 18 --> 19 <div id="qv-wrapper"> 20 <div id="qv"> 21 <h2>In this document</h2> 22 <ol id="auto-toc"> 23 </ol> 24 </div> 25 </div> 26 27 <p>If you are only interested in the kernel, you may use this guide 28 to download and build the appropriate kernel.</p> 29 <p>The following instructions assume that you have not downloaded all 30 of AOSP. If you have downloaded all of AOSP, you may skip the git 31 clone steps other than the step to download the actual kernel sources.</p> 32 <p>We will use the Pandaboard kernel in all the following examples.</p> 33 <h2 id="figuring-out-which-kernel-to-build">Figuring out which kernel to build</h2> 34 <p>This table lists the name and locations of the kernel sources and binaries: 35 <table> 36 <tr> 37 <th>Device</th> 38 <th>Binary location</th> 39 <th>Source location</th> 40 <th>Build configuration</th> 41 </tr> 42 <tr> 43 <td>manta</td> 44 <td>device/samsung/manta/kernel</td> 45 <td>kernel/exynos</td> 46 <td>manta_defconfig</td> 47 </tr> 48 <tr> 49 <td>mako</td> 50 <td>device/lge/mako-kernel/kernel</td> 51 <td>kernel/msm</td> 52 <td>mako_defconfig</td> 53 </tr> 54 <tr> 55 <td>grouper</td> 56 <td>device/asus/grouper/kernel</td> 57 <td>kernel/tegra</td> 58 <td>tegra3_android_defconfig</td> 59 </tr> 60 <tr> 61 <td>tilapia</td> 62 <td>device/asus/grouper/kernel</td> 63 <td>kernel/tegra</td> 64 <td>tegra3_android_defconfig</td> 65 </tr> 66 <tr> 67 <td>maguro</td> 68 <td>device/samsung/tuna/kernel</td> 69 <td>kernel/omap</td> 70 <td>tuna_defconfig</td> 71 </tr> 72 <tr> 73 <td>toro</td> 74 <td>device/samsung/tuna/kernel</td> 75 <td>kernel/omap</td> 76 <td>tuna_defconfig</td> 77 </tr> 78 <tr> 79 <td>panda</td> 80 <td>device/ti/panda/kernel</td> 81 <td>kernel/omap</td> 82 <td>panda_defconfig</td> 83 </tr> 84 <tr> 85 <td>stingray</td> 86 <td>device/moto/wingray/kernel</td> 87 <td>kernel/tegra</td> 88 <td>stingray_defconfig</td> 89 </tr> 90 <tr> 91 <td>wingray</td> 92 <td>device/moto/wingray/kernel </td> 93 <td>kernel/tegra</td> 94 <td>stingray_defconfig</td> 95 </tr> 96 <tr> 97 <td>crespo</td> 98 <td>device/samsung/crespo/kernel</td> 99 <td>kernel/samsung</td> 100 <td>herring_defconfig</td> 101 </tr> 102 <tr> 103 <td>crespo4g</td> 104 <td>device/samsung/crespo/kernel</td> 105 <td>kernel/samsung</td> 106 <td>herring_defconfig</td> 107 </tr> 108 </table> 109 110 <p>You will want to look at the git log for the kernel binary in the device 111 project that you are interested in.</p> 112 113 114 115 Device projects are of the form device/<vendor>/<name>.</p> 116 <pre><code>$ git clone https://android.googlesource.com/device/ti/panda 117 $ cd panda 118 $ git log --max-count=1 kernel 119 </code></pre> 120 121 <p>The commit message for the kernel binary contains a partial git log 122 of the kernel sources that were used to build the binary in question. 123 The first entry in the log is the most recent, i.e. the one used to 124 build that kernel. You will need it at a later step.</p> 125 126 <h2 id="downloading-sources">Downloading sources</h2> 127 <p>Depending on which kernel you want,</p> 128 <pre><code>$ git clone https://android.googlesource.com/kernel/common.git 129 $ git clone https://android.googlesource.com/kernel/exynos.git 130 $ git clone https://android.googlesource.com/kernel/goldfish.git 131 $ git clone https://android.googlesource.com/kernel/msm.git 132 $ git clone https://android.googlesource.com/kernel/omap.git 133 $ git clone https://android.googlesource.com/kernel/samsung.git 134 $ git clone https://android.googlesource.com/kernel/tegra.git 135 </code></pre> 136 <ul> 137 <li>The <code>goldfish</code> project contains the kernel sources for the emulated 138 platforms.</li> 139 <li>The <code>msm</code> project has the sources for ADP1, ADP2, Nexus One, Nexus 4, 140 and can be used as a starting point for work on Qualcomm MSM chipsets.</li> 141 <li>The <code>omap</code> project is used for PandaBoard and Galaxy Nexus, 142 and can be used as a starting point for work on TI OMAP chipsets.</li> 143 <li>The <code>samsung</code> project is used for Nexus S, 144 and can be used as a starting point for work on Samsung Hummingbird chipsets.</li> 145 <li>The <code>tegra</code> project is for Xoom and Nexus 7, 146 and can be used as a starting point for work on NVIDIA Tegra chipsets.</li> 147 <li>The <code>exynos</code> project has the kernel sources for Nexus 10, 148 and can be used as a starting point for work on Samsung Exynos chipsets.</li> 149 </ul> 150 <h2 id="downloading-a-prebuilt-gcc">Downloading a prebuilt gcc</h2> 151 <p>Ensure that the prebuilt toolchain is in your path.</p> 152 <pre>$ export PATH=$(pwd)/prebuilts/gcc/linux-x86/arm/arm-eabi-4.6/bin:$PATH</pre> 153 154 or 155 <pre>$ export PATH=$(pwd)/prebuilts/gcc/darwin-x86/arm/arm-eabi-4.6/bin:$PATH</pre> 156 157 <p>On a linux host, if you don't have an Android source tree, you can download 158 the prebuilt toolchain from: 159 <pre>$ git clone https://android.googlesource.com/platform/prebuilts/gcc/linux-x86/arm/arm-eabi-4.6</pre> 160 161 <h2 id="building">Building</h2> 162 <p>As an example, we would build the panda kernel using the following commands:</p> 163 <pre><code>$ export ARCH=arm 164 $ export SUBARCH=arm 165 $ export CROSS_COMPILE=arm-eabi- 166 $ cd omap 167 $ git checkout <commit_from_first_step> 168 $ make panda_defconfig 169 $ make 170 </code></pre> 171 <p>To build the tuna kernel, you may run the previous commands replacing all 172 instances of "panda" with "tuna".</p> 173 <p> 174 The kernel binary is output as `arch/arm/boot/zImage`, and needs to be copied 175 into the Android source tree in order to build the matching boot image. 176 </p>
