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4 | Yocto Project Terms | 4 | Yocto Project Terms |
5 | ******************* | 5 | ******************* |
6 | 6 | ||
7 | Following is a list of terms and definitions users new to the Yocto | 7 | Following is a list of terms and definitions users new to the Yocto Project |
8 | Project development environment might find helpful. While some of these | 8 | development environment might find helpful. While some of these terms are |
9 | terms are universal, the list includes them just in case: | 9 | universal, the list includes them just in case: |
10 | 10 | ||
11 | - *Append Files:* Files that append build information to a recipe file. | 11 | .. glossary:: |
12 | Append files are known as BitBake append files and ``.bbappend`` | 12 | |
13 | files. The OpenEmbedded build system expects every append file to | 13 | Append Files |
14 | have a corresponding recipe (``.bb``) file. Furthermore, the append | 14 | Files that append build information to a recipe file. Append files are |
15 | file and corresponding recipe file must use the same root filename. | 15 | known as BitBake append files and ``.bbappend`` files. The OpenEmbedded |
16 | The filenames can differ only in the file type suffix used (e.g. | 16 | build system expects every append file to have a corresponding recipe |
17 | ``formfactor_0.0.bb`` and ``formfactor_0.0.bbappend``). | 17 | (``.bb``) file. Furthermore, the append file and corresponding recipe file |
18 | 18 | must use the same root filename. The filenames can differ only in the | |
19 | Information in append files extends or overrides the information in | 19 | file type suffix used (e.g. ``formfactor_0.0.bb`` and |
20 | the similarly-named recipe file. For an example of an append file in | 20 | ``formfactor_0.0.bbappend``). |
21 | use, see the "`Using .bbappend Files in Your | 21 | |
22 | Layer <&YOCTO_DOCS_DEV_URL;#using-bbappend-files>`__" section in the | 22 | Information in append files extends or overrides the information in the |
23 | Yocto Project Development Tasks Manual. | 23 | similarly-named recipe file. For an example of an append file in use, see |
24 | 24 | the ":ref:`dev-manual/dev-manual-common-tasks:Using .bbappend Files in | |
25 | When you name an append file, you can use the "``%``" wildcard | 25 | Your Layer`" section in the Yocto Project Development Tasks Manual. |
26 | character to allow for matching recipe names. For example, suppose | 26 | |
27 | you have an append file named as follows: busybox_1.21.%.bbappend | 27 | When you name an append file, you can use the "``%``" wildcard character |
28 | That append file would match any ``busybox_1.21.``\ x\ ``.bb`` | 28 | to allow for matching recipe names. For example, suppose you have an |
29 | version of the recipe. So, the append file would match any of the | 29 | append file named as follows: busybox_1.21.%.bbappend That append file |
30 | following recipe names: busybox_1.21.1.bb busybox_1.21.2.bb | 30 | would match any ``busybox_1.21.``\ x\ ``.bb`` version of the recipe. So, |
31 | busybox_1.21.3.bb busybox_1.21.10.bb busybox_1.21.25.bb | 31 | the append file would match any of the following recipe names: |
32 | 32 | ||
33 | .. note:: | 33 | .. code-block:: shell |
34 | 34 | ||
35 | The use of the " | 35 | busybox_1.21.1.bb |
36 | % | 36 | busybox_1.21.2.bb |
37 | " character is limited in that it only works directly in front of | 37 | busybox_1.21.3.bb |
38 | the | 38 | busybox_1.21.10.bb |
39 | .bbappend | 39 | busybox_1.21.25.bb |
40 | portion of the append file's name. You cannot use the wildcard | 40 | |
41 | character in any other location of the name. | 41 | .. note:: |
42 | 42 | ||
43 | - *BitBake:* The task executor and scheduler used by the OpenEmbedded | 43 | The use of the " % " character is limited in that it only works |
44 | build system to build images. For more information on BitBake, see | 44 | directly in front of the .bbappend portion of the append file's |
45 | the `BitBake User Manual <&YOCTO_DOCS_BB_URL;>`__. | 45 | name. You cannot use the wildcard character in any other location of |
46 | 46 | the name. | |
47 | - *Board Support Package (BSP):* A group of drivers, definitions, and | 47 | |
48 | other components that provide support for a specific hardware | 48 | BitBake |
49 | configuration. For more information on BSPs, see the `Yocto Project | 49 | The task executor and scheduler used by the OpenEmbedded build system to |
50 | Board Support Package (BSP) Developer's | 50 | build images. For more information on BitBake, see the `BitBake User |
51 | Guide <&YOCTO_DOCS_BSP_URL;>`__. | 51 | Manual <&YOCTO_DOCS_BB_URL;>`__. |
52 | 52 | ||
53 | - *Build Directory:* This term refers to the area used by the | 53 | Board Support Package (BSP) |
54 | OpenEmbedded build system for builds. The area is created when you | 54 | A group of drivers, definitions, and other components that provide support |
