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author | Scott Rifenbark <scott.m.rifenbark@intel.com> | 2013-01-10 18:53:53 -0600 |
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committer | Richard Purdie <richard.purdie@linuxfoundation.org> | 2013-01-27 13:54:08 +0000 |
commit | 982637f27ae86d83a7ef425c84ab70345e269451 (patch) | |
tree | d4812df6c4411fb0c0a2facc317ef10e7012ddfe /documentation/profile-manual | |
parent | 0ac8eba57813dc85f8ad70dfaa1bbc381c5e4c9c (diff) | |
download | poky-982637f27ae86d83a7ef425c84ab70345e269451.tar.gz |
profile-manual: Copied in this raw text.
This is the raw text from Tom for the architecture chapter.
No editing at all.
(From yocto-docs rev: f402cc14ac7fef30460e130cc5bdfca731886aa3)
Signed-off-by: Scott Rifenbark <scott.m.rifenbark@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Diffstat (limited to 'documentation/profile-manual')
-rw-r--r-- | documentation/profile-manual/profile-manual-arch.xml | 392 |
1 files changed, 23 insertions, 369 deletions
diff --git a/documentation/profile-manual/profile-manual-arch.xml b/documentation/profile-manual/profile-manual-arch.xml index b9401e9017..a0ea3b2d0d 100644 --- a/documentation/profile-manual/profile-manual-arch.xml +++ b/documentation/profile-manual/profile-manual-arch.xml | |||
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2 | "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd" | 2 | "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd" |
3 | [<!ENTITY % poky SYSTEM "../poky.ent"> %poky; ] > | 3 | [<!ENTITY % poky SYSTEM "../poky.ent"> %poky; ] > |
4 | 4 | ||
5 | <chapter id='dev-manual-start'> | 5 | <chapter id='profile-manual-arch'> |
6 | 6 | ||
7 | <title>Getting Started with the Yocto Project</title> | 7 | <title>Overall Architecture of the Linux Tracing and Profiling Tools</title> |
8 | 8 | ||
9 | <para> | 9 | <section id='architecture-of-the-tracing-and-profiling-tools'> |
10 | This chapter introduces the Yocto Project and gives you an idea of what you need to get started. | 10 | <title>Architecture of the Tracing and Profiling Tools</title> |
11 | You can find enough information to set up your development host and build or use images for | ||
12 | hardware supported by the Yocto Project by reading the | ||
13 | <ulink url='&YOCTO_DOCS_QS_URL;'>Yocto Project Quick Start</ulink>. | ||
14 | </para> | ||
15 | |||
16 | <para> | ||
17 | The remainder of this chapter summarizes what is in the Yocto Project Quick Start and provides | ||
18 | some higher-level concepts you might want to consider. | ||
19 | </para> | ||
20 | |||
21 | <section id='introducing-the-yocto-project'> | ||
22 | <title>Introducing the Yocto Project</title> | ||
23 | 11 | ||
24 | <para> | 12 | <para> |
25 | The Yocto Project is an open-source collaboration project focused on embedded Linux development. | 13 | It may seem surprising to see a section covering an 'overall architecture' |
26 | The project currently provides a build system, which is | 14 | for what seems to be a random collection of tracing tools that together |
27 | referred to as the OpenEmbedded build system in the Yocto Project documentation. | 15 | make up the Linux tracing and profiling space. |
28 | The Yocto Project provides various ancillary tools suitable for the embedded developer | 16 | The fact is, however, that in recent years this seemingly disparate |
29 | and also features the Sato reference User Interface, which is optimized for | 17 | set of tools has started to converge on a 'core' set of underlying |
30 | stylus driven, low-resolution screens. | 18 | mechanisms: |
31 | </para> | 19 | </para> |
32 | 20 | ||
33 | <para> | 21 | <para> |
34 | You can use the OpenEmbedded build system, which uses | ||
35 | BitBake to develop complete Linux | ||
