Understanding Yocto Layers
Why metadata is split into layers, what a layer may contain, and how a product layer keeps changes separate.
Layers
Yocto uses layers to organize metadata.
A layer can contain:
- Recipes
- Configuration
- Classes
- Machine definitions
- Distribution configuration
- Patches
- Image definitions
Instead of putting everything into one huge directory, functionality can be separated into layers.
For example:
meta/
meta-openembedded/
meta-freescale/
meta-my-product/
A custom product may have its own layer:
meta-my-product/
├── conf/
├── recipes-core/
├── recipes-apps/
├── recipes-kernel/
└── recipes-images/
This makes the system easier to maintain.