55 | ``source`` the setup environment script that is found in the Source | 55 | for a specific hardware configuration. For more information on BSPs, see |
56 | Directory (i.e. ````` <#structure-core-script>`__). The | 56 | the :ref:`bsp-guide/bsp-guide:Yocto Project Board Support Package |
57 | ```TOPDIR`` <#var-TOPDIR>`__ variable points to the Build Directory. | 57 | Developer's Guide`. |
58 | 58 | ||
59 | You have a lot of flexibility when creating the Build Directory. | 59 | Build Directory |
60 | Following are some examples that show how to create the directory. | 60 | This term refers to the area used by the OpenEmbedded build system for |
61 | The examples assume your `Source Directory <#source-directory>`__ is | 61 | builds. The area is created when you ``source`` the setup environment |
62 | named ``poky``: | 62 | script that is found in the Source Directory |
63 | 63 | (i.e. :ref:`ref-manual/ref-structure:\`\`oe-init-build-env\`\``). The | |
64 | - Create the Build Directory inside your Source Directory and let | 64 | :term:`TOPDIR` variable points to the Build Directory. |
65 | the name of the Build Directory default to ``build``: $ cd | 65 | |
66 | $HOME/poky $ source OE_INIT_FILE | 66 | You have a lot of flexibility when creating the Build Directory. |
67 | 67 | Following are some examples that show how to create the directory. The | |
68 | - Create the Build Directory inside your home directory and | 68 | examples assume your :term:`Source Directory` is named ``poky``: |
69 | specifically name it ``test-builds``: $ cd $HOME $ source | 69 | |
70 | poky/OE_INIT_FILE test-builds | 70 | - Create the Build Directory inside your Source Directory and let |
71 | 71 | the name of the Build Directory default to ``build``: | |
72 | - Provide a directory path and specifically name the Build | 72 | |
73 | Directory. Any intermediate folders in the pathname must exist. | 73 | .. code-block:: shell |
74 | This next example creates a Build Directory named | 74 | |
75 | ``YP-POKYVERSION`` in your home directory within the existing | 75 | $ cd $HOME/poky |
76 | directory ``mybuilds``: $ cd $HOME $ source | 76 | $ source oe-init-build-env |
77 | $HOME/poky/OE_INIT_FILE $HOME/mybuilds/YP-POKYVERSION | 77 | |
78 | 78 | - Create the Build Directory inside your home directory and | |
79 | .. note:: | 79 | specifically name it ``test-builds``: |
80 | 80 | ||
81 | By default, the Build Directory contains | 81 | .. code-block:: shell |
82 | TMPDIR | 82 | |
83 | , which is a temporary directory the build system uses for its | 83 | $ cd $HOME |
84 | work. | 84 | $ source poky/oe-init-build-env test-builds |
85 | TMPDIR | 85 | |
86 | cannot be under NFS. Thus, by default, the Build Directory cannot | 86 | - Provide a directory path and specifically name the Build |
87 | be under NFS. However, if you need the Build Directory to be under | 87 | Directory. Any intermediate folders in the pathname must exist. |
88 | NFS, you can set this up by setting | 88 | This next example creates a Build Directory named |
89 | TMPDIR | 89 | ``YP-POKYVERSION`` in your home directory within the existing |
90 | in your | 90 | directory ``mybuilds``: |
91 | local.conf | 91 | |
92 | file to use a local drive. Doing so effectively separates | 92 | .. code-block:: shell |
93 | TMPDIR | 93 | |
94 | from | 94 | $ cd $HOME |
95 | TOPDIR | 95 | $ source $HOME/poky/oe-init-build-env $HOME/mybuilds/YP-POKYVERSION |
96 | , which is the Build Directory. | 96 | |
97 | 97 | .. note:: | |
98 | - *Build Host:* The system used to build images in a Yocto Project | 98 | |
99 | Development environment. The build system is sometimes referred to as | 99 | By default, the Build Directory contains :term:`TMPDIR` , which is a |
100 | the development host. | 100 | temporary directory the build system uses for its work. TMPDIR cannot |
101 | 101 | be under NFS. Thus, by default, the Build Directory cannot be under | |
102 | - *Classes:* Files that provide for logic encapsulation and inheritance | 102 | NFS. However, if you need the Build Directory to be under NFS, you can |
103 | so that commonly used patterns can be defined once and then easily | 103 | set this up by setting TMPDIR in your local.conf file to use a local |
104 | used in multiple recipes. For reference information on the Yocto | 104 | drive. Doing so effectively separates TMPDIR from TOPDIR , which is the |
105 | Project classes, see the "`Classes <#ref-classes>`__" chapter. Class | 105 | Build Directory. |
106 | files end with the ``.bbclass`` filename extension. | 106 | |
107 | 107 | Build Host | |
108 | - *Configuration File:* Files that hold global definitions of | 108 | The system used to build images in a Yocto Project Development |
109 | variables, user-defined variables, and hardware configuration | 109 | environment. The build system is sometimes referred to as the development |