36 | images and associated user-space applications for architectures based on ARM, MIPS, PowerPC, | ||
37 | x86 and x86-64. | ||
38 | While the Yocto Project does not provide a strict testing framework, | ||
39 | it does provide or generate for you artifacts that let you perform target-level and | ||
40 | emulated testing and debugging. | ||
41 | Additionally, if you are an <trademark class='trade'>Eclipse</trademark> | ||
42 | IDE user, you can install an Eclipse Yocto Plug-in to allow you to | ||
43 | develop within that familiar environment. | ||
44 | </para> | ||
45 | </section> | ||
46 | |||
47 | <section id='getting-setup'> | ||
48 | <title>Getting Set Up</title> | ||
49 | |||
50 | <para> | ||
51 | Here is what you need to get set up to use the Yocto Project: | ||
52 | <itemizedlist> | 22 | <itemizedlist> |
53 | <listitem><para><emphasis>Host System:</emphasis> You should have a reasonably current | 23 | <listitem>static tracepoints</listitem> |
54 | Linux-based host system. | 24 | <listitem>dynamic tracepoints |
55 | You will have the best results with a recent release of Fedora, | 25 | <itemizedlist> |
56 | OpenSUSE, Debian, Ubuntu, or CentOS as these releases are frequently tested against the Yocto Project | 26 | <listitem>kprobes</listitem> |
57 | and officially supported. | 27 | <listitem>uprobes</listitem> |
58 | For a list of the distributions under validation and their status, see the | 28 | </itemizedlist> |
59 | "<ulink url='&YOCTO_DOCS_REF_URL;#detailed-supported-distros'>Supported Linux Distributions</ulink>" section | 29 | </listitem> |
60 | in the Yocto Project Reference Manual and the wiki page at | 30 | <listitem>the perf_events subsystem</listitem> |
61 | <ulink url='&YOCTO_WIKI_URL;/wiki/Distribution_Support'>Distribution Support</ulink>.</para> | 31 | <listitem>debugfs</listitem> |
62 | <para> | ||
63 | You should also have about 100 gigabytes of free disk space for building images. | ||
64 | </para></listitem> | ||
65 | <listitem><para><emphasis>Packages:</emphasis> The OpenEmbedded build system | ||
66 | requires certain packages exist on your development system (e.g. Python 2.6 or 2.7). | ||
67 | See "<ulink url='&YOCTO_DOCS_QS_URL;#packages'>The Packages</ulink>" | ||
68 | section in the Yocto Project Quick Start for the exact package | ||
69 | requirements and the installation commands to install them | ||
70 | for the supported distributions.</para></listitem> | ||
71 | <listitem id='local-yp-release'><para><emphasis>Yocto Project Release:</emphasis> | ||
72 | You need a release of the Yocto Project. | ||
73 | You set that up with a local <link linkend='source-directory'>Source Directory</link> | ||
74 | one of two ways depending on whether you | ||
75 | are going to contribute back into the Yocto Project or not. | ||
76 | <note> | ||
77 | Regardless of the method you use, this manual refers to the resulting local | ||
78 | hierarchical set of files as the "Source Directory." | ||
79 | </note> | ||
80 | <itemizedlist> | ||
81 | <listitem><para><emphasis>Tarball Extraction:</emphasis> If you are not going to contribute | ||
82 | back into the Yocto Project, you can simply download a Yocto Project release you want | ||
83 | from the website’s <ulink url='&YOCTO_HOME_URL;/download'>download page</ulink>. | ||
84 | Once you have the tarball, just extract it into a directory of your choice.</para> | ||
85 | <para>For example, the following command extracts the Yocto Project &DISTRO; | ||
86 | release tarball | ||
87 | into the current working directory and sets up the local Source Directory | ||
88 | with a top-level folder named <filename>&YOCTO_POKY;</filename>: | ||
89 | <literallayout class='monospaced'> | ||
90 | $ tar xfj &YOCTO_POKY_TARBALL; | ||
91 | </literallayout></para> | ||
