61 lines
1.3 KiB
Markdown
61 lines
1.3 KiB
Markdown
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# Layer
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A layer is a bundle of configuration files.
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It can contain:
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- Recipes to build specific software
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- Machines
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- Distributions
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- Classes
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- Images
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- ...
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## Layer list
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Layers are listed in `$POKY/build/conf/bblayers.conf` using __absolute__ path:
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```sh
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BBLAYERS = " \
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/home/me/poky/meta \
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/home/me/poky/meta-yocto \
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/home/me/poky/meta-yocto-bsp \
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/home/me/poky/build/meta-ab3000 \
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"
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```
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<info data-markdown>
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The layer can be in another directory than under `$POKY`.
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</info>
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<warn data-markdown>
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Don't forget to add any newly created layer in this list to use it
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</warn>
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Generally this folder is versioned (with git).
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The layers shipped with Yocto are in `$POKY/meta*`.
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## Layer configuration
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_Minimal configuration:_
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```sh
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BBPATH .= ":${LAYERDIR}"
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BBFILES += "${LAYERDIR}/recipes-*/*/*.bb \
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${LAYERDIR}/recipes-*/*/*.bbappend"
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BBFILE_COLLECTIONS += "ab3000"
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BBFILE_PATTERN_ab3000 = "^${LAYERDIR}/"
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BBFILE_PRIORITY_ab3000 = "6"
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```
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Variable|Use
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---|---
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`BBFILES`|Where to search for recipes & recipe append files (ie `recipes-group/recipename/recipename.bb`)
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`BBFILE_COLLECTIONS`|Layer name. Will be used to get/set variables only for this layer (ie `VAR_ab3000`)
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[More about layers](http://www.yoctoproject.org/docs/1.7.1/dev-manual/dev-manual.html#understanding-and-creating-layers)
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