110 | information. These files tell the OpenEmbedded build system what to | 110 | host. |
111 | build and what to put into the image to support a particular | 111 | |
112 | platform. | 112 | Classes |
113 | 113 | Files that provide for logic encapsulation and inheritance so that | |
114 | Configuration files end with a ``.conf`` filename extension. The | 114 | commonly used patterns can be defined once and then easily used in |
115 | ``conf/local.conf`` configuration file in the `Build | 115 | multiple recipes. For reference information on the Yocto Project classes, |
116 | Directory <#build-directory>`__ contains user-defined variables that | 116 | see the "`Classes <#ref-classes>`__" chapter. Class files end with the |
117 | affect every build. The ``meta-poky/conf/distro/poky.conf`` | 117 | ``.bbclass`` filename extension. |
118 | configuration file defines Yocto "distro" configuration variables | 118 | |
119 | used only when building with this policy. Machine configuration | 119 | Configuration File |
120 | files, which are located throughout the `Source | 120 | Files that hold global definitions of variables, user-defined variables, |
121 | Directory <#source-directory>`__, define variables for specific | 121 | and hardware configuration information. These files tell the OpenEmbedded |
122 | hardware and are only used when building for that target (e.g. the | 122 | build system what to build and what to put into the image to support a |
123 | ``machine/beaglebone.conf`` configuration file defines variables for | 123 | particular platform. |
124 | the Texas Instruments ARM Cortex-A8 development board). | 124 | |
125 | 125 | Configuration files end with a ``.conf`` filename extension. The | |
126 | - *Container Layer:* Layers that hold other layers. An example of a | 126 | :file:`conf/local.conf` configuration file in the :term:`Build Directory` |
127 | container layer is OpenEmbedded's | 127 | contains user-defined variables that affect every build. The |
128 | ```meta-openembedded`` <https://github.com/openembedded/meta-openembedded>`__ | 128 | :file:`meta-poky/conf/distro/poky.conf` configuration file defines Yocto |
129 | layer. The ``meta-openembedded`` layer contains many ``meta-*`` | 129 | "distro" configuration variables used only when building with this |
130 | layers. | 130 | policy. Machine configuration files, which are located throughout the |
131 | 131 | :term:`Source Directory`, define variables for specific hardware and are | |
132 | - *Cross-Development Toolchain:* In general, a cross-development | 132 | only used when building for that target (e.g. the |
133 | toolchain is a collection of software development tools and utilities | 133 | :file:`machine/beaglebone.conf` configuration file defines variables for |
134 | that run on one architecture and allow you to develop software for a | 134 | the Texas Instruments ARM Cortex-A8 development board). |
135 | different, or targeted, architecture. These toolchains contain | 135 | |
136 | cross-compilers, linkers, and debuggers that are specific to the | 136 | Container Layer |
137 | target architecture. | 137 | Layers that hold other layers. An example of a container layer is |
138 | 138 | OpenEmbedded's `meta-openembedded | |
139 | The Yocto Project supports two different cross-development | 139 | <https://github.com/openembedded/meta-openembedded>`_ layer. The |
140 | toolchains: | 140 | ``meta-openembedded`` layer contains many ``meta-*`` layers. |
141 | 141 | ||
142 | - A toolchain only used by and within BitBake when building an image | 142 | Cross-Development Toolchain |
143 | for a target architecture. | 143 | In general, a cross-development toolchain is a collection of software |
144 | 144 | development tools and utilities that run on one architecture and allow you | |
145 | - A relocatable toolchain used outside of BitBake by developers when | 145 | to develop software for a different, or targeted, architecture. These |
146 | developing applications that will run on a targeted device. | 146 | toolchains contain cross-compilers, linkers, and debuggers that are |
147 | 147 | specific to the target architecture. | |
148 | Creation of these toolchains is simple and automated. For information | 148 | |
149 | on toolchain concepts as they apply to the Yocto Project, see the | 149 | The Yocto Project supports two different cross-development toolchains: |
150 | "`Cross-Development Toolchain | 150 | |
151 | Generation <&YOCTO_DOCS_OM_URL;#cross-development-toolchain-generation>`__" | 151 | - A toolchain only used by and within BitBake when building an image for a |
152 | section in the Yocto Project Overview and Concepts Manual. You can | 152 | target architecture. |
153 | also find more information on using the relocatable toolchain in the | 153 | |