92 | <para>This method does not produce a local Git repository. | ||
93 | Instead, you simply end up with a snapshot of the release.</para></listitem> | ||
94 | <listitem><para><emphasis>Git Repository Method:</emphasis> If you are going to be contributing | ||
95 | back into the Yocto Project or you simply want to keep up | ||
96 | with the latest developments, you should use Git commands to set up a local | ||
97 | Git repository of the upstream <filename>poky</filename> source repository. | ||
98 | Doing so creates a repository with a complete history of changes and allows | ||
99 | you to easily submit your changes upstream to the project. | ||
100 | Because you cloned the repository, you have access to all the Yocto Project development | ||
101 | branches and tag names used in the upstream repository.</para> | ||
102 | <para>The following transcript shows how to clone the <filename>poky</filename> | ||
103 | Git repository into the current working directory. | ||
104 | <note>You can view the Yocto Project Source Repositories at | ||
105 | <ulink url='&YOCTO_GIT_URL;/cgit.cgi'></ulink></note> | ||
106 | The command creates the local repository in a directory named <filename>poky</filename>. | ||
107 | For information on Git used within the Yocto Project, see the | ||
108 | "<link linkend='git'>Git</link>" section. | ||
109 | <literallayout class='monospaced'> | ||
110 | $ git clone git://git.yoctoproject.org/poky | ||
111 | Initialized empty Git repository in /home/scottrif/poky/.git/ | ||
112 | remote: Counting objects: 141863, done. | ||
113 | remote: Compressing objects: 100% (38624/38624), done. | ||
114 | remote: Total 141863 (delta 99661), reused 141816 (delta 99614) | ||
115 | Receiving objects: 100% (141863/141863), 76.64 MiB | 126 KiB/s, done. | ||
116 | Resolving deltas: 100% (99661/99661), done. | ||
117 | </literallayout></para> | ||
118 | <para>For another example of how to set up your own local Git repositories, see this | ||
119 | <ulink url='&YOCTO_WIKI_URL;/wiki/Transcript:_from_git_checkout_to_meta-intel_BSP'> | ||
120 | wiki page</ulink>, which describes how to create both <filename>poky</filename> | ||
121 | and <filename>meta-intel</filename> Git repositories.</para></listitem> | ||
122 | </itemizedlist></para></listitem> | ||
123 | <listitem id='local-kernel-files'><para><emphasis>Yocto Project Kernel:</emphasis> | ||
124 | If you are going to be making modifications to a supported Yocto Project kernel, you | ||
125 | need to establish local copies of the source. | ||
126 | You can find Git repositories of supported Yocto Project Kernels organized under | ||
127 | "Yocto Linux Kernel" in the Yocto Project Source Repositories at | ||
128 | <ulink url='&YOCTO_GIT_URL;/cgit.cgi'></ulink>.</para> | ||
129 | <para>This setup can involve creating a bare clone of the Yocto Project kernel and then | ||
130 | copying that cloned repository. | ||
131 | You can create the bare clone and the copy of the bare clone anywhere you like. | ||
132 | For simplicity, it is recommended that you create these structures outside of the | ||
133 | Source Directory (usually <filename>poky</filename>).</para> | ||
134 | <para>As an example, the following transcript shows how to create the bare clone | ||
135 | of the <filename>linux-yocto-3.4</filename> kernel and then create a copy of | ||
136 | that clone. | ||
137 | <note>When you have a local Yocto Project kernel Git repository, you can | ||
138 | reference that repository rather than the upstream Git repository as | ||
139 | part of the <filename>clone</filename> command. | ||
140 | Doing so can speed up the process.</note></para> | ||
141 | <para>In the following example, the bare clone is named | ||
142 | <filename>linux-yocto-3.4.git</filename>, while the | ||
