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authorScott Rifenbark <scott.m.rifenbark@intel.com>2011-07-27 12:10:25 -0700
committerRichard Purdie <richard.purdie@linuxfoundation.org>2011-08-04 15:06:47 +0100
commit3aef350c390a270a410673435de63ee5d21d117b (patch)
tree54a662f8d46b1aa0a75f2e6bc764d10f24db6b6d /documentation/dev-manual/dev-manual-model.xml
parent6d7c8f6398813bb527c102344cb3a5009d334af1 (diff)
downloadpoky-3aef350c390a270a410673435de63ee5d21d117b.tar.gz
documentation/dev-manual/dev-manual-model.xml: Moved BSP dev summary here
The "models" chapter is going to be the overview section for the cases. Thus, the cases chapter will disappear. This is a first step in that direction. (From yocto-docs rev: fe3985db8e1dbc7bff6565d3624bccac0f809621) Signed-off-by: Scott Rifenbark <scott.m.rifenbark@intel.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
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1 files changed, 182 insertions, 7 deletions
diff --git a/documentation/dev-manual/dev-manual-model.xml b/documentation/dev-manual/dev-manual-model.xml
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--- a/documentation/dev-manual/dev-manual-model.xml
+++ b/documentation/dev-manual/dev-manual-model.xml
@@ -20,19 +20,194 @@
20</para> 20</para>
21 21
22<section id='place-holder-section-one'> 22<section id='place-holder-section-one'>
23 <title>Place-Holder Section One</title> 23 <title>Place-Holder Section for Development in General</title>
24 24
25 <para> 25 <para>
26 Text needed here. 26 Text needed here.
27 </para> 27 </para>
28</section>
29 28
30<section id='place-holder-section-two'> 29 <section id='developing-a-board-support-package-bsp-model'>
31 <title>Place-Holder Section Two</title> 30 <title>Developing a Board Support Package (BSP)</title>
32 31
33 <para> 32 <para>
34 Text needed here. 33 A BSP is a package of recipes that when applied while building an image results in
35 </para> 34 an image you can run on a particular board.
35 Thus, the package, when compiled into the new image, supports the operation of the board.
36 </para>
37
38 <note>
39 For a brief list of terms used when describing the development process in the Yocto Project,
40 see <xref linkend='yocto-project-terms'>Yocto Project Terms</xref> in this manual.
41 </note>
42
43 <para>
44 The remainder of this section presents the basic steps to create a BSP basing it on an
45 existing BSP that ships with the Yocto Project.
46 You can reference <xref linkend='dev-manual-bsp-appendix'>BSP Development Case</xref>
47 for a detailed example that uses the Crown Bay BSP as a base BSP from which to start.
48 </para>
49
50 <para>
51 Here are the basic steps involved in creating a BSP:
52 <orderedlist>
53 <listitem><para><emphasis>Set up your host development system to support
54 development using the Yocto Project</emphasis>: See
55 <ulink url='http://www.yoctoproject.org/docs/1.1/yocto-project-qs/yocto-project-qs.html#the-linux-distro'>
56 The Linux Distributions</ulink> section and
57 <ulink url='http://www.yoctoproject.org/docs/1.1/yocto-project-qs/yocto-project-qs.html#packages'>
58 The Packages</ulink> section both
59 in the Yocto Project Quick Start for requirements.
60 You will also need a release of Yocto Project installed on the host.</para></listitem>
61 <listitem><para><emphasis>Establish a local copy of the Yocto Project files on your
62 system</emphasis>: You need to have the Yocto Project files available on your host system.
63 Having the Yocto Project files on your system gives you access to the build
64 process and tools you need.
65 For information on how to get these files, see the
66 <xref linkend='getting-setup'>Getting Setup</xref> section in this manual.</para></listitem>
67 <listitem><para><emphasis>Choose a Yocto Project-supported BSP as your base BSP</emphasis>:
68 The Yocto Project ships with several BSPs that support various hardware.
69 It is best to base your new BSP on an existing BSP rather than create all the
70 recipes and configuration files from scratch.
71 While it is possible to create everything from scratch, basing your new BSP
72 on something that is close is much easier.