154 | `Yocto Project Application Development and the Extensible Software | 154 | - A relocatable toolchain used outside of BitBake by developers when |
155 | Development Kit (eSDK) <&YOCTO_DOCS_SDK_URL;>`__ manual. | 155 | developing applications that will run on a targeted device. |
156 | 156 | ||
157 | - *Extensible Software Development Kit (eSDK):* A custom SDK for | 157 | Creation of these toolchains is simple and automated. For information on |
158 | application developers. This eSDK allows developers to incorporate | 158 | toolchain concepts as they apply to the Yocto Project, see the |
159 | their library and programming changes back into the image to make | 159 | ":ref:`overview-manual/overview-manual-concepts:Cross-Development |
160 | their code available to other application developers. | 160 | Toolchain Generation`" section in the Yocto Project Overview and Concepts |
161 | 161 | Manual. You can also find more information on using the relocatable | |
162 | For information on the eSDK, see the `Yocto Project Application | 162 | toolchain in the :ref:`sdk-manual/sdk-manual:Yocto Project Application |
163 | Development and the Extensible Software Development Kit | 163 | Development and the Extensible Software Development Kit (eSDK)` manual. |
164 | (eSDK) <&YOCTO_DOCS_SDK_URL;>`__ manual. | 164 | |
165 | 165 | Extensible Software Development Kit (eSDK) | |
166 | - *Image:* An image is an artifact of the BitBake build process given a | 166 | A custom SDK for application developers. This eSDK allows developers to |
167 | collection of recipes and related Metadata. Images are the binary | 167 | incorporate their library and programming changes back into the image to |
168 | output that run on specific hardware or QEMU and are used for | 168 | make their code available to other application developers. |
169 | specific use-cases. For a list of the supported image types that the | 169 | |
170 | Yocto Project provides, see the "`Images <#ref-images>`__" chapter. | 170 | For information on the eSDK, see the :ref:`sdk-manual/sdk-manual:Yocto |
171 | 171 | Project Application Development and the Extensible Software Development | |
172 | - *Layer:* A collection of related recipes. Layers allow you to | 172 | Kit (eSDK)` manual. |
173 | consolidate related metadata to customize your build. Layers also | 173 | |
174 | isolate information used when building for multiple architectures. | 174 | Image |
175 | Layers are hierarchical in their ability to override previous | 175 | An image is an artifact of the BitBake build process given a collection of |
176 | specifications. You can include any number of available layers from | 176 | recipes and related Metadata. Images are the binary output that run on |
177 | the Yocto Project and customize the build by adding your layers after | 177 | specific hardware or QEMU and are used for specific use-cases. For a list |
178 | them. You can search the Layer Index for layers used within Yocto | 178 | of the supported image types that the Yocto Project provides, see the |
179 | Project. | 179 | ":ref:`ref-manual/ref-images:Images`" chapter. |
180 | 180 | ||
181 | For introductory information on layers, see the "`The Yocto Project | 181 | Layer |
182 | Layer Model <&YOCTO_DOCS_OM_URL;#the-yocto-project-layer-model>`__" | 182 | A collection of related recipes. Layers allow you to consolidate related |
183 | section in the Yocto Project Overview and Concepts Manual. For more | 183 | metadata to customize your build. Layers also isolate information used |
184 | detailed information on layers, see the "`Understanding and Creating | 184 | when building for multiple architectures. Layers are hierarchical in |
185 | Layers <&YOCTO_DOCS_DEV_URL;#understanding-and-creating-layers>`__" | 185 | their ability to override previous specifications. You can include any |
186 | section in the Yocto Project Development Tasks Manual. For a | 186 | number of available layers from the Yocto Project and customize the build |
187 | discussion specifically on BSP Layers, see the "`BSP | 187 | by adding your layers after them. You can search the Layer Index for |
188 | Layers <&YOCTO_DOCS_BSP_URL;#bsp-layers>`__" section in the Yocto | 188 | layers used within Yocto Project. |
189 | Project Board Support Packages (BSP) Developer's Guide. | 189 | |
190 | 190 | For introductory information on layers, see the | |
191 | - *Metadata:* A key element of the Yocto Project is the Metadata that | 191 | ":ref:`overview-manual/overview-manual-yp-intro:The Yocto Project Layer |
192 | is used to construct a Linux distribution and is contained in the | 192 | Model`" section in the Yocto Project Overview and Concepts Manual. For |
193 | files that the `OpenEmbedded build system <#build-system-term>`__ | 193 | more detailed information on layers, see the |
194 | parses when building an image. In general, Metadata includes recipes, | 194 | ":ref:`dev-manual/dev-manual-common-tasks:Understanding and Creating |