143 | copy is named <filename>my-linux-yocto-3.4-work</filename>: | ||
144 | <literallayout class='monospaced'> | ||
145 | $ git clone --bare git://git.yoctoproject.org/linux-yocto-3.4 linux-yocto-3.4.git | ||
146 | Initialized empty Git repository in /home/scottrif/linux-yocto-3.4.git/ | ||
147 | remote: Counting objects: 2468027, done. | ||
148 | remote: Compressing objects: 100% (392255/392255), done. | ||
149 | remote: Total 2468027 (delta 2071693), reused 2448773 (delta 2052498) | ||
150 | Receiving objects: 100% (2468027/2468027), 530.46 MiB | 129 KiB/s, done. | ||
151 | Resolving deltas: 100% (2071693/2071693), done. | ||
152 | </literallayout></para> | ||
153 | <para>Now create a clone of the bare clone just created: | ||
154 | <literallayout class='monospaced'> | ||
155 | $ git clone linux-yocto-3.4.git my-linux-yocto-3.4-work | ||
156 | Cloning into 'my-linux-yocto-3.4-work'... | ||
157 | done. | ||
158 | </literallayout></para></listitem> | ||
159 | <listitem id='poky-extras-repo'><para><emphasis> | ||
160 | The <filename>poky-extras</filename> Git Repository</emphasis>: | ||
161 | The <filename>poky-extras</filename> Git repository contains metadata needed | ||
162 | only if you are modifying and building the kernel image. | ||
163 | In particular, it contains the kernel BitBake append (<filename>.bbappend</filename>) | ||
164 | files that you | ||
165 | edit to point to your locally modified kernel source files and to build the kernel | ||
166 | image. | ||
167 | Pointing to these local files is much more efficient than requiring a download of the | ||
168 | kernel's source files from upstream each time you make changes to the kernel.</para> | ||
169 | <para>You can find the <filename>poky-extras</filename> Git Repository in the | ||
170 | "Yocto Metadata Layers" area of the Yocto Project Source Repositories at | ||
171 | <ulink url='&YOCTO_GIT_URL;/cgit.cgi'></ulink>. | ||
172 | It is good practice to create this Git repository inside the Source Directory.</para> | ||
173 | <para>Following is an example that creates the <filename>poky-extras</filename> Git | ||
174 | repository inside the Source Directory, which is named <filename>poky</filename> | ||
175 | in this case: | ||
176 | <literallayout class='monospaced'> | ||
177 | $ cd ~/poky | ||
178 | $ git clone git://git.yoctoproject.org/poky-extras poky-extras | ||
179 | Initialized empty Git repository in /home/scottrif/poky/poky-extras/.git/ | ||
180 | remote: Counting objects: 618, done. | ||
181 | remote: Compressing objects: 100% (558/558), done. | ||
182 | remote: Total 618 (delta 192), reused 307 (delta 39) | ||
183 | Receiving objects: 100% (618/618), 526.26 KiB | 111 KiB/s, done. | ||
184 | Resolving deltas: 100% (192/192), done. | ||
185 | </literallayout></para></listitem> | ||
186 | <listitem><para id='supported-board-support-packages-(bsps)'><emphasis>Supported Board | ||
187 | Support Packages (BSPs):</emphasis> | ||
188 | The Yocto Project provides a layer called <filename>meta-intel</filename> and | ||
189 | it is maintained in its own separate Git repository. | ||
190 | The <filename>meta-intel</filename> layer contains many supported | ||
191 | <ulink url='&YOCTO_DOCS_BSP_URL;#bsp-layers'>BSP Layers</ulink>.</para> | ||
192 | <para>Similar considerations exist for setting up the <filename>meta-intel</filename> | ||
193 | layer. | ||
194 | You can get set up for BSP development one of two ways: tarball extraction or | ||
195 | with a local Git repository. | ||
196 | It is a good idea to use the same method that you used to set up the Source Directory. | ||
197 | Regardless of the method you use, the Yocto Project uses the following BSP layer | ||
198 | naming scheme: | ||
199 | <literallayout class='monospaced'> | ||