73 Or, at a minimum, it gives you some structure with which to start.</para>
74 <para>At this point you need to understand your target hardware well enough to determine which
75 existing BSP it most closely matches.
76 Things to consider are your hardware’s on-board features such as CPU type and graphics support.
77 You should look at the README files for supported BSPs to get an idea of which one
78 you could use.
79 A generic Atom-based BSP to consider is the Crown Bay that does not support
80 the Intel® Embedded Media Graphics Driver (EMGD).
81 The remainder of this example uses that base BSP.</para>
82 <para>To see the supported BSPs, go to the Yocto Project
83 <ulink url='http://www.yoctoproject.org/download'>download page</ulink> and click
84 on “BSP Downloads.”</para></listitem>
85 <listitem><para><emphasis>Establish a local copy of the base BSP files</emphasis>: Having
86 the BSP files on your system gives you access to the build
87 process and tools you need.
88 For information on how to get these files, see
89 <xref linkend='getting-setup'>Getting Setup</xref> earlier in this manual.</para></listitem>
90 <listitem><para><emphasis>Create your own BSP layer</emphasis>: Layers are ideal for
91 isolating and storing work for a given piece of hardware.
92 A layer is really just a location or area in which you place the recipes for your BSP.
93 In fact, a BSP is, in itself, a special type of layer.
94 Consider an application as another example that illustrates a layer.
95 Suppose you are creating an application that has library or other dependencies in
96 order for it to compile and run.
97 The layer, in this case, would be where all the recipes that define those dependencies
98 are kept. The key point for a layer is that it is an isolated area that contains
99 all the relevant information for the project that the Yocto Project build
100 system knows about.</para>
101 <note>The Yocto Project supports four BSPs that are part of the
102 Yocto Project release: <filename>atom-pc</filename>, <filename>beagleboard</filename>,
103 <filename>mpc8315e</filename>, and <filename>routerstationpro</filename>.
104 The recipes and configurations for these four BSPs are located and dispersed
105 within local Yocto Project files.
106 Consequently, they are not totally isolated in the spirit of layers unless you think
107 of <filename>meta-yocto</filename> as a layer itself.
108 On the other hand, BSP layers for Crown Bay, Emenlow, Jasper Forest,
109 N450, and Sugar Bay are isolated.</note>
110 <para>When you set up a layer for a new BSP you should follow a standard layout.
111 This layout is described in the
112 <ulink url='http://www.yoctoproject.org/docs/1.1/bsp-guide/bsp-guide.html#bsp-filelayout'>
113 Example Filesystem Layout</ulink> section of the Board Support Package (BSP) Development
114 Guide.
115 In the standard layout you will notice a suggested structure for recipes and
116 configuration information.
117 You can see the standard layout for the Crown Bay BSP in this example by examining the
118 directory structure of the <filename>meta-crownbay</filename> layer inside the
119 local Yocto Project files.</para></listitem>
120 <listitem><para><emphasis>Make configuration and recipe changes to your new BSP
121 layer</emphasis>: The standard BSP layer structure organizes the files you need to edit in
122 <filename>conf</filename> and several <filename>recipes-*</filename> within the
123 BSP layer.</para>
124 <para>Configuration changes identify where your new layer is on the local system
125 and identify which kernel you are going to use.
126 Recipe changes include altering recipes (<filename>.bb</filename> files), removing
127 recipes you don't use, and adding new recipes that you need to support your hardware.
128 </para></listitem>
129 <listitem><para><emphasis>Prepare for the build</emphasis>: Once you have made all the
130 changes to your BSP layer there remains a few things
131 you need to do for the Yocto Project build system in order for it to create your image.
132 You need to get the build environment ready by sourcing an environment setup script
133 and you need to be sure two key configuration files are configured appropriately.</para>
134 <para>The entire process for building an image is overviewed in the
135 <ulink url='http://www.yoctoproject.org/docs/1.1/yocto-project-qs/yocto-project-qs.html#building-image'>
136 Building an Image</ulink> section of the Yocto Project Quick Start.
137 You might want to reference this information.</para></listitem>
138 <listitem><para><emphasis>Build the image</emphasis>: The Yocto Project uses the BitBake
139 tool to build images based on the type of image
140 you want to create.