195 | configuration files, and other information that refers to the build | 195 | Layers`" section in the Yocto Project Development Tasks Manual. For a |
196 | instructions themselves, as well as the data used to control what | 196 | discussion specifically on BSP Layers, see the ":ref:`bsp-guide/bsp:BSP |
197 | things get built and the effects of the build. Metadata also includes | 197 | Layers`" section in the Yocto Project Board Support Packages (BSP) |
198 | commands and data used to indicate what versions of software are | 198 | Developer's Guide. |
199 | used, from where they are obtained, and changes or additions to the | 199 | |
200 | software itself (patches or auxiliary files) that are used to fix | 200 | Metadata |
201 | bugs or customize the software for use in a particular situation. | 201 | A key element of the Yocto Project is the Metadata that |
202 | OpenEmbedded-Core is an important set of validated metadata. | 202 | is used to construct a Linux distribution and is contained in the |
203 | 203 | files that the `OpenEmbedded build system <#build-system-term>`__ | |
204 | In the context of the kernel ("kernel Metadata"), the term refers to | 204 | parses when building an image. In general, Metadata includes recipes, |
205 | the kernel config fragments and features contained in the | 205 | configuration files, and other information that refers to the build |
206 | ```yocto-kernel-cache`` <&YOCTO_GIT_URL;/cgit/cgit.cgi/yocto-kernel-cache>`__ | 206 | instructions themselves, as well as the data used to control what |
207 | Git repository. | 207 | things get built and the effects of the build. Metadata also includes |
208 | 208 | commands and data used to indicate what versions of software are | |
209 | - *OpenEmbedded-Core (OE-Core):* OE-Core is metadata comprised of | 209 | used, from where they are obtained, and changes or additions to the |
210 | foundational recipes, classes, and associated files that are meant to | 210 | software itself (patches or auxiliary files) that are used to fix |
211 | be common among many different OpenEmbedded-derived systems, | 211 | bugs or customize the software for use in a particular situation. |
212 | including the Yocto Project. OE-Core is a curated subset of an | 212 | OpenEmbedded-Core is an important set of validated metadata. |
213 | original repository developed by the OpenEmbedded community that has | 213 | |
214 | been pared down into a smaller, core set of continuously validated | 214 | In the context of the kernel ("kernel Metadata"), the term refers to |
215 | recipes. The result is a tightly controlled and an quality-assured | 215 | the kernel config fragments and features contained in the |
216 | core set of recipes. | 216 | ```yocto-kernel-cache`` <&YOCTO_GIT_URL;/cgit/cgit.cgi/yocto-kernel-cache>`__ |
217 | 217 | Git repository. | |
218 | You can see the Metadata in the ``meta`` directory of the Yocto | 218 | |
219 | Project `Source | 219 | OpenEmbedded-Core (OE-Core) |
220 | Repositories <http://git.yoctoproject.org/cgit/cgit.cgi>`__. | 220 | OE-Core is metadata comprised of |
221 | 221 | foundational recipes, classes, and associated files that are meant to | |
222 | - *OpenEmbedded Build System:* The build system specific to the Yocto | 222 | be common among many different OpenEmbedded-derived systems, |
223 | Project. The OpenEmbedded build system is based on another project | 223 | including the Yocto Project. OE-Core is a curated subset of an |
224 | known as "Poky", which uses `BitBake <#bitbake-term>`__ as the task | 224 | original repository developed by the OpenEmbedded community that has |
225 | executor. Throughout the Yocto Project documentation set, the | 225 | been pared down into a smaller, core set of continuously validated |
226 | OpenEmbedded build system is sometimes referred to simply as "the | 226 | recipes. The result is a tightly controlled and an quality-assured |
227 | build system". If other build systems, such as a host or target build | 227 | core set of recipes. |
228 | system are referenced, the documentation clearly states the | 228 | |
229 | difference. | 229 | You can see the Metadata in the ``meta`` directory of the Yocto |
230 | 230 | Project `Source | |
231 | .. note:: | 231 | Repositories <http://git.yoctoproject.org/cgit/cgit.cgi>`__. |
232 | 232 | ||
233 | For some historical information about Poky, see the | 233 | OpenEmbedded Build System |
234 | Poky | 234 | The build system specific to the Yocto |
235 | term. | 235 | Project. The OpenEmbedded build system is based on another project |
236 | 236 | known as "Poky", which uses `BitBake <#bitbake-term>`__ as the task | |
237 | - *Package:* In the context of the Yocto Project, this term refers to a | 237 | executor. Throughout the Yocto Project documentation set, the |