200 | meta-<BSP_name> | ||
201 | </literallayout> | ||
202 | where <filename><BSP_name></filename> is the recognized BSP name. | ||
203 | Here are some examples: | ||
204 | <literallayout class='monospaced'> | ||
205 | meta-crownbay | ||
206 | meta-emenlow | ||
207 | meta-n450 | ||
208 | </literallayout> | ||
209 | See the | ||
210 | "<ulink url='&YOCTO_DOCS_BSP_URL;#bsp-layers'>BSP Layers</ulink>" | ||
211 | section in the Yocto Project Board Support Package (BSP) Developer's Guide for more | ||
212 | information on BSP Layers. | ||
213 | <itemizedlist> | ||
214 | <listitem><para><emphasis>Tarball Extraction:</emphasis> You can download any released | ||
215 | BSP tarball from the same | ||
216 | <ulink url='&YOCTO_HOME_URL;/download'>download site</ulink> used | ||
217 | to get the Yocto Project release. | ||
218 | Once you have the tarball, just extract it into a directory of your choice. | ||
219 | Again, this method just produces a snapshot of the BSP layer in the form | ||
220 | of a hierarchical directory structure.</para></listitem> | ||
221 | <listitem><para><emphasis>Git Repository Method:</emphasis> If you are working | ||
222 | with a local Git repository for your Source Directory, you should also use this method | ||
223 | to set up the <filename>meta-intel</filename> Git repository. | ||
224 | You can locate the <filename>meta-intel</filename> Git repository in the | ||
225 | "Yocto Metadata Layers" area of the Yocto Project Source Repositories at | ||
226 | <ulink url='&YOCTO_GIT_URL;/cgit.cgi'></ulink>.</para> | ||
227 | <para>Typically, you set up the <filename>meta-intel</filename> Git repository inside | ||
228 | the Source Directory. | ||
229 | For example, the following transcript shows the steps to clone the | ||
230 | <filename>meta-intel</filename> | ||
231 | Git repository inside the local <filename>poky</filename> Git repository. | ||
232 | <literallayout class='monospaced'> | ||
233 | $ cd ~/poky | ||
234 | $ git clone git://git.yoctoproject.org/meta-intel.git | ||
235 | Initialized empty Git repository in /home/scottrif/poky/meta-intel/.git/ | ||
236 | remote: Counting objects: 3380, done. | ||
237 | remote: Compressing objects: 100% (2750/2750), done. | ||
238 | remote: Total 3380 (delta 1689), reused 227 (delta 113) | ||
239 | Receiving objects: 100% (3380/3380), 1.77 MiB | 128 KiB/s, done. | ||
240 | Resolving deltas: 100% (1689/1689), done. | ||
241 | </literallayout></para> | ||
242 | <para>The same | ||
243 | <ulink url='&YOCTO_WIKI_URL;/wiki/Transcript:_from_git_checkout_to_meta-intel_BSP'> | ||
244 | wiki page</ulink> referenced earlier covers how to | ||
245 | set up the <filename>meta-intel</filename> Git repository.</para></listitem> | ||
246 | </itemizedlist></para></listitem> | ||
247 | <listitem><para><emphasis>Eclipse Yocto Plug-in:</emphasis> If you are developing | ||
248 | applications using the Eclipse Integrated Development Environment (IDE), | ||
249 | you will need this plug-in. | ||
250 | See the | ||
251 | "<link linkend='setting-up-the-eclipse-ide'>Setting up the Eclipse IDE</link>" | ||
252 | section for more information.</para></listitem> | ||
253 | </itemizedlist> | 32 | </itemizedlist> |
254 | </para> | 33 | </para> |
255 | </section> | ||
256 | |||
257 | <section id='building-images'> | ||
258 | <title>Building Images</title> | ||
259 | |||
260 | <para> | ||
261 | The build process creates an entire Linux distribution, including the toolchain, from source. | ||
262 | For more information on this topic, see the | ||
263 | "<ulink url='&YOCTO_DOCS_QS_URL;#building-image'>Building an Image</ulink>" | ||
264 | section in the Yocto Project Quick Start. | ||
265 | </para> | ||
266 | |||
267 | <para> | ||
268 | The build process is as follows: | ||
269 | <orderedlist> | ||