141 You can find more information on BitBake
142 <ulink url='http://bitbake.berlios.de/manual/'>here</ulink>.</para>
143 <para>The build process supports several types of images to satisfy different needs.
144 When you issue the BitBake command you provide a “top-level” recipe that essentially
145 starts the process off of building the type of image you want.</para>
146 <para>[WRITER'S NOTE: Consider moving this to the Poky Reference Manual.]</para>
147 <para>You can find these recipes in the <filename>meta/recipes-core/images</filename> and
148 <filename>meta/recipes-sato/images</filename> directories of your local Yocto Project
149 file structure (Git repository or extracted release tarball).
150 Although the recipe names are somewhat explanatory, here is a list that describes them:
151 <itemizedlist>
152 <listitem><para><emphasis>Base</emphasis> – A foundational basic image without support
153 for X that can be reasonably used for customization.</para></listitem>
154 <listitem><para><emphasis>Core</emphasis> – A foundational basic image with support for
155 X that can be reasonably used for customization.</para></listitem>
156 <listitem><para><emphasis>Direct Disk</emphasis> – An image that you can copy directory to
157 the disk of the target device.</para></listitem>
158 <listitem><para><emphasis>Live</emphasis> – An image you can run from a USB device or from
159 a CD without having to first install something.</para></listitem>
160 <listitem><para><emphasis>Minimal</emphasis> – A small image without a GUI.
161 This image is not much more than a kernel with a shell.</para></listitem>
162 <listitem><para><emphasis>Minimal Development</emphasis> – A Minimal image suitable for
163 development work.</para></listitem>
164 <listitem><para><emphasis>Minimal Direct Disk</emphasis> – A Minimal Direct
165 Disk image.</para></listitem>
166 <listitem><para><emphasis>Minimal RAM-based Initial Root Filesystem</emphasis> –
167 A minimal image
168 that has the <filename>initramfs</filename> as part of the kernel, which allows the
169 system to find the first “init” program more efficiently.</para></listitem>
170 <listitem><para><emphasis>Minimal Live</emphasis> – A Minimal Live image.</para></listitem>
171 <listitem><para><emphasis>Minimal MTD Utilities</emphasis> – A minimal image that has support
172 for the MTD utilities, which let the user interact with the MTD subsystem in
173 the kernel to perform operations on flash devices.</para></listitem>
174 <listitem><para><emphasis>Sato</emphasis> – An image with Sato support, a mobile environment
175 and visual style that works well with mobile devices.</para></listitem>
176 <listitem><para><emphasis>Sato Development</emphasis> – A Sato image suitable for
177 development work.</para></listitem>
178 <listitem><para><emphasis>Sato Direct Disk</emphasis> – A Sato Direct
179 Disk image.</para></listitem>
180 <listitem><para><emphasis>Sato Live</emphasis> – A Sato Live image.</para></listitem>
181 <listitem><para><emphasis>Sato SDK</emphasis> – A Sato image that includes the Yocto Project
182 toolchain and development libraries.</para></listitem>
183 <listitem><para><emphasis>Sato SDK Direct Disk</emphasis> – A Sato SDK Direct
184 Disk image.</para></listitem>
185 <listitem><para><emphasis>Sato SDK Live</emphasis> – A Sato SDK Live
186 image.</para></listitem>
187 </itemizedlist>
188 </para></listitem>
189 </orderedlist>
190 </para>
191
192 <para>
193 You can view a video presentation of the BSP creation process
194 <ulink url='http://free-electrons.com/blog/elc-2011-videos'>here</ulink>.
195 You can also find supplemental information in the
196 <ulink url='http://yoctoproject.org/docs/1.1/bsp-guide/bsp-guide.html'>
197 Board Support Package (BSP) Development Guide</ulink>.
198 Finally, there is wiki page write up of the example located
199 <ulink url='https://wiki.yoctoproject.org/wiki/Transcript:_creating_one_generic_Atom_BSP_from_another'>
200 here</ulink> you might find helpful.
201 </para>
202 </section>
203
204 <section id='place-holder-section-two'>
205 <title>Place-Holder Section For Application Development</title>
206
207 <para>
208 Text needed here.
209 </para>
210 </section>
36</section> 211</section>
37 212
38</chapter> 213</chapter>
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