238 | recipe's packaged output produced by BitBake (i.e. a "baked recipe"). | 238 | OpenEmbedded build system is sometimes referred to simply as "the |
239 | A package is generally the compiled binaries produced from the | 239 | build system". If other build systems, such as a host or target build |
240 | recipe's sources. You "bake" something by running it through BitBake. | 240 | system are referenced, the documentation clearly states the |
241 | 241 | difference. | |
242 | It is worth noting that the term "package" can, in general, have | 242 | |
243 | subtle meanings. For example, the packages referred to in the | 243 | .. note:: |
244 | "`Required Packages for the Build | 244 | |
245 | Host <#required-packages-for-the-build-host>`__" section are compiled | 245 | For some historical information about Poky, see the |
246 | binaries that, when installed, add functionality to your Linux | 246 | Poky |
247 | distribution. | 247 | term. |
248 | 248 | ||
249 | Another point worth noting is that historically within the Yocto | 249 | Package |
250 | Project, recipes were referred to as packages - thus, the existence | 250 | In the context of the Yocto Project, this term refers to a |
251 | of several BitBake variables that are seemingly mis-named, (e.g. | 251 | recipe's packaged output produced by BitBake (i.e. a "baked recipe"). |
252 | ```PR`` <#var-PR>`__, ```PV`` <#var-PV>`__, and | 252 | A package is generally the compiled binaries produced from the |
253 | ```PE`` <#var-PE>`__). | 253 | recipe's sources. You "bake" something by running it through BitBake. |
254 | 254 | ||
255 | - *Package Groups:* Arbitrary groups of software Recipes. You use | 255 | It is worth noting that the term "package" can, in general, have |
256 | package groups to hold recipes that, when built, usually accomplish a | 256 | subtle meanings. For example, the packages referred to in the |
257 | single task. For example, a package group could contain the recipes | 257 | "`Required Packages for the Build |
258 | for a company’s proprietary or value-add software. Or, the package | 258 | Host <#required-packages-for-the-build-host>`__" section are compiled |
259 | group could contain the recipes that enable graphics. A package group | 259 | binaries that, when installed, add functionality to your Linux |
260 | is really just another recipe. Because package group files are | 260 | distribution. |
261 | recipes, they end with the ``.bb`` filename extension. | 261 | |
262 | 262 | Another point worth noting is that historically within the Yocto | |
263 | - *Poky:* Poky, which is pronounced *Pock*-ee, is a reference embedded | 263 | Project, recipes were referred to as packages - thus, the existence |
264 | distribution and a reference test configuration. Poky provides the | 264 | of several BitBake variables that are seemingly mis-named, (e.g. |
265 | following: | 265 | ```PR`` <#var-PR>`__, ```PV`` <#var-PV>`__, and |
266 | 266 | ```PE`` <#var-PE>`__). | |
267 | - A base-level functional distro used to illustrate how to customize | 267 | |
268 | a distribution. | 268 | Package Groups |
269 | 269 | Arbitrary groups of software Recipes. You use | |
270 | - A means by which to test the Yocto Project components (i.e. Poky | 270 | package groups to hold recipes that, when built, usually accomplish a |
271 | is used to validate the Yocto Project). | 271 | single task. For example, a package group could contain the recipes |
272 | 272 | for a company’s proprietary or value-add software. Or, the package | |
273 | - A vehicle through which you can download the Yocto Project. | 273 | group could contain the recipes that enable graphics. A package group |
274 | 274 | is really just another recipe. Because package group files are | |
275 | Poky is not a product level distro. Rather, it is a good starting | 275 | recipes, they end with the ``.bb`` filename extension. |
276 | point for customization. | 276 | |
277 | 277 | Poky | |
278 | .. note:: | 278 | Poky, which is pronounced *Pock*-ee, is a reference embedded |
279 | 279 | distribution and a reference test configuration. Poky provides the | |
280 | Poky began as an open-source project initially developed by | 280 | following: |
281 | OpenedHand. OpenedHand developed Poky from the existing | 281 | |
282 | OpenEmbedded build system to create a commercially supportable | 282 | - A base-level functional distro used to illustrate how to customize |
283 | build system for embedded Linux. After Intel Corporation acquired | 283 | a distribution. |
284 | OpenedHand, the poky project became the basis for the Yocto | 284 | |
285 | Project's build system. | 285 | - A means by which to test the Yocto Project components (i.e. Poky |
286 | 286 | is used to validate the Yocto Project). | |
287 | - *Recipe:* A set of instructions for building packages. A recipe | 287 | |
288 | describes where you get source code, which patches to apply, how to | 288 | - A vehicle through which you can download the Yocto Project. |