270 | <listitem><para>Make sure you have set up the Source Directory described in the | ||
271 | previous section.</para></listitem> | ||
272 | <listitem><para>Initialize the build environment by sourcing a build environment | ||
273 | script.</para></listitem> | ||
274 | <listitem><para>Optionally ensure the <filename>conf/local.conf</filename> configuration file, | ||
275 | which is found in the | ||
276 | <link linkend='build-directory'>Build Directory</link>, | ||
277 | is set up how you want it. | ||
278 | This file defines many aspects of the build environment including | ||
279 | the target machine architecture through the | ||
280 | <filename><ulink url='&YOCTO_DOCS_REF_URL;#var-MACHINE'>MACHINE</ulink></filename> variable, | ||
281 | the development machine's processor use through the | ||
282 | <filename><ulink url='&YOCTO_DOCS_REF_URL;#var-BB_NUMBER_THREADS'>BB_NUMBER_THREADS</ulink></filename> and | ||
283 | <filename><ulink url='&YOCTO_DOCS_REF_URL;#var-PARALLEL_MAKE'>PARALLEL_MAKE</ulink></filename> variables, and | ||
284 | a centralized tarball download directory through the | ||
285 | <filename><ulink url='&YOCTO_DOCS_REF_URL;#var-DL_DIR'>DL_DIR</ulink></filename> variable.</para></listitem> | ||
286 | <listitem><para>Build the image using the <filename>bitbake</filename> command. | ||
287 | If you want information on BitBake, see the user manual inculded in the | ||
288 | <filename>bitbake/doc/manual</filename> directory of the | ||
289 | <link linkend='source-directory'>Source Directory</link>.</para></listitem> | ||
290 | <listitem><para>Run the image either on the actual hardware or using the QEMU | ||
291 | emulator.</para></listitem> | ||
292 | </orderedlist> | ||
293 | </para> | ||
294 | </section> | ||
295 | |||
296 | <section id='using-pre-built-binaries-and-qemu'> | ||
297 | <title>Using Pre-Built Binaries and QEMU</title> | ||
298 | |||
299 | <para> | ||
300 | Another option you have to get started is to use pre-built binaries. | ||
301 | The Yocto Project provides many types of binaries with each release. | ||
302 | See the "<ulink url='&YOCTO_DOCS_REF_URL;#ref-images'>Images</ulink>" | ||
303 | chapter in the Yocto Project Reference Manual | ||
304 | for descriptions of the types of binaries that ship with a Yocto Project | ||
305 | release. | ||
306 | </para> | ||
307 | |||
308 | <para> | ||
309 | Using a pre-built binary is ideal for developing software applications to run on your | ||
310 | target hardware. | ||
311 | To do this, you need to be able to access the appropriate cross-toolchain tarball for | ||
312 | the architecture on which you are developing. | ||
313 | If you are using an SDK type image, the image ships with the complete toolchain native to | ||
314 | the architecture. | ||
315 | If you are not using an SDK type image, you need to separately download and | ||
316 | install the stand-alone Yocto Project cross-toolchain tarball. | ||
317 | </para> | ||
318 | |||
319 | <para> | ||
320 | Regardless of the type of image you are using, you need to download the pre-built kernel | ||
321 | that you will boot in the QEMU emulator and then download and extract the target root | ||
322 | filesystem for your target machine’s architecture. | ||
323 | You can get architecture-specific binaries and filesystems from | ||
324 | <ulink url='&YOCTO_MACHINES_DL_URL;'>machines</ulink>. | ||
325 | You can get installation scripts for stand-alone toolchains from | ||
326 | <ulink url='&YOCTO_TOOLCHAIN_DL_URL;'>toolchains</ulink>. | ||
327 | Once you have all your files, you set up the environment to emulate the hardware | ||
328 | by sourcing an environment setup script. | ||
329 | Finally, you start the QEMU emulator. | ||
330 | You can find details on all these steps in the | ||
331 | "<ulink url='&YOCTO_DOCS_QS_URL;#using-pre-built'>Using Pre-Built Binaries and QEMU</ulink>" | ||
332 | section of the Yocto Project Quick Start. | ||
333 | </para> | ||
334 | |||
335 | <para> | ||
336 | Using QEMU to emulate your hardware can result in speed issues | ||
337 | depending on the target and host architecture mix. | ||
338 | For example, using the <filename>qemux86</filename> image in the emulator | ||
339 | on an Intel-based 32-bit (x86) host machine is fast because the target and | ||
340 | host architectures match. | ||
341 | On the other hand, using the <filename>qemuarm</filename> image on the same Intel-based | ||
342 | host can be slower. | ||
343 | But, you still achieve faithful emulation of ARM-specific issues. | ||
344 | </para> | ||
345 | |||
346 | <para> | ||
347 | To speed things up, the QEMU images support using <filename>distcc</filename> | ||
348 | to call a cross-compiler outside the emulated system. | ||
349 | If you used <filename>runqemu</filename> to start QEMU, and the | ||
350 | <filename>distccd</filename> application is present on the host system, any | ||
351 | BitBake cross-compiling toolchain available from the build system is automatically | ||
352 | used from within QEMU simply by calling <filename>distcc</filename>. | ||
353 | You can accomplish this by defining the cross-compiler variable | ||
354 | (e.g. <filename>export CC="distcc"</filename>). | ||
355 | Alternatively, if you are using a suitable SDK image or the appropriate | ||
356 | stand-alone toolchain is present in <filename>/opt/poky</filename>, | ||
357 | the toolchain is also automatically used. | ||
358 | </para> | ||
359 | 34 | ||
360 | <note> | 35 | <note> |
361 | Several mechanisms exist that let you connect to the system running on the | 36 | Tying It Together: Rather than enumerating here how each tool makes use of |
362 | QEMU emulator: | 37 | these common mechanisms, textboxes like this will make note of the |
363 | <itemizedlist> | 38 | specific usages in each tool as they come up in the course |
364 | <listitem><para>QEMU provides a framebuffer interface that makes standard | 39 | of the text. |
365 | consoles available.</para></listitem> | ||
366 | <listitem><para>Generally, headless embedded devices have a serial port. | ||
367 | If so, you can configure the operating system of the running image | ||
368 | to use that port to run a console. | ||
369 | The connection uses standard IP networking.</para></listitem> | ||
370 | <listitem><para>SSH servers exist in some QEMU images. | ||
371 | The <filename>core-image-sato</filename> QEMU image has a Dropbear secure | ||
372 | shell (ssh) server that runs with the root password disabled. | ||
373 | The <filename>core-image-basic</filename> and <filename>core-image-lsb</filename> QEMU images | ||
374 | have OpenSSH instead of Dropbear. | ||
375 | Including these SSH servers allow you to use standard <filename>ssh</filename> and | ||
376 | <filename>scp</filename> commands. | ||
377 | The <filename>core-image-minimal</filename> QEMU image, however, contains no ssh | ||
378 | server.</para></listitem> | ||
379 | <listitem><para>You can use a provided, user-space NFS server to boot the QEMU session | ||
380 | using a local copy of the root filesystem on the host. | ||
381 | In order to make this connection, you must extract a root filesystem tarball by using the | ||
382 | <filename>runqemu-extract-sdk</filename> command. | ||
383 | After running the command, you must then point the <filename>runqemu</filename> | ||
384 | script to the extracted directory instead of a root filesystem image file.</para></listitem> | ||
385 | </itemizedlist> | ||
386 | </note> | 40 | </note> |
387 | </section> | 41 | </section> |
388 | </chapter> | 42 | </chapter> |