289 | configure the source, how to compile it and so on. Recipes also | 289 | |
290 | describe dependencies for libraries or for other recipes. Recipes | 290 | Poky is not a product level distro. Rather, it is a good starting |
291 | represent the logical unit of execution, the software to build, the | 291 | point for customization. |
292 | images to build, and use the ``.bb`` file extension. | 292 | |
293 | 293 | .. note:: | |
294 | - *Reference Kit:* A working example of a system, which includes a | 294 | |
295 | `BSP <#board-support-package-bsp-term>`__ as well as a `build | 295 | Poky began as an open-source project initially developed by |
296 | host <#hardware-build-system-term>`__ and other components, that can | 296 | OpenedHand. OpenedHand developed Poky from the existing |
297 | work on specific hardware. | 297 | OpenEmbedded build system to create a commercially supportable |
298 | 298 | build system for embedded Linux. After Intel Corporation acquired | |
299 | - *Source Directory:* This term refers to the directory structure | 299 | OpenedHand, the poky project became the basis for the Yocto |
300 | created as a result of creating a local copy of the ``poky`` Git | 300 | Project's build system. |
301 | repository ``git://git.yoctoproject.org/poky`` or expanding a | 301 | |
302 | released ``poky`` tarball. | 302 | Recipe |
303 | 303 | A set of instructions for building packages. A recipe | |
304 | .. note:: | 304 | describes where you get source code, which patches to apply, how to |
305 | 305 | configure the source, how to compile it and so on. Recipes also | |
306 | Creating a local copy of the | 306 | describe dependencies for libraries or for other recipes. Recipes |
307 | poky | 307 | represent the logical unit of execution, the software to build, the |
308 | Git repository is the recommended method for setting up your | 308 | images to build, and use the ``.bb`` file extension. |
309 | Source Directory. | 309 | |
310 | 310 | Reference Kit | |
311 | Sometimes you might hear the term "poky directory" used to refer to | 311 | A working example of a system, which includes a |
312 | this directory structure. | 312 | :term:`BSP<Board Support Package (BSP)>` as well as a |
313 | 313 | :term:`build host<Build Host>` and other components, that can | |
314 | .. note:: | 314 | work on specific hardware. |
315 | 315 | ||
316 | The OpenEmbedded build system does not support file or directory | 316 | Source Directory |
317 | names that contain spaces. Be sure that the Source Directory you | 317 | This term refers to the directory structure |
318 | use does not contain these types of names. | 318 | created as a result of creating a local copy of the ``poky`` Git |
319 | 319 | repository ``git://git.yoctoproject.org/poky`` or expanding a | |
320 | The Source Directory contains BitBake, Documentation, Metadata and | 320 | released ``poky`` tarball. |
321 | other files that all support the Yocto Project. Consequently, you | 321 | |
322 | must have the Source Directory in place on your development system in | 322 | .. note:: |
323 | order to do any development using the Yocto Project. | 323 | |
324 | 324 | Creating a local copy of the | |
325 | When you create a local copy of the Git repository, you can name the | 325 | poky |
326 | repository anything you like. Throughout much of the documentation, | 326 | Git repository is the recommended method for setting up your |
327 | "poky" is used as the name of the top-level folder of the local copy | 327 | Source Directory. |
328 | of the poky Git repository. So, for example, cloning the ``poky`` Git | 328 | |
329 | repository results in a local Git repository whose top-level folder | 329 | Sometimes you might hear the term "poky directory" used to refer to |
330 | is also named "poky". | 330 | this directory structure. |
331 | 331 | ||
332 | While it is not recommended that you use tarball expansion to set up | 332 | .. note:: |
333 | the Source Directory, if you do, the top-level directory name of the | 333 | |
334 | Source Directory is derived from the Yocto Project release tarball. | 334 | The OpenEmbedded build system does not support file or directory |
335 | For example, downloading and unpacking ```` results in a Source | 335 | names that contain spaces. Be sure that the Source Directory you |
336 | Directory whose root folder is named ````. | 336 | use does not contain these types of names. |
337 | 337 | ||
338 | It is important to understand the differences between the Source | 338 | The Source Directory contains BitBake, Documentation, Metadata and |
339 | Directory created by unpacking a released tarball as compared to | 339 | other files that all support the Yocto Project. Consequently, you |
340 | cloning ``git://git.yoctoproject.org/poky``. When you unpack a | 340 | must have the Source Directory in place on your development system in |
341 | tarball, you have an exact copy of the files based on the time of | 341 | order to do any development using the Yocto Project. |
342 | release - a fixed release point. Any changes you make to your local | 342 | |
343 | files in the Source Directory are on top of the release and will | 343 | When you create a local copy of the Git repository, you can name the |
344 | remain local only. On the other hand, when you clone the ``poky`` Git | 344 | repository anything you like. Throughout much of the documentation, |
345 | repository, you have an active development repository with access to | 345 | "poky" is used as the name of the top-level folder of the local copy |
346 | the upstream repository's branches and tags. In this case, any local | 346 | of the poky Git repository. So, for example, cloning the ``poky`` Git |
347 | changes you make to the local Source Directory can be later applied | 347 | repository results in a local Git repository whose top-level folder |
348 | to active development branches of the upstream ``poky`` Git | 348 | is also named "poky". |
349 | repository. | 349 | |
350 | 350 | While it is not recommended that you use tarball expansion to set up | |
351 | For more information on concepts related to Git repositories, | 351 | the Source Directory, if you do, the top-level directory name of the |
352 | branches, and tags, see the "`Repositories, Tags, and | 352 | Source Directory is derived from the Yocto Project release tarball. |
353 | Branches <&YOCTO_DOCS_OM_URL;#repositories-tags-and-branches>`__" | 353 | For example, downloading and unpacking ```` results in a Source |
354 | section in the Yocto Project Overview and Concepts Manual. | 354 | Directory whose root folder is named ````. |
355 | 355 | ||
356 | - *Task:* A unit of execution for BitBake (e.g. | 356 | It is important to understand the differences between the Source |
357 | ```do_compile`` <#ref-tasks-compile>`__, | 357 | Directory created by unpacking a released tarball as compared to |
358 | ```do_fetch`` <#ref-tasks-fetch>`__, | 358 | cloning ``git://git.yoctoproject.org/poky``. When you unpack a |
359 | ```do_patch`` <#ref-tasks-patch>`__, and so forth). | 359 | tarball, you have an exact copy of the files based on the time of |
360 | 360 | release - a fixed release point. Any changes you make to your local | |
361 | - *Toaster:* A web interface to the Yocto Project's `OpenEmbedded Build | 361 | files in the Source Directory are on top of the release and will |
362 | System <#build-system-term>`__. The interface enables you to | 362 | remain local only. On the other hand, when you clone the ``poky`` Git |
363 | configure and run your builds. Information about builds is collected | 363 | repository, you have an active development repository with access to |
364 | and stored in a database. For information on Toaster, see the | 364 | the upstream repository's branches and tags. In this case, any local |
365 | `Toaster User Manual <&YOCTO_DOCS_TOAST_URL;>`__. | 365 | changes you make to the local Source Directory can be later applied |
366 | 366 | to active development branches of the upstream ``poky`` Git | |
367 | - *Upstream:* A reference to source code or repositories that are not | 367 | repository. |
368 | local to the development system but located in a master area that is | 368 | |
369 | controlled by the maintainer of the source code. For example, in | 369 | For more information on concepts related to Git repositories, |
370 | order for a developer to work on a particular piece of code, they | 370 | branches, and tags, see the "`Repositories, Tags, and |
371 | need to first get a copy of it from an "upstream" source. | 371 | Branches <&YOCTO_DOCS_OM_URL;#repositories-tags-and-branches>`__" |
372 | section in the Yocto Project Overview and Concepts Manual. | ||
373 | |||
374 | Task | ||
375 | A unit of execution for BitBake (e.g. | ||
376 | ```do_compile`` <#ref-tasks-compile>`__, | ||
377 | ```do_fetch`` <#ref-tasks-fetch>`__, | ||
378 | ```do_patch`` <#ref-tasks-patch>`__, and so forth). | ||
379 | |||
380 | Toaster | ||
381 | A web interface to the Yocto Project's `OpenEmbedded Build | ||
382 | System <#build-system-term>`__. The interface enables you to | ||
383 | configure and run your builds. Information about builds is collected | ||
384 | and stored in a database. For information on Toaster, see the | ||
385 | `Toaster User Manual <&YOCTO_DOCS_TOAST_URL;>`__. | ||
386 | |||
387 | Upstream | ||
388 | A reference to source code or repositories that are not | ||
389 | local to the development system but located in a master area that is | ||
390 | controlled by the maintainer of the source code. For example, in | ||
391 | order for a developer to work on a particular piece of code, they | ||
392 | need to first get a copy of it from an "upstream" source. | ||